für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Polycyclic Aromatic Hydrocarbons (PAHs) are important chemical species in combustion processes, energy, environment, health and industry. In this work, the recombination of the azulene, acenaphthene, anthracene, and pyrene PAHs ions with electrons is studied with the FlaPI (Flowing Afterglow with Photo Ions) method. The ionic species in the flowing afterglow are spatially characterized by a MS and the electron concentration is measured by means of a movable Langmuir probe. A new method L2DI (laser desorption / laser ionization) combined with the FlaPI methods developed for studying the recombination kinetics of much larger PAHs. The PAH ions concentration decay in time in function of the presence of electrons is measured. Different methods for recovering the recombination rate coefficient are assessed. A CRESU reactor is used to produce nanoparticles of PAH molecules at low temperature, which are deposited onto chosen surfaces. The samples were then analyzed ex-situ by AFM (Atomic Force Microscopy) in tapping mode. This method of characterization was tested previously by analyzing small soot particles generated by a diffusion flame and deposited onto mica surfaces. ····· 10361101230
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray A recent approach taken to improve the efficiency of sonochemical processes and ultrasound reactors is to combine multiple transducers, operating at either the same or at different fundamental frequencies. This book investigates several different dual-frequency systems, looking at their potential advantages and limitations in ultrasonic processes, and the nature of the interaction between the different sound fields. This is ascertained through analysis of sonoluminescence and acoustic emissions, high-speed photographic imaging, cavitation bubble dynamics and interactions, and of the comparative reaction rates of selected sonochemical reactions. The influence of various parameters on the relative efficiency of the dual-frequency system is also examined. Additionally, this work sheds light on various peripheral, nevertheless highly important, issues such as the interactions between gas bubbles in the presence of electroyltes and other solutes. ····· 10361100874
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The range of topics addressed in this publication is considerable from phenols and nitro substituted toxic phenols to low cost clay. The study examines the effectiveness of nearly inexpensive sorbent clay in removing phenols from wastewater by sorption. The influences of various factors, such as particle size, pH, concentration and temperature on the sorption capacity have been studied. This study showed that clay could be used as an efficient sorbent material for the sorption of phenols from aqueous solutions. Langmuir isotherm and Kinetics adsorption constants were calculated and it is seen that the sorption data for phenols onto clay fitted well in this model. The study is important for designing batch reactor treatment plant for phenolic effluents where continuous removal can be achieved on a large scale. This publication represents an advanced textbook for graduate students and as well as offering to research workers who are working in the field of adsorption. The publication will appeal to workers, researchers and will act as a vital resource for chemists, environmentalists, sorption scientists, post-graduate students, doctoral and post-doctoral fellows. ····· 10361100688
····· lezzter Preis 71.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book gives the Physical Chemistry Principles of the effectivenss of security features of different Universal Paper Banknotes upon modification by CMC and accelerating ageing. It clarifies the CMC addition effect on the security features involve secure complex process such as watermark, security thread, micro printing,etc. of different banknote papers (Egyptian 5 pounds `EGP`, Egyptian 10 pounds `EGP`, 1 Riyal `SAR`, 5 Dirham `AED`, 1 Dolar `U$`, 5 Euro `EUR`) even after accelerated ageing thermal ageing at 140 °C for 2 hours and UV-radiation ageing with two different wavelengths (l1= 256 nm, l2 = 336 nm) through transmitted light, IR and UV-light. From this book,we concluded that CMC modification has no effect even small on paper Banknote security features which elucidate in turn that the effectiveness of security features within Banknote papers is marvelous after CMC addition. This pointed out that CMC coating is a major industrial operation used to improve appearance, strength properties and printability of paper. It can be concluded that paper CMC modification has wonderful reflection on the industrial side in the paper industry field. ····· 10361100675
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Dlya opisaniya svoystv polyarnykh rastvoriteley ispol`zovana predel`naya vysokochastotnaya (VCh) elektroprovodnost` (EP), kotoraya predstavlyaet soboy otnoshenie absolyutnoy dielektricheskoy pronitsaemosti k vremeni dipol`noy dielektricheskoy relaksatsii. Dlya vodnykh rastvorov neorganicheskikh soley vmesto pravila Val`dena predlozheno uravnenie, v kotorom konstanta imeet razmernost` kontsentratsii. Udel`naya EP kontsentrirovannykh vodnykh rastvorov neorganicheskikh soley sostavlyaet nekotoruyu dolyu ot predel`noy VCh EP vody. Predlozheny uravneniya, kotorye pozvolyayut otsenit` udel`nuyu EP kontsentrirovannykh vodnykh rastvorov na osnove koordinatsionnykh chisel ionov i dielektricheskikh svoystv rastvoritelya. Pri uvelichenii temperatury udel`naya EP rastvorov soley vozrastaet pryamo proportsional`no velichine predel`noy VCh EP rastvoritelya. Eta proportsional`nost` nablyudaetsya v vodnykh, nevodnykh i smeshannykh vodno-organicheskikh rastvoritelyakh i vypolnyaetsya v oblasti, gde EP rastvorov umen`shaetsya s rostom temperatury. Provedeno obobshchenie temperaturnoy i kontsentratsionnoy zavisimostey udel`noy EP rastvorov ionnykh zhidkostey, sil`nykh i slabykh elektrolitov. ····· 10361100417
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Reactive oxygen species have been implicated in various diseases, but attempts to find efficient antioxidant treatments for such conditions have met with only limited success. This work describes an antioxidant nanoreactor obtained by encapsulating a dual-enzyme mimic in polymeric nanovesicles. As the mimic detoxifies in situ both superoxide radicals and related hydrogen peroxide, the nanoreactor exhibits antioxidant activity in THP-1 cells. Development of this simple, robust antioxidant nanoreactor represents a new direction in efficiently fighting oxidative stress. ····· 10361100362
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The electrochemical behavior of Zr finds growing interest, because of the stability of its passive film towards corrosion and its small cross-section for neutron absorption, which make it a suitable material for nuclear fuels, but also for its wide application in chemical industry. Surface oxide films such as those formed on Zr metal are of increased interest in many applications as e. g. electrocatalysis, electrochromic, electroplating and electrical charge storage. It is important to get information on the characteristics of the metal and the anodic oxide film formed on its surface, as well as comparing the behavior of the film formed under different conditions and various media. The alkali halides are class of the important solutions in which the electrochemical behavior of zr metal and its oxide film still needs further study. In the present book, it is intended to fulfill this aim by measuring the effect of some parameters including surface pretreatment, the applied cd used for oxide electroformation, electrolyte composition as well as its temperature. Special interest was given to the role played by iodine on the reactivity of oxide growth in absence or presence of the field. ····· 1036199861
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The aqueous solutions of two triblock copolymers of poly(oxybutylene/oxyethylene /oxybutylene) were studied by surface tensiometry, viscometry and dynamic laser light scattering techniques at various temperatures (293, 303, 313 and 323K).Effect of block architecture and temperature on surface and miceller properties was also studied. Critical micelle concentration (CMC) and thermodynamics of micellization were determined by surface tensiometry. Surface activity of these triblock copolymers was studied by measuring surface parameter i.e surface pressure ( ), surface excess concentration ( ), area per molecule (oA), of polymer and standard Gibb s free energy of adsorption ( Gads) at different temperature. Miceller parameter like CMC, surface tension at CMC ( CMC) were determined. Thermodynamic parameters, standard free energy of micellization ( Gmic), standard entropy of micellization ( Smic) and enthalpy ( Hmic) was calculated from CMC value at different temperature.Viscometry was used to determine intrinsic viscosity ( ) and intermicellar interactions (KH) using Huggins s equation. Dynamic light scattering was used for determination of hydrodynamic radius (Rh). ····· 1036199572
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Hydrodynamics of Proteins model compounds (Glycine, DL-Alanine, DL-Amino-n-butyric acid, L-Valine, L-leucine) & Peptides (Diglycine) in aqueous solutions of various mineral salts (Alkali & Alkaline metal salts) at various temperatures (T=288.15-318.15)K have been very informative for calculating relative viscosities, interaction parameters, transfer B coefficients, regression parameters, activation free energies, thermodynamic activation parameters, activation enthalpies and entropies etc. The present salts have been selected for study because they are important constituent of biofluids and soil fluids. Sodium / potassium ions are playing a very important role in sodium-potassium ion pump to maintain the blood pressure whereas magnesium is a mineral of primary importance in the body as it aids in the activation of adenosine triphosphate (ATP), the main energy source to carry out various functions of the cell. It also activates several enzymes systems and is important for the synthesis of RNA and DNA. ····· 1036199448
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Free radicals as by-products are produced from oxidation processes occurring continuously in living cells in the body. These free radicals are source of causing damage to human body. Antioxidants are organic compounds which are present as nutrients in food. One of their roles is to scavenge free radicals and thus slow down damaging processes in our body. The text covers detailed investigations and comprehensive description of antioxidants in quenching environmental toxicants as well as biological free radicals by using cyclic voltammetry and spin trapping ESR techniques. By these techniques types of interactions, extent of antioxidants to interact with free radicals in model lipid system, diffusion coefficients, rate constants, antioxidant activities and possible reaction mechanistic paths were determined. These studies give an insight to understand mechanism of antioxidant action and to determine the relative effectiveness of antioxidants as free radical quencher and would further help to explore new and more effective antioxidants for medicinal, pharmaceutical, cosmetics and food industries. ····· 1036199395
····· lezzter Preis 79.00€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Many industries use dyes and pigments to color their products. The largest consumers of these dyes are textile industries. The proper treatment of textile waste water is fundamental for the preservation of environmental equilibria and quality of aquatic system. The present study emphasizes the water pollution due to textile dyes which are the main component of the dyeing industries. It is quite difficult to remove dyes from effluents since most of them are stable to light, heat and oxidizing agents and they are biologically non-degradable. The textile effluents are considered as potential source of water contamination so effective methods should be adopted for the decolorization and detoxification of textile waste water. In the present study adsorption and ion exchange chromatographic technique were employed as treatment methods for the removal of textile dyes. From the current study it is concluded that different low cost natural materials and their modified surfaces can be used for the removal of textile dyes. ····· 1036199224
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Dipyrone is a well known water soluble white crystalline powder, a non-opiate and non-steroidal anti-inflammatory analgesic drug (NSAID) which belongs to the group of pyrazolones and widely used as analgesic, antipyretic, and antispasmodic drug in many pharmaceutical dosage forms. This work was aimed to develop suitable voltammetric methods such as CV, SW, and DPV for dipyrone study using glassy carbon electrode and to study the electrochemical behavior of dipyrone in a buffer solution at different concentrations, pH, and scan rates. In cyclic voltammetry and square wave voltammetry techniques, dipyrone undergoes four consecutive irreversible oxidation reactions at different oxidation potentials. While using differential pulse voltammetry, dipyrone undergoes two consecutive irreversible oxidation reactions. The peak at 0.45 V shows consistent behavior in all the techniques used under different experimental conditions. The anodic peak current of dipyrone decreases as pH increases but at higher pH the first oxidation reaction takes place at lower potential. the effect of concentration and scan rate is the same for all techniques. ····· 1036198969
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Using dye-sensitized solar cells (DSSCs) as a facile exploratory platform, Dr. Yang replaced the conventional planar transparent conducting oxides (TCO) electrodes in DSSCs with nanoarchitectured 3-dimensional (3-D) TCO electrodes, on which a PV layer is conformally coated, so as to drastically enlarge the TCO/PV interface area. Such 3-D TCO/PV structures not only provide sufficient PV materials to accommodate the incident solar flux, but radically shorten the transport path length in the PV layer. The built-in potential at the omnipresent TCO/PV interface promote the fast drift transport to prevail over the slow diffusive transport. Furthermore, special light-trapping optical structures such as photonic crystal-structured TCO are invented to synergistically enhance light harvesting so that the conflicting relationship between light harvesting and charge transport is transformed into synergistic relationship. This novel concept in her dissertation provides an effective solution to tackle the grand challenge and will have significant impact in the filed of photovoltaics. ····· 1036198751
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Water in itself is beautiful in terms of Structure, interactions (physiochemical, biochemical & chemical). In order to explore this beauty we have to study various models(Continuum model,Mixture models, Flickering Cluster Model & Frank Wen flickering cluster model of liquid water) which are explained in a concise manner in this book. One must know the models and interactions because all scientists/researchers interact with water directly or indirectly during their research activities. ····· 1036198501
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This Book is basically aimed at synthesis, solid state reactivity, crystallographic characterization and electrical measurements on titania and zirconia based ceramic materials, which have been identified as potential matrix for process development in technology of radioactive waste management. Though their applications in this area are well documented but their structure property relationship is not yet investigated to the desired level, therefore, it is necessary to understand thoroughly the structural complexities of the interactions of the effluent cations vis-à-vis ceramic precursors. Powder diffraction data and GSAS software based calculations of cell parameters, crystal symmetry, isotropic and thermal parameters, inter-atomic distances and other structural factors provide a good data base for process development. The electrical properties of substituted ceramic phases have been investigated with a view to find their applications in electrical and electronic materials, insulators and sensor technology. Impedance spectroscopy is used as a prime technique for such investigations. ····· 1036198444
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Water flooding with addition of polymers cross-linked by polyvalent ions (LPS) has proven to increase the oil recovery both in field applications and laboratory studies, but with constraints on the brine salinity. With of an offshore LPS-application on the Norwegian continental shelf in mind, the contents of this book aims to characterize and discuss the pressure build-up mechanisms thought to be responsible for the oil mobilization, for LPS in solvents with high ionic strengths, containing both mono- and divalent ions. The experiments presented in the book concerns dilute solutions of Partial Hydrolyzed Polyacrylamide (HPAM), cross-linked by Aluminium ions, dissolved in brines with various concentrations of Sodium Chloride and Calcium Chloride. ····· 1036192344
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The aim of this work is the study of viscosity influence on the diffusion of Ferrocene/ferrocenium, Ferrocenyl methyl aniline/ferrocenium and N-(ferrocenyl methyl)-2-nitro aniline/ferrocenium couples within solutions contain aqueous ethanol at different percentages as the solvent and potassium chloride as the supporting electrolyte. The dynamic viscosity of prepared solutions was calculated using the most adequate models of Faulkenhagen and of Teja-Rice. The electrochemical behavior and diffusion coefficients are investigated using two voltammetry techniques: cyclic and rotating disc electrode, on two different indicator electrode materials: glassy carbon and platinum. Cyclic voltammetry investigated at scan rates vary from 25, 50, 75, 100 to 150 mV/s, using Randles-Sevcik relation and rotating disc electrode voltammetry at angular velocities vary from 1200, 1600, 1800 to 2000 rpm, at scan rate equals to 100 mV/s, using Levich relation. The diffusion coefficient is influenced by several factors such as indicator electrode material and used voltammetry technique. ····· 1036191786
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Chromic acid [Cr(VI)] is an important and useful tool in the hands of chemists both for preparative and analytical purposes .It has been used to oxidize almost all organic and some inorganic compounds. Aromatic anils and substituted aromatic anils were prepared, characterized and the cooxidation of aromatic anils and oxalic acid by chromic acid in aqueous acetic acid medium proceeds much faster than that of either of the two substrates alone.The rate of the reaction increases when electron-releasing groups introduced on one ring or both rings of the anils whereas,electron-withdrawing groups decreasing the rate of oxidation at the same manner. The oxidation kinetics of aromatic anils by Cr(VI) in presence of oxalic acid in aqueous acetic acid follows first order in [oxidant] and fractional order in [substrate] and [oxalic acid] with the corresponding yields benzaldehyde and azobenzene. The rate of oxidation is enhanced with increasing concentration of hydrogen ions.Aluminium ions suppress the reaction. The intermediate is believed to be formed from aromatic anils and chromic acid-oxalic acid complex.Thus, this is a suitable mechanism proposed for the cooxidation reaction. ····· 1036191429
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The increase of anthropogenic inorganic CO2 concentration in the atmosphere is creating global challenging problem for the future generation. The climate change and global warming can be reduced through utilization of greenhouse gases. Reduction/oxidation of CO2 changes the electronic arrangement on the atom due to loss or gain of the electron. Linear shape changes to angular shape, which can able to decrease heat (IR radiation) absorption capacity. The liner shape (O=C=O), highly stable molecule undergoes molecular vibrational transition due to its change of dipole moment, by receiving solar (IR) radiation reflected from earth, which causes global warming. But, it cannot re-radiate heat radiation into the earth atmosphere by change of its shape. CO2 is an abundant, inexpensive, nontoxic at low concentration, biorenewable, and economical resource. Whereas, red mud is composed of micro-nanomaterials of heterogeneous metal oxides of Fe2O3, Al2O3, SiO2, Na2O, CaO, TiO2, etc. Both are attractive future generation resources green chemistry for the socio-economical-ecological sustainable development of industry. ····· 1036191344
für 62.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En esta Memoria se estudian la estructura molecular y las propiedades fotofísicas de pirrometenos con el fin de relacionarlas con sus características láser. Para ello, se registran los espectros de absorción UV-Vis y de fluorescencia y las curvas de decaimiento fluorescente de diversos pirrometenos en diferentes medios, y se realizan cálculos mecanocuánticos a distintos niveles computacionales. El fin último del trabajo es buscar, desde un punto de vista fotofísico, aquellas condiciones estructurales y ambientales que optimicen las prestaciones láser de estos colorantes. La incorporación de pirrometenos en matrices sólidas de polímero tiene la gran ventaja de aumentar considerablemente la fotoestabilidad del colorante, manteniendo sus óptimas propiedades fotofísicas y de laseo, sobre todo con el anclaje covalente. Los estudios realizados demuestran la buena correlación existente entre las propiedades fotofísicas y láser de pirrometenos con diferentes sustituyentes, en diversos disolventes y polímeros. ····· 1036191116
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La importancia de analizar el fenómeno de corrosión en materiales metálicos utilizados en la industria electrónica, ubicada en ambientes áridos y marinos de ciudades del noroeste de México, es para evaluar los niveles de corrosividad en los interiores de las empresas, para determinar el grado de deterioro de los materiales metálicos. Los dos factores de importancia en la generación de corrosión en estos metales son: los climáticos (humedad y temperatura) y las concentraciones principalmente de sulfatos en zonas áridas y cloruros en regiones marinas que sobrepasan los estándares de calidad del aire. En toda investigación de corrosión en metales usados en la industria electrónica, se determina controlar parámetros climáticos como humedad y temperatura, para evitar la formación de una película húmeda en superficies metálicas que fomenta el proceso electroquímico y la corrosión. El deterioro de los materiales por corrosión, genera un mal funcionamiento de los dispositivos y equipos electrónicos, debido a fallas eléctricas ocasionadas por vías de conductividad (dendritas) entre conexiones que no deben estar unidas. ····· 1036191012
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La Tierra es el único planeta de nuestro sistema solar en el que la vida se ha abierto camino. En este sentido la atmósfera terrestre ha jugado un papel decisivo en modular las condiciones de habitabilidad del planeta. Pero las características de la atmósfera no son estables y los seres vivos interaccionan recíprocamente con ella. Así, desde que el hombre se desarrolla no hay actividad humana que no incida de una manera u otra sobre la atmósfera. El presente trabajo pretende realizar una evaluación de la compatibilidad medioambiental de algunos sustitutos de clorofluorocarbonos (CFCs) que se emplean actualmente o bien se prevé su empleo en un fututo próximo. Para ello, se obtendrán los tiempos de vida troposféricos de los mismos frente a radicales Cl y OH y se realizará un estudio radiativo obteniendo sus forzamientos radiativos (RF) y potenciales de calentamiento global (GWPs). Todos estos datos son necesarios para establecer el posible impacto de estas especies como posibles agentes de smog, destructores de la capa de ozono o gases invernadero. ····· 1036190932
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Los mayores triunfos de la ciencia en el último siglo se debieron al desarrollo de técnicas capaces de estudiar el tamaño y forma de los objetos a niveles moleculares y atómicos. Esto permitió comprender la forma en que interactúan los átomos y moléculas y abrió las puertas al diseño , a estas escalas, de nuevos materiales, dando origen al nacimiento de las llamadas nanotecnologías. Una de las formas de describir a nivel molecular las interfases gas sólido, es a través de la adsorción desde sólidos porosos, superficies fractales y nanotubos de carbono. La adsorción de gases ha contribuido a brindar información de las estructuras presentes en materiales porosos inclusive poco cristalinos como son los carbones activados. Dado que los poros de carbones activados tienen forma de ranuras, algunos métodos resultan particularmente adecuados para determinar sus parámetros como son volúmen, superficie efectiva o ancho del poro. ····· 1036190902· 1 ·· 2 ·· 3 ·· 4 ·· 5 ·· 6 ·· 7 ·· 8 ·· 9 ·
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