No abstract available

[en] Short communication

[en] ''Chemical risks'' can only be determined with accurate figures in a few extraordinary cases. The difficulties lie, as has been shown by the example of the Flixborough catastrophe, mostly in the determination of the probabilities of occurrence. With a rough semiquantitative estimate of the potential hazards and the corresponding probabilities we can predict the risks with astonishing accuracy. Statistical data from incidents in the chemical industry are very useful, and they also show that ''chemical catastrophes'' are only to a very small extent initiated by uncontrolled chemical reactions. (orig.)

[en] The first level in handling an emergency, such as leaks, operating mistakes and fire, is the on-site operator. According to the risk catalogue, he is trained to take measures which should limit the incident to a small area and eliminate danger. At the second level, the specially trained house fire department, responsible for a particular building or area, extinguishes small fires or at least prevents the fire from spreading until the plant fire department arrives. In case of doubt the plant fire department, level three, is always summoned. Then a member of the incident team is simultaneously informed. According to his own judgment, this person takes any other necessary steps and if called for, goes to the site. If from the start the incident shows characteristics of having possibly critical consequences, a part or the whole incident team is alerted and at the same time police, the public fire department and co-operating firms are informed. At the fourth level, the overall command of the situation is passed over to the state catastrophe staff if the aftermath should spread beyond plant borders

[en] Hydrocarbons are compounds of the elements carbon and hydrogen. They make up natural gas and oil thus is essential for our modern life. Burning of hydrocarbons is used to generate energy in our power plants and heat our homes. Derived gasoline and diesel oil propel our cars, trucks, and airplanes. Hydrocarbons are also the feedstock for practically every man-made material from plastic to pharmaceuticals. What nature is giving us needs, however, to be processed and modified. We will eventually also need to make hydrocarbons ourselves, as our natural resources are depleted. Many of the used processes are acid catalyzed involving chemical reactions proceeding through positive ion intermediates. Consequently, the knowledge of these intermediates and their chemistry is of substantial significance both as fundamental, as well as practical science. Carbocations are the positive ions of carbon compounds. It was in 1901 that Norris and Kehrman independently discovered that colorless triphenylmethyl alcohol gave deep yellow solutions in concentrated sulfuric acid. Triphenylmethyl chloride similarly formed orange complexes with aluminum and tin chlorides

[en] ''The Chemical Industry - Friend to the Environment?'' was a symposium organised by the North East Region committee of the Industrial Division of the Royal Society of Chemistry. This volume contains typescripts from all the lectures given at the symposium. The general public appreciate the material comforts the Chemical Industry provides, for example textiles, ceramics, steel, speciality chemicals, drugs, prosthetics etc. However, for many their comfort is spoiled by the chemical poisoning of the environment through slag heaps, beaches and countryside littered with non-biodegradable unsightly plastic containers, poor air quality through NO_x, CO₂ and chlorofluorocarbon emissions, and of course, nuclear waste. The occasional spillage of hazardous chemicals through road, rail and sea accidents do nothing to improve the Industry's image. The majority of these topics were discussed, though no one presumed to know how to remove the problems entirely but many suggestions were put forward as to how this might be achieved. Of the 13 papers presented three were specifically concerned with recycling of plastics, 9 with the environmental impacts of chemicals and one, which is indexed separately, was concerned with radioactive discharges into the environment from the Sellafield reprocessing plant. (Author)

[en] The development of the Middle-German chemical region is, as the processing industry in general, characterized by a structural change which is going on for the time being. By promoting the structure of the land there were created the preconditions to transform enterprises of the previous planning economy into modern, compatible and efficient plants of the chemical industry in the region, thus preserving another essential industrial branch of the land and the jobs that can be procured by this way. At the same time the implementation of the energy concept of the land laid the corner stone for the competition-determining stable and inexpensive energetic supply from environmentally compatible power plants being operated on the basis of state-of-the-art technologies. (orig.)

[en] The development is reviewed of tracer techniques applied at the Institute for the Research, Production and Application of Radioisotopes (UVVVR), Prague. The research of these methods is concentrated mainly on application in water management, engineering, semiconductor technology, electrochemistry and expertise activities. The range of applications in these fields is continuously expanding. (author)

[en] α-Amino acids (α-AAs) are in extremely high demand in nearly every sector of the food and health-related chemical industries and continue to be the subject of intense multidisciplinary research. The self-disproportionation of enantiomers (SDE) is an emerging and one of the least studied areas of α-AA or enantiomeric properties, critically important for their production and application. In the present work, we report a detailed study of the SDE via achiral, gravity-driven column chromatography for a set of N-acylated, N-carbonylated, N-fluoroacylated, and N-thioacylated α-amino acid esters. As well as thioacylation, attention was paid to the effect of altering the R group of the ester functionality, the side chain, or that of the acyl group attached to the amide nitrogen, whereby it was found that electron-withdrawing groups in the latter moiety had a pronounced effect on the magnitude and behavior of the resulting SDE phenomenon. Intriguingly, in the case of N-fluoroacylated derivatives, by favoring the formation of dimeric associates and effecting a strong bias toward homochiral associates over heterochiral associates, the SDE magnitude was greatly reduced contrary to intuitive expectations. Energy estimates resulted from DFT calculations.

No abstract available