Elsevier bv jan 1995 (5 resultados)

Buch. Condición: Neu. Neuware - A large number of solar cell and solar cell systems are described in this volume. The theory of their operation, their design and the levels of their performance is discussed. Originally the book appeared in 1978 but extensive change over the intervening years in the fields of energy generation and consumption, solar energy and solar cells, has necessitated the publication of an updated version.The text initially surveys the requirements of humanity, the subsequent need for solar cells, the nature of sunlight and the properties of semiconductors. Concrete examples, extensive references and theoretical arguments are then used to present a comparison of options available in the design and operation of solar cells and solar cell systems. The cells - constructed from single, crystal, polycrystalline and amorphous semiconductors - and the systems - have varying designs and differing levels of solar energy for input and produce electricity or electrical and thermal energies. Solar cell production, economics and environmental effects are considered throughout the publication.…

Buch. Condición: Neu. Neuware - The editors invited selected authors who had participated in or observed developments in biochemistry and molecular biology, particularly in the second half of this century, to record their personal recollections of the times and circumstances in which they worked. Having been given free reign, both content and style of the contruibutions reflect the flavour of the personality of the author.The book reflects the explosive development of biochemistry and molecular biology and related sciences that had led to the almost unique situation of these fields coming of age at a time when their founding fathers, or their scientific children, were alive and well.The contributions in this volume encompass a wide variety of experiences in many different countries and in very different fields of biochemistry. …

Buch. Condición: Neu. Neuware - This book brings together a number of studies which examine the ways in which the retention and selectivity of separations in high-performance liquid chromatography are dependent on the chemical structure of the analytes and the properties of the stationary and mobile phases. Although previous authors have described the optimisation of separations by alteration of the mobile phase, little emphasis has previously been reported of the influence of the structure and properties of the analyte.The initial chapters describe methods based on retention index group increments and log P increments for the prediction of the retention of analytes and the ways in which these factors are influenced by mobile phases and intramolecular interactions. The values of a wide range of group increments in different eluents are tabulated.Different scales of retention indices in liquid chromatography are described for the comparison of separations, the identification of analytes and the comparison of stationary phases. Applications of these methods in the pharmaceutical, toxicology, forensic, metabolism, environmental, food and other fields are reviewed. The effects of different mobile phases on the selectivity of the retention indices are reported. A compilation of sources of reported retention index values are given.Methods for the comparison of stationary phases based on the interactions of different analytes are covered, including lipophilic and polar indices, shape selectivity comparisons, their application to novel stationary phases, and chemometric methods for column comparisons.…

Buch. Condición: Neu. Neuware - Hardbound. Natural products chemistry covers a fascinating area of organic chemistry and its study has enriched organic chemistry in a myriad of different ways. In recent years the thrust has been in three major directions: advances in stereoselective synthesis of bioactive natural products, developments in structure elucidation of complex natural products through the applications of multidimensional NMR and mass spectroscopy, and the integration of bioassay procedures with the isolation processes leading to the isolation of active principles from the extracts.The present volume reflects these developments, and the growing emphasis on bioactive natural products, chemical constituents of echinoderms, diterpenoids from Rabdosia and Eremophila sp., structural studies on saponins, marine sesquiterpene quinones and antimicrobial activity of amphibian venoms. The reviews on bioactive metabolites of Phomophis, cardenolide detection.…

Buch. Condición: Neu. Neuware - The field of membrane separation technology is presently in a state of rapid growth and innovation. Many different membrane separation processes have been developed during the past half century and new processes are constantly emerging from academic, industrial, and governmental laboratories. While new membrane separation processes are being conceived with remarkable frequency, existing processes are also being constantly improved in order to enhance their economic competitiveness. Significant improvements are currently being made in many aspects of membrane separation technology: in the development of new membrane materials with higher selectivity and/or permeability, in the fabrication methods for high-flux asymmetric or composite membranes, in membrane module construction and in process design. Membrane separation technology is presently being used in an impressive variety of applications and has generated businesses totalling over one billion U.S. dollars annually.The main objective of this book is to present the principles and applications of a variety of membrane separation processes from the unique perspectives of investigators who have made important contributions to their fields. Another objective is to provide the reader with an authoritative resource on various aspects of this rapidly growing technology. The text can be used by someone who wishes to learn about a general area of application as well as by the knowledgeable person seeking more detailed information.…