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  • Author or Editor: Gy. Szabó x
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Abstract  

A new method has been developed for the separation and determination of low-level activity of strontium-90 through its daughter product yttrium-90 from natural water. Yttrium was separated and isolated from 1001 water at pH 5.5–5.7 by 8-quinolinol substituted silica gel. The yttrium was eluted with hydrochloric acid and precipitated with ammonium oxalate. The precipitate of yttrium oxalate was counted with a low-background beta-counter. The recovery of yttrium-90 is (64±4)% (n=5).

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The crystal data of theα- andγ-modifications of KH(IO3)2 were determined. The rhombicβ-modification which has been described by earlier authors could not be obtained. In the course of thermal decomposition both crystal types release water, then I2O5 and O2, leaving a residue of KI. As an intermediate, K2I4O11 is formed. The temperatures of the DTA and DTG peaks of theα- andγ-modifications, were found to be different.

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Abstract  

The northwestern prevailing wind direction and episodic south-to-north trajectories connect Hungarian atmosphere to the west and middle European as well as Mediterranean and Scandinavian regions that were covered by the 21 sampling sites active in an international collaboration on air quality. Our present set of data collected in Debrecen during the past decade is added to their data for comparison and the outcome is presented in this paper.

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The effects of regular NPK fertilization on the amounts of winter wheat yield and the amounts and proportion of different N forms (NO 3 -N, NH 4 -N, N org , N total ) of a Luvic Phaeosem soil determined in 0.01 M CaCl 2 were studied in the B1740 variant of the National Long-Term Fertilization Experiment at Karcag. According to the yield data, N and P fertilization increased winter wheat yield significantly. When applying the 200 kg N·ha -1 dose, P fertilization resulted in a more than 2 t·ha -1 yield increase, as compared to the treatments without P fertilization. K fertilization had no effect on the yield, similarly to preceding years. These findings may be adapted to fields of the Middle-Tisza Region with similar conditions to the trial site. The N forms of the soil determined in CaCl 2 reflected fertilization well. All of the fractions, but especially NO 3 -N and N total , increased significantly in response to N fertilization. Close relationships (r = 0.87–0.88) were found among the NO 3 -N and N total fractions and the N balance, which means that the amounts of NO 3 -N and N total are suitable for assessing both the N deficit and the N surplus. The strength of the correlation between the NH 4 -N content and N balance was moderate (r = 0.65). The N org fraction increased significantly as a function of N and P fertilization. These results can be explained with the yield increase. A significant correlation (r = 0.55) was found between the N org fraction and yield amounts. It can be established that organic residuals remaining on the site resulted in a significant increase in the N org content of soils. The gained results confirm that the N org fraction is suitable for the characterization of the readily mobilizable N reserves previously ignored in fertilization practice. On the basis of the presented results the CaCl 2 method is recommended for the precise estimation of nutrient requirements.

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Abstract  

Thermogravimetric (TG) and varied temperature Raman spectroscopic measurements of melt-blended polypropylene composites (PP) with double wall (DWNT) and multi-wall carbon nanotubes (MWNT) revealed that the incorporation of carbon nanotubes into polymer matrix increased the thermal stability comparing to the virgin polypropylene. The characterization of reference nanotubes was also done by Raman microscopy and TG measurements. Varied temperature rheological analysis provided further information about the thermal decomposition of the composites indicating the formation of high strength char in case of MWNT and limited applicability of DWNT at high temperature. The residue of the decomposition of PP-MWNT nanocomposites consists of nanotubes of spectroscopically higher purity comparing to the original one indicating the thermally induced chemical changes in the solid phase.

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Summary  

Thirty-seven episodes of dust intrusion were observed between February 12, 1991 and August 31, 2000 in the Hungarian atmosphere and found to be of Saharan origin. They have been assigned to typical source areas in Northern Africa selected by systematic investigations related to the Mediterranean Basin. Elemental concentrations and regional signatures deduced from PIXE analysis, total suspended particle mass, and black carbon mass have been measured on dust samples collected in Debrecen, Hungary. These data combined with Aerosol Index data, and dust plume axes obtained from TOMS data from NASA satellites were used for assigning the most probable source areas of the dust transported to the sampling site. Our data and conclusions are in accordance with other published investigations on the predominant role of Saharan dust emission in building up the aerosol load of the global atmosphere.

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Abstract  

Elemental concentrations of P, S, Cl, K, Ca, Fe, Ni, Cu, Zn, Br, Rb have been determined in erythrocyte and blood plasma samples from normal and diabetic human pregnancies. Average values, the dependence of the concentrations on the time during gestation period, the correlation coefficients for pairs of elements as well as for the same elements in plasma and erythrocyte samples are given. A marked difference appeared in a number of cases between normal and diabetic pregancies.

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Abstract  

It is demonstrated that combined PIXE and PIGE measurements are suitable for the accurate determination of the elemental concentration of glass samples. Borosilicate glasses used as high voltage insulators in Van de Graaff accelerators and tested for the relevant physical properties have been analyzed. A correlation between concentrations and physical properties has been found, supporting the additivity rule.

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