52 research outputs found

    Highly-effective purification of air on the fibrous filtering nozzles

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    A series of experiments by air purification on fibrous filtering nozzles was made. It is experimentally shown that the fibrous filter can operate in a wide rate range. The degree of trapping of fine aerosols of glass was 99% at a linear rate of 0.01 m/s. the degree of capture decreased to 85% at the increasing of filtration rate up to 0.06 m/s. Dustiness of the air ranged from 3 to 5 g/m3 at the course of the experiment. Hydraulic resistance changed from 5 to 25 mm of water column. The calculated data of resistance and falling of pressure on fibrous filters are given; these data were received on the equations from various sources in comparison with experimentally obtained data. According to the results of series of experiments the amendment of the well-known Fuchsian equation is calculated for calculation of the resistance of fibrous air filter. This amendment considers a form and defects of surface of the fibers received by centrifugal-spinneret method

    RESULTS OF EARLY PHYSICAL REHABILITATION IN PATIENTS AFTER CORONARY ARTERY BYPASS SURGERY

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    The study objective is to examine the effectiveness of physical rehabilitation in patients after coronary bypass surgery at the stationary stage.Materials and methods. The study included 112 patients with ischemic heart disease and saved systolic function of the left ventricle (heart ejection fraction >35%) after coronary artery bypass surgery (CABS). The first group consisted of 60 patients who received standard program of physical rehabilitation with controlled training on treadmill in early postoperative period. Cardiovascular exercises with intensity of 3–6 metabolic equivalents (MET) started at 3–4 days after surgery on treadmill and continued until discharge from the hospital; simultaneously careful monitoring Β of hemodynamic parameters was performed. The second (control) group included 52 patients who received standard physical rehabilitation activities. At the end of stationary stage of physical rehabilitation all patients completed the questionnaire SF-36 Health Status Survey.Results. Initially, according to clinical, demographic and perioperative characteristics the compared groups did not differ statistically. At the end of the program of physical rehabilitation for the average value of the total post-operative bed-day in the first (median was 8) and in the second group (median was 9) statistically significant differences were obtained (p <0.0001), which were in favor of the studied population. In the first group tolerance to physical exertion increased by 3 MET and in general it was 6 MET. According to the results of the questionnaire SF-36 in the group of patients with cardiovascular exercises, the average indexes of physical, role functioning, mental health were significantly different from the results in the control group (accordingly p = 0.0038, p <0.0001, p = 0.033).Conclusion. Implementation in the program of physical rehabilitation in patients after CABG controlled cardiovascular exercise on treadmill at a hospital stage does not increase the incidence of complications, and the use of elements of early rehabilitation help to improve tolerance to physical exertion. In addition, the program of early physical rehabilitation improves subjective health parameters according to the questionnaire of life quality assessment SF-36 and reduces the duration of the postoperative bed-day

    Control system of parameters of the azimuthal module

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    Analytical and experimental studies of the azimuthal module of two-component vibrational micromechanical gyroscope were conducted. It is shown that the micromechanical gyroscope is a system with distributed parameters. The frequency analysis is performed using software T-Flex. The influence of mechanical disturbances on the movement of azimuthal module in the form of translational and angular oscillations is shown; the natural frequencies of the azimuth are defined

    Physico-chemical Modification of the Fibrous Filter Nozzles for Purification Processes of Water and Air

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    A set of experiments to study physical and chemical modification of the surface of fibers is conducted to expand the area of their application for purification of water, gas and air (including that in conditions of space). The possibility of modification of filter nozzles in the process of fiber formation by particles of coal of BAU type, copper sulfide and silver chloride is experimentally shown. The fraction of the copper sulfide powder less than 50 microns in size was crushed in a spherical mill; it was deposited on fiber at air temperature of 50Β° C and powder consumption of 0.5 g/l of air. The resulting material contained 6–18 CuS particles per 1 cm of the fiber length. An effective bactericidal fibrous material can be produced using rather cheap material – CuS and relatively cheap natural compounds of sulphides and oxides of heavy metals

    Numerical Solution of Rare Metal Leaching Problem

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    It is well known that a lot of chemical and physical processes take place on the surfaces of interaction between solid and li quid substances. These processes include a very important technological process of uranium, nickel, copper, precious metal and other solid compound extraction - in-situ leaching. In this article we will rely on the mathematical description of these complex systems proposed by A.M. Meirmanov, where the main idea is the presence of new conditions on a free (unknown) boundary between liquid and solid phase

    Monitoring and Quality Control of Diesel Fraction Production Process

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    In this work the mathematical model of diesel fraction and atmospheric gasoil catalytic dewaxing process has been developed. Also the pattern of applying the created model to solving such problems as monitoring and quality control of diesel fraction production in the catalytic dewaxing process. It has been represented that to meet such challenges, the model should take into consideration thermodynamic and kinetic laws of hydrocarbon conversion on the catalyst surface, and instability factors that are specified by catalyst deactivation. The developed model allows controlling the quality of obtained diesel fraction depending on feed and temperature regime in the reactor. The value of model calculation absolute error does not exceed 2%, which corroborates the adequacy of the model to actual process. The computations using the model have shown that to provide the desired product yield (not less than 40% wt. of overall yield of the unit products) of programmed quality (cold filtering plugging point not higher than minus 34Β°C for winter diesel fuels and not lower than minus 40Β°C for arctic ones) at long-time catalyst operation (during 4 years), it is necessary to sustain the reactor temperature at the average level of 19Β°C higher than when working with fresh catalyst. This must be done to compensate catalyst activity loss due to its deactivation

    The development of radio and 3G based telemetry system for the remote gas accounting and control nodes

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    In this article we have described the use of vortex and recently developed ultrasonic flowmeters with high dynamic range of 1 to 1500 for industrial applications. Its software and the software of corresponding computing device is able to avoid gas leakage, to minimize energy consumption and to save human resources while maintaining metrological data. Described is the low power consumption that makes it possible to use this ultrasonic flowmeter in hard remote environment without direct management for a period of several month

    LEDs based upon AlGaInP heterostructures with multiple quantum wells: comparison of fast neutrons and gammaquanta irradiation

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    The paper presents the research results of watt and volt characteristics of LEDs based upon AlGaInP heterostructures with multiple quantum wells in the active region. The research is completed for LEDs (emission wavelengths 624 nm and 590 nm) under irradiation by fast neutron and gamma-quanta in passive powering mode. Watt-voltage characteristics in the average and high electron injection areas are described as a power function of the operating voltage. It has been revealed that the LEDs transition from average electron injection area to high electron injection area occurs by overcoming the transition area. It disappears as it get closer to the limit result of the irradiation LEDs that is low electron injection mode in the entire supply voltage range. It has been established that the gamma radiation facilitates initial defects restructuring only 42% compared to 100% when irradiation is performed by fast neutrons. Ratio between measured on the boundary between low and average electron injection areas current value and the contribution magnitude of the first stage LEDs emissive power reducing is established. It is allows to predict LEDs resistance to irradiation by fast neutrons and gamma rays

    Pneumatic device of the preload and dynamic loads balancing to reduce the intensity of thermal processes in the metal cutting process

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    Improved reliability of the technological system "machine-tool-instrument-detail" is an important current task. Backlashes and insufficient stiffness of technological system lead to intensive wear of the cutting tool, increasing the heat in the cutting zone. Due to high temperature in the thin surface layers of the workpiece and tool thermal processes may occur which are similar to release and can cause the structural changes of the material. The current article presents the final design of the device which has been developed to reduce the intensity of thermal processes in metal cutting

    Determination technique of quasireference value of a carrier radio signal frequency of uncooperated onboard lighting source during radio monitoring

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    The article discloses the technique defining quasireference value of a carrier radio signal frequency of uncooperated onboard lighting source by calculation and compensation of the Doppler shift at radio monitoring. Provided simulation results show checked operability of the offered technique with assessment of observation accuracy and received quasireference value of a carrier frequency accepted a radio signal compared with real sample under various conditions
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