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  • Author or Editor: M. Bilić x
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Abstract  

The objective of this investigation was to verify the degradation of endrin by gamma irradiation. 60Co was used as radiation source for irradiation of 50 mg L−1 endrin with a varied dose of 1–6 kGy. High performance liquid chromatography (HPLC) coupled with diode array detector was used as an analytical technique to monitor the degradation rate along with numbers of degradation products formed. At dose rate of 6 kGy ≥99% of endrin was degraded. It is proposed that utilization of ionization radiations can be an effective and efficient tool for the removal of halogenated pesticides.

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Abstract  

For the determination of trace elements in neutron irradiated, selenium by gamma-ray spectrometry the separation of the matrix activity is often necessary. In model experiments the decontamination of cation and anion impurities from the matrix solution was investigated by the counter current ion migration. After a processing of 3 hrs the trace activities of Co, Cr, Ga, Na and Zn were decontaminated from Se with a factor of >103. For the trace elements As and Te representing the anionic constituents, a decontamination factor of 3·102 was obtained.

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In this work the influence of addition of different plant extracts (olive leaf, green tea, pine bark PE 95%, pine bark PE 5:1, red wine PE 30%, red wine PE 4:1, and bioflavonoids) to blackberry juice during heating (at 30, 50, 70 and 90 °C) on the anthocyanin and phenol contents, polymeric colour, and antioxidant activity was investigated. Also, reaction rate constant, half-lives of degradation, and activation energy were calculated. Control sample was juice without addition of extracts. The highest anthocyanin content at 30 °C was in samples with the addition of olive leaf and green tea. At 90 °C the highest anthocyanin content was measured in samples with the addition of extract of red wine and bioflavonoides. Samples supplemented with the extracts had much higher antioxidant activity in comparison to the control sample. Results showed that at 90 °C the sample with green tea supplementation had the lowest reaction rate constant and the highest half-life. Activation energy ranged from 29 to 44 kJ mol−1.

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Abstract  

Elemental analyses of 10 geological samples from Morocco and some Standard Reference Materials were performed by Energy Dispersion X-Rays Fluorescence, Wavelength Dispersion X-Rays Fluorescence and Neutron Activation Analysis techniques in order to assess the accuracy and sensitivity of the concentrations determined with regard to requirements in geochemical exploration. The possibilities of utilization of EDXRF as an appropriate and economic technique for the analysis of various elements which are important in interpretation of geochemical data were evaluated.

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Despite the recent increase in the number of mayfly studies in karst freshwater habitats, their biology and ecology in springs are still poorly characterized. Therefore, we studied mayfly assemblages in a European karst rheocrene spring at five microhabitats monthly over a one-year period. Three species were recorded: Baetis alpinus (Pictet, 1843), Baetis rhodani (Pictet, 1843) and Rhithrogena braaschi (Jacob, 1974). The latter species represents a new record for the fauna of Bosnia and Herzegovina. All three species inhabited all studied microhabitats but with varying abundance. Individual species were associated with a specific substrate type and/or water velocity and/or water depth. The grazer/scraper Rh. braaschi was most common at microhabitats with inorganic substrate (cobbles, mixture of pebbles and sand), moderate water velocity and higher water depth. The rheophilic grazer/scraper and gatherer/collector B. alpinus was most common at microhabitats with mosses and highest water velocity. The grazer/scraper and gatherer/collector B. rhodani was recorded at all microhabitats, yet due to its preference for moderate water velocity, the highest number of individuals were collected from cobbles. We recorded movements of mayfly nymphs among the available microhabitats during their life cycles, due likely to their dietary requirements and search for suitable refugia. Baetis alpinus has a bivoltine, B. rhodani polyvoltine and Rh. braaschi univoltine life cycle with a long emergence period. The results presented here contribute to the knowledge of spring and mayfly ecology.

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