CHEMISTRY GLOSSARY

nuclear reactor    →   nuklearni reaktor

Nuclear reactor is an assembly of fissionable material (uranium-235 or plutonium-239) designed to produce a sustained and controllable chain reaction for the generation of electric power.

The essential components of a nuclear reactor are:

1. The core, metal rods containing enough fissionable material to maintain a chain reaction at the necessary power level (as much as 50 t of uranium may be required).
2. A source of neutrons to initiate the reaction (such as a mixture of polonium and beryllium)
3. A moderator to reduce the energy of fast neutrons for more efficient fission (material such as graphite, beryllium, heavy water, and light water are used)
4. A coolant to remove the fission-generated heat (water, sodium, helium, and nitrogen may be used)
5. A control system such as rods of boron or cadmium that have high capture cross sections (to absorb neutrons)
6. Adequate shielding, remote-control equipment, and appropriate instrumentation are essential for personnel safety and efficient operation.

organic    →   organski

1. Organic refers to any chemical compound based on carbon (C) with the exception of some of the simple compounds of carbon, such as carbon dioxide, which are frequently classified as inorganic compounds. Additional elements that are commonly found in organic compounds are hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P) and sulfur (S).

2. Organic or organically-grown foods are grown or raised without synthetic fertilizers, pesticides, growth stimulators, or antibiotics and other drugs. Pests are controlled by cultivation techniques and the use of pesticides derived from natural sources and the use of natural fertilizers. In addition, organically grown foods must also be stored without the use of chemicals such as artificial additives and preservatives, and without food irradiation.

reactant    →   reaktant

Reactants are initial materials in a chemical reaction.

rheology    →   reologija

Rheology is the study of the deformation and flow of materials. Has important bearing on the behaviour of viscous liquids in plastic molding.

salt fog chambers    →   slana komora

Salt fog chambers are designed for corrosive atmosphere testing. The samples being tested are inserted into the chamber and then the salt-containing solution is sprayed as a very fine fog mist over the samples. The temperature within the chamber is maintained constant (usually 35 °C). These test chambers are constructed of non-corrosive materials.

silos    →   silos

Silos are conical or straight sided vessels. Often used as loose material containers (flour, wheat, cement, etc.).

spectrophotometry    →   spektrofotometrija

Spectrophotometry is a determination of the concentration of a material in a sample by measurement of the amount of light the sample absorbs.

plutonium    →   plutonij

Plutonium was discovered by Glenn T. Seaborg, Edwin M. McMillan, J. W. Kennedy and A. C. Wahl (USA) in 1940. Named after the planet Pluto. It is silvery-white, extremely radioactive artificially produced metal. Reacts with oxygen and acids; resists alkalis. Attacked by steam. Highly toxic. Plutonium is found rarely in some uranium ores. Made by bombarding uranium with neutrons. Used in bombs and reactors. Small quantities are used in thermo-electric generators.

polychlorinated biphenyls    →   poliklorirani bifenili

Polychlorinated biphenyls (PCB) are poisonous and carcinogenic compounds. They are pollutants of both live and inanimate environment, and they are used as insulation and refrigerating materials in transformers and condensers.

polymer    →   polimer

Polymer is a substance composed of molecules of high relative molecular mass (molecular weight), the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass (monomers). In most cases the number of monomers is quite large and is often not precisely known. A single molecule of a polymer is called a macromolecule. Polystyrene is light solid material obtained by polymerisation of styrene (vinyl benzene).