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  • Author or Editor: K. Ciesla x
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Abstract  

The influence of heavy ion-irradiation (Ar 5.5 MeV amu-1, 51011 ion cm-2) on the melting and crystallization of two PBT films subjected to different modes of thermal treatment was investigated. Differences were observed between the processes occurring in both initial films, due to differences in crystalline phase content. The course of melting and crystallization in heavy ion-irradiated films during first heating, cooling and second heating differs from that in the initial films. The density data and DSC results indicate a decreased crystalline phase content in the PBT films after irradiation.

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Influence of gamma irradiation ( 60 Co-rays) with doses in the range up to 30 kGy was studied on gelatinisation of wheat starch, wheat flour and potato starch. Differential scanning calorimetry was then applied at several heating and cooling cycles for studies of the effect of irradiation with a 30 kGy dose on interaction of wheat starch with their native lipids and potato starch with admixed 1-mono-lauroyl glycerol.Amylose-lipid complex transition occurs after irradiation at decreased temperature and is accompanied by decreased enthalpy in respect to that recorded in the case of non-irradiated wheat starch, wheat flour as well as potato starch and admixed lipid. Differences between the initial and irradiated starch were easier to detect on the foregoing heating or cooling cycles than during the preceding ones and after the gels’ retrogradation. The complex was less influenced by the less advanced retrogradation taking place in the irradiated than in the non-irradiated wheat flour. Radiation-induced modification of structural properties of the complex results due to degradation of starch granules confirmed at present by essential reduction in pasting properties and by the increased amount of short molecular products leached during gelatinisation and their higher branching.

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Abstract  

A method for the determination of the industrial source of air pollution is described. The method is based on the analysis of elemental composition of dust samples taken at a single station and the relationships among concentrations of metals emitted by each kind of industrial plants. The method was experimentally confirmed in two industrial districts of Poland.

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Abstract  

Differential scanning calorimetry was applied in studies of the effect of gamma irradiation on the potato starch and wheat flour. Essential differences were noticed between endothermal effects observed in concentrated suspensions of the initial and irradiated potato starch and wheat flour heated at a rate of 2.5C min-1, while only small differences were noticed between gelatinization thermal effects recorded for ca. 20% suspensions of the initial and irradiated potato starch samples heated at a rate 10C min-1. Moreover, in the case of wheat flour, a decrease of decomposition temperature of the amylose-lipid complex was concluded.

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Summary

Identification of closely related plant species is not a trivial task, and is often difficult on the basis of morphological or anatomical features. To differentiate among analyzed species, a chromatographic fingerprint is usually constructed. This is not easy for very complex samples, however, especially those containing substances spanning a wide polarity range. In such circumstances more than one fingerprint is constructed, e.g. one for polar and the other for apolar constituents. In this paper a new method has been used for resolution of a mixture of 17 coumarins and flavonoids and, subsequently, construction of a fingerprint of closely related species belonging to the Peucedanum genus. This is the first time multidimensional planar chromatography has been applied for such purpose. Distinctive fingerprints are produced for every analyzed plant species, without the need to construct two fingerprints and without the application of more sophisticated multidimensional methods (e.g. hyphenation of HPLC and TLC, HPLC-MS, etc).

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