42 research outputs found
Control system of parameters of the azimuthal module
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
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 6β18 CuS particles per 1 cm of the fiber length. An effective bactericidal fibrous material can be produced using rather cheap material β CuS and relatively cheap natural compounds of sulphides and oxides of heavy metals
The development of radio and 3G based telemetry system for the remote gas accounting and control nodes
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
Monitoring and Quality Control of Diesel Fraction Production Process
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
Pneumatic device of the preload and dynamic loads balancing to reduce the intensity of thermal processes in the metal cutting process
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
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
Evaluation of the potential accuracy of the pulsed radio signals source coordinate determination by the positioning system using a single UAV-sensor
An approach to determining the coordinates of pulsed radio signals sources by the positioningsystem in the application of a single unmanned aerial vehicles sensor is shown in this article. Therange-difference location method allows to determinate an informative coordinate parameter withoutretransmission and internal synchronization of receiving points. The result is achieved by improving thewell-known scientific and methodological apparatus with considering some features of the operationmode of pulsed radio signals sources. Presenting results of the simulation allow to estimate theinfluence of main input factors on the potential accuracy of the pulsed radio signal source coordinatedetermination
LEDs based upon AlGaInP heterostructures with multiple quantum wells: comparison of fast neutrons and gammaquanta irradiation
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
Diagnostics and treatment challenges of Ph-like acute lymphoblastic leukemia: a description of 3 clinical cases
B-cell acute lymphoblastic leukemia (B-ALL) is a diverse group of malignant blood disorders both with regard to the biological properties of the tumor and to therapeutic approaches. Immunophenotyping, molecular genetic techniques, whole-genome sequencing characterize B-ALL as a very diverse group for sensitivity to chemotherapy and prognosis. We present three clinical cases of patients with B-ALL and expected good response to standard therapy, in whom standard protocol treatment failured: refractoriness, persistence of minimal residual disease (MRD), and progression (MRD increase). The remission in these patients was achieved after chemotherapy change to immunological targeted therapy. Nowadays a unified therapeutic approach to all primary patients of the B-ALL is considered generally outdated. Great efforts are carrying out to develop molecular genetic classifications. The molecular dissection of subtypes of B-ALL goes on, and new protocols for selective treatment with targeting are clearly outlined for each subtype of B-ALL
Impact of graft-versus-host disease prophylaxis on immune reconstitution in patients after allogeneic hematopoietic stem cell transplantation
The graft-versus-host disease (GVHD) is among the most common complications after hematopoietic stem cell transplantation (allo-HSCT). The main tools for GVHD prevention remain calcineurin inhibitors (cyclosporin A, tacrolimus), methotrexate, mycophenolate mofetil. Upon implementation of reduced-intensity conditioning regimens, antithymocyte globulin was widely introduced. However, negative effects upon reconstitution of T-cell immunity have been noted, thus increasing risk of severe infectious complications and disease relapse. With extended practice of HSCT from alternative (partially matched or haploidentical) donors, cyclophosphamide was increasingly used. Our aim was to study reconstitution of immune cell subpopulations in the patients undergoing bone marrow transplantation (BMT), when using different GVHD prophylaxis regimens, including the schedules with post-transplant CP usage. The study concerned 44 cases classified into 2 groups. The first one included patients with standard immunosuppressive therapy, antithymocyte therapy, cyclosporine A, methotrexate, mycophenolate mofetil. The second group included the patients who received CP as immunosuppressive drug combined with other treatments (cyclosporine A, methotrexate, mycophenolate mofetil). At specified control terms, (D+14, +30, +60, +90) the blood leukocyte subpopulations were assayed by means of multicolor flow cytometry. Absolute counts of CD4+ cells in HSCT recipients treated with CP post-BMT proved to be sufficiently lower at D+14 and +30, than in those treated with classical immunosuppressive therapy. However, at later terms, (D+60, +90), these differences were not observed. Moreover, in CP-treated bone marrow recipients, absolute numbers of CD8+ cells was significantly higher, compared to the patients who received conventional GVHD prophylaxis. Reconstitution of the studied lymphocyte populations in hematopoietic cell recipients did not depend on the GVHD prophylaxis regimen. Usage of CP combined with bone marrow as a source of stem cells, brings about sufficient decrease of some cell populations (CD4+; CD8+; NK cells) at early terms post-transplant. Administration of CP combined with hematopoietic stem cells as the source of hematopoietic graft seems to be more reasonable