251 research outputs found

    Thermal coal drying with the high volatile matter output

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    Наведено аналіз сучасних технологій сушіння вугілля з високим вмістом летких. Промислове застосування набули парові сушарки з киплячим шаром продуктивністю 55 т/год, в яких теплоносієм є інертний азот, а необхідне тепло отримують за рахунок відхідних газів газифікатора, при цьому теплопередача здійснюється за допомогою гарячої води.Приведен анализ современных технологий сушки углей с высоким содержанием летучих. Промышленное применение получили паровые сушилки с кипящим слоем производительностью 55 т/ч, в которых теплоносителем служит инертный азот, а необходимое тепло получают за счет отходящих газов газификатора, при этом теплопередача осуществляется посредством горячей воды.An analysis of modern technologies of drying of coals with high content of volatile. Industrial applications received steam dryer with a fluidized bed with capacity of 55 tons/h, in which the coolant is inert nitrogen, and the necessary heat is generated by waste gases of the gasifier, the heat transfer is carried out by means of hot water

    Mapping Complex Land Use Histories and Urban Renewal Using Ground Penetrating Radar: A Case Study from Fort Stanwix

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    Fort Stanwix National Monument, located in Rome, NY, is a historic park with a complex use history dating back to the early Colonial period and through the urban expansion and recent economic revitalization of the City of Rome. The goal of this study was to conduct a GPR investigation over an area approximately 1 acre in size to identify buried historic features (particularly buildings) so park management can preserve these resources and develop appropriate educational programming and management plans. The GPR recorded reflection events consistent with our expectations of historic structures. Differences in size, shape, orientation, and depth suggest that these responses likely date to different time periods in the site’s history. The GPR recorded other reflection anomalies that are difficult to interpret without any additional information, which suggests that pairing high-density geophysical data with limited excavations is critical to elaborate a complex site’s intricate history

    South Asian monsoon history over the past 60 kyr recorded by radiogenic isotopes and clay mineral assemblages in the Andaman Sea

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    The Late Quaternary variability of the South Asian (or Indian) monsoon has been linked with glacial‐interglacial and millennial scale climatic changes but past rainfall intensity in the river catchments draining into the Andaman Sea remains poorly constrained. Here we use radiogenic Sr, Nd, and Pb isotope compositions of the detrital clay‐size fraction and clay mineral assemblages obtained from sediment core NGHP Site 17 in the Andaman Sea to reconstruct the variability of the South Asian monsoon during the past 60 kyr. Over this time interval εNd values changed little, generally oscillating between −7.3 and −5.3 and the Pb isotope signatures are essentially invariable, which is in contrast to a record located further northeast in the Andaman Sea. This indicates that the source of the detrital clays did not change significantly during the last glacial and deglaciation suggesting the monsoon was spatially stable. The most likely source region is the Irrawaddy river catchment including the Indo‐Burman Ranges with a possible minor contribution from the Andaman Islands. High smectite/(illite + chlorite) ratios (up to 14), as well as low 87Sr/86Sr ratios (0.711) for the Holocene period indicate enhanced chemical weathering and a stronger South Asian monsoon compared to marine oxygen isotope stages 2 and 3. Short, smectite‐poor intervals exhibit markedly radiogenic Sr isotope compositions and document weakening of the South Asian monsoon, which may have been linked to short‐term northern Atlantic climate variability on millennial time scales

    Model selection in systems biology depends on experimental design.

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    Experimental design attempts to maximise the information available for modelling tasks. An optimal experiment allows the inferred models or parameters to be chosen with the highest expected degree of confidence. If the true system is faithfully reproduced by one of the models, the merit of this approach is clear - we simply wish to identify it and the true parameters with the most certainty. However, in the more realistic situation where all models are incorrect or incomplete, the interpretation of model selection outcomes and the role of experimental design needs to be examined more carefully. Using a novel experimental design and model selection framework for stochastic state-space models, we perform high-throughput in-silico analyses on families of gene regulatory cascade models, to show that the selected model can depend on the experiment performed. We observe that experimental design thus makes confidence a criterion for model choice, but that this does not necessarily correlate with a model's predictive power or correctness. Finally, in the special case of linear ordinary differential equation (ODE) models, we explore how wrong a model has to be before it influences the conclusions of a model selection analysis

    Effect of Ba(II), Eu(III), and U(VI) on rat NRK-52E and human HEK-293 kidney cells in vitro

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    Heavy metals pose a potential health risk to humans when they enter the organism. Renal excretion is one of the elimination pathways and, therefore, investigations with kidney cells are of particular interest. In the present study, the effects of Ba(II), Eu(III), and U(VI) on rat and human renal cells were investigated in vitro. A combination of microscopic, biochemical, analytical, and spectroscopic methods was used to assess cell viability, cell death mechanisms, and intracellular metal uptake of exposed cells as well as metal speciation in cell culture medium and inside cells. For Eu(III) and U(VI), cytotoxicity and intracellular uptake are positively correlated and depend on concentration and exposure time. An enhanced apoptosis occurs upon Eu(III) exposure whereas U(VI) exposure leads to enhanced apoptosis and (secondary) necrosis. In contrast to that, Ba(II) exhibits no cytotoxic effect at all and its intracellular uptake is time-independently very low. In general, both cell lines give similar results with rat cells being more sensitive than human cells. The dominant binding motifs of Eu(III) in cell culture medium as well as cell suspensions are (organo-) phosphate groups. Additionally, a protein complex is formed in medium at low Eu(III) concentration. In contrast, U(VI) forms a carbonate complex in cell culture medium as well as each one phosphate and carbonate complex in cell suspensions. Using chemical microscopy, Eu(III) was localized in granular, vesicular compartments near the nucleus and the intracellular Eu(III) species equals the one in cell suspensions. Overall, this study contributes to a better understanding of the interactions of Ba(II), Eu(III), and U(VI) on a cellular and molecular level. Since Ba(II) and Eu(III) serve as inactive analogs of the radioactive Ra(II) and Am(III)/Cm(III), the results of this study are also of importance for the health risk assessment of these radionuclides

    Nanocrystalline transition-metal gallium oxide spinels from acetylacetonate precursors via solvothermal synthesis

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    The synthesis of mixed-metal spinels based on substituted γ-Ga2O3 is reported using metal acetylacetonate precursors in solvothermal reactions with alcohols as solvents at 240 °C. New oxides of Cr, Mn and Fe have been produced, all of which are formed as nanocrystalline powders, as seen by high-resolution transmission electron microscopy (HR-TEM). The first chromium-gallium mixed oxide is thus formed, with composition 0.33Ga1.87Cr0.8O4 ( = vacant site). X-ray absorption near-edge spectroscopy (XANES) at the chromium K-edge shows the presence of solely octahedral Cr3+, which in turn implies a mixture of tetrahedral and octahedral Ga3+, and the material is stable on annealing to at least 850 °C. An analogous manganese material with average chemical composition close to MnGa2O4 is shown to contain octahedral Mn2+, along with some Mn3+, but a different inversion factor to materials reported by conventional solid-state synthesis in the literature, which are known to have a significant proportion of tetrahedral Mn2+. In the case of iron, higher amounts of the transition metal can be included to give an Fe:Ga ratio of 1:1. Elemental mapping using energy dispersive X-ray spectroscopy on the TEM, however, reveals inhomogeneity in the distribution of the two metals. This is consistent with variable temperature 57Fe Mössbauer spectroscopy that shows the presence of Fe2+ and Fe3+ in more than one phase in the sample. Variable temperature magnetisation and electron paramagnetic resonance (EPR) indicate the presence of superparamagnetism at room temperature in the iron-gallium oxides. View Full-Tex

    A large fraction of HLA class I ligands are proteasome-generated spliced peptides

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    The proteasome generates the epitopes presented on human leukocyte antigen (HLA) class I molecules that elicit CD8(+) T cell responses. Reports of proteasome-generated spliced epitopes exist, but they have been regarded as rare events. Here, however, we show that the proteasome-generated spliced peptide pool accounts for one-third of the entire HLA class I immunopeptidome in terms of diversity and one-fourth in terms of abundance. This pool also represents a unique set of antigens, possessing particular and distinguishing features. We validated this observation using a range of complementary experimental and bioinformatics approaches, as well as multiple cell types. The widespread appearance and abundance of proteasome-catalyzed peptide splicing events has implications for immunobiology and autoimmunity theories and may provide a previously untapped source of epitopes for use in vaccines and cancer immunotherapy
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