1,779 research outputs found

    A high-pressure hydrogen time projection chamber for the MuCap experiment

    Full text link
    The MuCap experiment at the Paul Scherrer Institute performed a high-precision measurement of the rate of the basic electroweak process of nuclear muon capture by the proton, μ+pn+νμ\mu^- + p \rightarrow n + \nu_\mu. The experimental approach was based on the use of a time projection chamber (TPC) that operated in pure hydrogen gas at a pressure of 10 bar and functioned as an active muon stopping target. The TPC detected the tracks of individual muon arrivals in three dimensions, while the trajectories of outgoing decay (Michel) electrons were measured by two surrounding wire chambers and a plastic scintillation hodoscope. The muon and electron detectors together enabled a precise measurement of the μp\mu p atom's lifetime, from which the nuclear muon capture rate was deduced. The TPC was also used to monitor the purity of the hydrogen gas by detecting the nuclear recoils that follow muon capture by elemental impurities. This paper describes the TPC design and performance in detail.Comment: 15 pages, 13 figures, to be submitted to Eur. Phys. J. A; clarified section 3.1.2 and made minor stylistic corrections for Eur. Phys. J. A requirement

    The cardiovascular system in patients with functional and inflammatory bowel diseases

    Get PDF
    Aim. Identification of subclinical and metamanifests state changes of cardiovascular system in patients with functional and inflammatory bowel diseases (IBD) without a background of cardiac pathology. Materials and methods. Was examined 79 patients with colon diseases, 20 patients were diagnosed with irritable bowel syndrome (IBS) with diarrhea, 37 - with undifferentiated colitis (UdC) and 22 patients with ulcerative colitis (UC). As a control group were examined in 50 healthy subjects. All patients received treatment in accordance with international and national guidelines. Prescribed medications had effect on the function of the cardiovascular system. Patients with contacting the hospital and against the onset of remission was performed ultrasound of the heart. Determines the size of the left atrium, heart rate, end-diastolic volume, end-systolic volume, ejection fraction (EF), cardiac index (CI), total peripheral vascular resistance, the presence of right heart failure, blood flow, the area of the right atrium and right ventricle in systole and diastole, and calculated the proportion of contractility of the right atrium and right ventricle. Determined systolic pressure in PA (SPPA), the average pressure in PA (APPA). Results. Clinical manifestations of cardiac syndrome was identified in 75,0% of patients with IBS, 54,1% of patients NK and 68,2% patients with UC. When performing correlation analysis in the patients with UdC and UC was noted the relationship of hemodynamic parameters and disease severity was more pronounced in UC. So, when comparing the duration of the disease and levels of the MLC - r=0,52 and r=0,73 (

    Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g_P

    Full text link
    The MuCap experiment at the Paul Scherrer Institute has measured the rate L_S of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a time projection chamber filled with 10-bar, ultra-pure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. L_S is determined from the difference between the mu- disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 10^10 mu- decays, from which we extract the capture rate L_S = (714.9 +- 5.4(stat) +- 5.1(syst)) s^-1 and derive the proton's pseudoscalar coupling g_P(q^2_0 = -0.88 m^2_mu) = 8.06 +- 0.55.Comment: Updated figure 1 and small changes in wording to match published versio

    Inflammatory bowel diseases: Transformation of representations. A review

    Get PDF
    The global burden of inflammatory bowel disease (IBD) is currently significant and continues to grow due to the increasing prevalence of ulcerative colitis (UC) and Crohn's disease (CD), the increasing costs of diagnosis and treatment, and the high level of disability in patients with this disease. Categories, which leads to the search for risk factors and predictors of aggressive course and extraintestinal manifestations. According to the latest data, the prevalence of UC in Russia is 16.6 per 100 000 population, the annual registered increase is 11.3%; the prevalence of CD is 5.6 per 100 000 population, and the increase is 13.7%. In the Russian population of patients with IBD, the average age of disease onset is 35.3 years for UC and 31.2 years for CD. Moreover, in 89.3% of patients with UC, it took at least 2 years to verify the diagnosis, and in CD, within 2 years from the onset of clinical symptoms, the diagnosis was established in only 72.6% of patients. One of the dominant characteristics of IBD is its multisystem nature, which leads to the development of extraintestinal manifestations (ECM), which can be observed in 50–60% of patients, while up to 25% of patients with IBD have several EMC and the most common variants are joint lesions. A higher frequency of extraintestinal manifestations is observed in CD (up to 45% of patients), in female patients, in smokers and with a longer duration of the disease. To predict clinical remission, the level of fecal calprotectin and CRP, the need for glucocorticosteroids are important, to predict endoscopic remission – the level of fecal calprotectin, and to predict histological remission, an endoscopic Schroeder index value of ≤1 is important. The absolute risk of developing colorectal cancer in IBD remains relatively low, ranging from 1.1 to 5.4% after 20 years of disease. The main risk factors for IBD are total intestinal damage, high inflammatory activity, the stricturing phenotype of CD and the presence of primary sclerosing cholangitis

    Measurement of the Rate of Muon Capture in Hydrogen Gas and Determination of the Proton's Pseudoscalar Coupling gPg_P

    Full text link
    The rate of nuclear muon capture by the proton has been measured using a new experimental technique based on a time projection chamber operating in ultra-clean, deuterium-depleted hydrogen gas at 1 MPa pressure. The capture rate was obtained from the difference between the measured μ\mu^- disappearance rate in hydrogen and the world average for the μ+\mu^+ decay rate. The target's low gas density of 1% compared to liquid hydrogen is key to avoiding uncertainties that arise from the formation of muonic molecules. The capture rate from the hyperfine singlet ground state of the μp\mu p atom is measured to be ΛS=725.0±17.4s1\Lambda_S=725.0 \pm 17.4 s^{-1}, from which the induced pseudoscalar coupling of the nucleon, gP(q2=0.88mμ2)=7.3±1.1g_P(q^2=-0.88 m_\mu^2)=7.3 \pm 1.1, is extracted. This result is consistent with theoretical predictions for gPg_P that are based on the approximate chiral symmetry of QCD.Comment: submitted to Phys.Rev.Let

    To the Question of the Use of Mobile Educational Game Apps as a Simulator in Russian Language Teaching

    Get PDF
    В статье рассматривается перспектива использования учебно-игровых мобильных приложений в обучении русскому языку как средства закрепления и контроля усвоения языкового материала в общеобразовательной школе.The urgency of this study can be attributed to the high pace of development of modern distance learning practice and the need for analysis and theoretical understanding of new training formats in line with computer linguodidactics. In this regard, the purpose of the study is to analyze the prospects for using mobile training and gaming applications as a means of fixing and diagnosing language mistakes and controlling theacquisition. The object of research includes the methods of application of mobile learning game apps in teaching
    corecore