973 research outputs found

    Выявление резервов производства методами статистического моделирования по пассивным данным

    Get PDF
    Предложенные методы позволяют использовать цеховую контрольно-измерительную информацию для получения модели конкретного технологического процесса (операции)

    Особенности электрохимического осаждения тугоплавких сплавов на алмазах

    Get PDF
    The analysis of theoretical foundations of electrochemical separation of refractory elements (tungsten and molybdenum) from aqueous solutions of electrolytes and practical production of refractory alloys (nickel-tungsten and nickel-molybdenum) for diamond grit’s metal coatings is shown. The influence of current load on the metallization degree and alloy output current is established. The structure of the surface coatings, their composition and effect of composition on the dynamic strength of coated diamond powders are defined. The areas for further work on granulation of high-strength metal-coated diamond grits and the creation of heterogeneous wear-resistant metal-diamond structures are identified

    General practitioners' prescribing behaviour as a determinant of poor persistence with inhaled corticosteroids in children with respiratory symptoms:Mixed methods study

    Get PDF
    OBJECTIVES: To evaluate general practitioners’ (GPs’) prescribing behaviour as a determinant of persistence with and adherence to inhaled corticosteroids (ICS) in children. DESIGN: Prospective observational study of persistence with and adherence to ICS followed by a focus group study of the GPs prescribing this treatment. SETTING: 7 primary care practices in the area of Zwolle, the Netherlands. PARTICIPANTS: 134 children aged 2–12 years had been prescribed ICS in the year before the study started by their 19 GPs. MAIN OUTCOME MEASURES: Patterns and motives of GPs’ prescribing behaviour and the relationship with persistence with and adherence to ICS. RESULTS: GPs’ prescribing behaviour was characterised by prescribing short courses of ICS to children with various respiratory symptoms without follow-up for making a diagnosis of asthma. This was driven by the GPs’ pragmatic approach to deal with the large number of children with respiratory symptoms, and by beliefs about ICS which differed from currently available evidence. This prescribing behaviour was the main reason why 68 (51%) children did not persist with the use of ICS. In children with persistent use of ICS and a GP's advice to use ICS on a daily basis, the median (IQR) adherence was 70% (41–84%), and was similar for patients with persistent asthma and children lacking a diagnosis or symptoms of asthma. CONCLUSIONS: Inappropriate prescription of ICS to children by GPs is common and drives the lack of persistence with ICS therapy in primary care. This finding should be taken into account when interpreting data from large prescription database studies. Improving primary healthcare providers’ knowledge and competence in diagnosing and managing asthma in children is needed

    BeppoSAX measurements of the bright gamma-ray burst 010222

    Full text link
    We analyze the BeppoSAX measurements of the prompt and afterglow emission of the gamma-ray burst GRB010222. Among 45 GRBs detected with the Wide Field Cameras on BeppoSAX, the 40-700 keV fluence of (9.3+/-0.3)E-5 erg cm-2 is only surpassed by GRB990123. In terms of the isotropic 20-2000 keV energy output of 7.8E53 erg, it ranks third of all GRBs with measured distances. Since this burst is so bright, the data provide complete and valuable coverage up to 65 hr after the event, except for a gap between 3.5 and 8.0 hr. The 2-10 keV flux history shows clear signs of a break which is consistent with a break seen in the optical, and provides supporting evidence for the achromatic nature of the break. An explanation for the break in the context of a collimated expansion is not straightforward. Rather, a model is favored whereby the fireball is braked to the non-relativistic regime quickly (within a fraction of day) by a dense 1E6 cm-3 circumburst medium. This implies that, after a mild beaming correction, GRB010222 may be the most energetic burst observed thus far. The X-ray decay index after the break is 1.33+/-0.04, the spectral index 0.97+/-0.05. The decay is, with unprecedented accuracy, identical to that observed in the optical.Comment: Accepted on June 6 for publication in ApJ part I. Publication due in October 2001. Accepted version has only minor modification

    Sedimentation and Type I X-ray Bursts at Low Accretion Rates

    Get PDF
    Neutron stars, with their strong surface gravity, have interestingly short timescales for the sedimentation of heavy elements. Motivated by observations of Type I X-ray bursts from sources with extremely low persistent accretion luminosities, L_X < 10^{36}\usp\ergspersecond (\simeq 0.01\ensuremath{L_{\mathrm{Edd}}}), we study how sedimentation affects the distribution of isotopes and the ignition of H and He in the envelope of an accreting neutron star. For local mass accretion rates \mdot \lesssim 10^{-2}\medd (for which the ignition of H is unstable), where \medd = 8.8\times 10^{4}\nsp\gpscps, the helium and CNO elements sediment out of the accreted fuel before reaching a temperature where H would ignite. Using one-zone calculations of the thermonuclear burning, we find a range of accretion rates for which the unstable H ignition does not trigger unstable He burning. This range depends on the emergent flux from reactions in the deep neutron star crust; for F = 0.1\nsp\MeV(\dot{m}/\mb), the range is 3\times 10^{-3}\medd\lesssim\mdot\lesssim 10^{-2}\medd. We speculate that sources accreting in this range will build up a massive He layer that later produces an energetic and long X-ray burst. At mass accretion rates lower than this range, we find that the H flash leads to a strong mixed H/He flash. Surprisingly, even at accretion rates \mdot \gtrsim 0.1\medd, although the H and He do not completely segregate, the H abundance at the base of the accumulated layer is still reduced. While following the evolution of the X-ray burst is beyond the scope of this introductory paper, we note that the reduced proton-to-seed ratio favors the production of \iso{12}{C}--an important ingredient for subsequent superbursts.Comment: 15 pages, 14 figures, submitted to ApJ, revised versio

    Actual persuasiveness : Impact of personality, age and gender on message type susceptibility

    Get PDF
    The authors would like to acknowledge and thank all the volunteers who participated in the experiment and provided helpful comments. The first author is funded by an EPSRC doctoral training grant.Postprin

    Discovery of the neutron star nature of SLX 1737-282

    Full text link
    SLX 1737-282 is a persistent moderately bright X-ray source 1.2 deg from the Galactic center. X-ray observations with the Wide Field Cameras on BeppoSAX have for the first time revealed the true nature of SLX 1737-282: a 15-min long thermonuclear flash was detected exposing the source as a neutron star in a binary system. The flash was Eddington-limited constraining the distance to between 5 and 8 kpc. We analyze BeppoSAX, ROSAT, and RXTE data on SLX 1737-282. The persistent 0.5-200 keV luminosity is close to or less than 1% of the Eddington limit which implies a rarely-seen circumstance for thermonuclear flash activity.Comment: Accepted for publication in A&A Letter

    A randomized controlled trial comparing tibial migration of the ATTUNE cemented cruciate-retaining knee prosthesis with the PFC-sigma design

    Get PDF
    AimsThe primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs).MethodsA single blinded randomized, non-inferiority study was conducted including 74 patients. Radiostereometry examinations were made after weight bearing, but before hospital discharge, and at three, six, 12, and 24 months postoperatively. PROMS were collected preoperatively and at three, six, 12, and 24 months postoperatively. Radiographs for measuring radiolucencies were collected at two weeks and two years postoperatively.ResultsThe overall migration (mean maximum total point motion (MPTM)) at two years was comparable: mean 1.13 mm (95% confidence interval (CI), 0.97 to 1.30) for the ATTUNE and 1.16 mm (95% CI, 0.99 to 1.35) for the PFC-sigma. At two years, the mean backward tilting was -0.43 degrees (95% CI, -0.65 to -0.21) for the ATTUNE and 0.08 degrees (95% CI -0.16 to 0.31), for the PFC-sigma. Overall migration between the first and second postoperative year was negligible for both components.The clinical outcomes and PROMs improved compared with preoperative scores and were not different between groups. Radiolucencies at the implant-cement interface were mainly seen below the medial baseplate: 17% in the ATTUNE and 3% in the PFC-sigma at two weeks, and at two years 42% and 9% respectively (p = 0.001).ConclusionIn the first two postoperative years the initial version of the ATTUNE tibial component was not inferior with respect to overall migration, although it showed relatively more backwards tilting and radiolucent lines at the implant-cement interface than the PFC-sigma. The version of the ATTUNE tibial component examined in this study has subsequently undergone modification by the manufacturer.Development and application of statistical models for medical scientific researc
    corecore