····· lezzter Preis 17.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Fluoridglas eignet sich aufgrund seiner hohen Transparenz vom ultravioletten bis zum nahinfraroten Spektralbereich sowie der geringen Phononenenergien außerordentlich gut für Anwendungen im sichtbaren Spektralbereich. Als Wirtsmaterial kann es große Mengen an Seltenerdionen als Dotierung aufnehmen. Erbiumdotiertes ZBLAN zeigt bei Anregung mit Wellenlängen von 970 - 980 nm starke grüne Fluoreszenz, welche durch die schrittweise Absorption von zwei Photonen in einem Aufwärtskonversionsprozess in den langlebigen angeregten Zustand 4S3/2 erfolgt. Die genaue Analyse der thermischen Eigenschaften vom Fluoridglas ZBLAN und weiteren Gläsern, welche entweder einen gewissen Bleianteil oder einen Hafniumanteil aufweisen, gibt Aufschluss über Glasstabilität, Wärmeausdehnung und charakteristische Temperaturen. Die Refraktometrie und Ellipsometrie zeigen, in welchem Maße der Brechungsindex durch Blei- und Hafniumanteile variiert werden kann. Diese Informationen sind nicht zuletzt hilfreich für die Wahl eines passenden Substratmaterials, welche auf CaF2 fiel. Das modifizierte Spin-Coating-Verfahren hat sich als eine erfolgreiche Methode erwiesen, um dämpfungsarme Glasfilme mit sehr glatter Oberfläche aus Fluoridglas herzustellen. Die Glasfilme können mit beliebigen Seltenerdionen in unterschiedlichen Konzentrationen dotiert werden. Dabei sind die Fluoreszenzspektren von erbiumdotierten Glasstücken und Filmen im grünen Spektralbereich vergleichbar. Mit Fotolithografie und anschließendem nasschemischen Ätzprozess gelingt die Strukturierung der Filme zu Streifenwellenleitern. Anhand von Mikroskopaufnahmen IR-gepumpter und fluoreszierender Streifenwellenleiter sind keine Streuverluste an den strukturierten Kanten sichtbar, so dass die durch das Ätzen zusätzlich eingebrachten Verluste gering sind. Die hergestellten erbiumdotierten Streifenwellenleiter aus Fluoridglas besitzen Querschnitte zwischen 40 x 40 µm2 und 40 x 230 µm2 und zeigen Wellenführung. In einer Simulation wurde gezeigt, dass ein IR-gepumpter, effizienter grüner Wellenleiterlaser realisierbar ist, jedoch hohe Pumpleistungen benötigt, um die Laserschwelle zu erreichen. Die Kombination mehrerer Ansätze sollte jedoch zum Erfolg führen: Zum einen kann eine Kodotierung mit Ytterbium die Pumpabsorption verbessern. Desweiteren führt ein kleinerer Wellenleiterquerschnitt bei guter Fokussierung und Einkopplung des Pumplasers in den Wellenleiter zu höheren Intensitäten im Resonator. Kleinere Wellenleiterquerschnitte werden durch dünnere Schichten erreicht, welche ihrerseits durch das Aufbringen einer Deckschicht aus Fluoridglas erzielt werden. Optische und thermische Eigenschaften von erbiumdotiertem ZBLAN in Kombination mit weiter optimierten Methoden zur Herstellung von verlustarmenWellenleitern werden in absehbarer Zukunft zur Realisierung einer kompakten grünen Laserquelle führen. ····· 10361192688
····· lezzter Preis 19.90€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Joseph John Thomson erhielt 1906 den Nobelpreis für Physik. Er war Entdecker des Elektrons. Nachdruck des Originals von 1909. ····· ····· ····· ····· ····· ····· ····· ····· ····· 10361150806
····· lezzter Preis 24.95€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Statistische Methoden in der Experimentalphysik In der Physik haben Datenanalysen zentrale Bedeutung für die Bewertung von experimentellen Resultaten. Dieses Lehrbuch startet mit den elementaren Konzepten der Statistik, zeigt die wichtigsten Wahrscheinlichkeitsverteilungen und erklärt die Datenanalysemethoden für Experimente der Laborpraktika. Darüber hinaus werden Konzepte moderner wissenschaftlicher Datenanalysen von der Computer-Simulation bis zur Klassifizierung mit neuronalen Netzwerken vorgestellt. ····· 10361185263
····· lezzter Preis 25.27€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this work scanning probe techniques, namely frequency-modulated atomic force microscopy (FM-AFM) in the non-contact regime and related methods like Kelvin probe force microscopy (KPFM), magnetic force microscopy (MFM), and magnetic exchange force microscopy (MExFM), are utilized in ultra high vacuum and at low temperatures to structurally, electronically and magnetically study the monolayer regime of iron on tungsten (001) in real space. Implementing the spectroscopic mode of MExFM, that is, magnetic exchange force spectroscopy (MExFS), the exchange interaction between single iron atoms with antiparallel coupling is experimentally accessed for the rst time. Iron grows pseudomorphically on W(001) whereby the layers are highly strained. Di erences in strain between rst and second layer iron and hybridization with the substrate lead to di erences in electronic properties and magnetism: both layers exhibit a di erent work function, mapped with KPFM. Interestingly, even on the same layer, di erent work functions are observed. Moreover, both layers are magnetically di erent. The second layer is ferromagnetic (FM) with in-plane anisotropy as veri ed by MFM, while the rst layer is antiferromagnetic (AF) with out-of-plane anisotropy. Using MexFM the AF alignment of the monolayer magnetic moments is resolved by detecting the short-ranged magnetic exchange force between tip and sample. The origin of the magnetic contrast formation is discussed and compared to ab initio calculations. Later, MExFS, which allows to directly measure the distance dependence of the magnetic exchange interaction between an atomically sharp magnetic tip and the antiferromagnetically ordered Fe monolayer on W(001), is employed. The site speci c distance dependence of the total tip-sample interaction is recorded above Fe atoms which exhibit parallel as well as antiparallel atomic magnetic moments. The contribution of the magnetic exchange interaction between both sites can be extracted by subtracting the two curves from each other. All other interactions are identical on both sites. The experimental results are compared to ab initio calculations accounting for magnetically di erent tips composed of either Cr or Fe, or mixtures of both. Depending on symmetry and stability of the experimentally used probe tips, qualitatively di erent MExFM contrasts and MExFS data with a stronger distance dependence are observed. By analyzing the energy loss per single cantilever oscillation cycle, simultaneously recorded with topography and frequency shift in the experiments, a bottom-up characterization of the structurally and magnetically unknown probe tip apex is given. Considering the tip apex as magnetically and structurally independent cluster allows to explain the observed tip behavior. ····· 10361193075
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El objetivo del presente libro es realizar una descripción de campos ópticos utilizando como parámetros de control las frecuencias espaciales implícitas en el modelo del espectro angular. En particular se describe la generación de campos libres de difracción y su interacción física mediante el proceso de interferencia utilizando haces Bessel de orden cero. Se muestra que es posible generar mediante un proceso de Filtraje espacial nuevos campos ópticos que conserven la propiedad de ser libres de difracción y en particular describimos propiedades de focalizacion que presentan características adiabáticas. Estos campos de luz son llamados haces capilares. ····· 103611729
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Las fuerzas entre corrientes mediadas por campos magnéticos magnificados miles de veces por la polarización de materiales ferro-magnéticos (motores) y campos eléctricos inducidos por campos magnéticos variables (generadores y transformadores) son los fenómenos físicos fundamentales subyacentes en el funcionamiento de las máquinas eléctricas que sostienen la matriz mundial de energía eléctrica. Dichos desarrollos tecnológicos se basa en el descubrimiento de fenómenos electromagnéticos realizados hacia principios del siglo XIX por los físicos Oersted, Ampere, Faraday y otros. Es sobre esta base que desde mediados del siglo XIX, físicos, ingenieros e inventores, como Jedlik, Pixi, Pacinotti, Gramme (era de la corriente continua) y Ferraris, Tesla, Dolivo-Dovrovolski (era moderna de la corriente alterna) desarrollaron una variedad de dispositivos y sistemas que potenciaron la primera fase de la Revolución Tecnológica. El portentoso desarrollo de las máquinas eléctricas durante ese período se extiende con pocos cambios hasta nuestros días y a las épocas por venir, continuando con la generación, transmisión y empleo de la energía eléctrica esencial a nuestra Civilización Tecnológica. ····· 103612585
····· lezzter Preis 26.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Este libro está dirigido a trabajadores de redes, empresas de energía, centros de capacitación, educadores técnicos, estudiantes, técnicos y a profesionales de la industria representando una introducción indispensable para contribuir a implementar prácticas, cumplir normas y seguir pasos necesarios para trabajar de una manera segura con tensión en redes de distribución y transmisión una fuerza de talento técnico-artesanal especializada utilizando equipos y herramientas modernas, aumentando así la seguridad laboral, la eficiencia de maniobras y poder ofrecer un valor agregado a empresas de energía a nivel global. Asimismo, se presenta de una manera sencilla los aspectos más importantes relacionados con la capacitación y seguridad laboral requerida en Transmisión y Distribución con el objetivo de mejorar niveles de calidad del servicio y satisfacer las necesidades cada vez más exigentes de los consumidores y sus demandas por alcanzar un buen servicio sin interrupción en el siglo XXI. ····· 1036124272
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Dentro de este trabajo se considera al nervio óptico con una forma cilíndrica ya que con esta geometría es posible resolver la ecuación de onda para una guía de ondas cilíndrica dándole un tratamiento físico y analítico como una primera aproximación a su funcionamiento y algunos componentes. De esta forma es muy simple dar este tratamiento ya que los componentes de la ecuación de onda del sistema modelan algunos de los parámetros como lo son las cuatro porciones que se distinguen en su trayecto. ····· 1036191079
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Este libro está dedicado a los láseres de semiconductor. Debido a su muy alta eficiencia, rapidez, bajo consumo de energía, tamaño diminuto y confiabilidad, así como por su bajo costo de producción en masa, hoy en día estos dispositivos tienen numerosas y variadas aplicaciones. Los principales fenómenos y efectos físicos que toman lugar dentro de un láser durante su operación son complejos y su descripción rigurosa requiere de un gran aparato matemático. Debido a que el objetivo de los autores del presente libro es discutir el tema de los láseres de semiconductor utilizando un lenguaje accesible y simple, que no involucre cálculos matemáticos complicados, algunos temas son explicados de una forma sencilla aunque en algunas ocasiones no con el suficiente rigor. En estos casos se privilegió la simplicidad en la exposición por sobre la formalidad y la precisión. ····· 10361136705
····· lezzter Preis 31.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book discusses design, modeling, and the characterization of slow-light photonic crystal waveguides. Guidelines are developed to obtain slow-light waveguides with broadband characteristics and with low disorder-induced losses. Three functional devices are proposed and studied: A tunable dispersion compensator, a tunable optical delay line, and a high-speed electro-optic modulator. Optical and microwave measurements confirm the designs. ····· 10361164339
····· lezzter Preis 32.30€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Spin-sensitive low temperature Scanning Tunneling Microscopy (STM) measurements provide the unique capability to study structural, electronic and magnetic properties of individual and coupled magnetic atoms on surfaces with high energy resolution. In this thesis, spin-polarized STM (SP-STM) and Inelastic Scanning Tunneling Spectroscopy (ISTS) are utilized to investigate Fe atoms on the semiconducting InSb(110) surface and the metallic Cu(111) and Ag(111) surfaces. Model calculations of tunneling through an excitable quantum spin system and analytical investigations of the model, as well as quasi-classical and Ising model calculations of coupled spin systems prepare the ground for the theoretical description of the experiments. The ISTS measurements of Fe on InSb(110) are the first observation of spin excitations of individual magnetic atoms on a semiconductor surface. By comparing the experimental data to Density Functional Theory (DFT) calculations performed by S. Schuwalow and F. Lechermann and to model calculations, it is found that the Fe atoms behave like quantum spins with spin quantum number S = 1, which are subject to magnetic anisotropy in the meV range. The Fe atoms are coupled to a two dimensional electron system (2DES) which is induced at the surface by positively charged adsorbates. The spectroscopic peaks of the spin-split Landau levels of this 2DES show an asymmetry of their amplitudes when the tunnel current is passed through the Fe atoms. It is shown that the Landau level asymmetry, recorded as a function of external magnetic field, can be interpreted as a new type of Single Atom Magnetization Curve (SAMC). Measurements of the Landau level asymmetry with magnetic tips can be used to quantitatively determine the spin polarization of the tip. SP-STM measurements of the SAMCs of single Fe atoms on Cu(111) show that the Fe atoms behave paramagnetically with a broad statistical distribution of the effective magnetic moment, centered around 3.5 µB. ISTS measurements on the same system reveal a magnetic anisotropy energy in the meV range, a g-factor of about 2.1, and a very broad, energy dependent spin-excitation line width in the meV range. Analogous ISTS measurements of Fe on Ag(111) show similar behavior, but with a three times larger anisotropy energy, and a g-factor of roughly 3.1. The observations can be interpreted in the context of advanced calculations including spin-orbit coupling and the Cu/Ag(111) surface state performed by S. Lounis et al..Atomic manipulation is used to construct pairs, chains and other structures of coupled Fe atoms on Cu(111). Their magnetization and coupling behavior is studied with the SAMC technique using spin-polarized tips and compared to Ising model calculations. The extracted RKKY pair coupling as a function of pair separation shows deviations from the isotropic case. The larger structures behave approximately as expected from the measured pair couplings, with deviations for small external magnetic fields. Even and odd numbered antiferromagnetically coupled chains show distinctly different magnetic ground states. A model type spin logic OR gate is constructed by connecting an Fe ¿output` atom by magnetically coupled Fe chains to two ferromagnetic ¿input` Co nanoislands. The functionality of the OR gate is demonstrated experimentally, constituting the first operation of an atomic spin logic function in this kind of magnetic nanostructure. Ising model calculations complement the experiments. ····· 10361193077
für 32.31€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El documento se divide en dos capítulos: En el primer capítulo se expone el método de obra civil para la construcción de un domo Geodésico El segundo capítulo expone una metodología general para el apantallamiento de dicha estructura. La metodología de protección contra el impacto directo de la descarga(Rayos) aplicada al domo geódesico como estructura natural, es la de mayor interés en este documento. ····· 103612212
für 32.31€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Turnkey projects have been highly regarded yet the adoption of the approach in the implementation of projects by majority of organizations in Kenya is still very low. The aim of this study was to investigate the factors that influence the adoption of turnkey approach in implementation of projects in Kenya. The study adopted a descriptive survey research design. The target population comprised the 37 staff working for Projects departments using census technique. Data was collected through a questionnaires structured using both open ended and closed ended. Chisquare( X2) analysis was used to investigate the associations between the variables. Statistical Package for Social Sciences (SPSS) was used for the analysis. The finding of the study shows a significant relationship between contractors capacity, organizational policies and terms of reference for turnkey projects and the adoption of turnkey project implementation. Project costs were not found to have significant association with the adoption of the turnkey project implementation approach. The study recommends the development of local contractors capacities technically to meet KPLC expectations for implementing turnkey projects. ····· 1036120419
für 32.31€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray An average-value model of a rotating rectifier circuit in a brushless excitation system is set forth,where a detailed simulation is required to extract the essential averaged-model parameters usingnumerical averaging. In the proposed approach, a synchronous machine model with saturation and cross saturation and an arbitrary rotor network representation that uses a voltage-behind-reactance representation for the field winding of the main machine is proposed. ····· 1036120789
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La Construcción de Circuitos de Media Tensión es de vital importancia en la actualidad debido al crecimiento urbano y a la necesidad de brindar el servicio de Energía Eléctrica de Calidad en los hogares. Este libro muestra como llevar a cabo un Mantenimiento correctivo en la línea de Media Tensión derivado de un análisis de la misma, es un gran apoyo para la realización de la Electrificación Rural pero sobre todo alcanzar el objetivo principal que todas los hogares cuenten con el servicio eléctrico. ····· 103612939
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Hoy en día las aplicaciones de sistemas de comunicación satelitales demandan un mayor ancho de banda, mayor integración de componentes y una mayor potencia de entrada. Estos tres requerimientos implican mayores densidades de campo eléctrico dentro de los dispositivos. Por eso es indispensable analizar su impacto en la operación normal de un satélite por medio de modelos teóricos y su interpretación en programas computacionales. Existen muchos fenómenos que limitan la capacidad de un subsistema dentro de un satélite de aumentar su potencia. En particular, los más relevantes son, en componentes pasivos, intermodulación pasiva (PIM), descarga corona y ruptura multipactor. En este trabajo se analiza el efecto corona en filtros tipo Ku y guías de onda rectangulares empleados en SAT-COM con aislamiento en aire atmosférico, considerando la respuesta de los dispositivos a bajas y altas presiones. Se discute la variabilidad de las frecuencias de colisión entre electrones y moléculas de aire y, en su caso, la presencia de humedad. Se muestran y analizan las ecuaciones que describen el comportamiento de la descarga corona y se comparan con simulaciones de la ruptura de los dispositivos. ····· 1036122022
····· lezzter Preis 35.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En este trabajo se presenta un estudio sobre heteroestructuras compuestas por la combinación de al menos dos redes cristalinas con diferente estructura de bandas. Cada una de las redes presenta bandas de energía permitida y bandas de energía prohibida. Las bandas de energía prohibida se encuentran ubicadas en longitudes de onda que tienen un tamaño similar a la periodicidad del cristal. La idea general de este trabajo es la de sumar las bandas de energía prohibida para obtener una heteroestructura con un rango de frecuencias prohibidas gigante. Presentamos una extenso estudio de los métodos de cálculo de la estructura de bandas y de las propiedades ópticas. Las ideas presentadas en este libro pueden ser aplicadas al estudio de otro tipo de heteroestructuras, tales como las heteroestructuras fonónicas y de metamateriales. ····· 1036122703
····· lezzter Preis 35.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Para desarrollar la aplicación del efecto corona en materiales cerámicos, en la Universidad Central y desde el grupo ESSOPTO, se diseñó y desarrolló una cámara de descarga con electrodos flotantes en donde se simularon las condiciones de atmósferas densas y el comportamiento del campo eléctrico. Las pruebas experimentales desarrolladas y las simulaciones obtenidas en el proceso de investigación, se compararon con los modelos teóricos reportados en la literatura, logrando con lo anterior, optimizar el proceso de preparación de las muestras cerámicas objeto de estudio. La técnica empleada de efecto corona, condujo a mejorar la conductividad térmica y eléctrica de las muestras que después fueron empleadas para la fabricación de sensores de humedad relativa de piso y aire. ····· 1036123180
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El modelamiento del terreno para el análisis de puestas a tierra es un punto importante que determina la calidad de los resultados en una simulación. Normalmente los parámetros eléctricos del terreno se asumen invariantes con la frecuencia, pero ellos presentan variaciones significativas tal como es presentado en este trabajo de investigación. Se realizaron pruebas a un tipo de arena y se calcularon las curvas de resistividad y permitividad de dicha arena que varian con la frecuencia. Adicionalmente, se pudo establecer y cuantificar un fenómeno no lineal presente en las pruebas debido a la ionización de los electrodos. Tambien, se presenta la formulación matemática del modelo electromagnético híbrido, con el cual se pueden obtener los potenciales transitorios en cualquier configuración de puesta a tierra y se presentan los resultados de un programa implementado. Se presentan validaciones del programa con resultados de otros programas y con resultados de una prueba experimental. ····· 1036189923
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La posibilidad de construir sistemas ópticos análogos a los electrónicos como: transistores, diodos, puertas lógicas, condensadores, etc. nos ha hecho soñar, a los que nos dedicamos a la óptica, con una computadora cuyos procesos sean hechos con luz y no con electricidad, es decir con fotones en lugar de electrones. Evidentemente la principal ventaja de una unidad de proceso totalmente óptica sería la velocidad, sin embargo, nuestra ciencia y tecnología, para la `manipulación` de la luz, se encuentra muy lejos del nivel de su contra-parte electrónica. Es aquí donde el presente trabajo, entre muchos otros, colabora con un poco de realidad a este sueño. Actualmente la investigación en nuevos materiales nos permite ver mas cercana la meta de construir al menos una compuerta lógica totalmente óptica, por medio del control óptico de luz. En este escrito el lector encontrará una humilde recopilación de una investigación de procesos de empatamiento de fases entre campos ópticos y la influencia de la polarización en el control óptico de la luz. Tómese como un limitado intento de plasmar experiencias de investigación científica. ····· 10361136630
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La propagación y el esparcimiento de ondas que interaccionan con objetos compuestos de materiales que tienen ciertas propiedades físicas engloban a una gran cantidad de fenómenos en electromagnetismo, óptica, mecánica cuántica, etc. En esta tesis doctoral, dirigida por el Dr. Eugenio Méndez Méndez, se presenta un estudio teórico y experimental de la propagación y esparcimiento de luz difusa a través de sistemas con geometrías confinantes, tales como rendijas y guías de ondas con estrechamientos. De interés especial es la posibilidad de encontrar Efectos de Cuantización en la Transmitancia de este tipo de sistemas. Los efectos de cuantización se revelan por la forma escalonada de las curvas de transmitancia en función de las dimensiones de la abertura de la rendija o de la sección estrecha de la guía, lo cual contrasta con la dependencia lineal que se podría esperar con base en argumentos de óptica geométrica. ····· 10361136739
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Dada la abundancia de dispositivos visuales y pantallas construidos en bases a medios transparentes cuyo índice de refracción cambia de un sector a otro de manera gradual o abrupto, es interesante considerar la solución formal de las ecuaciones electromagnéticas bajo estas restricciones tecnológicas. Es ilustrativo darse cuenta que la simple adición de un medio distinto a una interface plana, tiene como consecuencia que los campos propagantes en dicha región no se pueden expresar en términos de un número finito de ondas planas en contraste con lo que ocurre cuando se tienen solo dos medios. Estas modificaciones originan que la luz reflejada por dichos dispositivos posea una distribución espectral de vectores de onda. La solución exacta de este sistema se expresa en términos de ecuaciones integrales. Proponemos soluciones aproximadas e iterativas en términos de la razón de contraste. ····· 10361137227
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Actualmente, la mayoría de los sistemas de control para turbogeneradores contemplan esquemas de control descentralizados con lazos de control independientes para la turbina y el generador. Estos esquemas no consideran la interacción entre los lazos de control de potencia y voltaje, lo que puede degradar la respuesta del turbogenerador. Para remediar esta situación y desarrollar mejores esquemas de control es necesario contar con modelos matemáticos completos del conjunto turbina-generador que reproduzcan fielmente su dinámica en todo el rango de operación e incluyan los efectos de interacción. En este trabajo de investigación se desarrolló el modelo matemático de un generador síncrono que incluye devanados amortiguadores y saturación magnética del hierro del rotor. El modelo se programó modularmente, en parámetros por unidad, y se integró al modelo existente de una turbina de gas para conformar el modelo completo de un turbogenerador de combustión de 32 MVA. La estabilidad numérica de los modelos del generador y del turbogenerador se demostró mediante experimentos de simulación en estado estable. ····· 10361137838
für 38.90€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Es ist ein umfassender Einblick in das Wesen der elektrischen Energieverteilung mit dem Schwerpunkt Beleuchtungswesen, den Ferdinand Neureiter dem technisch interessierten Leser hier gewährt. Er gibt einen Überblick über die Grundsätze des elektrischen Stroms, ebenso wie über die unterschiedlichen Lampentypen mit ihren entsprechenden Eigenschaften. Neureiter erklärt, wie die Verteilung der elektrischen Energie in den Leitungsnetzen funktioniert und führt in verschiedene Verteilungssysteme ein.Sorgfältig bearbeiteter Nachdruck der Originalausgabe von 1894. ····· 10361139134
····· lezzter Preis 43.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this work two ideas of using individual metal organic molecules in applications for data storage are presented. On the one hand, metal-free phthalocyanine is used to form a GMR contact consisting of one single molecule leading to the world smallest magnetic sensor. On the other hand, chromium acetylacetonate was used to study the properties of magnetic molecules adsorbed on surfaces in order to build magnetic bits for date storage. ····· 10361164427
····· lezzter Preis 43.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Der Mensch definiert die funktionalen Anforderungen an Lichtsysteme im Automobil. So stellt sich mit der Integration neuer Konzepte im Fahrzeug vor allem die Frage nach deren Einfluss auf die Wahrnehmungsleistung des Fahrers. Daher bildet die physiologisch-psychologische Bewertung von Lichtfunktionen ein wichtiges Glied in der Entwicklungskette lichttechnischer Komponenten. Im Rahmen der vorliegenden Arbeit werden ausgewählte Systeme im In- und Exterieurbereich psychophysikalisch analysiert. ····· 10361164612
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This dissertation presents a multiple tabu search (MTS) algorithm to solve the load frequency control (LFC) and the economic dispatch (ED) problems in power system operation. The proposed MTS algorithm is the sequential execution of the individual tabu search (TS) algorithm by only one personal computer. MTS algorithm introduces additional techniques for improvement of search process, such as initialization, adaptive searches, multiple searches, replacing and restarting process. For LFC application, the proposed MTS algorithm has been applied to design a fuzzy logic controller using a proportional-integral (FLPI) and a proportional-integral-derivative (FLPID) for load frequency control. Conventionally, the membership functions and control rules of fuzzy logic control are obtained by trial and error method or experiences of designers. To overcome this problem, the MTS algorithm is proposed to simultaneously tune PI or PID gains, the membership functions and control rules of the FLPI or FLPID of fuzzy controller. The objective of the designed controller is to minimize the frequency deviations of the interconnected power system against load disturbances. ····· 10361310
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray A detailed derivation of rigorous coupled-wave analysis is given starting from Maxwell s equations and finishing by matching the boundary conditions in the grating and other regions of interest. This analysis is implemented in a MATLAB simulation which calculates transmitted power intensities of transverse electric (TE) and transverse magnetic (TM) mode light based on the wavelength of incident light, its angle of incidence, as well as the grating structure. Simulated results are shown for various grating parameters, including different metals used for the grating and the metal-line dimensions. Next, a light-emitting diode (LED) fabrication process is developed in detail including mesa etch conditions and metal stacks used for the contacts. Subsequently the procedure for fabricating a nanometer-scale wire-grid polarizer on the back of this LED is described. Experimental results on the wire-grid-polarizer LEDs are described, including a clear polarization preference of the light coming out of the wire-grid polarizer. A design is proposed that would allow for an LED embedded with a wire-grid polarizer to become a commercially viable option for generating polarized light. ····· 10361383
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray We both proceed to current mistakes and present new theories in E&M. Potential difference between two conductors of a capacitor is two times more than potential difference between two poles of the battery which has charged it we see influence of this in the experiments performed for determination of charge and mass of electron. Existence of conduction current isn`t because of existence of any electric field in conductor and the linear relation J = gE cannot be valid. Relaxation time and drift velocity are independent of charge and mass. Action mechanism of transistor is explained and a hydrodynamical analogue for it is introduced. In a gradient of magnetic field magnetic dipoles of air are attracted toward the region of intense field and create an air pressed pad there causing levitation in diamagnetism. Electrons get freed from hot core of Earth accompany it in revolving around stationary liquid core and so create a big magnet in it. Probably electron doesn t have a size so small compared with the dimensions of a molecule. We must take into account role of air pressure difference created at two sides of each of two parallel current-carrying wires in their repulsion or attraction. ····· 10361660
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El texto presenta un conjunto de guías para la auto preparación de los estudiantes previa a la realización de los laboratorios de los contenidos de Óptica y Física Moderna, que se imparten en las carreras de ciencias e ingeniería. La necesidad de realizar los laboratorios en ciclos, enfrenta a los estudiantes a la tarea de asistir a prácticas de laboratorio cuyos contenidos no han recibido, esto hace de la preparación anterior la única herramienta de que disponen para tener un conocimiento del contenido que se incluye en la misma. Lo anterior hace de la guía el medio indispensable para llegar al laboratorio con la preparación mínima que les permita un aprovechamiento óptimo del tiempo asignado. La evaluación previa del estudiante, se impone como un requisito para lograr el objetivo anterior, por ello se incluyen preguntas que los orienten en el contenido teórico y del manejo de los equipos. Se han incluido esquemas y fotografías del sistema experimental de cada práctica, para una mejor visualización de lo tratado, asimismo se han sugerido los pasos para la elaboración del informe, que incluyen las tablas y el método de procesamiento estadístico. ····· 103611361
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Este libro es el producto de varios años de docencia e investigación del grupo de investigación sobre adquisición y análisis de señales PAAS-UN y aplicación en el sistema eléctrico colombiano. Se divide en 10 capítulos que van desde la conceptualización del tema, confiabilidad, índices particulares que afectan la calidad como flickers, armónicos, variaciones de tensión y transitorios electromagnéticos hasta metodologías de evaluación de calidad de la potencia y un capítulo novedoso sobre la calidad de la potencia eléctrica aplicado a la generación distribuida. En cada uno de estos temas se analizan las normas nacionales e internacionales vigentes. Este libro fue posible gracias al trabajo académico de recopilación de los temas de las estudiantes del programa de maestría en Ingeniería Eléctrica de la Facultad de Ingeniería de la Universidad Nacional de Colombia: Leidy Buitrago, Diana Jiménez y Martha Camargo, el estudiante de doctorado Fabio Andrés Pavas y la estudiante de maestría Ana María Blanco quien realizó la recopilación final. A ellos reconocemos explícitamente su trabajo y aportes académicos. ····· 103611446
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Ferrimagnetic bioactive glass ceramics are expected to be potential candidates for the hyperthermia treatment of cancer. When placed in a high frequency magnetic field, these materials generate heat energy by hysteresis and eddy current losses. Unlike the conventional radiotherapy where it is very difficult to treat the deep seated tumors without harming the healthy cells, magnetic hyperthermia may be quite efficient in treating the deep seated tumors locally. Tumor cells usually perish around 43 °C whereas healthy body cells remain unaffected at this temperature. Magnetic parameters of the implant material and the applied field are tailored in such a way as to give the required optimum heat energy. Such materials should have the adequate ability to bond with the tissues (bio-activity). Much work has been done on Fe3O4 containing glass ceramics for this purpose but this work is the first ever detailed study of its kind on ZnFe2O4 containing biomaterials. Bioglass ceramic materials containing zinc ferrite nanoparticles may not only be useful for the hyperthermia therapy but also effective in re-enforcing the damaged bone by forming hydroxyapatite on material-solution interface. ····· 103613401
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Evanescent wave absorption sensing and spectroscopy are the widely used techniques for the detection of unknown chemicals. Tapered fibres are used in evanescent wave absorption sensing applications, due to the large fraction of modal power extended into the external environment as evanescent wave. The core-mode cut-off play a major role in the evanescent field absorption based tapered fibre sensors. The core-mode cut-off can be calculated by solving the eigen value equations of a tapered fibre considering as a weakly guiding three layer optical waveguide. Single mode tapered fibre has been fabricated to make a precision sensor element suitable for chemical detection. Finally, the sensor element has been used to detect absorption peak of ethylenediamine (EDA). The results are presented in which the absorption peak at 1540nm is observed. In the last chapter a fibre loop cavity resonator has been theoretically analyzed. The resonance conditions and steady state response of fibre loop cavity resonator has been analyzed. The fibre loop cavity resonator can be used for chemical sensing applications. ····· 1036118636
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In radio astronomical applications, it may be essential to accurately evaluate the electromagnetic scattering and power dissipation losses of nearby dielectric objects, such as radomes. However, the numerical analysis becomes a burdensome task when the dielectric becomes thin, complex shaped, and electrically large. To mitigate these problems, we propose to employ high-resolution basis functions for accurate modeling of electromagnetic scattering from dielectric objects. Application of these basis functions significantly eases the computational burden of generating the on- and off-diagonal elements of the moment matrix. This method has been hybridized with the Characteristic Basis Function Method (CBFM) and the Adaptive Cross Approximation (ACA) algorithm to reduce both the size and generation time of the moment matrix equation. Furthermore, the proposed method is not only fast and memory efficient but it also generates the accurate solution of scattering problems associated with complex-shaped, thin and electrically large objects. ····· 1036119786
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this text book,the performance comparison of various Apodization profiles in terms of side lobe suppression is investigated.This research is aimed to develop the mathematical model of the Apodized Fiber Bragg Grating Scheme in order to suppress side lobes, while maintaining the reflectivity and narrow bandwidth. MATLAB codes are written to solve the coupled mode equations for the analysis of optimized reflection spectra under Fiber Bragg grating Strain Sensor.Finally the simulation results of MATLAB are compared with the results obtained by the standard software of Opti-grating version 4.2. ····· 1036120935
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Microbial fuel cell technology is an emerging technology with the potential to support renewable energy production and promote sustainable development. However, high cost of materials has militated against large scale implementation of this technology, especially when considering the high cost of Nafion used as proton exchange membrane. The successful application of Plaster of Paris slurry(gypsum) as proton exchange membrane as highlighted in this work, suggests the possibility of reduced cost in the development of this technology. Also, the architectural design described in this work makes this technology accessible to professional and non professionals interested in this research area. In addition, non governmental organizations (NGO`s) interested in the development of renewable technology for developing countries will find this simple and cost effective design very appealing. ····· 1036121083
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray One of the most serious problems in measurements electrical power systems is the possibility of over-voltages resulting from ferroresonance phenomenon. This can result in high overvoltages that can cause insulation failures in transformers, cables, and arresters. Ferroresonance is a general term applied to a wide variety of interactions between capacitors and iron-core inductors that result in unusual voltages and/or currents.This work is aimed at proposing a simplified model of ferroresonance phenomenon in single phase power transformers and analyzing the instantaneous wave shapes of voltage and current being distorted by the ferroresonance phenomenon by solving the Doffing equation. The transformer is modeled and the non linear equivalent resistance and inductance of the magnetizing branch are determined from open circuit test. The ferroresonance resulting from energizing the transformer through a series capacitor is assessed and the calculated primary voltage, input current, active power, reactive power and power factor values are compared with those measured experimentally. ····· 1036121481
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La interacción de la luz con la materia se manifiesta con gran diversidad, tanto que actualmente surgen publicaciones científicas describiendo sistemas con una nueva propiedad óptica. Sin embargo, las ecuaciones que describen al electromagnétismo se han establecido desde hace mucho tiempo. Claramente, el descubrimiento de nuevas propiedades ópticas está relacionado con la capacidad tecnológica de hoy en día en combinar los materiales disponibles y realizar compuestos de los mismos con formas y tamaños en la escala adecuada. Para entender dichas propiedades se debe afrontar el problema de representar tales morfologías y su interacción electromagnética. Una estrategia natural de hacer esto es imaginando al sistema compuesto por partes que podemos identificar con mayor o menor precisión dependiendo de que tanto nos acerquemos al mismo. En este trabajo abordamos computacionalmente ese problema para el caso de cúmulos de partículas nanométricas metálicas. Obtenemos que la intensidad de luz esparcida escala con el ángulo de dispersión sólo a partir de un tamaño mínimo que depende de la disipación de energía electromagnética cuando se excitan las resonancias ópticas del cúmulo. ····· 1036122332
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En este trabajo se presenta el estado del arte en lo relativo al daño óptico en materiales fotorrefractivos. Entender este fenómeno es de gran relevancia debido a que afecta a un número importante de aplicaciones fotónicas, que podrían significar el futuro de las telecomunicaciones. Para ello en este documento se lleva a cabo un estudio riguroso experimental de este fenómeno y se desarrolla un modelo teórico para explicarlo. La combinación de ambas aproximaciones (teórica y experimental) logra explicar de manera detallada al daño óptico, permitiendo tener el conocimiento necesario para generar aplicaciones donde se puede controlar totalmente la aparición de este efecto tan dañino, aumentando la eficiencia de operación y la vida útil de los dispositivos. ····· 1036122592
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book deals with analysis and simulation of ZVT based Boost PFC Converter with EMI Filter in PSpice software of version 9.2.The Boost converter of Power Factor Correction (PFC) Circuit is analyzed, designed and then simulated for resistive load. It gives better power factor at the input side and constant voltage and current at the output side. The drawback is the current has more noise i.e. EMI.The power factor is further improved using ZVS technique. In the converter circuit, the active clamping branch composed of a clamping capacitor and an active switch is placed in parallel with resonant inductor. Also, the main switch, the auxiliary switch, the clamping capacitor, the boost diode and the output capacitor form a voltage loop. The power factor is further improved using ZVT technique.The ZVT technique allows the increase in switching frequency without increase in switching losses .ZVT converter operates at a fixed frequency while achieving zero voltage turn on of the main switch and zero current turn off of the boost diode.In this book,it is proposed that ZVT based Boost PFC Converter with EMI Filter is a better solution for power factor improvement in AC to DC Converters. ····· 1036124838
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This manuscript describes different methods for transferring, in the most efficient way, power from the solar cells to the battery system, and from the battery system to all loads..Since overcharging a battery can cause damage to the battery, this project describes/analyzes DC-DC Buck choppers that will not just reduce/regulate the voltage for solar cell charging.. In order to understand the use of PI controller in minimizing the output voltage oscillation cycles and its magnitude, the model is provided with a manual switch and PI controller. Using the manual switch provided, the model of a time varying DC voltage source is provided as the input to simulate the effect of variation of the input voltage from its normal value. Thus we can visually observe the effect of variation of input voltage on the output, both by including and excluding The PI controller in the same model. This report is intended to provide the designer with a method of buck/step down DC voltage from high Voltage to low Voltage, by using a DC-DC switching buck chopper designed specifically for this task, the results are validated by using MATLAB/SIMULINK. ····· 1036125155
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Today the world is looking towards the efficient energy generation from renewable energy sources because of extinction of fossil fuels.Wind energy is a promising source of green energy.But the problem associated with this kind of energy id due to varying wind speeds the out put is also varying so it is not possible to integrate it to grid.Here Induction generators are dominantly used because of their advantages in variable speed torque characteristics.In this book an attempt is made to discuss different types of generators used in wind energy and different topologies for control of voltage and frequency of Self Excited induction generator are discussed and new promising methods are proposed for low cost power generation. ····· 1036125963
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Advanced epitaxial techniques such as molecular beam epitaxy or metal-organic chemical vapour deposition have made it possible to grow interfaces between two semiconductors flat up to one atomic monolayer. The possibility of fabricating a heterostructure of strictly-defined parameters, a quasi-two-dimensional nature and sharp density of states, has stimulated both theoretical and experimental research and shortly found many applications including LEDs, lasers, high electron mobility transistors, IR photodetectors, etc. In this work a detailed study of optical properties of excitons in double quantum wells subject to magnetic and electric fields is presented. Starting from the well-known Luttinger formulae we developed an efficient way to solve the Schrödinger equation of a coulombically-bound pair electron-hole forming an exciton. The results are illustrated on relevant figures, giving an opportunity to better understand the effects of external fields on the studied system. The book should shed light on methods used for calculations of magnetooptical properties and may be useful to anyone who is interested in theoretical or experimental research on semiconductor quantum structures. ····· 1036186562
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In the time of current trend of increasing energy consumption, the wind-power engineering may compensate considerable part of required electric energy. Rapid wind-power engineering development is considered to be one of the important sources of human need satisfaction. Conventional wind turbine control strategies are dedicated to ensure high energy conversion efficiency under varying wind conditions. The challenge in wind power control engineering is to design an adaptive wind turbine control strategy, which provides the dynamic system stability and the effectiveness of energy conversion. The aim of this book is to design and implement the control algorithm, which implies the electromagnetic torque control in order to adapt the rotor speed and keep high energy conversion efficiency. Wind turbine operation is considered in the partial-load regime. The stability of the purposed control system is studied using linear control theory concepts. The effectiveness of the wind energy conversion is proved by the simulation results in MATLAB Simulink environment. ····· 1036186722
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The field of plasmonics has offered the promise to combine electronics and photonics at the nanometer scale for ultrafast information processing speeds and compact integration of devices. Various plasmonic waveguide schemes were proposed with the potential to achieve switching functionalities and densely integrated circuits using optical signals instead of electrons. Among these, the hybrid plasmonic waveguide stands out thanks to two sought-out properties: long propagation lengths and strong modal confinement. In this work, hybrid plasmonic waveguides and passive devices were theoretically investigated and experimentally demonstrated on an integrated silicon platform. A thin silicon dioxide gap between a gold conductive layer and a silicon core provides subwavelength confinement of light inside the gap. A long propagation length of 40 m was experimentally measured. A system of taper coupler connects the plasmonic waveguide to conventional photonic waveguides at a high efficiency of 80%. Passive devices were also fabricated and characterized, including S-bends and Y-splitters. ····· 1036186809
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Due to some of their advantages, HVDC systems become more and more popular in power systems. Up to now, many HVDC models have been developing. Each HVDC model has its own function and control scheme base on purposes of application. Before practical application, these HVDC have to be tested for the feasibility of these HVDC models in term of technical criteria by using power system simulation programs such as Pss/e, EMTP and EMTDC. Pss/e is a popular commercial programme for power system simulation using RMS value. This paper will show you how to make an HVDC user defined model. The control scheme of the HVDC and the case study will be presented in this thesis. ····· 1036186856
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray For taking into account electromagnetic wave propagation within a transformer a length unit inductance is proposed to be connected in series to the length unit turn-to-turn capacitance and a unit length inductance is proposed to be connected in series to the unit length layer-to-layer capacitance within the distributed and quasi distributed parameter model of transformers. As a result the model is able to take into account the wave propagation along the turn-to-turn and layer-to-layer capacitance current path of the coil. This model is able to meet the circuit regularity requirements as well. The quasi distributed parameter model contains several identical lumps for modelling the wave propagation but being easily applicable for the practical use with circuit simulator software. A high frequency model of transformer shielding is proposed for the use with circuit simulator software modelling the high frequency behaviour of the shielding. A comprehensive model containing the proposed elements can help in evaluating electromagnetic compatibility (EMC) of a future transformer during its design period. ····· 1036186995
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Organic light emitting diode technology is evolving rapidly with commercial applications in recent years. OLED materials and design are moving into an advanced stage with optimising techniques becoming more important. This work presents the use of porphyrin materials for organic electronics, specifically for organic light emitting diodes using phosphorescent emission. The porphyrins show interesting photophysical properties which allow for an exploitation of the normally forbidden triplet energy states to achieve a significant enhancement in the device efficiency. This research presents a simple host-guest system where this concept is demonstrated. Various porphyrin structures are synthesised and tuned for OLED performance, from this, we can learn how chemical structure relates to the exciton dynamics and their resulting light emission. It is hoped that this work outlines a possible route to phosphorescent OLED technologies. ····· 1036187057
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Modeling and design of a single photon detector and its various characteristics are presented. It is a type of avalanche photo diode (APD) designed to suit the requirements of a Quantum Key Distribution (QKD) detection system. The device is modeled to operate in a gated mode at liquid nitrogen temperature for minimum noise and maximum gain. Different types of APDs are compared for best performance. The APD is part of an optical communication link, which is a private channel to transmit the key signal. The encrypted message is sent via a public channel. The optical link operates at a wavelength of 1.55 m. The design is based on InGaAs with a quantum efficiency of more than 75% and a multiplication factor of 1000. The calculated dark current is below 10-12A with an overall signal to noise ratio better than 18dB. The device sensitivity is better than -40dBm, which is more than an order of magnitude higher than the dark current, corresponding to a detection sensitivity of two photons in pico-second pulses. ····· 1036187079
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Electrical mismatching losses in photovoltaic systems are of great interest to system designers. In this book, an adaptive photovoltaic (PV) system is proposed based on novel flexible switch matrixes that form different possible topologies. This system maximizes the generated power in real-time for utility interactive systems in a modified inverter configuration. The proposed system uses fewer components and achieves maximum efficiency during shading and module mismatches by reconfiguring the PV modules based on real-time solar insolation, current operational conditions, and maximum efficiency criterion. Simulation tools are used to demonstrate that the proposed topologies provide improvement in efficiency over existing traditional PV systems. Furthermore, a prototype has been designed and developed. Experimental results for efficiency comparison between traditional PV system configurations are described in this work. Potential improvement using the proposed adaptive configuration is analyzed. The overall results validate the adaptive system and its benefits for a wide range of applications. ····· 1036187160
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Magnetostatics of thin wires is a specific branch of theoretical physics. Its main equation always contains a source, which can only be an endless curve in form. The field of an arc, which has endpoints, is not defined, therefore, there exists only entire field of an entire endless wire. This feature of the subject does not allow to employ the method of Green`s functions, which requires that a wire is divided into small pieces. Therefore, only entire filed of an endless wire exists, therefore, such a wire plays the role of the `elementary` source. In this book an approach is outlined, which allows to construct magnetic fields of a quite broad variety of curves. ····· 1036187595
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Different films of silicon oxynitride (SiOxNy) were grown using a glass-assisted CO2 laser technique. The samples were prepared on P- type silicon substrates (111) at temperatures from (750, 800, 850 oC) using two different gases of NH3 and O2 as the source of nitrogen and oxygen in open air. Fourier Transform Infrared (FTIR) Spectroscopy, Reflectometry, Spectroscopic Ellipsometry and C-V measurements were used for films characterization. FTIR spectra shows a strong stretching bond of Si-N at wave number range from (700-1000 cm-1) depending on the films composition, and Si-O stretching bond at wave number around (1088 cm1). The peak position and the corresponding full width at half maxima (FWHM) for Si-O stretching bond have been also analyzed. The Reflectometry was used to measure the refractive index which is equal to 1.66 for SiOxNy film growing at 750 oC. It was found that the samples are non uniform in their thickness (16-142 nm) and the refractive index of the films is graded (1.44-1.97) through the Spectroscopic Ellipsometry. The C-V characterization, dielectric constant and flat band voltage (VFB) were determined at high frequency of 1MHz. ····· 1036187892
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Many developments in finite-difference time domain (FDTD) computational modelling of Maxwell s equations and computed tomography (CT) imagery have caused important progress in heat delivery method, temperature monitoring, and thermal dosimetry. Electromagnetic hyperthermia method in the treatment of cancer is an application which had been revealed by these developments. The objective of electromagnetic hyperthermia is to destroy the tumor or cancer cells by achieving the highest possible temperature in the tumor or cancer cells without exceeding 42ºC in the surrounding healthy tissues. Many studies have shown that high temperatures can damage and kill cancer cells. Electromagnetic field is supplied to induce a temperature increase on tumor or cancer cells. In this thesis, the electromagnetic power deposition within the discretized cells is observed by solving the Maxwell s equations with FDTD. Further the thermal process is investigated by solving the Pennes bio-heat transfer equation with finite difference method. Moreover, this thesis is serving as an introduction for electromagnetic hyperthermia in the human issues. To that end an extensive study is planned. ····· 1036187974
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book represents different types of renewable energy, the behavior of renewable energy.The world is hunger of energy. The conventional energy is decreasing day by day. The use and necessity of renewable energy is discussed with respect to all over the world. A wind farm consists of several wind turbines.It is essential to connect the wind farm. Wind energy and wind firm are also discussed then it covers essential topics about wind turbine systems such as wind turbine generation system, wind power output, mechanical power extracted from wind.The speed of wind is not constant as well as the generated voltage is not also constant.Finally a wind farm integrated power system is designed and in simulation it is tried to keep the voltage constant by controlling the pitch angle of the wind turbine. ····· 1036188395
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Actualmente, el Silicio es en uno de los materiales más importantes en la industria de la electrónica. Sin embargo, el carburo de silicio (SiC) presenta en gran medida propiedades que superan por mucho al silicio en dispositivos a altas temperaturas. Desde 1998, el uso de este material de manera comercial principalmente en dispositivos basados en SiC ha aumentado considerablemente, debido a la necesidad de obtener dispositivos electrónicos capaces de operar a altas temperaturas y soportar altos campos eléctricos. Este libro permite dar un panorama más amplio de las propiedades ópticas y estructurales del PSiC. Los innovadores resultados encontrados en este trabajo, permiten desarrollar una metodología de caracterización del PSiC mediante técnicas no destructivas y de no contacto, que permiten dar información de la muestra sobre pequeños volúmenes de forma rápida. ····· 1036189530
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Este libro está enfocado en el estudio de las unidades de medición de fasores sincronizados (PMU) y la importancia de su utilidad en los sistemas de potencia a nivel mundial. A quienes sea de su interés, en el documento encontrarán información acerca de la historia, el origen técnico, el principio de funcionamiento, la arquitectura básica y las principales aplicaciones de las PMU en las redes potencia. ····· 1036189618
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En este trabajo se logra la reconstrucción de la superficie de objetos 3D así como la determinación de sus respectivas dimensiones. Para este propósito se utiliza un arreglo óptico que consiste de un proyector con una rejilla de Ronchi y una cámara CCD. Se proyecta la rejilla sobre un plano referencia en el que genera un patrón de franjas de periodo espacial conocido y se captura esta imagen (imagen portadora). Luego se proyecta la rejilla sobre la superficie del objeto bajo análisis y se captura esta nueva imagen del patrón de franjas modulado por la superficie del objeto (imagen modulante con portadora incluida). Posteriormente, se calcula la fase envuelta asociada con el patrón de franjas para cada imagen, usando el método del desplazamiento de fase o el método de la transformada rápida de Fourier. Luego, se restan las fases, obteniéndose la información de fase envuelta. A la información de fase envuelta se le aplica un algoritmo de desenvolvimiento y luego un algoritmo de conversión de fase a altura, logrando así la reconstrucción de la superficie del objeto y la obtención de sus respectivas dimensiones. ····· 1036191170
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Capillary optical fibers have a broad spectrum of uses, and are distinguished from conventional fibers by the presence of a hollow central void in the core. This work investigates the modal properties of capillary based optical fibers with an emphasis on their application to attain large effective mode area, and to realize tunable optical fiber couplers. It starts with a comprehensive review of the field, followed by analytical results and full-vectorial numerical simulations of the mode area of various fiber geometries. It is shown that novel designs such as the trench-assisted capillary optical fiber transcend the existing limits of effective mode area in conventional fibers. Moreover, the use of magnetic nanoparticle fluid filled three-core optical fibers to obtain dynamically tunable fiber couplers via resonant tunneling is explored. The present work was honoured with the best undergraduate thesis project award in the Indian Institute of Technology, Kharagpur in the year 2010-2011. ····· 1036191562
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Mastering of the terahertz (THz) spectral range has motivated intensive studies aimed at developing applications of THz radiation. Spectroscopy is one of them, as molecular absorption lines corresponding to the vibrational and/or rotational frequencies belong to the THz range. Subwavelength sample thicknesses impose great difficulties to conventional THz spectroscopy, yet sensing of such samples is essential. Potentialities of thin film THz spectroscopy are considerably enlarged if a sample is probed by surface plasmon-polaritons (SPP) - the complex of an evanescent EM wave coupled to a wave of free charges propagating nonradiatively along the surface. The book describes principles and achievements in the field of THz SPP spectroscopy. Two concepts (absorption and amplitude-phase) of the method are described. Designs of static and dynamic SPP spectrometers, techniques for determining the dielectric function of metals via measured characteristics of SPP, interferometers able of measuring the SPP complex refractive index and principles of dispersive THz SPP Fourier-transform spectroscopy are considered. ····· 1036191744
····· lezzter Preis 44.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Since the last decade, the development of ultrafast laser technology have led to various new and fascinating application in scientific research, industry and medicine. This is due to the great feature of the laser that produce superior performance. Since the discovery of laser action in Ti:sapphire in 1982, Ti:sapphire becomes one of the most popular solid-state laser material for ultrafast laser system. It combines the excellent thermal, physical and optical properties of sapphire with the broadest tunable range of crystal based laser material. The output spectrum cover the entire band from 660 to 1100 nm.This book explains the basics knowledge of the ultrafast laser and the Ti:sapphire laser oscillator construction for femtosecond pulse laser generation. ····· 1036191813
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray A general introduction to ac conductivity and a specific introduction to Complex Impedance Spectroscopy (CIS) technique are dealt with in Chapter 1. To acquire information on the work done already in this direction, literature survey is being carried out. Chapter 2 comprises of the review of the literature, namely the various experimental techniques developed by earlier workers in this direction. The third chapter is divided into two parts. The first part deals with the instrumentation developed in the present study. The second part of this chapter comprises of the calibration of the developed circuit. Chapter 4 deals with the synthesis of new samples. Studies made and the results obtained using the developed circuit is discussed in Chapter 5. In essence, the thesis highlights the development of instrumentation for ac conductivity measurement and investigations made on certain polymers. The technique developed in the present work is cost effective since costly instruments such as impedance analysers, ac conductivity bridges are not used. A personal computer with interfacing hardware and suitable software is what is needed in carrying out the investigations. ····· 1036192391
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The Green functions are especially useful for summing over the restricted classes of perturbation theory of diagrams, and are very powerful when combined with spectral representations. They play the most important part in the field-theoretical treatment of the many-body problem, and they are flexible enough to describe the effects of retarded interactions and all quantities of physical interest like thermodynamic properties can be derived from them. There are different types of Green functions,or propagators: One particle, two-particle,..., n particle, advanced, retarded, zero-temperature, finite-temperature, real-time, imaginary time, and so on. The Green s functions enjoy popularity because they yield, in a direct way, the most important physical properties in a systematic way. Among the types, we prefer the retarded double-time Green s function (GF) for our theoretical work because this implies the principle of causality. ····· 1036199135
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Synthesis and characterization of nano-sized particles has currently been a topic of intense investigation. In recent years, much effort has been devoted to the research of doped nanostructured materials. This kind of nanomaterials exhibits unusual physical and chemical properties in comparison with their bulk counterpart. As an important II-VI material, ZnS is chemically more stable and technologically better than other chalcogenides. In this thesis, we report an effective doping process by chemical route method to obtain nanosized ZnS:Cu particles. I have prepare five different samples with different concentration of copper. I have taken pure Zinc sulphide nanoparticle and after that I have put the copper in percentage of 0.005%, 0.01%, 0.015% and 0.02%. The influence of Cu doping concentration on electroluminescence has been studied. ····· 1036199416
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray A quasi-Landstorfer antenna exhibits both the characteristics of a high-gain antenna as well as a small-sized antenna. This antenna extracts the advantages of both the quasi-Yagi antenna and the Landstorfer antenna. The quasi-Landstorfer antenna will be suitable for wireless applications. Moreover, there will be more developments on this antenna in the future but this book will be the pioneer for all of them. All the necessary theories and working principle of the antenna have been described explicitly in this book. A detailed description of all the measurement setup has also been provided. The book is aimed to provide the reader a complete knowledge about designing the antenna as well as understanding the theories behind this antenna. The theory has been described from both the designer perspective as well as from field perspective for the academics. ····· 1036199427
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book presents theoretical and application topics in power quality in distribution systems.With this book we wished to create a resource that is relevant to the needs of the working Power System engineers by helping bridge the theory and simulation work. A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a mal-operation of end use equipments. Utility distribution networks, sensitive industrial loads and critical commercial operations suffer from various types of outages and service interruptions which can cost significant financial 1oss. With the restructuring of Power Systems and with shifting trend towards distributed and dispersed generation, the issue of Power Quality is going to take newer dimensions. In developing countries like India, where the variation of power frequency and many such other determinants of power quality are themselves a serious question, it is very vital to take positive steps in this direction. The present work is to identify the prominent concerns in this area and hence the measures that can enhance the quality of the power are recommended. ····· 1036199456
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Sustainable Electricity Production in a Developing Economy, the case study of Ghana is geared toward policy makers in developing economies and to students taking engineering courses. The book s material is also applicable to researchers working to make electricity production in developing countries sustainable. The energy system and electricity inaccessibility is a global concern which calls for immediate action. This book focuses on thermal electricity production as a complimentary option. In addition to providing updated material in the rapidly developing electricity production system in Africa,it emphasizes on the major causes of electricity supply shortages and the main barrier to electricity sustainability in a typical developing economy such as Ghana and Nigeria. The concept of alternative thermal production options are based on fuel sources. In keeping with contemporary concerns of climate change, marginal efficiencies were used to determine the fuel required in oil- equivalent and emissions in the form of carbon dioxide, sulphur dioxide and nitrogen oxides into the atmosphere. ····· 1036199489
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Present work concerned with preparation of bio-waste reinforced polymer composites which enhances optimal utilization of natural resources and particularly of renewable resources. Coir dust composites prepared by hand lay up method. In this work we have investigated the dielectrical and wear behaviour of bio waste reinforced polymer composites.Experimental results shows that the strong dependence of dielectrical properties on frequency of applied electric field and testing temperature. In order to improve the strength and to reduce the sensitivity to environmental influences the interfacial adhesion between the natural fiber and matrix was improved by chemical treatment of the coir dust.Dielectric constant of treated coir dust composite was lower than of that of untreated coir dust composite, i.e. the dielectric strength of the composite increases and the increased dielectric strength make these composites quite suitable for use as insulators.This book is dedicated to my father late Aireddy Krishna Reddy. ····· 10361100356
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Renewable power can`t compete with fossil fuels without financial support because they are expensive and their technologies are not yet mature enough. As a result, support schemes are in place. However, the multitude of support schemes raises concerns from the angle of a single EU electricity market. Solutions at the national level may alter competition in the EU internal market. Then, is there a need to integrate the support schemes and have a single support scheme applicable throughout the EU Since there are benefits and drawbacks to integration, is integration required This analysis sheds more light on this issue and should be relevant to policy makers in EU member states. It should also be relevant to academics around the world that conduct research in this field. ····· 10361101009
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray There has been an unfortunate tendency among most of the empirical econometricians to ignore model adequacy diagnostic checking, indispensably required to verify the empirical validity of the residual whiteness assumptions underlying the model. Most of these studies have also failed to account for possible non-stationarity in the data series and to benefit from an analytical framework for a meaningful long-run equilibrium and short-run causality` in a cointegrating space of error correction. Again, these studies, by adopting a methodology suitable to a developed power system in advanced economies, have sought to correlate the less correlatables in the context of an underdeveloped power system in a less developed economy. The present study, while casting scepticism on the validity and value of the results of these studies, also finds that cointegration approach is superfluous given the model adequacy criteria if the regression model is adequate, then it is as valid as supported by a residual-based cointegration! ····· 10361101343
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray World is facing severe energy crisis, the most excellent way to overcome the energy crisis is using renewable energy resources. Thousands of gallon of water have been wasted through our sewage system, if we use that water to produce electricity that will be beneficial. The main purpose of this project is to present a new alternative method for electric power generation based on utilizing waste water. ····· 10361113958
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Brushless dc motors with Hall sensors are widely used in various industrial and electromechanical applications. These machines have often been considered in the literature, under one common assumption ideal placement of the sensors, which is often not the case, especially for low-precision motors. This thesis is composed of three manuscripts which investigate the unbalance of Hall sensors and propose methods to eliminate its adverse effects. The studies presented here show that misalignment of Hall sensors leads to unbalanced operation of the inverter and motor phases, which in turn results in increased low-frequency harmonics in torque ripple, possible acoustic noise, and degradation of the overall drive performance. The presented research considers a typical industrial brushless dc motor and includes measurements, detailed models and hardware experiments to validate the analysis. The proposed averaging approach is shown to achieve performance characteristics very close to those of a motor with perfectly balanced Hall sensors. ····· 10361115449
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Este libro explica en forma clara y amena los principios que rigen la regulación del voltaje y la frecuencia en los sistemas eléctricos interconectados. El estilo simple, directo, y profundo que emplea el autor, hacen que este texto sea de gran valor para estudiantes, operadores de centrales eléctricas, administradores del despacho de energía a través de líneas de transmisión, profesionales de los sistemas de control, y del área electromecánica. Prácticamente sin el empleo de fórmulas matemáticas, este libro describe los modos y límites operativos de la máquina sincrónica en el plano P-Q, y analiza el significado de la curva de capacidad (capability curve) del generador. A modo de ejemplo, provee datos pertenecientes al régimen de operación de un generador sincrónico interconectado a la red eléctrica de la República Argentina. Menciona los principales equipos que contribuyen a la regulación del voltaje a través de los métodos tradicionales de provisión de potencia reactiva a las redes eléctricas interconectadas y además, describe las estrategias destinadas a lograr un balance entre la potencia generada y consumida en las mismas, con la finalidad de regular la frecuencia. ····· 10361116242
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this thesis the interaction between a single quantum dot and a cavity is investigated. Quantum dots embedded in a micropillar cavity are investigated by measuring the spectra, and by performing time-resolved measurements. The enhancement of the spontaneous decay of the quantum dot is measured to 18.9 with a resonant lifetime of 28.1 ps under the assumption of an exponential decay. A model is constructed with measurable parameters, and the calculated decay curves are not exponential. As a result the mean decay rate, which coincides with the exponential rate for an exponential decay, is calculated for the measured rates. A large deviation is seen, with an enhancement of the mean decay rate of 9.1 with a resonant lifetime of 56.5 ps. The non-exponential decay of the quantum dot is caused by non- Markovian processes in the dot-cavity interaction. Furthermore, the second order coherence is measured to determine the quality of the single-photon emission, and two-photon interference measurements are likewise performed. These measurements show an indistinguishability of 48%. Finally, cavity-assisted resonant excitation of a quantum dot with another quantum dot is demonstrated. ····· 10361133293
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Conduction electrons in CrO2, a metallic oxide are known to have only one kind of spin which makes it a very interesting material to study for spin dependent transport phenomena. Thin film growth of CrO2 for its different crystallographic orientations, namely (100) and (110) are found to be different on iso-structural TiO2 substrates and therefore, their transport and magnetic properties, that was confirmed with detailed X-ray diffraction and magnetic characterization. Low pressure growth of CrO2 was explored. Although CrO2 phase is possible at lower than atmospheric pressure, it is less pure than it`s atmospheric pressure phase. On fabricated tunnel junctions, magneto-transport properties with (110) CrO2 and its natural oxide barrier shows TMR at low temperatures with energy barrier height of 0.4 eV. ····· 10361134420
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La estructura microscópica de un material tiene una gran influencia sobre las propiedades ópticas que éste presenta a nivel macroscópico. Aprovechando esta dependencia, es posible optimizar la respuesta óptica no lineal de un material mediante la manipulación de su estructura física o química. En este trabajo se explora la relación entre la estructura y la respuesta óptica no lineal para dos grupos de materiales: moléculas orgánicas de tipo donador-aceptor y nanopartículas embebidas en una red vítrea. El análisis de la respuesta no lineal se hizo mediante la técnica de la compuerta Kerr óptica con resolución temporal de femtosegundos. La efectividad de la técnica se demostró al lograr resolver los diferentes tiempos de respuesta presentes en una muestra de disulfuro de carbono, utilizada como material de referencia. La gran resolución temporal obtenida con pulsos de femtosegundos permitió identificar los mecanismos físicos que originan la no linealidad en los materiales estudiados. ····· 10361137030
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En este trabajo se brinda a los interesados en el tema, contar con un soporte el cual les permita desarrollar un análisis de estabilidad transitoria y de pequeña señal en sistemas de potencia.Para las empresas del sector eléctrico y las universidades, es importante contar con la documentación y un procedimiento adecuado para realizar las investigaciones o nuevos desarrollos sobre el tema. En este trabajo se realiza un estudio de estabilidad transitoria y de pequeña señal. Para el estudio se utiliza la herramienta computacional NEPLAN en donde se modela el sistema de control (AVR) y el estabilizador de sistemas de potencia (PSS) dentro del sistema de potencia estándar IEEE39. Este sistema de potencia se modifica para cumplir con las restricciones operativas para aplicar los estudios de estabilidad ya mencionados. En el estudio se realizan las simulaciones y análisis sin el sistema de control (AVR) y sin el estabilizador de sistema de potencia (PSS), útil a la hora de instalar o ajustar un sistema de control, después se hacen las simulaciones con el sistema de control (AVR) y con el estabilizador de sistemas de potencia (PSS) y se mira el efecto de éstos dentro del sistema. ····· 10361137735
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Las técnicas de confinamiento óptico y manipulación de partículas neutras microscópicas usando haces de luz láser han proporcionado una herramienta única para controlar la dinámica de éstas partículas. Esta dinámica y las propiedades de interacción se obtienen al cambiar la composición de las partículas (cristales líquidos, partículas huecas, material biológico) o incluso cambiar el medio donde se encuentran inmersas. Otra alternativa que constituye un campo extenso, consiste en modelar la distribución y propiedades de la luz (haces `adifraccionales`, vórtices ópticos, gradientes de intensidad, patrones de interferencia). Este trabajo constituye una introducción a los conceptos básicos y teoría en micro manipulación con luz láser. Adicionalmente se presenta la descripción del montaje de un sistema de pinzas ópticas y sistemas de guía óptica para separar micro particulas. ····· 10361137957
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Nowadays power drives are the essential part almost of all technological processes. Improvement of efficiency and reduction of losses require development of semiconductor switches. It has a particular meaning for the constantly growing market of renewable sources, especially for wind turbines, which demand more powerful semiconductor devices for control, while power of turbines constantly grows. Also at present semiconductor switches are the key component in energy transmission, optimization of generation and network connection. The aim of this book is to make a survey of contemporary semiconductor components, showing difference in structures, advantages, disadvantages and most suitable applications. There is topical information about voltage, frequency and current limits of different switches. The book also tells about future prospects of semiconductor market. ····· 10361146612
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this research, we characterized magnetic and electromagnetic interferences of a two-stage pulse tube cryocooler to a LTc SQUID attached directly to the cold stage of the cryocooler and found the noise sources and proposed methods to reduce their interference on the operation of the LTc SQUID. In chapter one an introduction to cryocoolers and cryocooler based SQUID systems is given. Chapter two presents our method to measure the conducted high frequency electromagnetic interference into the cryocooler cold head via noise paths. In chapter three characterization of low frequency magnetic noises of a two-stage pulse tube cryocooler is presented. Because of the similarity of the profile of the magnetic noise during cool down process with that of the temperature variation we attributed a main noise source to the presence of magnetic regenerative materials located in the second stage. Finally a superconducting lead shield covering over the section containing magnetic regenerative materials at the second stage is proposed to reduce the interference of the noise to the SQUID attached directly on the second stage cold head. ····· 10361146793
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In recent years there has been a substantial increase in the demand for controllable reactive power sources which can compensate for large lagging loads. These requirements involve precise and continuous reactive power control with fast response time and avoidance of harmonic line current generation. Solid state Var compensators using forced commutated converters have been developed and are being used for this purpose. Active power filtering (APF) can provide VAr compensation by injecting equal but opposite distortion at selected points in a network. The objective of this project is to design an Active Power Filter (APF) using Voltage Source Inverter (VSI) to achieve reactive power compensation. It is achieved by forcing the inverter line current to follow a reactive sinusoidal reference at a constant switching frequency. The current reference generator has been designed for both lagging and leading reactive power conditions. The reactive power requirements of a bridge rectifier connected load are estimated using the above current reference generator. Using this, an APF is designed to compensate the reactive power requirements of the above load. ····· 10361147104
für 44.90€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In dem vorliegenden Werk Elektrizität direkt aus Kohle widmet sich Etienne de Fodor der zentralen Frage seiner Zeit in den elektrischen Wissenschaften: wie kann man die Energie der Brennstoffe direkt in elektrische Ladung umwandeln Hierzu trägt er Quellenmaterial zusammen, skizziert Denkansätze und beschreibt Versuche. Das Ergebnis ist eine umfangreiche Übersicht über einen entscheidenden Abschnitt der Elektrizitätsgeschichte. Qualitativ hochwertiger und bearbeiteter Nachdruck der Originalausgabe von 1897. ····· 10361138931
····· lezzter Preis 45.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The linear and nonlinear resonance behaviour of optical antennas (metallic nanostructures showing resonance behaviour at optical frequencies) made of gold and aluminum using electron-beam lithography is investigated. Specifically, it is of interest how the emission behaviour is changed by the coupling of two antenna arms via a small gap. Experimental techniques applied include dark-field spectroscopy and two-photon luminescence. ····· 10361164476
für 45.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Anwendungen eines hochauflösenden Röntgendetektors sind die Kleinwinkelstreuung an Muskelfasern, um deren Kontraktion zu bestimmen oder die Verwendung in üblichen Kristalluntersuchungen bei hohen Energien. In der medizinischen Forschung mit Röntgenstrahlung, speziell bei Untersuchungen der Herzdynamik, werden hochauflösende Röntgendetektoren benötigt, die sowohl eine Auslesegeschwindigkeit im Submillisekundenbereich, als auch eine Kontrastauflösung von besser als 1 % leisten können. Eine medizinische Untersuchung der Flussdynamik wird nur durch die Verwendung eines Kontrastmittels möglich, so dass man Gefäße durch die K-Kanten Subtraktionsmethode deutlich vom restlichen Gewebe unterscheiden und den Absolutbetrag der Konzentration des Kontrastmittels bestimmen kann. Übliche Kontrastmittel sind Iod und Gadolinium, so dass Energien bis 51 keV benötigt werden. Verschiedene Detektoren bzw. Detektormaterialien sind im Gebrauch bzw. im Test um diese Bedingungen zu erfüllen. Si-, Ge-, CdZnTe-, CdMnTe- und CdTe-Halbleiterdetektoren werden hauptsächlich benutzt oder getestet, wobei jeder Typ physikalische und/oder technische Schwierigkeiten besitzt, die eine Erfüllung der Forderungen verhindern. Diese Schwierigkeiten sind die geringe Absorptionseffizienz (Si) und verschlechterte Ortsauflösung unter Verwendung von Szintillatoren, Kühlung und schlechte Auflösung (Ge) und Elektronenüberlaufen der Pixel sowie technische Probleme beim Bau eines Detektorchips (CdZnTe-, CdMnTe- und CdTe). Der Ansatz dieser Arbeit ist nun eine gasgefüllte Ionisationskammer, als integrierender Zeilendetektor aufgebaut. Allgemein besteht bei einer Ionisationskammer immer der Nachteil der geringeren Absorptionseffizienz. Betreibt man die Ionisationskammer allerdings bei einem hohen Druck in der Größenordnung von 50 bar, kann man unter Verwendung der Edelgase Ar, Kr oder Xe für eine entsprechende Länge des sensitiven Bereichs (im Bereich von cm) dieses Problem lösen. Bei diesen Längen der Auslesestreifen machen sich allerdings Parallaxefehler bemerkbar, deshalb muss man eine Strahlungsquelle verlangen, deren Strahl eine minimale Divergenz aufweist. In Kombination mit der eingangs geforderten Zeitauflösung und dem gewünschten Kontrast, sind nur Synchrotronstrahlungsquellen der 3. Generation wie das ESRF in Grenoble oder der DORIS Ring in Hamburg in der Lage, eine entsprechend kleine Strahldivergenz bei sehr hohem Photonenfluss zu liefern. Die Aufgabe dieser Arbeit ist es nun, herauszufinden wo die Grenzen der Ortsauflösung einer oben beschriebenen gasgefüllten Ionisationskammer liegen. Dazu wurde eine Simulationssoftware entwickelt und ein Testdetektor gebaut. Die Simulation berücksichtigt sowohl die physikalischen Effekte im Gasvolumen nach einer Belichtung mit monoenergetischen Photonen als auch die Geometrie des Detektordesigns zur Berechnung der Ausdehnung der Ladungswolke. Der Bau des Detektors erfüllt nun zum Einen den Zweck, die technische Realisierung eines solchen Designs zu demonstrieren, als auch über eine einfache Messung die physikalischen Grenzen der Simulation aufzuzeigen. Desweiteren soll über diese Software eine Voraussage über mögliche Ortsauflösungen eines solchen Detektors gemacht werden. ····· 10361107392
für 45.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Low-field NMR techniques are used to study porous system, from simple to complex structures, and objects of cultural heritage. It is shown that NMR relaxometry can be used to study the fluid dynamics inside a porous system. A simple theoretical model for multi-site relaxation exchange NMR is used to extract exchange kinetic parameters when applied on a model porous systems. It provides a first step towards the study of more complex systems, where continuous relaxation distributions are present, such as soil systems or building materials. Moisture migration is observed in the soil systems with the help of 1D and 2D NMR relaxometry methods. In case of the concrete samples, the difference in composition makes a significant difference in the ability of water uptake. The single-sided NMR sensor proves to be a useful tool for on-site measurements. This is very important also in the case of the cultural heritage objects, as most of the objects can not be moved out of their environment. Mobile NMR turns out to be a simple but reliable and powerful tool to investigate moisture distributions and pore structures in porous media as well as the conservation state and history of objects of cultural heritage. ····· 10361107595
für 45.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Aufgrund ihrer vielfältigen Anwendbarkeit z.B. im Explosionsschutz, zur Detektion von Gaslecks, zu Emissionsmessungen oder in der Prozessüberwachung wächst der globale Markt für Gassensor- und Gasanalysesysteme stetig. Als optischer Gassensor findet dabei gerade der Halbleiterlaser ein immer breiteres Anwendungsspektrum. Im Wellenlängenbereich von ca. 2,8 µm bis ca. 4 µm standen bis vor kurzem jedoch keine Halbleiterdiodenlaser zur Verfügung, die bei Raumtemperatur im Dauerstrichbetrieb arbeiten und dabei die benötigte Leistung erbringen. Ziel der vorliegenden Arbeit war es daher, den Wellenlängenbereich GaSb-basierter Laser zu erweitern und so die fundamentalen Absorptionsmoden weiterer Gase für die Detektion zugänglich zu machen. Parallel wurde die Untersuchung und Verbesserung fundamentaler Wachstums- und Laserparameter angestrebt. ····· 10361108000
····· lezzter Preis 46.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Diese Arbeit befasst sich mit verschiedenen nano- und mikrotechnologischen Konzepten zur Steigerung der Auskoppeleffizienz von OLEDs.Hierfür werden drei bottom-up-Ansätze, bei denen Nanopartikel während der OLED-Herstellung in die OLED eingebracht werden, beschrieben und zwei top-down-Ansätze vorgestellt, bei denen vor der eigentlichen OLED-Herstellung die Substratoberfläche durch Nano- und Mikrostrukturierung modifiziert wird. ····· 10361164440
für 48.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Gallium arsenide (GaAs) is a group III/V semiconductor and is a very important material for modern technology. It has a broad range of applications and it is extensively used in light emitting diodes, laser diodes [81, 37, 46, 40], sensors and detectors [81, 55] among others. In electronics it complements silicon devices, where its applications reach from robust logic circuitry and transistors to microwave waveguides [36, 81, 13]. Gallium arsenide also serves as a photovoltaic power source [37, 46, 40]. Especially due to the ever advancing technological applications, there is a keen scientific interest in new and improved methods for the analysis of the material properties, the development of new techniques and experimental schemes. Motivated by the timescale of the dynamics of a nuclear spin system in a solid state device, a very active field of research is the realisation of semiconductor-based devices for spintronics [56], quantum computation [45, 17, 88] and quantum memories [65]. GaAs is often used, not as a bulk semiconductor, but in nanoscale assemblies of different semiconductors, i.e. heterostructures. Due to their unique properties, heterostructures are of particular interest to ongoing academical and industrial research efforts. It is possible to construct devices with significantly different characteristics compared to those of the bulk material. Especially at nanometer-scale miniaturisation, quantum effects have a significant impact on the electronic and optical properties [81, 29]. In material analysis nuclear magnetic resonance (NMR) techniques are commonly applied to semiconductor systems and NMR is the natural choice to implement a spintronic device and operate on a quantum device. Nevertheless, applying classical NMR techniques can be challenging, especially when it comes to the detection of small nuclear spin sub-ensembles in nanometer-sized heterostructures or the probing of such sub-ensemble when a much larger group, such as a substrate, contributes as significant background. In these cases the sensitivity can be greatly enhanced by optical methods [1]. Laser assisted nuclear magnetic resonance methods can be divided into two major flavours, optically polarised and optically detected nuclear magnetic resonance. Both methods require the use of coherent light in order to polarise the electron spin system in the semiconductor. The electron spin system can exchange angular momentum with the nuclei, causing a polarisation of the nuclear spin system as well. ····· 10361107389
für 48.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Die Motivation dieser Arbeit ist die Erforschung potentieller Seltenerd-dotierter Laserkristalle auf Basis von oxidischen Wirtsmaterialien, welche mit Hilfe von blauem Pumplicht sichtbares Laserlicht erzeugen können. Oxide weisen im Vergleich zu anderen Materialklassen meistens bessere thermomechanische Eigenschaften auf und sind zumeist einfacher herzustellen. Es wurden die schmalbandigen intrakonfiguralen 4 f -4 f -Übergänge des Pr 3+ - und des Ho 3+ - Ions sowie die zur Realisierung durchstimmbarer Laser geeigneten interkonfiguralen 5d-4 f - Übergänge des Ce 3+ -Ions untersucht, welche in unterschiedliche Oxidkristalle dotiert wurden. Neben der Herstellung der Kristalle, welche größtenteils mit dem Czochralski- und dem Nacken-Kyropoulos-Verfahren erfolgte, lag das Hauptaugenmerk auf der spektroskopischen Charakterisierung der Materialien in Bezug auf ihre Lasereigenschaften und - sofern möglich - der Charakterisierung der entsprechenden Laser. Anders als bei vielen anderen Pr 3+ -dotierten Oxiden ist bei Pr 3+:SrAl12O19 der Verlustprozess durch Multiphononenrelaxation vom oberen Laserniveau in das benachbarte 1 D2-Multiplett vernachlässigbar gering. Weiterhin tritt keine Absorption aus angeregten Zuständen (ESA) im sichtbaren Spektralbereich auf, so dass weder Pump- noch Laserwellenlängen durch diesen Verlustprozess beeinträchtigt sind. Unter Verwendung von InGaN-Laserdioden als Pumpquellen konnte mit Pr 3+:SrAl12O19 erstmals Lasertätigkeit im Dauerstrichbetrieb gezeigt werden. Mit einem differentiellen Wirkungsgrad von 47% bei einer Wellenlänge von 643,5 nm stellt dieses System den effizientesten, jemals demonstrierten Pr 3+ -Festkörperlaser im sichtbaren Spektralbereich auf der Basis von Oxiden dar. Bei einer absorbierten Pumpleistung von 281 mW wurde eine maximale Ausgangsleistung von 75 mW erzielt. Die Ausgangsleistung ist vor allem durch die zur Verfügung stehende Pumpleistung begrenzt. Im tiefroten Spektralbereich bei 724,4 nm wurde mit diesem Material zum ersten Mal Lasertätigkeit nachgewiesen. Für Pr 3+:LuAlO3 konnte erstmals Lasertätigkeit im roten und tiefroten Spektralbereich im Dauerstrichbetrieb demonstriert werden. Bei 724,1 nm wurde eine maximale Ausgangsleistung von 6,7 mW bei einem differentiellen Wirkungsgrad von 14% erzielt. Spektroskopischen Untersuchungen zeigen, dass es prinzipiell möglich sein sollte, einen Laser mit Ho 3+:Lu2O3 im grünen und mit Pr 3+:Gd3Sc2Al3O12 im orangenen Spektralbereich zu realisieren. Für Ce 3+:Ca3Sc2Si3O12, Ce 3+:Y3Al5O12 und Ce 3+:Sr3SiO5 ist gemäß den Messungen zur ESA kein Laserbetrieb zu erwarten. Bei Ce 3+:CaSc2O4 ist die Verstärkung durch stimulierte Emission in Teilen des sichtbaren Spektralbereichs größer als die Verluste durch ESA, so dass die Realisierung eines Lasers möglich sein sollte. Die energetische Lage des untersten 5d-Zustandes wurde mit spektroskopischen Messungen relativ zum Leitungsband bestimmt. Aufgrund der berechneten Breite des Leitungsbandes von maximal 1,6 eV finden ESA-Prozesse vom untersten 5d-Zustand in das Leitungsband hauptsächlich im nahen infraroten Spektralbereich statt. Insgesamt zeigen die Ergebnisse, dass auf Basis oxidischer Wirtsmaterialien effiziente Festkörperlaser im sichtbaren Spektralbereich erzielt werden können. ····· 10361107661
für 48.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Im Mittelpunkt dieser Arbeit stehen die Herstellung und die Charakterisierung von Halbleiter- Heterostrukturen der Gruppe-III-Nitride, welche für einen Einsatz in Lichtemittern im grünen Spektralbereich bestimmt sind. Das Wachstum der Halbleiterschichten erfolgt dabei mittels Metallorganischer Gasphasenepitaxie sowohl auf der konventionellen c-plane Fläche der Wurtzitstruktur als auch auf nicht- oder semipolaren Oberflächen, die in den letzten Jahren zunehmend an Bedeutung gewonnen haben. Im ersten Teil der Arbeit werden Ergebnisse an c-plane GaInN/GaN QW-Strukturen mit hohen Indium-Gehalten vorgestellt. Dabei wurde untersucht, wie die Qualität von hoch-In-haltigen QW-Strukturen durch verschiedene Wachstumsparameter sowie die Wahl des Substrats beeinflusst wird. Es zeigt sich, dass eine verspannungsinduzierte Bildung von Defekten in der aktiven Zone die Hauptursache für die starke Abnahme der Effizienz im grünen Spektralbereich sein könnte. In Experimenten zur Temperaturstabilität von GaInN/GaN QW-Strukturen wurde zudem beobachtet, dass das Wachstum einer Deckschicht bei hohen Temperaturen zu einer Degradation der QWs führen kann. Auch in diesem Fall deutet sich an, dass die zusätzliche Bildung von Defekten, die während des Deckschichtwachstums erfolgt, wiederum verspannungsinduziert ist. Der zweite Teil der Arbeit ist dann der Untersuchung von nitridbasierten Halbleiter-Heterostrukturen auf nicht- und semipolaren Oberflächen der Wurtzitstruktur gewidmet. Beim Wachstum von GaInN/GaN QW-Strukturen wurde beobachtet, dass unter identischen Wachstumsbedingungen die Wachstumsraten sowie der Indium-Einbau auf den nichtpolaren Oberflächen (a-plane und m-plane) vergleichbar sind mit denen auf der konventionellen c-plane Oberfläche. Auf der semi-polaren (1122) Fläche deutet sich hingegen ein etwas höherer Indium-Einbau an. In der Analyse der optischen Eigenschaften zeigt sich anhand der Übergangsenergien sowie der Rekombinationsdynamik, dass der Einfluss des elektrischen Feldes in den nichtpolaren QW-Strukturen tatsächlich verschwindet. Darüber hinaus zeigen die optischen Experimente, dass in QW-Strukturen auf m-plane SiC, die eine hohe Stapelfehlerdichte aufweisen, an den Kreuzungspunkten zwischen Stapelfehlern und QWs quantendrahtartige Strukturen ausgebildet werden, die eine effektive strahlende Rekombination der Ladungsträger ermöglichen. Desweiteren wurden die Polarisationseigenschaften von nicht- und semipolaren Quantenfilm- Strukturen untersucht. Dabei konnte beobachtet werden, dass auf bulk GaN-Substraten die Polarisationsanisotropie von m-plane GaInN QWs mit zunehmendem Indium-Gehalt ansteigt. Dieser Anstieg des Polarisationsgrades geht auf die größere Verspannung mit zunehmendem Indium-Gehalt zurück, die zu einer stärkeren Aufspaltung der obersten Valenzbäder führt. Auf m-plane 6H-SiC-Substraten wird jedoch in allen QW-Strukturen ein sehr hoher Polarisationsgrad von 90 % oder mehr beobachtet. Dieser Effekt ist auf eine stark anisotrope Verspannung der QW-Strukturen zurückzuführen, welche zu einer starken Aufspaltung der obersten Valenzbänder und damit zu eben diesen hohen Polarisationsgraden führt. ····· 10361107863
für 49.41€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The rate of Iraqi power demand has been increased significantly faster than the infrastructure`s development and it becomes very difficult to keep the system stable especially with the current acts of vandalism against the country, so it`s very important to improve the power system stability. The object of this work is to improve the stability of the Iraqi National Super Grid System (INSGS) by installing Unified Power Flow Controller (UPFC) devices in different optimal locations under fault condition and comparing the results with those of without UPFC devices under the same condition. The optimal location of the UPFC device was specified based on Genetic Algorithm (GA) optimization method, it was utilized to search for optimum UPFC parameters setting and location based objective function that depends on the power and voltage as a fitness constraints. The results obtained showed that the installation of Unified Power Flow Controller (UPFC) devices at the optimal locations of the Iraqi grid gives an improvement in the stability by damping the voltage and rotor angle oscillations after subjected to the three phase fault to ground at different locations and different cases. ····· 1036121289
····· lezzter Preis 49.50€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Ausführlich und exakt präsentiert Otto Henker einen für Studieneinsteiger konzipierten Einblick in die Brillenlehre. Auf Grundlage seiner Vorlesungen und in gut verständlicher Sprache gibt der angesehene Jenaer Professor zunächst einen Überblick über die physikalischen Eigenschaften des Lichts und des menschlichen Auges an sich, bevor er anhand zahlreicher Abbildungen minutiös die Beschaffenheit und Anwendung diverser Brillentypen und -gläser erläutert. Nach wie vor ein Standardwerk für angehende Optiker.Otto Henker war Anfang der 1920er Jahre Mitbegründer des Optischen Museums in Jena und förderte die Entstehung der dortigen Optikerschule. Zudem arbeitete er als Leiter der Abteilung medizinisch-optischer Geräte in den Jenaer Zeiss-Werken. ····· 1036174592
für 49.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Graphene - a two-dimensional allotrope of carbon - offers many opportunities for research in fundamental science, as well as for technological applications. First, for being a single layer of carbon atoms, which are bound in a honeycomb geometry, it represents a two-dimensional electron gas that is accessible for investigation and manipulation directly, in contrast to conventional semiconductor-based, two-dimensional systems. Second, it is chemically and mechanically robust and offers a high electrical and thermal conductivity, while being widely transparent for visible light. And third, charge carriers in graphene mimic massless Dirac fermions as graphene exhibits a linear energy dispersion. In the present thesis, epitaxial graphene that is grown by the thermal decomposition of silicon carbide (SiC) on its (0001) basal plane is investigated. Here, monolayer graphene (MLG) with reproducible properties is formed when silicon atoms sublime at high temperatures in a well-controlled manner. In addition to MLG, a carbon-rich interface layer is formed between graphene and the SiC surface. It is electrically insulating but has a strong impact on the properties of MLG. The buffer layer can be converted to a quasi-free-standing monolayer graphene (QFMLG) by intercalation of hydrogen between buffer layer and SiC surface. This treatment reduces the coupling between QFMLG and SiC. The graphene-substrate interaction can be further reduced when free-standing epitaxial graphene (FEG) is patterned. With this method, the SiC substrate is selectively etched away with a photo-electrochemical reaction, while suspended graphene devices remain. The main topics of the present thesis are the fabrication and the electrical characterization of these three materials MLG, QFMLG and FEG. In particular, classical and quantum corrections to resistivity and conductivity, as well as the interaction with the substrate are investigated with transport and magnetotransport measurements. We observe Shubnikov-de Haas oscillations in strong fields for MLG and QFMLG samples. The sequence of maxima and minima is a strong indication that charge carriers in epitaxial graphene behave as quasi-relativistic, chiral particles. The observation of the half-integer quantum Hall effect in MLG confirms this finding. Consequently, the pseudo-relativistic physics, which is theoretically expected and is visible in exfoliated graphene, is also present in epitaxial graphene despite the graphene-substrate interaction. Furthermore, we study the weak localization (WL) correction, and present a routine which allows to extract the elastic scattering times for intravalley and intervalley scattering. The latter can be identified with the scattering of charge carriers on short-range potentials. Universal conductance fluctuations are observed in the mesoscopic FEG samples. In the presence of disorder (in the diffusive regime), electron-electron interaction (EEI) is enhanced and results in a resistivity correction that is logarithmic in temperature. Moreover, EEI causes a parabolic magnetoresistivity in intermediate fields. The curvature of these parabolas also exhibit a logarithmic temperature dependence. We show that the slope of this temperature dependence can unambiguously be identified with the EEI correction. In particular, it allows to separate the contribution of EEI from other quantum corrections that cause a logarithmic temperature dependence. We present a parameter-free description of the underlying physics. The Kondo effect - the interaction of the conduction electrons with local spin moments - also causes a logarithmic temperature dependence of the resistivity. Consequently, the contribution of the Kondo effect is difficult to identify from temperature-dependent resistivity measurements and EEI can easily be misinterpreted as Kondo effect. We discuss the similarity of the Kondo and EEI correction critically and present measurements of MLG samples that are decorated with ferrocenium ions, which carry an unpaired spin. In the latter, we observe a Kondo-like signal in the temperature-dependent resistivity whose amplitude increases with increasing ferrocenium concentration. ····· 10361107823
für 49.90€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Der Physiker Heinrich Weber präsentiert im vorliegenden Band eine umfassende Darstellung zur Technik der Metallfadenglühlampen, im Volksmund auch Glühbirnen , seinerzeit eine innovative Beleuchtungstechnik, heute wegen der geringen Energieeffizienz verpönt. Ausführlich erläutert Weber die geschichtliche Entwicklung der Metallfadenlampe, ihre unterschiedlichen Arten und insbesondere ihre Herstellung. Mit zahlreichen Abbildungen illustriert. Sorgfältig nachbearbeiteter Nachdruck der Originalausgabe aus dem Jahr 1914. ····· 10361138775
····· lezzter Preis 49.90€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Joseph John Thomson erhielt 1906 den Nobelpreis für Physik. Er war Entdecker des Elektrons. Nachdruck des Originals von 1909. ····· ····· ····· ····· ····· ····· ····· ····· ····· 10361150821
····· lezzter Preis 49.95€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Physik gilt nach wie vor als wichtigste Grundlage für eine ganze Reihe von Wissenschaften von den Natur- über die Technik- bis zu den Ingenieurwissenschaften. Giancoli Physik, der Lehrbuchklassiker zur Physik, wendet sich mit dieser Ausgabe an Schüler, die in der Oberstufe des Gymnasiums das Fach Physik in einem Grund- oder Leistungskurs gewählt haben. Es ist eine gekürzte Fassung des Lehrbuchs, das langjährig in der Lehre weltweit etabliert und für seine Verständlichkeit wie auch die lebendige Präsentation des Stoffes berühmt ist. Die vorliegende Ausgabe für die gymnasiale Oberstufe behält diese Merkmale und gibt einen umfassenden Überblick über die Physik - allerdings mit Schwerpunkt auf den wichtigen Themen der gymnasialen Oberstufe und mit einer reduzierten mathematischen Komplexität. Jedes Kapitel bietet viele durchgerechnete Beispiele, zusätzliche Aufgaben und Lösungen sowie eine Zusammenfassung des jeweiligen Fachgebietes. Besonders nützlich zur Abitur- und Klausurvorbereitung sind zudem die ausführlichen Lösungswege auf der Companion Website zu den zahlreichen Übungen im Buch. Dies alles zusammen macht dieses Schulbuch zum idealen Begleiter für Schüler, die ihr Verständnis der Physik mit ausführlichen Erklärungen vertiefen und an anspruchsvollen Aufgaben überprüfen wollen. Mit enthalten ist ein Zugangscode für MyMathLab | Brückenkurs (Nutzungsdauer 12 Monate). Damit kann der Schüler oder der Studierende gezielt mathematische Fähigkeiten, die für die Physik nötig sind, sich aneignen.
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This study concerns with the lasers which are safe for eye, since many lasers are dangerous for the eye. Their emission can damage the eye, and make the persons completely blind. Here we study particularly about Nd:YAG laser. But the emission from Nd:YAG laser is not safe for human eye. Here the task is to convert this eye damage emission to the safe region. This study deals with Nd:YAG laser, its properties, spectroscopic behaviour i.e., absorption and emission spectrum. Also deals with the pumping scheme for Nd:YAG laser, specially pumping by laser diodes. we also study about the semiconductor materials which are suitable for the pumping of Nd:YAG laser, i.e., whose emission lines matches with the absorption lines of Nd:YAG, also study about the nonlinear optical processes, especially based on the second order nonlinear processes. The second order nonlinear processes are second harmonic generation, optical sum and difference frequency generation, and optical parametric oscillation (OPO). For these processes a nonlinear material is required, which is placed between an optical cavity for amplification. KTP crytalv is used as a nonlinear material. ····· 103611150
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Future antenna architectures especially for space applications are becoming more and more complex due to the need of Electronic Reconfigurability. This reconfigurability is needed in terms of Radiation Pattern, Bandwidth, Reliability, and Power Consumption. In this context, Electronically Tunable Reflectarrays and Frequency Selective Surfaces (FSSs) are particularly the hottest domains of RF design. The accurate analysis of electromagnetic(EM) scattering from such reconfigurable antenna structures is of great practical interest these days. However due to their large electrical size and complex cellular patterns specially when tuning elements such as RF-MEMS switches are also integrated within the array elements, conventional full-wave EM Modeling of such multiscale structures either fail or require enormous amount of computational resources to resolve prohibitively large number of unknowns. A novel and efficient modular numerical technique called Scale Changing Technique (SCT) addresses all these problems. The focus of this book is on EM modeling of passive and active (electronically steerable by RF-MEMS Switches )microstrip reflectarray using this Technique. ····· 103613500
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray All samples were prepared using conventional solid state reaction technique and were sintered at two different temperatures in air for 1 hour. Structural and surface morphology were studied by x-ray diffraction (XRD) method and high resolution optical microscopy respectively. The magnetic properties of these ferrites were characterized by frequency (1 kHz-13MHz) and temperature dependence complex permeability measurements. DC magnetizations of all samples were measured using the Superconducting Quantum Interface Device (SQUID) magnetometer. The XRD patterns of all samples have clearly indicated the formation of spinel structure. The change in lattice parameter can be explained on the basis of the ionic radii. Resonance frequency and Neél temperature decreased as Zn content increased. Possible explanations for the observed characteristics of microstructures, initial permeability, DC magnetization, and Neél temperature of the studied samples have been discussed. ····· 1036118895
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book has been written based on PhD thesis. In this book, most fundamental dimensional analysis technique is used to develop some mathematical relationships to understand the flashover mechanism of contaminated insulator. The expression of time to flashover, flashover voltage in terms of ESDD and surface conductivity has been developed. In addition, the relationships between leakage resistance and ESDD, and ESDD and wind velocity have been developed. All mathematical models have been verified by the experiments. ····· 1036119191
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Low voltage (LV) network loss estimation and direct load control (DLC) can play an important role in the cost-efficient operation of distribution systems. In the first part of the book new power loss computation procedures for LV residential distribution networks are presented. The deterministic method is called the `Unified Loss Theory`, because it gives an estimate of the components of the power loss, and is therefore suitable for cost-benefit calculations of loss-reduction investments. A new stochastic residential load model and an identification procedure have also been elaborated. The model is suitable for accurate simulation of the stochastic variation of the time-dependent household currents (together with the harmonics). In the second part of the book a physical load model and an identification procedure for electric storage water heaters are shown. New optimization algorithms are presented to determine the schedule for DLC load groups, in order to achieve different objective functions and taking into consideration several constraints. Results show that DLC systems are very useful tools in shaping the daily load curve and in minimizig balancing energy. ····· 1036119434
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray DC to DC power converters find major applications in all central processing unit (CPU) power supplies. The modern trend is to go towards lower power supply voltages the reason for this is to limit power at high clock frequencies (in GHz) employed. The current demanded by the processors are high. On account of this development there is a great demand for DC to DC converters with low output voltages and high currents. Typically the operating voltage is 1.5V or less and current levels are higher than 50A as specified for the forthcoming INTEL P4 chips. The low voltage, high current power supplies have the option of powering from a 12V bus [1] or 48V bus [2]. The required efficiency of the power supply has to be greater than 80%. The challenge in such converters is achieving high efficiency. This thesis addresses the challenges involved in the design of efficient low voltage, high current DC to DC power supply. Synchronous rectifiers are used as a standard method for achieving high efficiency in low voltage output converters. This thesis, besides employing synchronous rectifiers, proposes two additional innovations towards the goal of high efficiency. ····· 1036120195
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Single-core underground power cables can induce voltages and currents in their metallic sheaths. The sheath induced currents are undesirable and generate power losses and reduce the cable ampacity whereas the induced voltages can generate electric shocks to the workers that keep the power line. This means that it is very important to know the values of sheath currents and induced voltages and the factors affecting them.So this bbbkdiscussed the following: - Calculations of the induced voltages in single-core cables with various voltages levels from 11 kV to 500 kV with briefly studying the factors affecting them. - Studying the factors affecting the sheath losses in single-core cables by calculating the sheath currents (eddy-circulating) and their sheath losses in single-core cables with various metallic sheath materials with taking into consideration the following factors: Types of sheath bonding methods (single-point bonding, two-points bonding, cross bonding) and cable layouts (trefoil, flat), cable parameters, cable spacing, sheath resistance, phase rotation, conductor current, power frequency, the minor section length in cross bonding. ····· 1036120410
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Around the world, there are a number of policies encouraging penetration of wind generation in the electricity industry. The proposed large increase in the penetration of wind generation has raised concerns about the continued security and reliability of the operation of the network. Together with the uncertainty associated to the generation of wind energy, the demand for balancing services is increasing. Under these windy scenarios, it might be more efficient to use preventive actions in the spot market rather than doing corrective actions in the market for balancing services. This book aims at showing the advantages of this new paradigm of the organization of the electricity market. With this purpose, an integrated model of the electricity market was built on the optimization GAMS software and run for different environments and configurations of the grid. Comparisons are made at the end of this document in order to point out the superiority of this new approach over the traditional corrective model. ····· 1036121165
····· lezzter Preis 53.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Spintronics is an area of electronics that studies the design of electronic devices based on the spin properties of electrons, taking advantage of their full potential. To date, despite the extended theoretical work done on this class of components, models are mainly physical and, due to their extreme complexity, cannot be implemented in circuit simulators. The aim of this work is to address the critical problems of modeling spintronic devices in a compact form. The main goal is to make a bridge between a purely physical description and a more electrical counterpart of spintronic elements in order to enable their use in Computer Assisted Design tools, just as for CMOS devices. The first part of the book gives an introduction to the different kinds of spin-orbit interactions, the materials used for realizing spintronic devices and the main spin-based devices currently developed. The second part is then dedicated to the modeling of simple transistor structures where the current depends on spin-polarized carriers. Moreover, a brief outlook on possible future spintronic devices is given. ····· 1036125431
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The capability of non-interfering measurements together with the vast range of detection schemes allows application of optical spectroscopy in a variety of experiments. The aim of this work was the development and application of some of these new spectroscopic methods for the study and diagnostics of gases and plasma. In the dielectric barrier discharge the interest was focused on the description of the excited electronic states population variations during the period of discharge by the use of the fast broad-band emission spectroscopy. The application of the Cavity ring-down spectrometer to detect the singlet oxygen in the microwave plasma afterglow is described as second application in plasma. In the field of new methods the work describes the development of a new laser source - Vertical external cavity surface emitting laser and of a small, fast, robust and low-cost NO2 and NO3 detector based on the Incoherent broad-band cavity enhanced absorption spectroscopy. The dissertation should be useful mainly for the readers thinking about the application of these methods in their experiments as well as to anyone who is interested to discover more about their physical background. ····· 1036187468
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray A comparison of the radial distribution of output HPM power produced by a relativistic magnetron driven by a traditional solid cathode and recently invented transparent cathode was performed. The transparent cathode was found to improve relativistic magnetron operation by providing faster start of microwave oscillations at a predetermined mode without mode competition. Comparison of output microwave pulses produced by the microwave pulse compressor equipped with a mechanically operated switch and a fast gas-discharge switch showed that the latter one sufficiently shortens the rise time of the output microwave pulse. Results of this research suggest that: i) the use of a transparent cathode in relativistic and, probably, nonrelativistic magnetrons provides better mode selection by locking the desired magnetron oscillations in a shorter period of time, and ii) the use of a faster switch (as fast as possible) in a waveguide of a microwave pulse compressor shortens the rise time of the compressed output microwave pulse. ····· 1036188611
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Bangladesh lacks sufficient electricity generation capacity and electricity grid networks to electrify the whole nation and has never enjoyed 100% electrification. Currently, electricity generation per capita in Bangladesh is the lowest in the world, about 154 kWh/per year. There is a huge unmet commercial demand for energy as the shortfall of power generation capacity is estimated to be around 2500 MW for the next five years.A recent survey found only 32 percent of rural firms with access to electricity compared to 60 percent in urban areas. The Southern region, including Chittagong, accounts for another 20 percent. The rest is fairly evenly split among the western, northwestern, and central zones. Most generation plant, are also located close to Dhaka, with smaller plants near the gas fields or other load centers approximately 70 percent of overall transmission capacity is in the Dhaka region. Most reasonable forecasts suggest that Bangladesh would need at least one utility-scale plant in the 500 to 700 MW range every year to catch up with demand. But efficient incessant supply of electricity is an obligation for the balanced regional growth and development of Bangladesh. ····· 1036188743
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El presente libro está dirigido a estudiantes de Ingeniería Eléctrica, Técnicos e Ingenieros en mantenimiento industrial que estan relacionados con actividades de mantenimiento en plantas industriales,presenta de forma clara los conceptos y terminos utilizados para interpretar los fenómenos eléctricos atribuidos a la calidad de la energía, asi mismo muestra una metodología para calcular el filtro de armónicas para una instalación que presenta problemas con las armónicas, proporciona una guía general para identificar equipos que producen armónicas, los efectos que ocasionan en los sistemas eléctricos industriales, las alternativas que existen para corregir el problema y muestra las mediciones realizadas durante la puesta en operación de un filtro de armónicas sintonizado a la armónica que ocasionaba problemas en un planta industrial. ····· 1036189462
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Ferromagnetism and superconductivity are usually competing types of order in Solid State systems and the possibility of their coexistence is still an open issue. On the other hand their interplay in hybrid structures like tunnel and Josephson junctions is known to yield extraordinarily rich and exotic physics which has been the foundation for the development of several experimental techniques to probe both ferromagnets and superconductors. Besides the interest from a fundamental physics viewpoint, such systems promise to be crucial for future device applications in Electronics, Spintronics, Information and Communication Technologies, and Quantum Computation. This Monograph focuses on unconventional manifestations of both ordered states of Condensed Matter. It both introduces the subject by reviewing part of the existing literature and it includes original results. Charge transport, Spin transport, Josephson effect, and Proximity effect are analyzed for several types of ferromagnet/superconductor hybrids. ····· 1036191319
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Periodic structures have renewed applications in microwave engineering, especially with the advent of unusual artificial materials such as EBG structures and metamaterials. In this work, it is shown that spatial modulation of periodic structures provides a multiband behavior that depends on the amplitude or position modulation function. The number of stop bands, band-widths, center frequencies depends on the modulation function and type. The effect of the modulation function selection, as well as the effect of increasing the number of modulated loads within the period on the band diagram in both Load Amplitude Modulation and Load Position Modulation cases is studied. The concept of spatial modulation is applied to Left Hand-Right Hand rectangular waveguides with dielectric filled corrugations, and is proved to create new LH bands. Also, applications to microwave filter design by selecting the suitable terminating impedance based on the Bloch impedance calculations, to provide better filtering response, is discussed. The concept of periodic spatial modulation is a step towards the optimal design of the unit cell to engineer the band diagram of the periodic structure. ····· 1036191893
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Metamaterials with their unusual properties, offer possibilities to manipulate electromagnetic waves in an extraordinary way. Since the pioneering work of Professor Victor Georgievich Veselago in 1968 on the general properties of wave propagation in a negative refractive index medium, a large number of researchers have contributed to the development and the growth of this new generation of materials. In this manuscript, we propose to investigate metamaterials at microwave and terahertz frequency ranges with the aim to provide improved functionalities and performances for millimeter and sub-millimeter applications. ····· 1036191995
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Layered structures of the high Tc superconductors have reinstigated the study of two dimensional (2D) antiferromagnetic spin systems and their charge dynamics for more than a couple of decades now. As a hole moves through such a system it interacts with spin waves and phonons at finite temperature. This book contains systematic derivation of the hole spectral functions in a 2D t-J model and its extensions numerically by first finding the spin waves using linear spin wave approximation and then solving the hole Dyson`s equation within the Non-crossing approximation. The role of different parameters and scenario on the hole dynamics in such a system is investigated in detail. Particularly the three main chapters in this book deals with hole dynamics (i) when optical phonons are present in the system at finite temperature, (ii) when small but finite hole density is present in the system and (iii) when periodic antiferromagnetic domain walls are present. This book shows computational results extrapolated to thermodynamic limit and its comparison with the angle-resolved-photo-emission spectra of the high Tc Cuprates in order to understand some aspects of charge flow in such compounds. ····· 1036192432
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Phased arrays have been traditionally used in military applications for several decades. Recent growth in civilian radar-based sensors and communication systems has drawn increasing interest in utilizing phased array technology for commercial applications. Despite the broad range of potential phased array applications, phased array technology has not been widely deployed in the commercial arena. The high cost and complexity of phased arrays is the primary impediment to their deployment in any large-scale commercial application. In order to deploy phased arrays in a wide range of applications, ongoing efforts are underway to develop new architectures that allow complexity of phased array to be reduced. In this book, conventional designs of phased arrays are reviewed and various new approaches are presented to realize phased arrays with reduced complexity. ····· 1036198750
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In recent years, the demand for processing of biomedical images has been steadily growing due to an emerging developments of imaging tools in biomedical area. The main task of this book was to reconstruct the 3D image of a mouse axon from its 2D cross-section images. New mathematical methods were designed to achieve this. The 3D reconstruction involves three steps: preprocessing, segmenting and tracking of the images. For each step, commonly used methods have been applied but the results were unsatisfactory, hence a new method for each step was designed. The newly designed methods not only work well in the mice axon reconstruction, but also can be applied to other images of similar tasks. The flowcharts provided in this book could be generalized to many application, and therefore, will be of importance to academics, researchers and practitioners in a wide range of disciplines that require 3-D reconstruction as well as image segmentations. ····· 10361114280
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This study was initiated as a response to a challenge faced by coal fired power stations both nationally and internationally. It was found that there was a large degree of damage caused by `pitting`to the turbines in spite of the high purity of water used, possibly related to the acids generated at high temperatures. In light of this, a relatively simple method for determination of short chain organic acids was identified by comparing the efficiency of several methods. This book contains the comparative study between high performance liquid chromatography methods using ion exclusion and partition chromatography in order to find the most feasible method that can be used with aqueous environmental samples. The information in this book is therefore not only useful to improve the industrial health of power stations but is also applicable to environmental studies as well. ····· 10361115189
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Se presenta una metodología para la determinación de pérdidas técnicas y no técnicas que se producen en la red subterránea de distribución, a través del desglose de cada componente representativo de la red para analizarlo y cuantificarlo, en función de información existente y criterios de ingeniería de distribución. La metodología se fundamenta en la veracidad de la información, por cual se realizó un trabajo en campo para recopilar información: del alimentador, transformadores, redes de baja tensión, acometidas, contadores de energía, alumbrado público, equipos de ventilación, entre otros. Con esta información se realizaron los análisis de cada componente, llegando a determinar las pérdidas técnicas. Para determinar la energía suministrada se instalaron analizadores de energía en la cabecera del alimentador y en el secundario de los transformadores de distribución. Para la energía registrada se recopiló la energía facturada de los clientes y consumos propios de la empresa. Del balance de energía se determinaron las pérdidas no técnicas. En algunos casos no existió suficiente información lo cual no permitió llegar al grado de precisión esperado. ····· 10361117237
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Pequeñas Centrales Hidroelectricas Este libro permite al diseñador ayudar a escojer el tipo de turbina y equipos principales de la subestación. En los capítulos se describen los procedimientos para determinar el caudal y la altura de diseño utilizando métodos de medición. Se realiza una descripción de la clasificación de las turbinas hidráulicas, y los pasos para calcular las dimensiones de referencias de las turbinas y las caracteristicas del generador.En los capítulos se desarolla el procedimiento para seleccionar una turbina hidráulica y de acuerdo al nivel de voltaje se seleccionara el nivel de voltaje del transformador y los equipos principales de la subestación. ····· 10361117306
····· lezzter Preis 53.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Las empresas de distribución de energía eléctrica, en ocasiones suministran el servicio de energía eléctrica usando las redes subterráneas. Estas redes subterráneas están expuestas a problemas de funcionamiento derivados al comportamiento del aislamiento del conductor o cable o instalación de la red subterránea, los cuales pueden originar fenómenos que afectan la prestación del servicio. Para mejorar la calidad de servicio a los clientes, las empresas de distribución hacen uso de herramientas de simulación que permiten el modelamiento de cables y que además permitan realizar distintos tipos de análisis, como Flujos de Carga, Corto Circuito, Coordinación de Protecciones, entre otras. Además se tiene la necesidad de analizar, diagnosticar y definir estudios necesarios para los sistemas subterráneos con el propósito u objetivo de garantizar el buen funcionamiento del sistema eléctrico. El objetivo principal de este trabajo es realizar el modelamiento de circuitos de distribución subterránea, pertenecientes a una red de distribución para análisis térmico mediante el módulo Análisis Térmico para Sistemas Subterráneos disponible en el software ETAP. ····· 10361117476
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Large sized planar structures are increasingly being employed in satellite and radar applications. But due to large electrical size and complex cellular patterns of modern designs, full-wave analysis of these structures requires enormous memory and processing requirements. Therefore conventional techniques based on linear meshing either fail to simulate such structures or require resources not available to a common antenna designer. A novel technique called Scale-changing Technique (SCT) addresses this problem by partitioning the cellular array geometry in numerous nested domains defined at different scale-levels in the array plane. Multi-modal networks, called Scale-changing Networks (SCN), are then computed to model the electromagnetic interaction between any two successive partitions. The cascade of these networks allows the computation of the equivalent surface impedance matrix of the complete array which in turn can be utilized to compute far-field scattering patterns. Since the computation of scale-changing networks is mutually independent, execution times can be reduced significantly by employing multiple processing units. ····· 10361132065
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Recently, series compensation is widely used in transmission. However, this creates several problems to conventional protection approaches.This book presents a comprehensive distance and overcurrent protection approach for series compensated transmission line using support vector machine (SVM).SVM is considered as a new powerful Artificial Intelligence (AI) technique. In a short period of time, SVM has been applied to numerous applications such as transformer faultdiagnosis, power system disturbances, relay coordination, transient stability of power system and fault classification of transmission line. This is due to the advantages of SVM over traditional approaches. The SVMs are trained with different kernel functions with different parameter values to get the most optimized model. Simulation studies have been considered for different operating conditions, including wide variations of load angle, fault inception angle, fault resistance and fault location.In addition to series compensated transmission line protection studies, the book also includes fault analysis of high voltage transmission linewithout compensation. ····· 10361132919
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray We succeed in the generation of an intense THz pulse with maximum electric field of 250 kV/cm via non-collinear process in LiNbO3. We optimize the generation process and discuss the mechanism of High power THz generation. Using this source we drive large-amplitude motions in L-arginine micro crystals. Absorption spectra show the suppression of peaks and enhancement of low frequency absorption. These results are reproduced by simu- lation based on coherent transition in quantum levels of anharmonic potential. We have demonstrated that it is possible to use intense terahertz pulses to climb 20 ladder steps on the anharmonic intermolecular potential in the microcrystal. This opens the door to the possibility of manipulating large molecules, thereby increasing understanding of the properties of molecular complexes such as proteins. ····· 10361133691
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray We have developed a statistical analysis model for a gas detection system using a pulsed laser source and photo-detector, and then simplified the statistical analysis model to obtain the results efficiently. In this book our statistical analysis model is used for a generic mid-IR pulsed-laser gas detection system to predict trace gas detection and concentration estimation. The overall system statistical analysis model allows us to comprehensively evaluate and analyze a gas detection system as a whole, instead of merely looking at the system components individually. The generic analysis model can be specified with other system component (laser source, optical cavity, and photo-detector) parameter values, representing systems for different applications thus, this generic analysis model can be used to evaluate the performance of a variety of gas detection systems represented by this model. ····· 10361133798
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Metallic pipelines are used to transmit the natural gas and petrolum products. Usually pipelines are constucted in the same pathway of the High Voltage Transmission Lines to save the right-way cost. AC voltage is induced on these pipelines due to the electric and magnetic fields of the overhead transmission lines. This book gives the calculations of electric and magnetic fields around the H.V.T.L and studies the hazards appear due to electromagnetic field on the workers, the damage of the pipelines coating and corrosion of the metallic pipelines construction. ····· 10361134282
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In electromagnetics, Green s functions, i.e. the fields or potentials created by a point source, are the most important building blocks for the numerical methods like Method of Moments, Multiple Multipole Program, FEM-BEM, etc. In these methods, after a magnitude and position deciding process is carried out for the point sources, the field scattered or generated by the objects are obtained as a superposition of the Green s functions. In free-space, the Green s functions are given as analytical functions, but in the case of a layered geometry, which is the case for most of the applications, the field generated by the point source is obtained as a superposition of plane waves that propagate in all the directions. This gives rise to an integral with infinite bounds where the integrands are oscillatory and singular in general. In this book, a detailed analysis is carried out to obtain the layered Green s functions in a fast, robust and efficient way, with a special emphasis on the integrands for all different layer types (lossy, left handed, metal, ) and geometrical parameters. Several MATLAB codes (incl. plane wave visualizer, GPOF) used in the book are also included as an appendix. ····· 10361134458
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The most important element in lightning protection system is grounding. A good grounding system is a system that dissipates the lightning current into the ground efficiently. For designing optimal and effective grounding systems better understanding of the behavior of grounding systems under transient currents is essential. An optimal design is important for achieving Electromagnetic Compatibility (EMC) requirements as well as protection against high currents and voltage hazards. In this work, a model for calculating the response of a vertical electrode to lightning current is presented. The model is based on electromagnetic field theory, which is the most rigorous method for approaching the problem. The model takes into account the radius of the electrode, the conductivity and permittivity of the ground. ····· 10361147131
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The purpose of this book is to study the transmitting of the optical signal (laser) via optical fibers to reach long distances about 600km and find suitable solutions to fix the problems of attenuation and dispersion and possibility of using optical regenerators which were used as an alternative to traditional ways (electronic regenerators) and showing the benefits of using optical regenerators. Virtual photonics programs have been used to find simulation to optical systems in order to represent special modules for research A dense wavelength division multiplexing was described, whereas 64 channels have been amplified at the same time and was obtain (constant signal output) without going to use automatic gain control. Also a preamplifier module was studied including optical pumping, amplifier length and the effect on gain and noise. ····· 10361147244
····· lezzter Preis 58.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Durch die Zusammenführung der Traditionen von Mathematik und Physik gilt der deutsche Physiker Franz Ernst Neumann (1798-1895) als Begründer der theoretischen Physik.Er war Professor für Mineralogie und Physik und später Rektor an der Universität Königsberg. Dort schloss er auch Freundschaft mit dem Astronom Friedrich Wilhelm Bessel und dem Naturwissenschaftler Karl Gottfried Hagen.Zu Neumanns zentralen Forschungsthemen gehören vor allem die Kristallographie, die spezifische Wärme, die Wellentheorie des Lichts, der Elektromagnetismus sowie mathematische Methoden in der Physik. ····· 10361159280
für 58.41€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Debido al aumento incesante de la demanda de energía eléctrica, la reducción significativa de los recursos naturales, las necesidades medioambientales, además de las limitaciones en la coordinación y operación distantes de las necesidades de los sistemas energéticos de hoy en día, el mercado de energía eléctrica se enfrenta a un enorme desafío. A pesar de las diferentes propuestas de estrategias centralizadas para el control, no solo de la tensión y de potencia reactiva, sino también para la gestión de intercambios, se siguen presentando inestabilidades en distintas partes del mundo. En esta trabajo se propone una metodología de optimización de la operación y coordinación en sistemas globales de energía, mediante un esquema descentralizado del sistema multiagente y multiobjetivo, que considera la descomposición tanto de la red eléctrica, como del problema de optimización. Los resultados aplicados a dos sistemas de prueba muestran la posibilidad de estimar una operación óptima global, con menores requerimientos de información operativa, simplicidad en los equivalentes de red y mejora en los tiempos de cómputo, semejantes a una estrategia centralizada. ····· 103611707
····· lezzter Preis 59.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray An experiment and theoretical analysis have been done to measure the nonlinear refractive index n2 of LiNbO3 for different three wavelengths laser light of a continuous Ar-ion laser and observe the variation of the value and sign of the nonlinear refractive index. The Z-scan is a simple technique for measuring the change in phase induced on a laser beam upon propagation through a nonlinear material. It gives both the sign and magnitude of this phase change , which is simply related to the change in index of refraction, . For different wavelength the sign and the value of index of refraction is different. Additionally, for third-order nonlinear responses the real part of the third-order nonlinear susceptibility, , can be measured. However, Z- scan is sensitive to any nonlinear processes which results in , so that great care must be taken in interpreting data taken with this or any other nonlinear materials characterization technique. ····· 10361146395
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this book, adaptive protection schemes for power systems with DG units are proposed by integrating fault diagnosis with protection relay coordination strategies. An automated fault diagnosis method is developed using three staged radial basis function neural network (RBFNN) in which the first RBFNN determines the fault distance from each source, the second RBFNN identifies the exact faulty line and the third RBFNN determines the circuit breakers that must be open or close for isolating the faulty zone. After identifying the exact faulty line, then protection relay coordination is implemented. A new protection coordination strategy using the backtracking algorithm is proposed in which it considers the main protection algorithm to coordinate the open/close states of relays so as to isolate the faulty line. Then a backup protection algorithm is considered to complete the protection coordination scheme for isolating the malfunction relays of the main protection system. The fault diagnosis based on RBFNN and protection coordination using the backtracking algorithm were developed in MATLAB and the fault simulations on the test systems were carried out using the DIgSILENT software. ····· 1036175
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray V monografii rassmatrivaetsya teoriya vosstanovleniya signalov i izobrazheniy nauchnoe napravlenie po razrabotke metodov i sredstv kompensatsii iskazheniy, vnosimykh v signal ili v izobrazhenie v protsesse ikh formirovaniya razlichnymi neodnorodnymi sredami. Izlagayutsya novye teoreticheskie rezul`taty analiza i sinteza optimal`nykh bazisov dlya predstavleniya signalov i izobrazheniy, proshedshikh turbulentnuyu sredu, reguliruyushchie algoritmy ikh optimal`nogo vosstanovleniya. Bol`shoe vnimanie udeleno sintezu veyvlet i veyvlet-paket bazisov obladayushchikh ierarkhicheskoy strukturoy vlozhennosti, predstavleniyu differentsial`nykh i integral`nykh operatorov v lokal`nykh bazisakh. Monografiya budet poleznoy dlya nauchnykh rabotnikov i aspirantov v oblasti fizicheskoy i adaptivnoy optiki, radiofiziki, kibernetiki, radiolokatsii, prikladnoy matematiki i vychislitel`noy tekhniki. Mozhet byt` poleznoy spetsialistam drugikh oblastey, svyazannykh s obrabotkoy signalov i izobrazheniy. ····· 103615124
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This work is an investigation and study of the mechanism of internal discharges in micro cavities in solid dielectrics with application to power cables. The magnitude, repetition rate and energy, in micro cavities in solid dielectric samples and electrical cables were studied. The field distribution in these cavities was simulated, modeled and calculated for certain applied voltage. Alternating high voltage at power frequency at room temperature was applied to different materials.The cavity shape, cylindrical or spherical, and its dimensions were changed. The size of the cavity was much smaller than the sample thickness. The cavities location and w.r.t electrodes were changed. The study was done on samples of low density polyethylene (LDPE), polyvinylchloride (P.V.C) and ethylene polypropylene rubber (E.P.R) because of their important industrial applications. ····· 1036120912
····· lezzter Preis 61.20€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Thin-film silicon solar cell is a promising technology for solar energy due to their low-cost large-scale manufacturability, but one of the major challenges is to absorb light at infrared wavelengths where the absorption length is much larger than the active layer thickness. This book overviews the state-of-the-art light trapping technology for efficiency improvement in thin-film Si solar cells. we propose an all-dielectric, textured photonic crystal (TPC) as an effective light trapping scheme, which integrates dielectric gratings and a distributed Bragg reflector (DBR) in the backside of thin film silicon. We understand the operation principles for this design by using photonic band theories and electromagnetic wave simulations. We also developed a self-assembled method to fabricate the proposed photonic structures. Finally, we explored the fundamental performance limits for thin-lm Si solar cells. ····· 1036124945
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Electromagnetic acoustic transducers (EMATs) are non-contact, non-destructive testing devices for conducting specimens. The efficiency of EMATs is inherently low and methods for increasing it have been the subject of intense research. In publications, the finite element (FE) technique has been applied to the diffusion equation in order to model EMATs. However, electromagnetic theory indicates that the diffusion equation must be solved for the magnetic vector potential (MVP) in conjunction with an equation for the total current. An existing FE formulation considering the two equations becomes unstable when modeling transient inputs in EMAT transmitters. The limitation posed by the instability prompted the development of an improved FE formulation, which solves the two equations and is suitable for the modeling of EMATs.The objective of the research work described in this thesis is to properly and accurately model EMATs, so that their efficiency could be improved at the design stage. The thesis describes the governing equations of EMATs, improved techniques for their solution, and the application of these techniques to the analysis of such devices. ····· 1036187487
····· lezzter Preis 61.20€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book presents transmission properties in one- and two-dimensional plasmonic metamaterials with periodically and randomly structured arrays of various shaped perforated-apertures on metallic surfaces in the terahertz region. At a specific frequency at which the plasmonic metamaterials are perfectly transparent, the metal materials become essentially invisible. In the case of one-dimensional arrays of slits, Fabry-Perot like shape resonance enhances transmission of nearby horizontal surface resonance by the periodicity. Whereas in the case of two-dimensional arrays of various shaped holes, the shape resonance supported by guided-mode resonance, generally cutoff frequency, enhances transmission to be essentially unity near specific resonance frequencies. These understanding for the perfect transmission in the plasmonic metamaterials can contribute to the development of sensitive imaging systems, waveguides, and terahertz and infrared transmission filters. ····· 1036199662
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Key Features: (1)An introductory look on multiferroics and their types.(2)Fabrication of nanomultiferroics and their characterizations.(3)Size dependent tuneability and intercoupling of magnetic and dielectric properties of some rare earth ferrites and chromites.(4)Probing the magnetoelectric coupling of nanomultiferroics.Introduction to Nanomultiferroics is designed to serve as a reference book for varied group of postgraduate & research students of Physics and many material chemistry discipline,research scientist.During the past five decades,revolutionary breakthrough has occurred in the understanding of multiferroics and magnetoelectric phenomena,both from perspective of theory and experiments.The book is divided into five parts.The first covers the brief overview of multiferroics,their types and applications.The second is devoted to the effect of reduced particle size by developing new routes from wet-chemical synthesis method,on the dielectric,magnetic,magnetoelectric properties and Raman spectra.Third and fourth parts deal the rich interplay of competing magnetic interactions between rare earth ions.The part fifth concludes summary and future prospects of nanomultiferroics. ····· 1036199837
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En este libro se analizan diferentes técnicas utilizadas para la estimación de los parámetros contantes de los modelos de la máquina de inducción trifásica. También Se diseña la técnica TR, con la cual se identifican los errores más relevantes del comportamiento simulado y se diseña la técnica Torque-Speed-Tracking (TST), que estima los parámetros constantes de los modelos a partir de los puntos proporcionados por el fabricante. Esta técnica es probada con datos experimentales y corrige considerablemente los errores identificados con a técnica TR. Los modelos seleccionados para este diseño son: de jaula sencilla y de doble jaula, sin pérdidas en el entrehierro. Además se diseña una técnica de estimación de parámetros variables (PP) para el modelo de jaula sencilla que parte de puntos experimentales, obteniendo un comportamiento muy similar al obtenido con el modelo de doble jaula de parámetros constantes. ····· 10361116388
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En este libro se analizan los efectos de los huecos de tensión sobre una máquina de inducción trifásica y la diferencia de los mismos cuando se utilizan los modelos de jaula sencilla y doble jaula con parámetros constantes. Las variables analizadas en este caso son los picos de: intensidad, par y deslizamiento (pérdida de velocidad). Finalmente se obtiene una clasificación de la severidad de los huecos de tensión, cando se utiliza tanto para el modelo de jaula sencilla como el modelo de doble jaula, por medio de las componentes de tensión sin transformar y por medio de la componente de tensión directa. ····· 10361116984
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Electricity transmission began with direct current. In 1880, Edison patented the first DC distribution system. That DC system was vital to broaden the use of his most famous invention, the electric lamp. However, at that time, low-voltage DC was proven inefficient. Despite the success of AC systems, the efforts for the development of practical high-voltage direct current transmission (HVDC) continued. The first HVDC transmission system was built in Sweden, in 1954, using mercury-arc valves. Nowadays, modern voltage-source converters (VSC) have smaller space requirements and improved reliability. VSC-HVDC has brought back the interest in the establishment of DC networks for applications such as DC supergrids and transnational networks for offshore wind farms. The goal of this work is to develop a more straightforward simulation model of VSC-HVDC systems which can be inputted into simulation software packages and still provide realistic and reliable data on the system operation under all circumstances. The major contribution is the integration of the developed model, representing the whole DC transmission link, with the manifold control strategies possible for this new technology. ····· 10361134258
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Reactive compensation in distribution networks is a typical optimization problem of great technical and economic importance, which has been faced over five decades. It consists of determining installation points and operation control program of a certain number of capacitor banks in order to maximize the profits obtained from system losses reduction. The extent of the benefits from capacitor banks installation depends on electrical network configuration and its load states. Therefore, on this book, a great deal of attention has been focused on introducing methods to determine the size and location of shunt capacitor banks on distribution systems. The primary objective of this book is not based only on introducing new strategies but also to introduce and study the application of fuzzy set theory (FST) to the capacitor allocation problem. In addition, two methods are proposed in this book to study the impact of harmonics, which may exist in the distribution system on the capacitor allocation problem. ····· 10361146292
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The reconfiguration process for Shipboard Power System reroutes the electric power in the power system in order to achieve certain objectives, The reconfiguration process can improve the survivability and reliability of the power system. Most of today`s reconfiguration methodologies are centralized. In a Shipboard Power System s centralized reconfiguration approach, a single point of failure may happen if the system lacks redundancy. The Multi Agent System (MAS) technology is recently applied to the applications in power systems. The MAS is composed of agents that are intelligent entities with the capability of problem solving. However, current MAS applications on power system reconfiguration methodologies are topology dependent. Additionally, No MAS based reconfiguration methodology has been proposed for mesh structured power system reconfiguration.In this book, a completely decentralized MAS based reconfiguration methodology is proposed for Shipboard Power Systems. In this approach, an MAS is proposed for the reasoning of the reconfiguration. Each agent works autonomously and independently and the MAS works in a completely decentralized manner. ····· 10361146572
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The study of energy propagation and localization in optical lattices has become an important subject of research in several areas of science including mathematical physics, nonlinear optics and Bose-Einstein condensates. This book presents an original theoretical, numerical and experimental investigation of energy dynamics in nonlinear optical lattices. Theoretical work discusses nonlinear waves in both paraxial and nonparaxial regimes, the generation of solitons through nonlinear defects, the use of Lie groups in the study of universality of physical models and finally accelerated lattices with applications to dispersion spectroscopy. The numerical part consists in the realization of a nonlinear code to simulate light propagation in nematic liquid crystals, the latter being the material chosen for the experimental side of the work. Finally, experiments with voltage-driven nematic liquid crystals demonstrates tunable discrete diffraction, discrete solitons and their angular steering, multi-gap breathers and light driven Landau-Zener tunneling. The work discussed by this book led to the publication of 26 articles in peer-reviewed journals and 28 international conferences. ····· 10361146673
····· lezzter Preis 62.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Der schottische Physiker James Clark Maxwell (1831-1879) gilt als der Naturwissenschaftler des 19. Jahrhunderts mit dem größten Einfluss auf die theoretische und experimentelle Physik des 20. Jahrhunderts.JamesClark Maxwell studierte Naturphilosophie, Moralphilosophie und Mentale Philosophie sowie Mathematik und Physik. Zu seinen Lehrern gehörte Sir William Hamilton.Seine Ausarbeitungen über elektronmagnetische Gleichungen vollendete Maxwell noch zu Studienzeiten. Sie bilden heute die Grundlage der modernen Elektrizitätslehre und des Magnetismus. Die von ihm entdeckte Maxwellverteilung behandelt die Geschwindigkeitsverteilung von Gasmolekülen.Maxwell war ab 1856 Professor für Naturphilosophie in Aberdeen, bevor an den Lehrstuhl für Physik und Astronomie am King`s College in London berufen wurde. Im Jahre 1871 wurde er erster Cavendish-Professor für Experimentalphysik in Cambridge. ····· 10361159279
für 62.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Este libro es el resultado de analizar la máquina eléctrica como un conjunto de estructuras dispuestas adecuadamente por el fabricante, dónde el diseño de la máquina eléctrica armoniza las estructuras eléctricas y magnéticas en la geometría espacial de la misma y que ellas pueden expresarse matricialmente. Esta disposición espacial tiene como objetivo lograr que las variables (tensión y frecuencia en el generador y par y velocidad en el motor) de salida cumplan con ciertas pautas de diseño (y normativas) ante la excitación de la estructura eléctrica. Se considera a la falla como una modificación de la disposición espacial o de la estructura que se manifiesta a través de las variables a veces sutilmente y otras abiertamente. En base a dicha idea se desarrolló un método de diagnóstico basado en la manifestación que enlaza dichas estructuras: el flujo magnético de conversión. El análisis dinámico no es realizado en el texto. El diagnóstico a través de autovalores y autovectores de la matriz de flujo es el inicio un camino a recorrer. Como cada texto es una puerta abierta al análisis de un tema es de esperar que éste logre que cada uno avance un paso en su propia investigación. ····· 103611590
für 62.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En los sistemas eléctricos el equipo primario de las subestaciones eléctricas industriales debe mantenerse en las mejores condiciones operativas, para reducir las probabilidades de falla mejorando así, la continuidad del servicio. Por lo anterior, es necesario que los trabajos de preparación del equipo primario para su puesta en servicio y las actividades de mantenimiento sean de calidad, para evitar la salida prematura del equipo en operación. El presente trabajo es de utilidad al Ingeniero de mantenimiento y su personal técnico tiene la finalidad de proporcionar los elementos fundamentales de información, como apoyo en la manera de efectuar pruebas eléctricas al equipo primario de una subestación eléctrica. Los resultados obtenidos en las pruebas, deben cumplir con valores aceptables que se mencionan en este trabajo, que puede ser utilizado como material de consulta para la puesta en servicio de un equipo o si este, se encuentra en operación y requiere de mantenimiento. Se abordan técnicas de mantenimiento predictivo tales como, cromatografía de gases, análisis de furanos y termografía infrarroja aplicada al mantenimiento de equipo eléctrico en baja y alta tensión. ····· 10361136480
für 64.71€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book is aimed at investigating how the performance of wire-duct precipitators is influenced by the number of discharge wires, the wires` radius and the spacing between wires and the collecting plates. The precipitator performance is expressed in terms of the onset voltage of corona on discharge wires and the corona current voltage characteristic of the precipitators. The initiation of the corona discharge on the wire surface is located around the periphery of each wire. The onset voltage is measured for a laboratory model of a precipitator and calculated based on the criterion of self-recurrence of electron avalanches growing in the vicinity of the discharge wires. This calls for calculating the electric field in the vicinity of the discharge wires using the charge simulation method. The calculated onset voltage values agreed reasonably with those measured experimentally. A finite element method (FEM) has been adopted to model the corona characteristics in duct-type electrostatic precipitators (ESPs) with multi-discharge wires. In this way, Deutsch`s assumption is waived from the solution of the describing equations of the ionized field in the precipitator volume. ····· 103611113
für 67.41€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El dopado de guías de onda ópticas con iones de tierras raras permite el desarrollo de dispositivos fotónicos que combinan las ventajas de la propagación guiada con funcionalidades activas como la amplificación óptica o la emisión láser. En particular, los amplificadores y láseres basados en fibras y guías dopadas con erbio presentan numerosas e importantes aplicaciones en ámbitos como las comunicaciones ópticas, en medicina, en sensado, etc. En la actualidad la actividad científica en este campo se dirige a la mejora de las prestaciones y a la extensión de las aplicaciones a través del estudio de nuevos diseños y del uso de nuevos materiales y técnicas de fabricación. Presentaremos una introdución al problema, con los modelos teóricos empleados para simular el comportamiento de los amplificadores y láseres basados en fibras y guías dopados con alta concentración de erbio y codopados con erbio e iterbio. Continuaremos con la caracterización en régimen estático y dinámico de una fibra de cristal fotónico con alta concentración de erbio y de guias integradas escritas con láser codopadas con erbio e iterbio para finalizar con el estudio del uso de una SCF como sensor de tempertaura ····· 1036189895
für 69.21€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book presents novel approaches for efficient optimization techniques based on numerical simulations for photonic devices. It presents the recent advances in the application of the adjoint variable method to photonic devices as an efficient technique for sensitivity analysis. It also presents novel approaches for formulating the design of any photonic devices as an optimization problem. These optimization problems are then solved efficiently using gradient-based optimization algorithms. This book is the first one that shows how the optimization problem can be formulated as a convex optimization problem in photonics. Convex optimization programming allows for efficient solution of the design problem using interior point method. These approaches will highly accelerate the design cycle of novel structures to meet the ever demanding requirements of the photonic devices. ····· 1036119826
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Esta tesis doctoral aborda el problema de la gestión del riesgo de mercado en el medio plazo de una empresa de generación hidrotérmica en un entorno oligopolista mediante técnicas de optimización estocástica. Para ello propone, formula y desarrolla un modelo que permite representar un mercado mayorista de electricidad en el que participan varias empresas de generación cuyo objetivo es maximizar su margen operativo limitando su riesgo de mercado. Esto no sólo supone un importante reto de modelado, sino también algorítmico y práctico. El riesgo de mercado para una empresa de generación en un terreno desregulado se debe a su exposición a distintas fuentes de incertidumbre. Parte de ese riesgo está directamente relacionado con la incertidumbre de operar en varios mercados (variación de los precios de los combustibles o de la electricidad, por las propias decisiones o por las de la competencia), y con la incertidumbre propia de la actividad de generación eléctrica (aportaciones hidráulicas). Para la gestión del riesgo de mercado las empresas establecen una cobertura dinámica consistente en la toma de posiciones en derivados financieros, junto con la explotación de su parque generador. ····· 103611335
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray V rabote dan obzor sovremennogo sostoyaniya dvukhkomponentnoy diel`kometrii (DD) sel`skokhozyaystvennykh materialov, ispol`zuemoy dlya izmereniya deystvitel`nogo i mnimogo komponentov kompleksnoy dielektricheskoy pronitsaemosti i elektroprovodnosti, i pozvolyayushchey odnovremenno opredelyat` vlazhnost` i plotnost` zernovoy massy, vlazhnost` i elektroprovodnost` pochv. Rassmotreno novoe predlozhennoe i razrabotannoe avtorom napravlenie DD, osnovannoe na ispol`zovanii avtogeneratornykh dvukhkomponentnykh diel`kometricheskikh preobrazovateley (DDP) s emkostnymi ili induktivnymi datchikami, i obespechivayushchee vysokuyu tochnost` izmereniya. Izlozheny osnovy teorii i printsipy postroeniya avtogeneratornykh DDP, rezul`taty issledovaniy i razrabotok etikh DDP s emkostnymi datchikami dlya sredstv DD zerna i pochv, voprosy beskontaktnoy DD pochv na osnove DDP s induktivnoy antennoy. Monografiya yavlyaetsya izlozheniem doktorskoy dissertatsii, zashchishchennoy v Agrofizicheskom NII (Sankt-Peterburg, Rossiya) v 2009 g., s posleduyushchimi dopolneniyami, i prednaznachena dlya razrabotchikov perspektivnykh sredstv diel`kometricheskogo kontrolya materialov, uchenykh i inzhenerov elektrofizikov, aspirantov i studentov. ····· 103614918
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Blue jets and gigantic jets are transient luminous events in the middle atmosphere that form when conventional lightning leaders escape upward from thundercloud tops and propagate toward the lower ionosphere. Petrov and Petrova [1999] first expressed that jets could be the extension of classic lightning discharges initiated within the cloud boundaries. This dissertation demonstrates the fundamental physical similarities between the various electrical discharges known to occur in the thundercloud due to local and global charge imbalances. How charge imbalances form in the thundercloud has been first suggested by Wilson [1921], but their impact on the occurrence of blue and gigantic jets was not explored. This work shows that the accumulation of screening charges near the thundercloud top produces a charge configuration leading to the initiation of blue jets, and the effective mixing of these charges with the upper thundercloud charge to that of gigantic jets. Also, the physics of lightning and jets, and many of the small-scale features observed in jets can be interpreted in terms of streamers (needle-shaped filaments of ionization), and are further explored via numerical modeling. ····· 1036118512
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The book gives theoretical and experimental results in the field of interferential selectors for lasers with controllable parameters of radiation, diffraction optics, digital holography, digital signal processing and error analysis in optical metrology. Ray-tracing and plane-wave expansion methods are applied to build a generalized theory of a Fizeau wedge in reflection and transmission at illumination with typical intra-cavity laser beams. The newly established wedge properties are used for laser solutions, in which it acts as a spectrally selective tunable reflector, filter and optical coupler. Based on Fresnel diffraction integral, a theory of sinusoidal phase grating is proposed as an element for phase-shifting pattern projection profilometry of large-scale objects. Design, analysis and realization of two phase-shifting holographic systems for microscopic observations and for evaluation of plane mechanical stresses are included. The book provides theoretical description and uncertainty analysis of two systems based on a Michelson interferometer: a white light source Fourier spectrometer and a system for spectral fixation of laser diode emission to an atomic absorption line. ····· 1036118899
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The fast growth of wind generation has led to concern about the effect of wind power on the transient stability of the electric grid. New studies must be performed in order to evaluate the behaviour of the wind farms after severe faults and improve the design of the wind farms in an efficient and economical way. Under such circumstances, the most demanding requisite for wind farm is the Fault Ride-Through (FRT) capability. Wind farms connected to high voltage transmission system must stay connected when a voltage dip occurs in the grid, otherwise, the sudden disconnection of great amount of wind power may contribute to the voltage dip, with terrible consequences. Therefore, the dynamic and transient analyses of wind generators are necessary. This book proposes some methods with suitable control strategies for wind power application that helps wind farms to be connected during grid disturbances, achieving the grid code provisions in both steady and transient conditions. The results in this book can be significant in understanding the transient stability phenomena of fixed and variable speed wind turbines and also in designing of wind farms based on transient stability requirements. ····· 1036121243
····· lezzter Preis 71.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Los conductores aéreos de altas prestaciones térmicas y flecha pequeña son aquellos cuya temperatura de funcionamiento en régimen permanente es más elevada que la de los conductores convencionales, como el ACSR, cuya temperatura máxima está en torno a los 90 ºC. La sustitución de los conductores convencionales por otros de altas prestaciones térmicas y flecha pequeña se presenta como una alternativa que tiene varias ventajas frente a los métodos de repotenciación tradicionales. La principal virtud de esta sustitución es que la repotenciación se puede obtener sin necesidad de una actuación sobre los apoyos y cimentaciones. El presente trabajo de investigación, realizado en el seno de la Unidad de Formación e Investigación de la UPV/EHU CINIERSE, describe las características de estos conductores y revisa los métodos de cálculo mecánico y térmico considerando su aplicación a dichos conductores. Además, se propone una metodología de cálculo más adecuada para estos conductores. El contenido del libro debe resultar muy útil para los profesionales e investigadores del campo del transporte y distribución de energía eléctrica. ····· 1036122509
····· lezzter Preis 71.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book has investigated radioclimatological study in a clear-air environment as applicable to terrestrial line of sight link design problems. Radioclimatological phenomena are adequately reviewed both for the precipitation effect and clear-air effect. The research focuses more on the clear-air effect of radioclimatological studies. Two Southern African countries chosen for case study in the report are Botswana and South Africa. To this end, radiosonde data gathered in Maun, Botswana and Durban, South Africa are used for model formulation and verification. The data used in the book ranges from three years to ten years in these two stations. Three to ten years of refractivity data gathered in Botswana and South Africa is used for the model formulation. On the other hand, eight months signal level measurement data recorded from the terrestrial line of sight link set up between Howard College and Westville Campuses of the University of KwaZulu-Natal, Durban South Africa is used for model verification. ····· 1036125488
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book, Nonlinear Interactions of femtosecond pulses with transparent media, is an attempt to disseminate few important results obtained recently that enables the readers to understand the rich physics involved in the light-matter interactions in femtosecond (fs) regime. With the high intensities available from fs laser pulses, the subject becomes much richer, as the pulse itself affects and is affected by the material it propagates through, in dramatic ways. Interactions representing both these classes form the subject of this book. Considering the vast nature of this subject we limit ourselves in this book to the second and third order nonlinear phenomena namely, supercontinuum generation, mulitphoton absorption and surface enahanced third order processes demonstrated with four-wave mixing at surfaces. ····· 1036187195
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray A repetitive control method for output voltage control of a three phase uninterruptible power supply (UPS) with isolation transformer is investigated. In the method voltage control loop is employed in the stationary dq frame. The controller eliminates the periodic errors on the output voltages due to inverter voltage nonlinearity and load disturbances. The controller design and implementation details are given. The controller is implemented on a 5-kVA UPS prototype which is constructed in laboratory. Linear and nonlinear loads for balanced and unbalanced load operating conditions are considered. The steady-state and dynamic performance of the control method are investigated in detail. The theory of the control strategy is verified by means of simulations and experiments. ····· 1036187942
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray It presents a basic meaning for the distribution networks in united systems including city power systems and their classification. All components are inserted & their logic is illustrated. Renewable energy support is proposed while most important factors are studied. Power factor, voltage drop, power loss and load curves (with harmonics) are analyzed however, the coding systems were presented in details. Two major examples as a project style have been investigated with results. LAN, fire fighting and Telephone wiring are accounted. ····· 1036189057
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The book focuses on electromagnetic absorbing and shielding properties of multilayer materials. Nanomaterials are widely used and composite materials` dielectric characterization is deeply discussed. Very little academic literature exists on how to model(design) an electromagnetic absorber using matrix formalism of microwave propagation through multilayer materials. This book therefore, provides an interesting approach to the absorber`s design in which different branches of science are applied and where all of them are used to optimize the `quasi perfect absorber`: nanotechnology, electromagnetic wave propagation theory, composite materials manufacturing, evolutionary computation. With respect to the present literature, the method presented in this book computes the absorbing capability of materials, taking into account for the reflection and transmission coefficients, considering also oblique incidence of the electromagnetic field. Theoretical modeling of absorbers is experimentally validated. At the end of the book the electromagnetic shielding performance of carbon-carbon material and of high weight percentage carbon nanotubes based composite materials are throughly analyzed. ····· 1036189325
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Measurements of thallium and indium doped Silicon-On-Insulator rib waveguides show optical absorption at a wavelength of 1550nm, dependent on the charge state of the associated deep-level. Therefore, it is possible to use this effect to modulate waveguide transmission by means deep-level occupancy change induce by local depletion and/or injection of free-carriers. A one-dimensional model based on the generation and recombination process described by the modified Shockley-Read-Hall (SRH) mechanism was developed using MATLAB programming language in order to compute the optical absorption of a 1550nm wavelength as a function of the density of neutrally-charged thallium or indium centers. In addition, the influence of indium, as a dopant in silicon (utilizing the Impurity Photovoltaic Effect), as a means to increase the efficiency of a thin film silicon solar cell was investigated using the same samples. ····· 1036191705
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This work describes the work performed by the author at the ETH Zurich, under the supervision of Prof. Jerome Faist on the optimization of high performance quantum cascade lasers (QCLs) in the Mid-IR spectral region. The main factors influencing laser performance have therefore been analyzed. In particular the optimization of the laser design in order to improve the electron tranport and the optical gain. In addition a detailed analysis of the fabrication process is performed and a novel process scheme is presented for buried heterostructure lasers. ····· 1036191809
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book proposes several new utility interface converters to reduce cost, harmonic contents in line currents and to increase the reliability in interconnecting renewable energy sources such as wind, solar (photovoltaic), and fuel cells to electric utility. A new third harmonic current injection technique has been presented to reduce harmonic contents in the line current of controlled converters. A low cost, high efficiency, four-switch, three-phase PWM converter has been presented to interface small wind turbine with electric utility. A modular wind energy system along with modular utility interface converter concept is presented for higher power wind energy systems with increased reliability and power quality of the power electronics converter. A combined low cost, high efficient inverter and peak power tracker has been presented for photovoltaic energy systems. A combined low cost, high efficient inverter and peak power tracker has been presented for photovoltaic energy systems. A combined low cost, high efficiency inverter and peak power tracker has been proposed. This converter operates close to the maximum power point of the photovoltaic array and forms a DC to AC inverter. ····· 1036191937
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Fundamentals of electric circuit provides a very practical approach to a somewhat difficult subject. It provides basic coverage of electric components, circuits and its analysis. Chapters are organized in a step-by-step progression of concepts and theory. Each unit of instruction covers a short, concise topic. The key concepts presented in this book are discussed using a simplified approach that enhances learning. The use of mathematics is kept to the very minimum and is discussed through applications and illustrations. Each chapter begins with an introduction and discussion of important concepts and theories follows. Features of this book are detailed and accurate illustrations are provided in each chapter, network theorems are explained using typical examples and metering and measuring equipments are introduced. ····· 1036198432
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book presents a new transmission line protection scheme using voltage transient waveforms and fundamental voltage and current signals. The scheme integrates the high frequency transient protection algorithms with the synchronized sampling fault location algorithms to produce high speed fault detection and accurate location to the fault. The algorithms were enhanced by a new fault classification technique based on wavelet singular entropy and neural networks to classify different fault types and detect arcing activity within the faultIn order to reach better reliability and stability to the transmission network, transient adaptive single pole auto reclosing scheme (SPAR) was introduced. In the case of transient faults, the arcing extinction time can be accurately determined and in the case of a permanent fault, breaker re-closure can be avoided. ····· 1036199056
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The rapid expansion of photovoltaic (PV) systems has revealed the presence of losses due to module coupling, better known as mismatch losses, that deprive producers from additional and available electric energy. This book aims to better understand the causes and mechanisms of mismatch losses in grid-connected installations. Two solutions to reduce these losses are proposed, studied, and compared. Also, the modelling techniques for PV systems submitted to shade, along with experimental results, will be presented. The first solution proposed consists in modifying the connection scheme of the array. The second solution uses power electronic devices within the solar array to reduce mismatch losses. This study will conclude with a global comparison of the proposed solutions in both residential and commercial-sized installations. ····· 10361100993
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Superconducting radio-frequency (SRF) cavities are used to increase the energy of a charged particle beam in particle accelerators throughout the world. Bulk niobium is the material of choice to fabricate SRF cavities and their performance at cryogenic temperatures is characterized by a non-linearity of the surface resistance as a function of the RF field, in absence of field emission, which limits the operational accelerating gradient. This book presents the results on the investigation of such non-linearity in cavities which received different surface and bulk treatments as well as cavities made of single-crystal niobium. The experimental methods include measurements of the surface impedance as a function of temperature, of the quality factor as a function of the RF field below 4.2 K, and the excitation of different resonant modes. A thermometry system was used to better characterize the loss mechanisms. This book consists of the author s PhD dissertation at Old Dominion University (ODU) under the supervision of Prof. Colm T. Whelan of ODU and Dr. Peter Kneisel of Jefferson Lab. This book should be useful to students or young researchers in the field of SRF for accelerators. ····· 10361102401
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Definir los parámetros de polarización de la luz procedente de una muestra aporta una mayor información sobre las propiedades de ésta que la simple medida de la intensidad luminosa difundida. Cuando un haz luminoso sufre una perturbación debida a cualquier interacción con un medio, los campos electromagnéticos del haz incidente y el del haz emergente, expresados en términos de los parámetros de Stokes, pueden ser relacionados mediante la denominada matriz de Mueller. En este aspecto, el conocer la evolución de los parámetros de dicha matriz del sistema, nos permite definir cómo se comporta éste frente a la luz incidente.En esta memoria se presenta una metodología de trabajo y un conjunto de análisis realizados en muestras de diversos tipos: superficies planas micro estructuradas, suspensiones de micro partículas y nano partículas en coloide, sustancias quirales en medios turbios y componentes ópticos y polarimétricos. Además, se han llevado a cabo simulaciones computacionales a fin de estudiar patrones de comportamiento en sistemas complejos, demostrando la validez del método. ····· 10361116282
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Distribution networks reconfiguration (DNR) is the process of changing the topology of distribution systems by altering the open/closed status of switches to transfer loads among the feeders. One objective of the feeder reconfiguration of distribution systems is to minimize the total power losses for a specific load. This book adopts two new efficient heuristic techniques for reconfiguration of electrical distribution systems the real ants`-behavior-inspired Ant Colony Optimization (ACO) algorithm implemented in the Hyper Cube (HC) framework and the musicians`-behavior-inspired Harmony Search (HS) algorithm. To verify the effectiveness of the proposed algorithms, comparative studies are conducted on three test systems with encouraging results. The obtained results are compared with the results of other purely heuristic and AI-based approaches from literature to examine the performance. This book also emphasis the advantages of Insertion of Distributed Generation units (DGs) to the electrical distribution networks and the advantages of reconfiguration in presence of DGs on the total power loss reduction and bus voltage improvement. ····· 10361119179
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book presents the meaning of electric basics for electric stations. It discusses the major components electric connections inside a station. The classification of connections for different types of stations is analyzed. The types of power stations and substations are classified in details and the main contents on the single line diagram of a station are illustrated. The principle of the design of stations is given where the layout design is investigated in details. The transient profile between transmission and distribution borders is deduced. The renewal energy generation and connection with networks presented with classifications. The costing and energy pricing are delivered. The transmission lines are studied well and the towers are grouped for illustration. The book is a simple tool for graduate and post graduate students. It is a useful reference for electric engineers, researchers and designers. ····· 10361134041
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray To satisfy the development of nanoscience and nanotechnology, techniques to characterize and fabricate nanostructures and nanodevices are in great demand. Laser, as a unique monochromatic and coherent light source, meets the needs because it exhibits the potential to reveal some vital information of the materials. However, the applications of laser technology to nanoscience and nanotechnology are facing a severe challenge: the spatial resolution cannot be further enhanced to achieve nanometer scales due to the optical diffraction limit associated with conventional optics. In response to this challenge, near-field optics has been emerging as a new scientific area to deal with optical phenomena at that scales. The objective of this dissertation is to explore the possibility and extend the capability of laser technology into the fabrication and characterization of nanostructures and nanodevices using near-field optics. With the aim of establishing a frame to this objective, our goals of this study are to develop novel optical characterization techniques and platforms with nanoscale resolutions, and to fabricate nanostructures using laser technology. ····· 10361135672
für 80.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Kniga znakomit chitatelya s analiticheskimi modelyami opisaniya rasprostraneniya elektromagnitnogo polya v neodnorodnykh sredakh, a takzhe s primeneniem etikh modeley pri reshenii prakticheskikh zadach. Prednaznachena dlya studentov vsekh form obucheniya po napravleniyu podgotovki `Energetika, energeticheskoe mashinostroenie, elektrotekhnika`, stalkivayushchikhsya s neobkhodimost`yu izucheniya elektromagnitnogo polya, a takzhe dlya magistrov, aspirantov i inzhenerno-tekhnicheskikh rabotnikov elektrotekhnicheskikh spetsial`nostey. ····· 103615150
für 80.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Durante la última década un nuevo tipo de fibras ópticas, conocidas como microestructuradas o de cristal fotónico (FCF), están siendo ampliamente estudiadas debido a la gran potencialidad que presentan algunas de sus propiedades de cara a posibles desarrollos en diferentes aplicaciones. En el presente texto se presenta el análisis realizado sobre fibras ópticas de cristal fotónico dopadas con Erbio. Este elemento las dota de capacidad para ser utilizadas como amplificador o láser de fibra óptica. El proceso seguido y presentado es completo, desde la adquisición de la barra dopada con Erbio, construcción de las preformas y estiramiento de las distintas fibras (cambio en los valores de los parámetros estructurales de las mismas), hasta la construcción con dichas fibras de amplificadores y láseres. Comparando las prestaciones de cada una de ellas se han determinado las configuraciones y parámetros más eficientes. Además se han desarrollado técnicas de caracterización que unidas al modelo teórico presentado y adaptado a las características especiales que presentan las FCF permiten una optimización de los dispositivos amplificadores y láser basados en las FCF dopadas con Erbio. ····· 10361137417
····· lezzter Preis 88.20€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El aporte principal de este libro consiste en el desarrollo de una metodología basada en Economías Computacionales de Agentes, para modelar el comportamiento de los precios de oferta en el Mercado Eléctrico Colombiano. Esta metodología implica el desarrollo de distintos algoritmos de aprendizaje para los agentes que interactúan de manera repetida en el mismo. Como resultado final, se desarrolló un laboratorio experimental de interacciones entre los agentes generadores, los cuales exhiben capacidades adaptativas que les permiten mejorar, de manera autónoma, sus estrategias de oferta. La plataforma de simulación desarrollada permite experimentar con nuevas propuestas de diseño del mercado, que parten desde la diferenciación de cada central, hasta un modelo explícito de las restricciones operativas representadas por las redes de transmisión en Colombia. ····· 1036122969
für 88.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Actualmente, la protección de sistemas eléctricos de potencia es una de las áreas más importantes y complejas dentro del campo de la ingeniería eléctrica, ya que no solo es necesario comprender la filosofía de protección, sino considerar los problemas de aplicación de un esquema de protección. Por tanto, es necesario conocer los aspectos fundamentales del cálculo de cortocircuito, flujos de potencia, transitorios electromagnéticos, estabilidad transitoria, estabilidad dinámica, operación de sistemas eléctricos de potencia, procesamiento digital de señales y comunicaciones entre otras. Este libro no pretende abarcar todos los aspectos de la protección de sistemas eléctricos de potencia, por lo que se consideran los tópicos más importantes, como son los principios de operación de los relevadores, la protección de líneas de transmisión y la protección de equipos, como son los generadores, transformadores y barras. El libro incluye un capítulo que describe brevemente los fundamentos de la protección digital. De acuerdo al tratamiento de cada uno de los temas, este libro puede considerarse de un nivel medio de complejidad, que puede ser utilizado en cursos de licenciatura y postgrado. ····· 1036191055
für 88.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La ferrorresonancia es un fenómeno oscilatorio común asociado a sistemas eléctricos que comprenden, al menos, una inductancia no lineal, un condensador, una fuente de tensión y pérdidas débiles. Se caracteriza por presentar importantes sobretensiones y sobreintensidades con un contenido armónico apreciable, y afecta principalmente a los transformadores, debido a sus propiedades no lineales. El presente trabajo de investigación, realizado en el seno de la Unidad de Formación e Investigación CINIERSE de la UPV/EHU, analiza el fenómeno de la ferrorresonancia en transformadores de tensión, sus características y sus posibles causas y consecuencias. Igualmente analiza las medidas de actuación adoptadas en el ámbito de la ingeniería eléctrica frente a este fenómeno, destacando la tendencia actual de diseño de sistemas de detección del mismo. En este campo, propone una metodología de detección novedosa en base a la teoría de las redes neuronales artificiales. El contenido del libro debe resultar muy útil para los profesionales e investigadores que trabajan en el campo de la ingeniería eléctrica. ····· 1036191136
für 88.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La transformación y control de la energía eléctrica es uno de los procesos más importantes en Ingeniería Eléctrica. En los últimos años los equipos encargados de la misma, se han realizado utilizando semiconductores de potencia y elementos de almacenaje de energía tales como condensadores e inductancias. En la actualidad existe una gran variedad de aplicaciones industriales que demandan la utilización de frecuencia variable o la obtención de potencia a frecuencia fija a partir de un suministro a frecuencia variable por ejemplo: controladores de velocidad variable para impulsar motores a diferente velocidad, variando la frecuencia del suministro de alimentación al motor, la generación de energía eléctrica a partir de agua, aire o microturbinas de gas. Para esto se requieren convertidores CA-CA, los cuales se encargan de acondicionar la energía suministrada a las necesidades de tensión, frecuencia y fase que demanda la carga. Este trabajo trata del estudio de distintas topologías de convertidor matricial, para hacer la adaptación de un sistema trifásico (tensión y frecuencia variables) a otro sistema trifásico con tensión y frecuencia prefijadas. ····· 10361137278
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