Proceedings of the 9th International Conference on Positron Annihilation (ICPA-9), Szombathely, Hungary, 1991

This book provides a comprehensive and up-to-date account of the field of low energy positrons and positronium within atomic and molecular physics. Each chapter contains a blend of theory and experiment, giving a balanced treatment of all the topics. Useful for graduate students and researchers in physics and chemistry.

For one and a half decades, the application of positron annihilation to condensed-matter physics concentrated on the study of the Fermi surfaces of metals and alloys. As other, often more powerful, techniques for performing this type of study were developed, it appeared that condensed-matter positron physics was going to be relegated to being a niche interest. However, the situation changed dramatically when it was found that measurements of positron annihilation in metals were sensitive to the structures of well-known defects. This discovery, and subsequent research made it a major tool in materials science.

The only critical discussion available on the chemistry of the two "strange" light particles, the positron and positronium, with much space devoted to the excess electron. Positron annihilation allows the investigation of many unusual phenomena in the reaction kinetics of the positron, positronium, and excess electron, and in radiation chemistry and physics, while also providing important information on defects in solids.

The book is intended to describe the basic and newly developed elements of the physics of solids and materials science on mechanical properties of metals with as much continuity as is possible. Particular emphasis has been placed in atomistic and fractal approaches and continuum theory of dislocations is also introduced. Since the book is meant for the two main topics of progress in recent years, some interesting and important topics which have not been discussed or introduced are given in detail.For a long time, pair potentials were used very expensively in simulation studies. They can reproduce usefully total energies for many systems. But when one turns to elastic properties, fracture of surfaces, and the vacancy formation energy, deficiencies and limitations begin to emerge. These limitations of the simple pair potential approximation have been addressed by the development of empirical many-body potentials which is the major theme of our book.Over a decade or more, diverse scientists have recognized that many of the structures common in their experiments have a special kind of geometrical complexity. The key to this progress is the recognition that many random structures obey a symmetry that objects look the same on many different scales of observation. The concept of fractals was introduced by Mandelbrot and applied to fractures by himself and collaborators. Their work pointed to a correlation between toughness and the fractal dimension. Our interest is the fractal aspects of fractured surfaces. We will discuss more in our book.The strain field of a dislocation has a long range part and this part can be discussed rigorously from elasticity theory. Recent progress in elastic strain fields and dislocation mobility were made by Indenbom and Lothe. The elementary essentials will be introduced in our book.

This book provides a comprehensive description of the principles and applications of positron and positronium chemistry. Pedagogical and tutorial in nature, it will be ideal for graduate students and researchers in the area of positron annihilation spectroscopy. The contributing authors are authoritative scientists prominent in the frontiers of research, actively pursuing positron annihilation research on chemical and applied systems. Contents: Introduction to Positron and Positronium Chemistry (Y C Jean et al.); Compounds of Positrons and Positronium (D M Schrader); Experimental Techniques in Positron Spectroscopy (P G Coleman); Organic and Inorganic Chemistry of the Positron and Positronium (G Duplotre & I Billard); Physical and Radiation Chemistry of the Positron and Positronium (S V Stepanov & V M Byakov); Positrons and Positronium in the Gas Phase (D M Schrader); Positron Porosimetry (M H Weber & K G Lynn); Positron Annihilation Studies on Superconducting Materials (C S Sundar); Positronium in Si and SiO 2 Thin Films (R Suzuki); Applications to Polymers (P E Mallon); Applications of Slow Positrons to Polymeric Surfaces and Coatings (Y C Jean et al.); Positron Annihilation Induced Auger Spectroscopy (S Amdani et al.); Characterization of Nanoparticle and Nanopore Materials (J Xu); AMOC in Positron and Positronium Chemistry (H Stoll et al.). Readership: Materials science researchers; physical chemists; polymer scientists and engineers; chemical and mechanical engineers; solid state physicists; graduate students in chemistry, physics, engineering and polymer science; coating industry researchers."

Polymeric Gas Separation Membranes is an outstanding reference devoted to discussing the separation of gases by membranes. An international team of contributors examines the latest findings of membrane science and practical applications and explores the complete spectrum of relevant topics from fundamentals of gas sorption and diffusion in polymers to vapor separation from air. They also compare membrane processes with other separation technologies. This essential book will be valuable to all practitioners and students in membrane science and technology.