Background: Some Particular areas contain natural radionuclide at levels much higher than those usually present in earth's crust. The radiological impact of the use of zirconium ore in zirconium industry is due to internal exposure of the lung by alpha particles and external exposure of the body by the gamma rays. The result of gamma spectrometry measurement of the concentrations of th...

Taking an evolutionary view of markets, Harold Demsetz hypothesized that firms ., differ persistently in efficiency and that industry concentration results from growth of ., efficient firms at the expense of inefficient ones. We test the hypothesis with high quality microdata from the US hospital industry, an industry of keen policy and scientific interest. We measure efficiency by firm in the ...

Background & objectives: Since many plants have high efficiency in absorbing heavy elements, the use of phytoremediation is of great importance. The purpose of this study is to identify native plants that absorb heavy metals. Also, the possibility of using them in phytoremediation technology in soils contaminated with heavy metals (around the petrochemical industry of Razi fertilizer in Tehran ...

A statistical procedure for detecting “contagious” location patterns for manufacturing establishments is presented. Manufacturing industries’ establishment clustering tendencies are ranked based on the “dispersion parameter” of the negative binomial distribution. Establishment data are for three-digit SIC manufacturing industries, nonmetro counties of BEA Component Economic Areas, 1981 and 1992...

Sucrose thermal degradation is an important reaction in the food industry. When in concentrated and neutral solutions, pure sucrose presents a lag phase in the reaction. This work aimed at: (i) modelling sucrose thermal degradation autocatalytic behaviour and (ii) studying the concentration and temperature effects on kinetic parameters. Isothermal experiments were conducted at temperatures rang...