Properties of CsI(TI) — Renaissance of an old scintillation material

CsI(TI) is an interesting material for calorimeters in high energy physics. Properties of this material are reported.     

Carbon dioxide—new uses for an old refrigerant

Carbon dioxide has been used as a refrigerant in vapour compression systems of many types for over 130 years, but it is only in the last decade that inventive minds and modern techniques have found new ways to exploit the uniquely beneficial properties of this remarkable substance. This paper traces the development of the old carbon dioxide systems, considers the technical, commercial and social reasons for their slow development and subsequent decline and examines the recent renaissance across a surprisingly broad range of applications, from trans-critical car air conditioners to low temperature industrial freezer plants. The paper then concentrates on industrial refrigeration systems, which were the basis of early developments in the period 1865–1885, but which have been somewhat overlooked in the current renaissance. The paper concludes with a review of possible future developments, indicating the areas of research and product development required to maximise the potential of the only non-toxic, non-flammable, non-ozone-depleting, non-global-warming refrigerant available for Rankine cycle vapour compression systems in the 21st century.     

Dielectric barrier discharge — properties and applications

Dielectric barrier discharge (DBD) is a typical non-equilibrium high-pressure ac gas discharge. Recently, two types of DBD arrangements are developed; volume discharge (VD) and surface discharge (SD). Such devices are beneficial for industrial acceptance, since vacuum can be got rid of and devices operated in atmospheric pressure region. DBD is an excellent source of ideal energetic electrons with 1–10 eV and high density. Its unique advantageous is to generate low excited atomic and molecular species, free radicals and excimers with several electron volt energy. In this paper, the properties of microdischarge in DBD are discussed with their simulation. Due to its attractive characteristics, DBD is recently widely studied for potential industrial applications. Ozone generators, excimer radiation sources, free radical generation and their applications in pollution control and monitor are also discussed.     

Polysilanes—a new look at some old materials

In spite of the fact that the first polysilane derivatives were probably prepared in the mid 1920's, there was little scientific interest until recently. The synthesis of the first soluble homo and copolymers about 10 years ago has stimulated an explosive development of this class of materials. This brief review traces the historical development of the polysilanes and focuses on recent studies of polymer structure, electronic properties, photochemical reactions and mechanisms and finally on new applications.