The primary aim of this volume is to make the chemist familiar with the numerous stationary phases and column types, with their advantages and disadvantages, to help in the selection of the most suitable phase for the type of analytes under study. The book also provides detailed information on the chemical structure, physico-chemical behaviour, experimental applicability, physical data of liquid and solid stationary phases and solid supports. Such data were previously scattered throughout the literature. To understand the processes occurring in the separation column and to offer a manual both to the beginner and to the experienced chromatographer, one chapter is devoted to the basic theoretical aspects. Further, as the effectiveness of the stationary phase can only be considered in relation to the column type, a chapter on different column types and the arrangement of the stationary phase within the column is included. The secondary aim of this book is to stimulate the development of new and improved standardized stationary phases and columns, in order to improve the reproducibility of separations, as well as the range of applications.
This book investigates the concept of phase, aiming at a structural definition of the three domains that are assumed as the syntactic loci for interface interpretation, namely vP, CP and DP. In particular, three basic issues are addressed, that represent major questions of syntactic research within the Minimalist Program in the last decade. A) How is the set of minimally necessary syntactic operations to be characterised (including questions about the exact nature of copy and merge, the status of remnant movement, the role of head movement in the grammar), B) How is the set of minimally necessary functional heads to be characterised that determine the built-up and the interpretation of syntactic objects and C) How do these syntactic operations and objects interact with principles and requirements that are thought to hold at the two interfaces. The concept of phase has also implications for the research on the functional make-up of syntactic objects, implying that functional projections not only apply in a (universally given) hierarchy but split up in various phases pertaining to the head they are related to. This volume provides major contributions to this ongoing discussion, investigating these issues in a variety of languages (Berber, Dutch, English, German, Modern Greek, Hebrew, Italian, Norwegian and West Flemish) and combining the analysis of empirical data with the theoretical insights of the last years.
Current understanding of different phases as well as the phase transitions between them has only been achieved following recent theoretical advances on the effects of dimensionality in statistical physics. P S Pershan explains the connection between these two separate areas and gives some examples of problems where the understanding is still not complete. The most important example is the second order phase transition between the nematic and smectic-A phase. Others include the relation between the several hexatic phases that have been observed and the first order restacking transitions between phases that were all previously identified as smectic-B, but which should more properly be identified as crystalline-B. Some relatively recent experimental developments on the discotic phase, liquid crystal surfaces and lyotropic phases are also included. The book includes 41 major reprints of some of the recent seminal work on the structure of liquid crystals. They are introduced by a brief review of the symmetries and other properties of liquid crystalline phases. In addition, there is a discussion of the differences between true liquid crystalline phases and others that were described as liquid crystalline in the early literature, but which have since been shown to be true three-dimensional crystals. The progression from the isotropic fluid, through the nematic, smectic, and various crystalline phases can be understood in terms of a systematic decrease in symmetry, together with an accompanying variation in structure is explained. A guide to the selected reprints and a sort of ?Rosetta Stone? for these various phases is provided. The goal of this book is to explain the systematics of this progression to students and others that are new to this field, as well as to provide a useful handbook for people already working in the field.
Why is Western society in a state of moral crisis despite material affluence? By looking at the historical evolution of society, Peeters helps to explain this contradiction and predicts that a new form of society will emerge during the first decades of the 21st century capable of solving today's problems.
Release on 2004-04-01 | by Albert Jaeger,Ludger Schuknecht
Author: Albert Jaeger,Ludger Schuknecht
Pubpsher: International Monetary Fund
Category: Actif (Comptabilité) - Prix - Modèles économétriques
Boom and bust phases in asset prices have become a pervasive feature of macroeconomic developments in many advanced economies. This paper studies fiscal policy during boom-bust phases in asset prices and draws several conclusions. First, expansions and contractions in economic activity during such boom-bust phases tend to be highly persistent, cyclical turning points are harder to forecast, and the margins of error for output gap estimates can be large. Second, conventional estimates of revenue elasticities seem not to allow an accurate assessment of the fiscal stance and of the strength of underlying fiscal positions during boom-bust phases. And third, boom-bust phases tend to exacerbate already existing procyclical policy biases, as well as political-economy biases, toward higher spending and public debt ratios.
This monograph is intended to give the reader an appreciation of the wealth of phases, elements and inorganic compounds, which crystallize in layer-type or two dimensional structures. Originally this work was planned as a short review article but the large number of phases made it grow out to the size of a book. As is evident from the arrangement of the chapters our point of view was gradually transmuting from geometric to chemical. Moreover, the decision about the compounds that should be discussed was taken only during the course of the work, as is partly evident from the sequence of the references. For chemical or geometrical reason we have included also certain layered chain and molecular structures as well as some layered structures whose layers are linked by hydrogen bonds, thus are in fact three-dimensional. Instead of writing only a review with pseudo-scientific interpretations that later turn out to be wrong anyway we thought it more profitable to include the crystallographic data which are scattered in various original articles and hand books but never in one single volume. We have transcribed many of the data in order to make them correspond with the standard settings of the International Tables for X-Ray Crystallography. The figures are consistent with the data given in the tables. We apologize for errors and hope that their number is at a reasonably low level in spite of the time pressure.