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Abstract  

The Mössbauer spectrum of ferric oxinate exhibits and asymmetric quadrupole doublet. The modification of the dynamic Mössbauer parameters (to the equal values for each line) following the irradiation, was explained by the internal oxine ligands rotation inside of the octahedral coordination.

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Introduction Sintering of semi-crystalline polymers occurs in those industrial processes, such as rotational molding, where the material is heated in the absence of any external applied pressure [ 1 , 2 ]. Sintering of

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Among forced-flow layer chromatographic techniques, the centrifugally-driven variety was first developed, and named centrifugal layer chromatography, in 1947 by Hopf. In the 1980s Nyiredy further developed the technique and renamed it rotation planar chromatography. This paper summarizes the classifications and applicability of versions of this technique.

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Abstract  

The ammonium ion in the alkali halide lattice has the hindered rotational state. The rotational potential is expressed as crystal field, which depends upon only one rotational motion. The tetrahedral ion receives an octahedral field in this system. Four fundamental types of orientation appear due to the symmetry of ion and that of field. As the barrier height increases, the rotational levels approach to the librational levels with tunnel splitting. In particular, the tunneling part in the ground librational level is calculated using both free rotor bases and orientationally localized states. The level structure with the degeneracy is elucidated, which is peculiar in each type of orientation. Thermal properties are shown as model calculations.

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Abstract  

The neutron attenuation coefficient is determined in a double axis rotational system. The difference between a fixed system and a double axis rotational system is shown and curves for the neutron attenuation coefficient for the last case are drawn. The attenuated flux inside the sample is also drawn.

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Extraction of onion ( Allium cepa L.) with 80:20 ( v/v ) methanol-water in water by rotation planar extraction (RPE) and medium-pressure solid-liquid extraction (MPSLE) has been studied systematically. Rotation planar extraction was studied by use of an ExtraChrom separation instrument prototye. Only rotation planar extraction performed by use of the ExtraChrom enabled efficient extraction of dried onion. The equilibration time proved to be the most important variable in the extraction. The particle size of the sample had a variable effect on extraction efficiency, mainly because of the carbohydrates predominating in the extracts. It was possible to extract oligofructans with a degree of polymerization of up to 12, and these were the main components of the extract. Fructose, glucose, and saccharose, in total, accounted for 10% of the mass of the extract; their mass ratio in the extract was 3:1:6. After mild hydrolysis of the extract with oxalic acid only fructose and glucose were obtained. Although TLC screening of the extract before acid hydrolysis detected no flavonoids, one phenolic acid was observed. After acid hydrolysis with hydrochloric acid, quercetin could be detected.

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Abstract  

Thermodynamics of system composed of three possible isomeric dideuteriocyclobutadienes has been studied based on the best available theoretical structural and vibrational parameters. Particular attention is paid to the recently raised question of applicability of the conventional (one term proportional to T3/2) expression for the rotational part of partition functions of the isotopomers at low temperatures T in comparison with more sophisticated approximations viz. containing an additional term proportional to T1/2 or even a correction proportional to T–1/2. Mutual relative stabilities of the isomeric isotopomers are evaluated as well as the isomerism contributions to the system thermodynamics. The three approaches are proved to yield very close results even at very low temperatures. Consequences for structure interplay in isomeric isotopomer sets are discussed.

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Low temperature heat capacity of ammonium, rubidium and cesium perbromates has been studied by method of adiabatic calorimetry. Anomaly of the heat capacity of cesium perbromate has been found, which corresponds to a structural phase transition. The separation of heat capacity into components has been carried out by the additive scheme. The torsion oscillation of BrO4 anions in solid perbromates at low temperatures has been found. Ammonium ions retardedly rotate aroundC 2 axes in the crystal lattice of NH4BrO4.

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Abstract  

Total nitrogen content in organic explosives and relate materials can be determined by fast neutron activation analysis (FNAA) to an absolute accuracy comparable to wet chemical or combustion analysis, i.e. to within less than 0.1% N. This is accomplished by dual-axis rotation of the sample and a carefully selected reference standard during neutron irradiation. The optimum reference standard is one of similar composition, density, weight and volume to the sample being analyzed. Rapid pneumatic transfer of organic explosives of low mechanical shock sensitivity poses no special safety problems. For large numbers of individual samples, a multiple sample irradiation system with single-axis rotation can be used for more rapid analysis. Precision and accuracy by this method are not as good as compared to a dual-axis rotation technique. Absolute accuracy for total nitrogen is in the order of 0.2%. This method is useful only for those reactions where the half-life of the product is long enough to allow for sequential counting of multiple samples for a single irradiation.

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Current concerns about soil and water quality deterioration, limited possibility of fossil fuels, loss of biodiversity, and in general the viability of rural communities urge to work out methods of sustainable agriculture in the Nyírség region of Hungary. Sustainable agriculture seeks solutions for environmental, economic and agricultural problems at the same time. The aim is to develop new production methods which provide the protection of nature. In sustainable agricultural systems the management of organic matters and, more widely, the whole nutrient management are based on the total self-sufficiency of the farm. The entire cycle of organic matter production and decomposition takes place within the farm boundaries and makes the farm an actual biological system. The rate of metabolism and the organic matter cycle are characteristic features of each farm and define their activity for a long time. Present investigation conducted in Westsik's crop rotation experiment has found a highly significant correlation between organic nitrogen extracted by 0.01 M CaCl 2 solution and potato yield. It has shown that soil organic nitrogen extracted by 0.01 M CaCl 2 solution is a reliable indicator of nitrogen available for mineralization during the growing season. When precise nitrogen fertilizer recommendations are required, the method can supply additional information for environmentally friendly, sustainable agriculture.

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