H.M. Kalisz, Freiburg, FRG: "Microbial Proteinases." Proteinases play an important role as reagents in laboratory and clinical analyses and in industrial processes. The discovery of new, highly specific proteinases and improved enzyme technology, such as immobilisation and novel purification methods, should make the microbial enzymes even more attractive in biotechnology. M. Maestracci, K. Bui, A. Thiery, A. Arnaud, P. Galzy, Montpellier, France: "The " "Amidase from a Brevibacterium Strain: Study and " "Applications." In the first part of this paper different microbial enzyme systems able to hydrolyze the true amide function are reviewed. Following consideration of analytical techniques (NMR, GLC, TLC, colorimetric assay of the ammonium ion) useful in the study of amidases, the second part of the paper deals with the amidases of Brevibacterium sp. R312 and their applications.

In this special issue review articles summarize the most outstanding features of microorganisms that can survive under extreme conditions. These microorganisms are adapted to living at 100 Degrees C in volcanic springs, at low temperatures in the cold polar seas, at high pressure in the deep sea, at very low and high pH values (pH 0-1 or pH 10-11), or at very high salt concentrations (35%). The latest findings on the molecular biology and the protein structure of these exotic organisms are presented. In addition, the potential applications of extremophiles are reviewed, including the production of enzymes, compatible solutes and the use of these extremophiles in the degradation of xenobiotics.

1. I. Gutman, Kragujevac/Yugpslavia Topological Properties of Benzenoid Systems 2. I. Gutman, Kragujevac/Yugoslavia Total Pi-Electron of Benzenoid Hydrocarbons 3. B.N. Cyvin, J. Brunvoll, S.J. Cyvin, Trondheim/Norway Benzenoid Chemical Isomers and Their Enumeration 4. B.N. Cyvin, J. Brunvoll, S.J. Cyvin, Trondheim/Norway Enumeration of Benzenoid Systems and Other Polyhexes

This book provides a comprehensive review of a new generation of selective oxidation titanosilicate catalysts with the MWW topology (Ti-MWW) based on the research achievements of the past 12 years. It gives an overview of the synthesis, structure modification and catalytic properties of Ti-MWW. Ti-MWW can readily be prepared by means of direct hydrothermal synthesis with crystallization-supporting agents, using dual-structure-directing agents and a dry-gel conversion technique. It also can be post-synthesized through unique reversible structure transformation and liquid-phase isomorphous substitution. The structural conversion of Ti-MWW into the materials usable for processing large molecules is summarized. Taking advantage of the structure diversity of the lamellar precursor of Ti-MWW, it can be fully or partially delaminated, and undergo interlayer silylation to obtain a novel structure with larger porosity. In the selective oxidation (alkene epoxidation and ketone/aldehyde ammoximation) with hydrogen peroxide or organic peroxide as an oxidant, the unique catalytic properties of Ti-MWW are described in comparison to conventional titanosilicates such as TS-1 and Ti-Beta.

This book is derived from a Symposium held at the 190th National American Chemical Society Meeting, which was held in the Fall of 1985, in Chicago, and was sponsored by the Division of Polymeric Materials: Science & Engineering. This Symposium was, in turn, a follow-up on an earlier one held in Houston, TX, in the Spring of 1980, which was pub lished as the book *Biomedical and Dental Applications of Polymers* [Plenum Press, New York, 1981]. In that earlier book, our opening Preface passage quoted King David, *1 will praise Thee; for I am fearfully and made . ** * (Psalm 139:14). As we noted five years ago, sickness wonderfully of many types does occur in our wonderfully made bodies, but much human suffering can be aided by biomedical polymers. That earlier book con sidered much of the fantastic progress that had been made in biomedical polymers during the previous quarter century and brought many of these topics up to date. That Symposium, and book, noted that much help was available for the varied afflictions and problems that sometimes beset, and upset, our God-given bodies, and the promise of new and important advances was held out as a shining ray of hope amidst the gloom of sickness and affliction. The present volume is an update on the advances that have occurred since the 1981 book and sets the stage for even greater advances in the future.

Proceedings of the 1991 Cryogenic Engineering Conference held in Huntsville, Alabama, June 11-14, 1991.

In the last five years the potential value of immobilized enzymes has captured the imagination of an increasing number of scientists and engineers. The concept of being able to create an immobilized derivative of an enzyme which has long-term stability and is able to be recovered and reused is fascinating, to say the least. Since the industrial application of enzymes has been mostly in the food and microbial process industry it is not surprising that many of the applications of immobilized enzymes considered for commercial development fall within the area of this industry. It is for this reason that we organized a symposium on immobilized enzymes for the 166th National Meeting of the American Chemical Society. Appropriately, the symposium was jointly sponsored by the Division of Agricultural and Food Chemistry and the Division of Microbial Chemistry and Technology. Although there were at least half a dozen symposia at other meetings on various aspects of immobilized enzyme technology in the preceding ten months none had specifically addressed themselves to food and microbial processes and none had been held at a meeting such as the National ACS gathering, which is not only large but multidisciplinary. The enthusiastic response to this symposium prompted us, at the invita tion of Plenum Press, to publish the proceedings of this symposium."

The quantity and composition of aroma and avour compounds in foods and food products exert a marked in uence on the consumer acceptance and, consequently, on the commercial value of the products. It has been established many times that one of the main properties employed for the evaluation of the product quality is the avour, that is, an adequate avour composition considerably enhances the m- ketability. Traditional analytical methods are generally unsuitable for the accurate determination of the quantity of this class of compounds. Moreover, they do not contain any useful information on the concentration of the individual substances and they are not suitable for their identi cation. As the stability of the aroma compounds and fragrances against hydrolysis, oxidation and other environmental and tech- logical conditions shows marked differences, the exact determination of the avour composition of a food or food product may help for the prediction of the she- life of products and the assessment of the in uence of technological steps on the aroma compounds resulting in more consumer-friendly processing methods. Furthermore, the qualitative determination and identi cation of these substances may contribute to the establishment of the provenance of the product facilitating the authenticity test. Because of the considerable commercial importance of avour composition, much effort has been devoted to the development of methods suitable for the separation and quantitative determination of avour compounds and f- grancesinfoodsandinotherindustrialproducts.

The literature on cavitation chemistry is ripe with conjectures, possibilities, heuris tic arguments, and intelligent guesses. The chemical effects of cavitation have been explained by means of many theories, consisting of empirical constants, adjustable parameters, and the like. The chemists working with cavitation chemistry agree that the phenomenon is very complex and system specific. Mathematicians and physi cists have offered partial solutions to the observed phenomena on the basis of cavitation parameters, whereas chemists have attempted explanations based on the modes of reaction and the detection of intermediate chemical species. Nevertheless, no one has been able to formulate a unified theme, however crude, for its effects on the basis of the known parameters, such as cavitation and transient chemistry involving extremely high temperatures of nanosecond durations. When one surveys the literature on cavitation-assisted reactions, it is clear that the approach so far has been "Edisonian" in nature. While a large number of reactions have showed either enhanced yields or reduced reaction times, many reactions have remained unaffected in the presence of cavitation. The success or failure of cavitation reactions ultimately depends on the collapse of the cavity. Cavitation chemistry is based on the principles of the formation of small transient cavities, their growth and implosion, which produce chemical reactions caused by the generation of extreme pressures and temperatures and a high degree of micro turbulence.

The origin of optical methods for fluid flow investigations appears to be nontraceable. This is no matter for surprise. After all seeing provides the most direct and common way for humans to learn about their environment. But at the same time some of the most sophisticated methods for doing measurements in fluids are also based on light and often laser light. A very large amount of material has been published in this area over the last two decades. Why then another publication? Well, the field is still in a state of rapid development. It is characterised by the use of results and methods developed within very different areas like optical physics, spectroscopy, communication systems, electronics and computer science, mechanical engineering, chemical engineering and, of course, fluid dynamics. We are not aware of a book containing both introductory and more advanced material that covers the same material as presented here. The book is the result of a compilation and expansion of material presented at a summer school on Optical Diagnosticsfor Flow Processes, held at RiS0 National Laboratory and the Technical University of Denmark in September 1993. The aim of the course was to provide a solid background for understanding, evaluating, and using modem optical diagnostic methods, addressing Ph. D. students and researchers active in areas of fluid flow research. The disciplines represented by the participants ranged from atmospheric fluid dynamics to biomedicine

This book looks at new ways of tackling the problem of separating reaction products from homogeneous catalytic solutions. The new processes involve low leaching supported catalysts, soluble supports such as polymers and dendrimers and unusual solvents such as water, fluorinated organics, ionic liquids and supercritical fluids. The advantages of the different possibilities are discussed alongside suggestions for further research that will be required for commercialisation. Unlike other books, in addition to the chemistry involved, the book looks at the process design that would be required to bring the new approaches to fruition. Comparisons are given with existing processes that have already been successfully applied and examples are given where these approaches are not suitable. The book includes: - New processes for the separation of products from solutions containing homogeneous catalysts - Catalysts on insoluble or soluble supports - fixed bed catalysts - continuous flow or ultrafiltration - Biphasic systems: water - organic, fluorous - organic, ionic liquid - organic, supercritical fluids (monophasic or biphasic with water, organic or ionic liquid) - Comparisons with current processes involving atmospheric or low temperature distillation - Consideration of Chemistry and Process Design - Advantages and disadvantages of each process exposed - Consideration of what else is need for commercialisation

Chemical vapor sensing arrays have grown in popularity over the past two decades, finding applications for tasks such as process control, environmental monitoring, and medical diagnosis. This is the first in-depth analysis of the process of choosing materials and components for these "electronic noses", with special emphasis on computational methods. For a view of component selection with an experimental perspective, readers may refer to the complementary volume of Integrated Microanalytical Systems entitled "Combinatorial Methodologies for Sensor Materials."

"Process Analytical Technology" explores the concepts of PAT and its application in the chemical and pharmaceutical industry from the point of view of the analytical chemist. In this new edition all of the original chapters have been updated and revised, and new chapters covering the important topics of sampling, NMR, fluorescence, and acoustic chemometrics have been added.

Coverage includes: Implementation of Process Analytical TechnologiesUV-Visible Spectroscopy for On-line AnalysisInfrared Spectroscopy for Process Analytical ApplicationsProcess Raman SpectroscopyProcess NMR Spectrscopy: Technology and On-line ApplicationsFluorescent Sensing and Process Analytical ApplicationsChemometrics in Process Analytical Technology (PAT)On-Line PAT Applications of Spectroscopy in the Pharmaceutical IndustryFuture Trends for PAT for Increased Process Understanding and Growing Applications in BiomanufacturingNIR Chemical Imaging

This volume is an important starting point for anyone wanting to implement PAT and is intended not only to assist a newcomer to the field but also to provide up-to-date information for those who practice process analytical chemistry and PAT.

It is relevant for chemists, chemical and process engineers, and analytical chemists working on process development, scale-up and production in the pharmaceutical, fine and specialty chemicals industries, as well as for academic chemistry, chemical engineering, chemometrics and pharmaceutical science research groups focussing on PAT.

Review from the First Edition

"The book provides an excellent first port of call for anyone seeking material and discussions to understand the area better. It deserves to be found in every library that serves those who are active in the field of Process Analytical Technology."--"Current Engineering Practice"

Colloidal dispersions play a very important role in nature, industry, and daily life. Sometimes, long-term stability is observed or desired as in ferrotluids (composed of very small magnetic particles with radii of ~ 10 nm), which must be stable even in external fields. On the other hand, only short-term stable dispersions may be necessary during actual processing operations, for example, dispersions of magnetite particles during tape manufacture. The stability of dispersions and many of their physical properties are related to the interaction between the particles in the dispersion medium, which may contain surfactants or macromolecular species. If the net interparticle interaction forces are attractive, then aggregation may occur. Two general types of aggregation behavior may be distinguished: coagulation and flocculation. These two terms are frequently used synonymously but IUPAC has recommended the following definitions: Coagulation implies formation of compact aggregates, leading to the macroscopic separation. Flocculation implies the formation of a loose or open network, floc, which may or may not separate macroscopically. Flocculation brought about by the simultaneous coadsorption of polymer molecules on two (or more) particles is referred to as bridging flocculation. If coagulation results in the merging of two particles into one, as may occur with liquid droplets in emulsions, this process is referred to as coalescence.

Radioactive wastes resulting from over 40 years of production of nuclear weapons in the U. S. are currently stored in 273 underground tanks at the U. S. Department of Energy Hanford site, Idaho National Engineering and Environmental Laboratory, Oak Ridge Reservation, and Savannah River site. Combined, tanks at these sjtes contain approximately 94,000,000 gallons of waste in a variety of forms including liquid, concrete-like salt cake, and various sludges. More than 730,000,000 curies of several radioactive isotopes are present in the underground tanks. Certainly, one of the greatest challenges facing the U. S. Department of Energy is how to characterize, retrieve, treat, and immobilize the great variety of tank wastes in a safe, timely, and cost-effective manner. For several years now, the U. S. Department of Energy has initiated and sponsored scientific and engineering studies, tests, and demonstrations to develop the myriad of technologies required to dispose of the radioactive tank wastes. In recent times, much of the Department of Energy R&D activities concerning tank wastes have been closely coordinated and organized through the Tanks Focus Area (IF A); responsibility for technical operations of the TF A has been assigned to the Pacific Northwest National Laboratory.

The current state of the art of several aspects of minerals and petroleum is presented in this volume. It documents the proceedings of the Internationl symposium on Particle Technology and Surface Phenomena in Minerals and Petroleum sponsored by the Fine Particle Society (FPS). This meeting was held in San Diego, California, August 21-25, 1990. The symposium upon which this volume is based was organized in five sessions emphasizing various basic and applied aspects of research on minerals and petroleum technology. Major topics discussed involve surface phenomena in minerals, mineral flotation, characterization of aspaltenes, theoretical aspects of reservoir simulation, porosity, permeability, residual water saturation, hydrocarbon and gas potential in north slope Alaska, polymer/alkaline flooding, surfactant flooding and foam flooding for enhanced oil recovery. This edition includes eighteen selected papers presented in the symposium. These papers are divided in four broad categories: (1) Asphaltene Aggregation and Characterization, (2) Theoretical Aspects and Reservoir Characterization, (3) Colloidal Dispersions in Minerals/Petroleum, and (4) Surface Phenomena and Petroleum Recovery. Several mineral and oil recovery processes using various chemicals with special reference to surface phenomena and particle technology are described in these sections.

Incorporating all recent developments and applications of crystallization technology, this volume offers a clear account of the field's underlying principles, reviews of past and current research, and provides guidelines for equipment and process design. The book takes a balanced functional approach in its critical survey of research literature, and includes several problems based on real practical situations that illustrate theoretical development. Several new concepts and techniques used in process simulation and identification analysis are featured.

In light of recent alarming environmental trends combined with increasing commercial viability of fuel cells, the time is propitious for a book focusing on the systematic aspects of cell plant technology. This multidisciplinary text covers the main types of fuel cells, R&D issues, plant design and construction, and economic factors to provide industrial and academic researchers working in electrical systems design, electrochemistry, and engineering with a unique and comprehensive resource.

If a Writer would know how to behave himself with relation to Posterity; let him consider in old Books, what he finds, that he is glad to know; and what Omissions he most laments. Jonathan Swift This book emerges from a long story of teaching. I taught chemical engineering thermodynamics for about ten years at the University of Naples in the 1960s, and I still remember the awkwardness that I felt about any textbook I chose to consider-all of them seemed to be vague at best, and the standard of logical rigor seemed immensely inferior to what I could find in books on such other of the students in my first class subjects as calculus and fluid mechanics. One (who is now Prof. F. Gioia of the University of Naples) once asked me a question which I have used here as Example 4. 2-more than 20 years have gone by, and I am still waiting for a more intelligent question from one of my students. At the time, that question compelled me to answer in a way I didn't like, namely "I'll think about it, and I hope I'll have the answer by the next time we meet. " I didn't have it that soon, though I did manage to have it before the end of the course.

Practicing engineers and scientist will benefit from this book's presentation of the most accurate information on the subject. The equations for fifteen important cryogenic fluids are presented in a basic format, accompanied by pressure-enthalpy and temperature-entropy charts and tables of thermodynamic properties. The book is supported by ICMPROPRS - an interactive computer program for the calculation of thermodynamic properties of the cryogenic fluids - that can be downloaded from the World Wide Web.