CHEMISTRY GLOSSARY

frequency    →   frekvencija

Frequency (ν) is the number of cycles of a periodic phenomenon divided by time. Hertz (Hz) is the SI derived unit, with a special name, for frequency, equal to s^-1. It was named after the German scientist Heinrich Hertza (1857-1894).

fusion    →   fuzija

Fusion is nuclear reaction in which atomic nuclei are brought together into a larger nucleus, releasing a large amount of energy. It is also used in the production of hydrogen bombs.

galvanostat    →   galvanostat

Galvanostat is an electronic instrument that controls the current through an electrochemical cell at a preset value, as long as the needed cell voltage and current do not exceed the compliance limits of the galvanostat.

deionised water    →   deionizirana voda

Deionised water is water from which ionic salts have been removed by ion-exchange. It is used for many purposes as an alternative to distilled water.

deoxyribonucleic acid    →   dezoksiribonukleinska kiselina

Deoxyribonucleic acid (DNA) is a nucleic acid with 2-deoxy-D-ribose as the sugar in its nucleotides. DNA contains encoded genetic information, specifically templates for the synthesis of all of an organism’s proteins and enzymes.

DNA was first identified in the 1869 by Swiss chemist Friedrich Miescher (1844-1895). In 1953, American biologist James Dewey Watson (1928-) and English physicist Francis Harry Compton Crick (1916–2004) had discovered that DNA occurs in the cell as a double helix, with two long strands of the molecule wound around each other, and further that the chemical structure of the molecule dictates that adenine (A) always aligns or pairs with thymine (T), and cytosine (C) always pairs with guanine (G). It is this base pairing that allows DNA in a cell to copy itself, and transfer its information to a new cell. The diameter of the helix is 2.0 nm and there is a residue on each chain every 0.34 nm in the z direction. The angle between each residue on the same strand is 36°, so that the structure repeats after 10 residues (3.4 nm) on each strand.

desiccant dryers    →   sredstva za sušenje

Desiccant dryers (air dryers) use nonconsumable chemicals such as silica gel or active alumina, and can remove almost all the moisture from compressed air by adsorbing moisture on its surface. The method of regeneration, the process of removing adsorbed water from the desiccant, is the primary distinguishing feature among the various types of desiccant dryers. There are three ways to regenerate a desiccant: with air, internal or external heaters, or a heat pump.

gel    →   gel

Gels are colloids in which both dispersed and continuous phases have a three-dimensional network throughout the material, so that it forms a jelly-like mass (e.g. gelatine). One component may sometimes be removed to leave a rigid gel (e.g. heating silica gel).

glacial acetic acid    →   ledena octena kiselina

Glacial acetic acid (CH₃COOH) is the pure compound, as distinguished from the usual water solutions known as acetic acid. It is a colorless liquid or crystalline substance (melting point 16.6 °C) with a pungent, vinegar odor.

glass    →   staklo

Glass is a brittle transparent solid with the molecular structure of a liquid. It is made by fusing together sand (SiO₂), soda (Na₂CO₃), and lime (CaCO₃) with small quantities other compounds. It is used for window panes and mirrors, for articles of table and culinary use, for lenses, and various articles of ornament.

glass transition temperature    →   temperatura staklastog prijelaza

Glass transition temperature (T_g) is the temperature at which an amorphous polymer is transformed, in a reversible way, from a viscous or rubbery condition to a hard and relatively brittle one.