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Abstract  

The influence of -radiation, upon elongation, resistance to tearing, module of elasticity, as well as upon the following electrical properties has been studied: , tg, and breakdown resistance, for various sorts of rubber.

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Abstract  

The concentration levels of total iodine obtained by RNAA in different sorts of tobacco, including the reference sample Kentucky Tobacco 2RI, two new candidate reference materials, Oriental Tobacco Leaves /CTA-OTL-1/ and Virginia Tobacco Leaves /CTA-VTL-2/ prepared in the Institute of Nuclear Chemistry and Technology, Warsaw, and some biological SRMs, are presented and discussed.

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Abstract  

Soil surveys of radon conducted in the Coastal Plain of New Jersey, Alabama and Texas indicate that soil composition and grain size exert the strongest control on the concentration of radon measured. Soil-gas radon was measured in-situ using two techniques; one developed by G. Michael REIMER of the U. S. Geological Survey; the other developed by Rogers and Associates Engineering Corp. for use by the Environmental Protection Agency. The Reimer technique aquires a small-volume, grab sample of soil gas, whereas the Rogers and Associatess technique acquires a large-volume, flow-through sample of soil gas. The two techniques yield similar radon concentrations in well-sorted sands, but do not correlate as well for poorly sorted soils and clays.

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Abstract  

A fast digital oscilloscope based pulse shape discrimination (PSD) system has been tested with intrinsic germanium detectors large enough to allow ionizing events which generate localized electron-hole pairs at a single site to be segregated from those depositing energy at several different sites in the crystal. Drift velocities of the electrons and holes result in pulses several hundred nanoseconds long. Since the electric field varies by almost a factor of 10 between the outer and inner surfaces, collection of electrons and holes can frequently be dinstinguished, and pulses due to multi-site events can be distinguished from single site events.

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involving the quality and quantity for the produced biogas. Due to the mineral characteristics of the coal substrate, only the biomass material could be tested in fermentation process. The experiments using different sorts of waste biomass were

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Abstract  

A method for determination of the composition of binary mixtures of a metal or radionuclide species by optimized repeated two-phase separations (SORTS) was proposed and theoretically substantiated. Its principle consists in repeated equilibration of two immiscible phases, one being the original liquid or solid matrix with minimal adjustment of its composition and varying the phase ratio (separation stage cut) as the optimized parameter. The batch separation technique may consist in the repeated solvent extraction or aqueous biphasic distribution, or in the replicate equilibration with solvent or leaching solution. Results of SORTS can be presented e.g. by Tukey box diagrams as the characteristic fingerprints of original species composition.

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Abstract  

Brief history and current status of activation analysis in Korea are described. About 120 papers have been published since the first paper was reported in 1960. They are sorted out into 5 consecutive periods according to the publication year, and typical feature of each period is described.

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Abstract  

The thermal degradation of a sort of polyvinyl chloride was investigated. Complex processes for polyvinyl chloride degradation were evidenced. The kinetic analysis of dehydrochlorination and of subsequent processes was carried out. A change of mechanism was detected when dehydrochlorination goes to completion. The values of non-isothermal kinetic parameters determined by various methods are in a satisfactory agreement. The obtained results allowed some clarifications concerning the thermal degradation steps.

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Abstract  

Radioisotope induced X-ray fluorescence analysis is a rather simple and convenient method for investigating ashed plant material. In order to reduce matrix effects, thin samples (2 mg/cm2) are analyzed to obtain a reasonable compromise between maximum sensitivity and the lowest possible absorption effects. Concentrations are determined by standard addition method. A precision of 6–8% can be achieved. As an application, analytical results are given for whole grains of several sorts of wheat.

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Abstract  

Thermal investigation has allowed us to show the changes undergone by a sort of nitrile-butadiene rubber (NBR) as a consequence ofγ-radiation-induced ageing. The parameters of the processes, which occur at progressive heating of the investigated samples, were determined. It was shown that for γ-irradiated samples the activation parameters corresponding to the thermo-oxidative process leading to solid products are correlated through the relation of compensation effect. Also, it was shown that, by γ-irradiation, NBR undergoes a relatively rapid change of its thermal behaviour which can be due to structural changes.

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