37 research outputs found

    A Plasma Reactor for the Synthesis of High-Temperature Materials: Electro Thermal, Processing and Service Life Characteristics

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    The three-jet direct-flow plasma reactor with a channel diameter of 0.054 m was studied in terms of service life, thermal, technical, and functional capabilities. It was established that the near-optimal combination of thermal efficiency, required specific enthalpy of the plasma-forming gas and its mass flow rate is achieved at a reactor power of 150 kW. The bulk temperature of plasma flow over the rector of 12 gauges long varies within 5500±3200 K and the wall temperature within 1900±850 K, when a cylinder from zirconium dioxide of 0.005 m thick is used to thermally insulate the reactor. The specific electric power reaches a high of 1214 MW/m{3}. The rated service life of electrodes is 4700 hours for a copper anode and 111 hours for a tungsten cathode. The projected contamination of carbides and borides with elec-trode-erosion products doesn't exceed 0.0001% of copper and 0.00002% of tungsten

    Use of Technogenic Silica Fume and Brown Coal Semi-Coke in the Technology of Silicon Carbide

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    The paper describes thermodynamic experiments to determine the optimal temperature and time modes for the carbide production process from the briquette charge comprising silica fume and brown coal semi-coke, conditions for chemical enriching of silicon carbide, its phase, chemical and granulometric compositions and particle morphology

    Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

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    We present a determination of the gluon polarization Delta G/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6-LiD target. The helicity asymmetry for the selected events is = 0.002 +- 0.019(stat.) +- 0.003(syst.). From this value, we obtain in a leading-order QCD analysis Delta G/G=0.024 +- 0.089(stat.) +- 0.057(syst.) at x_g = 0.095 and mu^2 =~ 3 (GeV}/c)^2.Comment: 10 pages, 3 figure

    Measurement of the Spin Structure of the Deuteron in the DIS Region

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    We present a new measurement of the longitudinal spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 < Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised 6-LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03.Comment: 10 pages, 6 figures, subm. to PLB, revised: author list, Fig. 4, details adde

    The COMPASS Experiment at CERN

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    The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both hadron and electromagnetic calorimeters. The setup has been successfully operated from 2002 onwards using a muon beam. Data with a hadron beam were also collected in 2004. This article describes the main features and performances of the spectrometer in 2004; a short summary of the 2006 upgrade is also given.Comment: 84 papes, 74 figure

    Search for the Phi(1860) Pentaquark at COMPASS

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    Narrow Xi-pi+- and Xi-bar+pi+- resonances produced by quasi-real photons have been searched for by the COMPASS experiment at CERN. The study was stimulated by the recent observation of an exotic baryonic state decaying into Xi-pi-, at a mass of 1862 MeV, interpreted as a pentaquark. While the ordinary hyperon states Xi(1530)^0 and Xi-bar(1530)^0 are clearly seen, no exotic baryon is observed in the data taken in 2002 and 2003.Comment: 10 pages, 5 figure

    Differences between passport and biological (actual) age in the population of Russian patients suffering from arterial hypertension (analysis of the «Hyperion» register)

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    The age of the patient is the most important factor determining the high risk of cardiovascular diseases. The subject of modern research was the study of the clinical role of the patient's biological age and its difference from passport age. The aim of the study was to analyze the severity of the difference in these values in real clinical practice in patients suffering from arterial hypertension (AH) on the basis of an open multicenter register to monitor the effectiveness of therapy in patients with hypertension "HYPERION", conducted by the Eurasian Association of Therapists with the support of the company "Gedeon Richter" (Hungary). Materials and methods. The study was carried out within the open multi-center register "HYPERION". The final analysis of the register included 1441 patients, including 638 men (44%), 803 women (56%) aged 24 to 90 years. All patients were observed in primary health care (55 centers in 47 cities of Russia) for hypertension, received at least two hypotensive drugs. According to the data on 1424 patients using the qrisk-2 scale of 2017 modification, the biological age was calculated. Results and discussion. The absolute majority of patients (83,7%) had biological age >70 years, while the passport age of the absolute majority (65,3%) is in the range ≥50, but ≤69 years. Median difference between biological and passport age was 15 years. On average, in men suffering from hypertension, the biological age exceeded the passport age by 17.6 years, and in women – by 13.4 years. The difference between the value of biological and passport age and the level of systolic pressure in all age groups had a direct correlation. At systolic blood pressure >181 mm Hg. the difference between biological and passport age was the maximum, reaching the highest values in the youngest age group (30–39 years). Conclusion. Analysis of the actual (biological) age should be a mandatory procedure that allows a more complete assessment of the initial therapeutic status of the patient, which is especially important in patients aged 30–50 years. This is necessary not only from the standpoint of changing the current procedure, but also to understand the patient's prognosis
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