Elsevier bv mai 2001 (4 risultati)

Taschenbuch. Condizione: Neu. Neuware - This book is an attempt to give a systematic presentation of both logic and type theory from a categorical perspective, using the unifying concept of fibred category. Its intended audience consists of logicians, type theorists, category theorists and (theoretical) computer scientists.…

Buch. Condizione: Neu. Neuware - The liquid phase of soil (soil solution) is a very thin, penetrating and all-embracing water layer. It has the most extensive surface among the biosphere components and interacts with all these components. Presented in this work is a new complex approach developed for soil liquid phase investigation that is based on in situ measurements. Investigation of the soil liquid phase can be of great significance in environmental research.This volume sums up the vast experience of the authors' research into soil liquid phase composition in various ecosystems of Central and Eastern Europe. It describes the methodological basics of soil liquid phase research: methods of soil solution extraction, the main problems of application of ion-selective electrodes for immediate in situ assessment of ionic activity in soil liquid phase and redox potential, and ways to overcome those problems. Data are presented on soil liquid phase composition in natural and agricultural ecosystems, their redox, pH, carbonate and other regimes as well as the relations between the composition of the soil liquid phase and different ecological properties.This work is devoted to the pursuit of new approaches to soil liquid phase analysis with a goal of discovering the role of soil liquid phase in the functioning of natural and agricultural ecosystems in recent soil-formation, formation of primary biological production, and in bio-geochemical turnover of elements. It includes new field investigation data as well as all data generalization carried out by means of a special complex database (developed by the authors) on soil liquid phase composition and other soil-ecological properties in various ecosystems in Central and Eastern Europe. This book is the first English edition that integrally considers both methodological aspects and results of investigation of composition, formation, dynamics, spatial heterogeneity, and interrelations of soil liquid phase with other components of ecosystems. Soil scientists, agricultural chemists and ecologists will find this title of great interest.…

Buch. Condizione: Neu. Neuware - This book presents the ideas and industrial concepts in compact heat exchanger technology that have been developed in the last 10 years or so. Historically, the development and application of compact heat exchangers and their surfaces has taken place in a piecemeal fashion in a number of rather unrelated areas, principally those of the automotive and prime mover, aerospace, cryogenic and refrigeration sectors. Much detailed technology, familiar in one sector, progressed only slowly over the boundary into another sector. This compartmentalisation was a feature both of the user industries themselves, and also of the supplier, or manufacturing industries. These barriers are now breaking down, with valuable cross-fertilisation taking place. One of the industrial sectors that is waking up to the challenges of compact heat exchangers is that broadly defined as the process sector. If there is a bias in the book, it is towards this sector. Here, in many cases, the technical challenges are severe, since high pressures and temperatures are often involved, and working fluids can be corrosive, reactive or toxic. The opportunities, however, are correspondingly high, since compacts can offer a combination of lower capital or installed cost, lower temperature differences (and hence running costs), and lower inventory. In some cases they give the opportunity for a radical re-think of the process design, by the introduction of process intensification (PI) concepts such as combining process elements in one unit. An example of this is reaction and heat exchange, which offers, among other advantages, significantly lower by-product production.To stimulate future research, the author includes coverage of hitherto neglected approaches, such as that of the Second Law (of Thermodynamics), pioneered by Bejan and co- workers. The justification for this is that there is increasing interest in life-cycle and sustainable approaches to industrial activity as a whole, often involving exergy (Second Law) analysis. Heat exchangers, being fundamental components of energy and process systems, are both savers and spenders of exergy, according to interpretation.…

Buch. Condizione: Neu. Neuware - Thermal Analysis (TA) has become an indispensable family of analytical techniques in the polymer research. The increased importance of these techniques can be seen as the result of three more or less parallel developments:¿ a tempestuous development of TA measuring techniques in combination with a high degree of automation,¿ the strongly increased understanding of the underlaying theory and,¿ the increasing knowledge of the relation between the polymers' chemical structure and their physical properties.These areas are still in their developmental stages, especially the third area. The increasing knowledge of the dependence of physical properties on chemical structure just accentuated more and more the need for accurate thermoanalytical measurements, and this knowledge is very important for the first stages of the development of new polymeric systems. Besides, the contribution of TA remains necessary for the technical and commercial development of such a new polymer system. The use of the various TA techniques in these processes is described in this book in nine chapters, while chapter ten illustrates the information obtained about different polymers during special case studies.This book illustrates in this way, applications of a wide variety of TA techniques whilst it is written from a materials characterisation rather than from a TA point of view with attention being paid to the chemical structure/physical properties correlations.…