Radiation processing in many areas, particularly in radiation sterilization, demands control of the absorbed dose. Many dosimeters have been proposed for the high-level dose range (region of 10 to 50 kGy). However, in addition to the required reproducibility, reliability or uncertainty (< 5%), it is desirable for radiation processing that the selected dosimetric system is easy to operate. One o...

The applicability of the silver sulfate-acid dichromate oxidation (chemical oxygen demand) method for determining the carbon-bound electron compositions of microbial cells, substrates, and metabolic by-products was evaluated. An approach for approximating the carbon-bound electron composition of microbial cells from CHN data is also presented. Ten aliphatic and aromatic carboxylic acids, 17 ami...

Oxidation–reduction titrations and potentiometric methods provide a convenient experimental means to quantitatively determine compositions of unknown mixtures containing oxidizable/reducible species. Over the past decade, numerous titration methods have appeared in this Journal (1–6) and in standard laboratory manuals (7–10) involving common titrants such as potassium dichromate, iodine, potass...

A novel rapid methodology for determining the chemical oxygen demand (COD) based on a thermal sensor with a flow injection analysis system was proposed and experimentally validated. The ability of this sensor to detect and monitor COD was based on the degree of enthalpy increase when sodium hypochlorite reacted with the organic content in water samples. The measurement results were correlated w...

An 18-year-old girl developed acute renal failure 24 hr after ingestion of potassium dichromate. Laboratory data revealed associated intravascular haemolysis. Renal histology showed features suggestive of acute tubular necrosis. She went into diuretic phase after 11 days of oliguria and subsequently regained normal renal function. Both direct toxic damage by dichromate and intravascular haemoly...

Chromium is a widespread industrial waste. The soluble hexavalent chromium Cr (VI) is an environmental contaminant widely recognized to act as a carcinogen, mutagen and teratogen towards humans and animals. The fate of chromium in the environment is dependent on its oxidation state. Hexavalent chromium primarily enters the cells and undergoes metabolic reduction to trivalent chromium, resulting...

In the present investigation, the oxidizing roasting process of chromite with sodium carbonate to prepare potassium dichromate crystals was studied in the microwave field with air, by heating the chromite and sodium carbonate. The chromite and sodium carbonate heated separately at 1000 ◦C in the microwave oven (frequency: 2.45 GHz; power 1.5 kW) in order to study the microwave absorption proper...

Chromic oxide is an important basic chemical and finds many applications including metallurgical materials, green pigments, construction materials, refractory materials and catalysts. Presently, the industrial production of chromic oxide generally employs two processes (Ding, 2003): one is the reduction of sodium dichromate with ammonia sulfate; the other is the thermal decomposition of chromic...