72 research outputs found

    Biodesulphurized subbituminous coal by different fungi and bacteria studied by reductive pyrolysis. Part 1: Initial coal

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    One of the perspective methods for clean solid fuels production is biodesulphurization. In order to increase the effect of this approach it is necessary to apply the advantages of more informative analytical techniques. Atmospheric pressure temperature programming reduction (AP-TPR) coupled with different detection systems gave us ground to attain more satisfactory explanation of the effects of biodesulphurization on the treated solid products. Subbituminous high sulphur coal from ‘‘Pirin” basin (Bulgaria) was selected as a high sulphur containing sample. Different types of microorganisms were chosen and maximal desulphurization of 26% was registered. Biodesulphurization treatments were performed with three types of fungi: ‘‘Trametes Versicolor” – ATCC No. 200801, ‘‘Phanerochaeta Chrysosporium” – ME446, Pleurotus Sajor-Caju and one Mixed Culture of bacteria – ATCC No. 39327. A high degree of inorganic sulphur removal (79%) with Mixed Culture of bacteria and consecutive reduction by 13% for organic sulphur (Sorg) decrease with ‘‘Phanerochaeta Chrysosporium” and ‘‘Trametes Versicolor” were achieved. To follow the Sorg changes a set of different detection systems i.e. AP-TPR coupled ‘‘on-line” with mass spectrometry (AP-TPR/MS), on-line with potentiometry (AP-TPR/pot) and by the ‘‘off-line” AP-TPR/GC/MS analysis was used. The need of applying different atmospheres in pyrolysis experiments was proved and their effects were discussed. In order to reach more precise total sulphur balance, oxygen bomb combustion followed by ion chromatography was used

    Chronological and chemical approaches to obsidians from Bakla Tepe and Liman Tepe, Western Anatolia

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    In this study, the provenance of 42 obsidians from the Chalcolithic and Early Bronze Age levels of two settlements – Bakla Tepe and Liman Tepe – located on the Aegean coast of Anatolia were investigated with an interdisciplinary approach using fission-track (FT) dating, Instrumental Neutron Activation Analysis (INAA) and Epithermal Neutron Activation Analysis (ENAA). Some artefacts showed FT ages of a few thousand years. Apparent FT ages of the remaining samples are distributed over a wide range, from 0.53 ± 0.03 to 1.43 ± 0.20 Ma. After application of the size-correction method, most artefacts were distributed in a homogeneous group characterized by FT ages varying from 1.48 ± 0.47 to 1.80 ± 0.20 Ma, with a mean value of 1.65 ± 0.05 Ma and low induced track density corresponding to low U content. The remaining 3 samples showed relatively high induced track densities. One of them has an apparent age of 0.53 ± 0.03 Ma and a sizecorrected age of 1.02 ± 0.07 Ma. The probable potential sources for the studied samples were identified as the island of Melos in the Aegean, and the central Anatolian sources – particularly the Göllüdağ complex – through comparison of the FT data. INAA and ENAA studies have been carried out on 34 artefacts at the TRIGA Mark II research reactor of the University of Pavia. The identification of the sources was attained through cluster analysis of the chemical data. These results agree fully with those obtained by FT dating: most artefacts originated from the Melos–Dhemenegaki flow, and only 3 samples from central Anatolia. The current study provides a contribution to a better understanding of the circulation of obsidians in Anatolia

    Enhancement with inducers of lacasse production by some strains and application of enzyme to dechlorination of 2,4,5-trichlorophenol

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    Lacasse is one of the extracellular enzymes excreted from white and brown rot fungi, which is involved in ligninolysis. In the present study, the effects of the addition of lacasse inducers to the medium on enhancement of enzyme production under conditions of submerged fermentation were researched. At first, a culture medium was selected suitable for lacasse production. To increase the production of lacasse using different inducers and to examine the ability of dechlorination, this article focuses on screen lacasse activity of 21 basidiomycetes isolates grown in five culture media. All inducers evaluated influenced lacasse activity positively except for gallic acid, mannitol, and malt extract for studied isolates. Our findings showed that lacasse activity of Trametes versicolor ATCC (200801) when it was induced with wheat bran reached up to 29.08 U ml-1 and was examined the ability of dechlorination of 2,4,5-trichlorophenol (2,4,5-TCP). The parameters including pH, initial substrate concentration, amount of enzyme, period of reaction, and temperature were tested for dechlorination process. Correlation between oxygen consumption and dechlorination processes under the determined optimum conditions was analyzed. Toxicity of 2,4,5-TCP before and after enzymatic treatment was evaluated by Microtox test. The results demonstrated that toxicity of intermediates formed 2,4,5-TCP did not change

    Computer modeling for propagation of ultrasonic waves in solid polycrystalline structures.

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    M.S. - Master of Scienc

    Biobleaching of kraft cellulose pulp by Poliporus versicolor (2)

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    12th European Congress on Biotechnology (ECB 12) -- AUG 21-24, 2005 -- Copenhagen, DENMARKWOS: 000231195200627

    The relationship between chloride cells and salinity adaptation in the euryhaline teleost, Lebistes reticulatus

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    The present study elucidates, the relationship between chloride cells and salinity adaptation in the guppy, Lebistes reticulatus. Guppies were exposed to different salinities (2, 5, 8 and 11%) for 2 weeks to adapt them to salt water with the density of chloride cells was examined by light microscopy. The chloride cells of the gills were selectively stained by the fixator of Champy's modified by Maillet. The chloride cell density increased significantly in fish adapted to 8 and 11% salt concentration, which suggests that the densities of branchial chloride cells increased with environmental salinity. © Medwell Journals, 2009

    Evaluation of spatial and temporal changes in biomarker responses in the common carp (Cyprinus carpio L.) for biomonitoring the Meric Delta, Turkey

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    Erkmen, Belda (Aksaray, Yazar)The aim of this study is to examine the activity of several biomarkers in carp, Cyprinus carpio L., to determine their response to xenobiotics, such as organochlorine pesticides (OCPs), in the Meriç Delta. Fish were collected from contaminated sites and from areas regarded as relatively less contaminated in four sampling periods. Hepatic glutathione S-transferase (GST), carboxylesterase (CaE), lactate dehydrogenase, aspartate aminotransferase, and acid phosphatase activities were measured as biomarkers in the fish. For all fish, the condition factor and hepatosomatic index, were calculated to determine the condition of the fish. The results of this study indicated that the mean GST activity showed an increase in fish from the Meriç-Ergene junction site and a decrease in Enez site with respect to fish from Meriç site. Furthermore, the study shows that spatial and temporal changes of biomarkers such as GST and CaE might be useful for the assessment of environmental contamination in the Meriç Delta

    Inhibiting Inducible Nitric Oxide Synthase With Rutin Reduces Renal Ischemia/Reperfusion Injury

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    Background: Nitric oxide (NO) seems to play an important role during renal ischemia/reperfusion (I/R) injury. We investigated whether rutin inhibits inducible nitric oxide synthase (iNOS) and reduces 3-nitrotyrosine (3-NT) formation in the kidneys of rats during I/R. Methods: Wistar albino rats were nephrectomized unilaterally and, 2 weeks later, subjected to 45 minutes of left renal pedicle occlusion followed by 3 hours of reperfusion. We intraperitoneally administered L-N6-(1-iminoethyl)lysine (L-NIL; 3 mg/kg) for 30 minutes or rutin (1 g/kg) for 60 minutes before I/R. After reperfusion, kidney samples were taken for immunohistochemical analysis of iNOS and 3-NT. We measured plasma nitrite/nitrate and cyclic guanosine monophosphate (cGMP) to evaluate NO levels. Results: Ischemia/reperfusion caused plasma cGMP to increase significantly. Similarly, plasma nitrite/nitrate was elevated in the I/R group compared with the control group. Histochemical staining was positive for iNOS and 3-NT in the I/R group. Pretreatment with L-NIL or rutin significantly mitigated the elevation of plasma cGMP and nitrite/nitrate. These changes in biochemical parameters were also associated with changes in immunohistochemical appearance. Pretreatment with L-NIL or rutin significantly decreased the incidence and severity of iNOS and 3-NT formation in the kidney tissues. Conclusion: Our findings suggest that high activity of iNOS causes renal I/R injury, and that rutin exerts protective effects, probably by inhibiting iNOS.WoSScopu
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