1,701,294 research outputs found

    Review of trends and targets of complex systems for power system optimization

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    Optimization systems (OSs) allow operators of electrical power systems (PS) to optimally operate PSs and to also create optimal PS development plans. The inclusion of OSs in the PS is a big trend nowadays, and the demand for PS optimization tools and PS-OSs experts is growing. The aim of this review is to define the current dynamics and trends in PS optimization research and to present several papers that clearly and comprehensively describe PS OSs with characteristics corresponding to the identified current main trends in this research area. The current dynamics and trends of the research area were defined on the basis of the results of an analysis of the database of 255 PS-OS-presenting papers published from December 2015 to July 2019. Eleven main characteristics of the current PS OSs were identified. The results of the statistical analyses give four characteristics of PS OSs which are currently the most frequently presented in research papers: OSs for minimizing the price of electricity/OSs reducing PS operation costs, OSs for optimizing the operation of renewable energy sources, OSs for regulating the power consumption during the optimization process, and OSs for regulating the energy storage systems operation during the optimization process. Finally, individual identified characteristics of the current PS OSs are briefly described. In the analysis, all PS OSs presented in the observed time period were analyzed regardless of the part of the PS for which the operation was optimized by the PS OS, the voltage level of the optimized PS part, or the optimization goal of the PS OS.Web of Science135art. no. 107

    Circulating tissue factor-positive procoagulant microparticles in patients with type 1 diabetes

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    Aim: To investigate the count of circulating tissue factor-positive (TF+) procoagulant microparticles (MPs) in patients with type 1 diabetes mellitus (T1DM). Methods: This case-control study included patients with T1DM and age and sex-matched healthy volunteers. The counts of phosphatidylserine-positive (PS+) MPs and TF(+)PS(+)MPs and the subgroups derived from different cell types were measured in the peripheral blood sample of the two groups using multicolor flow cytometric assay. We compared the counts of each MP between groups as well as the ratio of the TF(+)PS(+)MPs and PS(+)MPs (TF(+)PS(+)MPs/PS(+)MPs). Results: We recruited 36 patients with T1DM and 36 matched healthy controls. Compared with healthy volunteers, PS(+)MPs, TF(+)PS(+)MPs and TF(+)PS(+)MPs/PS(+)MPs were elevated in patients with T1DM (PS(+)MPs: 1078.5 +/- 158.08 vs 686.84 +/- 122.04/mu L, P &lt;0.001; TF(+)PS(+)MPs: 202.10 +/- 47.47 vs 108.33 +/- 29.42/mu L, P &lt;0.001; and TF(+)PS(+)MPs/PS(+)MPs: 0.16 +/- 0.04 vs 0.19 +/- 0.05, P = 0.004), mostly derived from platelet, lymphocytes and endothelial cells. In the subgroup analysis, the counts of total and platelet TF(+)PS(+)MPs were increased in patients with diabetic retinopathy (DR) and with higher HbA1c, respectively. Conclusion: Circulating TF(+)PS(+)MPs and those derived from platelet, lymphocytes and endothelial cells were elevated in patients with T1DM.De tre första författarna delar förstaförfattarskapet.</p

    A revision of African Psammoecus (Coleoptera, Silvanidae) and descriptions of two new species from the collection of the Musée royal de l’Afrique centrale

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    A revision of the known African species of Psammoecus is given, including redescriptions and illustrations of diagnostic characters. Extensive material from the Musée royal de l’Afrique centrale (Tervuren) is studied. Two new species are described: Psammoecus leleupi sp. nov., and Ps. luchti sp. nov. Four specific names are synonymized: Psammoecus excellens Grouvelle, 1908 = Ps. trimaculatus Motschulsky, 1858; Ps. alluaudi Grouvelle, 1912 = Ps. trimaculatus Motschulsky, 1858; Ps. longulus Grouvelle, 1878 = Ps. longicornis Schaufuss, 1872; Ps. nitescens Grouvelle, 1914 = Ps. laetulus Grouvelle, 1914. A key to the African species is provided

    The role of positronium decoherence in the studies of positron annihilation in matter

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    A small difference between the energy of the para-positronium (p-Ps) and ortho-positronium (o-Ps) states suggests the possibility of superposition of p-Ps and o-Ps during the formation of positronium (Ps) from pre-Ps terminating its migration in the matter in a void ('free volume'). It is shown that such a superposition decohere in the basis of p-Ps and o-Ps and the decoherence time is estimated. The time scale of the decoherence estimated here motivates respective correction in decomposition of the positron annihilation lifetime spectra. The way of the correction is sketched. The timescale of the decoherence suggests a need of awareness when experimental data from positron annihilation techniques are processed. More generally, the superposited state of Ps should contribute to the evolution theory of positronium in matter.Comment: 15 pages, 6 figure

    Positronium scattering by atoms and molecules at low energies

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    The recent theoretical and experimental activities in positronium (Ps) scattering by atoms and molecules are reviewed with special emphasis at low energies. We critically compare the results of different groups −- theoretical and experimental. The theoretical approaches considered include the RR-matrix and close-coupling methods applied to Ps-H, Ps-He, and Ps-Li scattering, and a coupled-channel approach with a nonlocal model-potential for Ps scattering by H, He, H2_2, Ne, Ar, Li, Na, K, Rb, Cs, and Ps and for pickoff quenching in Ps-He scattering. Results for scattering lengths, partial, total and differential cross sections as well as resonance and binding energies in different systems are discussed.Comment: 6 revtex pages, 3 postscript figure

    Heparin-containing block copolymers, Part I: Surface characterization

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    Newly synthesized heparin-containing block copolymers, consisting of a hydrophobic block of polystyrene (PS), a hydrophilic spacer-block of poly(ethylene oxide) (PEO) and covalently bound heparin (Hep) as bioactive block, were coated on aluminium, glass, polydimethylsiloxane (PDMS), PS or Biomer substrates. Surfaces of coated materials were characterized by transmission electron microscopy (TEM), contact angle measurements and X-ray photoelectron spectroscopy for chemical analysis (XPS). It was demonstrated by TEM that thin films of PS-PEO and PS-PEO-Hep block copolymers consisted of heterogeneous microphase separated structures. Using sessile-drop and Wilhelmy plate dynamic contact angle measurements, insight was provided into the hydrophilicity of the surfaces of the coatings. Measurements with hydrated coatings of PS-PEO and PS-PEO-Hep block copolymers revealed that the surfaces became more hydrophilic during immersion in water, due to relaxation/reorientation, or swelling of PEO or PEO-Hep domains, respectively. XPS results for PS, PEO, heparin and PS-PEO as powder agreed well with qualitative and quantitative predictions. XPS results for films of PS-PEO and PS-PEO-Hep block copolymers showed enrichments of PEO in the top layers of the coatings. This effect was more pronounced for hydrated surfaces. Only small amounts of heparin were detected at the surface of coatings of PS-PEO-Hep block copolymers

    ps2, the gene responsible for functional sterility in tomato, due to non-dehiscent anthers, is the result of a mutation in a novel polygalacturonase gene

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    The recessive mutation ps-2, which appeared spontaneously in tomato, confers functional male sterility due to non-dehiscent anthers. In this study, we isolated and characterized the PS-2 gene. A single nucleotide mutation in a novel tomato polygalacturonase gene is responsible for the ps-2 phenotype. The mutation in ps-2 is responsible for an alternative splicing during maturation of the pre-mRNA, which leads to an aberrant mRNA. Differentiation between ps-2 and wild type (PS-2) anthers only appears in the final developmental stage in which the stomium remains closed in the mutant. To our knowledge, this is the first functional sterility gene isolated in the Solanaceae family. The specific expression of the Arabidopsis homolog of PS-2 in the anther dehiscence zone suggests a conserved mode of action over the plant kingdom, which means that the repression of PS-2 homologs may be a potential way to introduce functional sterility in other specie
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