81 research outputs found

    Evaluation of ambipolar potential barrier in the gas dynamic trap by Doppler spectroscopy

    Full text link
    The recently developed Doppler spectroscopy diagnostic has been used to evaluate the height of the ambipolar potential barrier forming in the gas dynamic trap (GDT) plasma between the central cell and the region with a large magnetic expansion ratio beyond the mirror. The diagnostic technique based on the gas jet charge exchange target, allowed to measure the potential profile along the line of sight covering the radial range from the axis to the limiter. The on-axis potential drop was found to be 2.6Ă·3.12.6 \div 3.1 in units of the central plane electron temperature, which supports the existing theoretical understanding of suppression of electron thermal conductivity in the GDT expander

    GP CC-OPF: Gaussian Process based optimization tool for Chance-Constrained Optimal Power Flow

    Full text link
    The Gaussian Process (GP) based Chance-Constrained Optimal Power Flow (CC-OPF) is an open-source Python code developed for solving economic dispatch (ED) problem in modern power grids. In recent years, integrating a significant amount of renewables into a power grid causes high fluctuations and thus brings a lot of uncertainty to power grid operations. This fact makes the conventional model-based CC-OPF problem non-convex and computationally complex to solve. The developed tool presents a novel data-driven approach based on the GP regression model for solving the CC-OPF problem with a trade-off between complexity and accuracy. The proposed approach and developed software can help system operators to effectively perform ED optimization in the presence of large uncertainties in the power grid.Comment: 6 pages, 2 figure

    Leukocyte telomere length and mitochondrial DNA copy number association with colorectal cancer risk in an aging population

    Get PDF
    In this study, we evaluated the association of blood leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNA-CN) with the risk of incident colorectal cancer (CRC). We studied and followed-up a cohort of Russian men and women (aged 45 – 69 years, n = 9360, 54% female) from the HAPIEE study for 15 years. Using the nested case-control design, we selected cases with incident CRC among those free from any baseline cancer (n = 146) and sex- and age-stratified controls among those free from baseline cancer and cardiovascular disease and alive at the end of the follow-up (n = 799). We employed multivariable-adjusted logistic regression to estimate the odds ratios (ORs) of CRC per 1 decile of LTL or mtDNA-CN. We observed an inverse association of LTL and mtDNA-CN baseline values with the 15-year risk of incident CRC. Carriers of shorter telomeres had an increased 15-year risk of incident CRC with adjusted OR 3.2 (95% CI: 2.56 – 3.87, P < 0.001) per 1 decile decrease in LTL, independent of baseline age, sex, smoking, body mass index, blood pressure, lipid levels, and education. Similarly, lower mtDNA-CN was associated with the higher risk of incident CRC with adjusted OR 1.7 (95% CI: 1.12 – 1.89, P < 0.001) per 1 decile decrease in mtDNA-CN, independent of the aforementioned factors. Using the modified values of LTL and mtDNA-CN adjusted for multiple factors and their interactions with a case–control status, the ORs of CRC were 2.53 and 1.52 per 1 decile decrease in adjusted baseline LTL and mtDNA-CN, respectively. In conclusion, LTL and mtDNA-CN were independent inverse predictors of the 15-year risk of CRC in the Russian cohort. These findings highlight the relevance for subsequent research to exploit the mechanisms through which LTL and mtDNA-CN may reflect human health

    The Relationship between All-Cause Natural Mortality and Copy Number of Mitochondrial DNA in a 15-Year Follow-Up Study

    Get PDF
    We explored the relationship between the copy number of mitochondrial DNA (mtDNA-CN) and all-cause natural mortality. We examined a random population sample in 2003/2005 (n = 9360, men/women, 45–69, the HAPIEE project) and followed up for 15 years. Using a nested case–control design, we selected non-external deaths among those free from baseline cardiovascular diseases (CVD) and cancer (n = 371), and a sex- and age-stratified control (n = 785). The odds ratios (ORs) of death were 1.06 (95%CI 1.01–1.11) per one-decile decrease in mtDNA-CN independent of age, sex, metabolic factors, smoking, alcohol intake and education. The age–sex-adjusted ORs of death in the second and first tertiles of mtDNA-CN vs. the top tertile were 2.35 (95% CI 1.70–3.26) and 1.59 (1.16–2.17); an increased risk was confined to the second tertile after controlling for smoking and metabolic factors. The multivariable-adjusted OR of CVD death was 1.92 (95% CI 1.18–3.15) in tertile 2 vs. the top tertile of mtDNA-CN, and for cancer-related death the ORs were 3.66 (95% CI 2.21–6.05) and 2.29 (95% CI 1.43–3.68) in tertiles 2 and 1 vs. the top tertile. In the Siberian population cohort, the mtDNA-CN was an inverse predictor of the 15-year risk of natural mortality, due to the greatest impact of CVD and cancer-related death. The findings merit attention for exploring further the role of mtDNA in human ageing and the diversity of mortality

    Carbon-Supported KCoMoS2 for Alcohol Synthesis from Synthesis Gas

    Get PDF
    KCoMoS2 was supported on various carbon support materials to study the support effect on synthesis gas conversion. Next to two activated carbons with high micropore volume, a traditional alumina (Îł-Al2O3) support and its carbon coated form (CCA) were studied for comparison. Coating alumina with carbon increases the selectivity to alcohols, but the AC-supported catalysts show even higher alcohol selectivities and yields, especially at higher temperatures where the conversions over the AC-supported catalysts increase more than those over the Îł-Al2O3-based catalysts. Increasing acidity leads to decreased CO conversion yield of alcohols. The two activated-carbon-supported catalysts give the highest yield of ethanol at the highest conversion studied, which seems to be due to increased KCoMoS2 stacking and possibly to the presence of micropores and low amount of mesopores

    Management of the Formation of Rating Preferences of Economic Entities upon Collective Choice

    Get PDF
    The applicability of a set of methods in the case of obtaining mixed results of the final ranking of economic entities in the process of their rating assessment has been substantiated. A new method of the formation of rating preferences upon collective choice has been proposed. The methodology is based on the following: an information base in the form of a summary table of ratings of compared entities; a procedure for the formation of rating preferences based on a rank-sum (or arithmetic means of ranks); a procedure for the formation of rating preferences with the joint application of rating arithmetic means and position indicators; a procedure for the formation of rating preferences using the Kemeny median. The proposals for the calculation of weighting factors of the voting procedures and modification of the procedure for profiling the preferences using the Kemeny median have been made. An algorithm for the use of the proposed method has been developed. Methodology testing has been conducted upon the rating assessment of the financial and economic condition of industrial enterprises. Keywords: system analysis, management of economic systems, economic-mathematical modeling, rating assessment, financial and economic condition JEL Classifications: P40, P4

    The Polarised Valence Quark Distribution from semi-inclusive DIS

    Get PDF
    The semi-inclusive difference asymmetry A^{h^{+}-h^{-}} for hadrons of opposite charge has been measured by the COMPASS experiment at CERN. The data were collected in the years 2002-2004 using a 160 GeV polarised muon beam scattered off a large polarised ^6LiD target and cover the range 0.006 < x < 0.7 and 1 < Q^2 < 100 (GeV/c)^2. In leading order QCD (LO) the asymmetry A_d^{h^{+}-h^{-}} measures the valence quark polarisation and provides an evaluation of the first moment of Delta u_v + Delta d_v which is found to be equal to 0.40 +- 0.07 (stat.) +- 0.05 (syst.) over the measured range of x at Q^2 = 10 (GeV/c)^2. When combined with the first moment of g_1^d previously measured on the same data, this result favours a non-symmetric polarisation of light quarks Delta u-bar = - Delta d-bar at a confidence level of two standard deviations, in contrast to the often assumed symmetric scenario Delta u-bar = Delta d-bar = Delta s-bar = Delta s.Comment: 7 pages, 3 figures, COMPASS, revised: details added, author list update
    • …
    corecore