100 research outputs found

    Features of diagnosis and treatment of encysted pleural empyema

    Get PDF
    The incidence of non-specific pathological processes of the lung and pleura increases every year. Encysted empyema is leading in terms of morbidity and mortality among all the diseases of the lungs and pleura. Just empyema remains one of the biggest problems in diagnosis for doctors of primary and secondary levels of medical care. Up to this point there is no single diagnostic algorithm for the disease. And as a result we don‘t have the single algorithm of treatment of encysted pleural empyema

    Future of medicine

    Get PDF
    Medicine is the science and practice of the diagnosis, treatment and prevention of disease. For the last years medicine has evolved greatly. And many new achievements have appeared. Health Watch, house call is back. Doctors can already gather your glucose from their gardens and check your liver from the links. Remote medical monitoring will be commonplace in the future and it promises to benefit both physicians and patients by saving time and money

    Investigation of Changes of Short-range Ordering and Electron Density in Simulating Alloys Based on Iron

    Get PDF
    Short-range ordering and electron density in simulation alloys, containing Cr, Mo, W and V as a doping addition, were studied by Mossbauer spectroscopy and positron annihilation methods. A number of peculiarities was observed in alloys with vanadium as a doping

    Experimental and theoretical study of swept-wing boundary-layer instabilities. Three-dimensional Tollmien-Schlichting instability

    Get PDF
    Extensive combined experimental and theoretical investigations of the linear evolution of three-dimensional (3D) Tollmien-Schlichting (TS) instability modes of 3D boundary layers developing on a swept airfoil section have been carried out. The flow under consideration is the boundary layer over an airfoil at 35 degrees sweep and an angle of attack of +1.5 degree. At these conditions, TS instability is found to be the predominant one. Perturbations with different frequencies and spanwise wavenumbers are generated in a controlled way using a row of elastic membranes. All experimental results are deeply processed and compared with results of calculations based on theoretical approaches. Very good quantitative agreement of all measured and calculated stability characteristics of swept-wing boundary layers is achieved

    Quantitative study of localized mechanisms of excitation of cross-flow instability modes in a swept-wing boundary layer

    Get PDF
    An experimental study of two efficient receptivity mechanisms of excitation of cross-flow (CF) instability modes is carried out in a boundary layer of a real airfoil section of a swept wing due to: (i) action of localized surface vibrations, and (ii) scattering of 2D freestream vortices on them. It is found that the two mechanisms lead to rather efficient excitation of CF-modes both at surface vibration frequency and at combination 'vortex-vibration' frequencies. First estimations of the corresponding localized receptivity coefficients are obtained. Direct comparison of the experimental amplification curves of the excited CF-modes with those calculated based on the linear stability theory (LST) has shown that the experimental data obtained at vibration frequency are in excellent agreement with the LST. At the same time, growth rates of the CF-modes excited at combination frequencies are found to be completely inconsistent with the LST. A possible explanation of this phenomenon via action of a new efficient distributed receptivity mechanism is suggested. This mechanism is associated with scattering of freestream vortices on rather high-amplitude CF-modes excited by surface vibrations

    Experimental and theoretical study of swept-wing boundary-layer instabilities: Unsteady crossflow instability

    Get PDF
    Extensive combined experimental and theoretical investigations of the linear evolution of unsteady (in general) Cross-Flow (CF) and threedimensional (3D) Tollmien-Schlichting (TS) instability modes of 3D boundary layers developing on a swept airfoil section have been carried out. CF-instability characteristics are investigated in detail at an angle of attack of −5○ when this kind of instability dominates in the laminarturbulent transition process, while the 3D TS-instability characteristics are studied at an angle of attack of +1.5○ when this kind of instability is predominant in the transition process. All experimental results are deeply processed and compared with results of calculations based on several theoretical approaches. For the first time, very good quantitative agreement of all measured and calculated stability characteristics of swept-wing boundary layers is achieved both for unsteady CF- and 3D TS-instability modes for the case of a boundary layer developing on a real swept airfoil. The first part of the present study (this paper) is devoted to the description of the case of CF-dominated transition, while the TS-dominated case will be described in detail in a subsequent second part of this investigation

    Influence of combined nitrate and fluoride intoxication on connective tissue disorders in rats gastric mucosa

    Get PDF
    We established that chronic excessive fluoride or nitrate intake can cause oxidative and nitrosative stress-depended collagen degradation, simultaneously decreasing the concentration of anti-inflammatory GAG. Combined intoxication leads to even more severe connective tissue degradation, but subsequently activates compensatory mechanisms through increase in concentration of anti-inflammatory GAG

    Verification and characterization of predominant instabilities of swept-wing boundary layers

    Get PDF
    The problem of identification and verification of the most important linear stability mechanisms of initial stages of laminar-turbulent transition in three-dimensional (3D) swept-wing boundary layers is discussed based on experimental and theoretical investigations performed, in particular, for real swept airfoil sections. Detailed analysis of all main boundary-layer stability characteristics with respect to the cross-flow (CF) instability modes and 3D Tollmien-Schlichting (TS) instability modes is carried out based on experimental data, as well as on computations within the framework of linear stability theories and the Parabolized Stability Equation (PSE) approach. The possibility of a very good agreement between all main measured and calculated stability characteristics is shown. Role of surface curvature and base-flow non-parallelism is discussed
    corecore