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

Radial-piston pump for drive of test machines

The article reviews the development of radial-piston pump with phase control and alternating-flow mode for seismic-testing platforms and other test machines. The prospects for use of the developed device are proved. It is noted that the method of frequency modulation with the detection of the natural frequencies is easily realized by using the radial-piston pump. The prospects of further research are given proof

Reduction of a fan vibration activity in a life support system of oil and gas stations

Relevance. Electromechanical fans are widely used in life support systems of oil and gas stations, operate in conditions of vibration, high rotational speeds and loads. Design, technological and operational reasons influence vibration activity of an electromechanical device. The greatest "contribution" to the existing vibrations, according to the frequency spectrum, is made by the imperfection of the design elements of the ball bearing. They are: separator movement, variable stiffness under the action of radial load, interaction of micro-dimensions of working surfaces, facet and waviness of working surfaces of rings and balls. In addition, the resulting vibrations negatively affect both the reliability and durability of the fan. Since it is technically impossible to completely eliminate the vibration activity of an electromechanical device, it is advisable to reduce it with the help of a technical solution by introducing a damping element into a kinematic circuit of the vibration source. In this regard, the development of a damping device is an integral technical task that helps to reduce the vibration activity of technical life support systems of oil and gas stations, as well as to improve the quality of environmental conditions of human life. To reduce vibration activity, a damper design is proposed that takes into account various types of energy dissipation. However, given the dense spectrum of vibration frequencies from ball bearings, a viscous friction element is introduced into the damper design. To determine the effectiveness of reducing vibration activity, a model of the damper in question was made based on the developed 3D model. For tests in determining the effectiveness of applying a viscous friction element, two variants of the damper design were used. In the first version of the damper design, there was no viscous friction element, and in the second version there was one. According to the test results of the damper layouts, it can be seen that the developed technical solution to reduce the vibration activity of the electromechanical device has practical confirmation. The studies underlying the developed design of the damper with a viscous friction element allows for reduction in the vibration amplitude. Object. Electromechanical device in operating mode. Aim. To describe the vibration activity in the operating mode of an electromechanical device in the entire spectrum of disturbing effects acting along the axes, taking into account the imperfect geometry of ball bearing parts; to develop a damper for reducing the vibration activity level in the electromechanical device. Methods. Vibration diagnostics, computational mathematics, measuring instruments, software "Vibration recorder-F", "Vibration Recorder-M2", "Logger"-recorder and "Bearing". Results. The paper demonstrated the effectiveness of the proposed technical solution to reduce the vibration amplitude in the operating frequency range of the electromechanical device rotor up to 4 times compared with the corresponding maximum amplitude value without its use

Selective electrochemical deposition of indium in-between silicon nanowire arrays fabricated by metal-assisted chemical etching

Indium electrodeposition in-between silicon nanowire arrays fabricated by silver-assisted chemical etching of lightly-doped (100)-oriented silicon wafers is evaluated. It is concluded based on SEM and EDX analysis of indium's distribution that, by utilizing pulsed-mode electrodeposition and maintaining a sufficiently low duty cycle value, indium particles can be formed exclusively at the very bottom of each consecutive pore on the residual silver particles left over from metal-assisted etching. This result differs significantly from irregular pore filling along with surface and subsurface deposition observed in the cases of continuous galvanostatic deposition regimes at prolonged durations or in the absence of residual silver particles. Bottommost fusible metal deposit localization, which is unattainable on porous silicon fabricated by electrochemical anodization, is presumed to be optimal for the growth of germanium crystallites inside the pores via the electrochemical liquid-liquid-solid approach and subsequent silicon-germanium alloy formation through thermal annealing

Germanium electrodeposition into porous silicon for silicon-germanium alloying

A method of germanium electrodeposition from a GeO2-based aqueous solution into the pore channels of anodic mesoporous silicon formed on n-type highly-doped (100) silicon wafers is described. The effect of deposition time, pore channel shape and preconditioning of porous silicon layers in hydrofluoric acid is evaluated. Recommendations are given in regards to the optimal parameter combinations to ensure uniform pore channel filling with germanium. The possibility of producing silicon-germanium alloys by subsequent rapid heat treatment of the germanium-filled porous silicon layers is established

Macrophage Pro-Inflammatory Response to Francisella novicida Infection Is Regulated by SHIP

Francisella tularensis, a Gram-negative facultative intracellular pathogen infecting principally macrophages and monocytes, is the etiological agent of tularemia. Macrophage responses to F. tularensis infection include the production of pro-inflammatory cytokines such as interleukin (IL)-12, which is critical for immunity against infection. Molecular mechanisms regulating production of these inflammatory mediators are poorly understood. Herein we report that the SH2 domain-containing inositol phosphatase (SHIP) is phosphorylated upon infection of primary murine macrophages with the genetically related F. novicida, and negatively regulates F. novicida–induced cytokine production. Analyses of the molecular details revealed that in addition to activating the MAP kinases, F. novicida infection also activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in these cells. Interestingly, SHIP-deficient macrophages displayed enhanced Akt activation upon F. novicida infection, suggesting elevated PI3K-dependent activation pathways in absence of SHIP. Inhibition of PI3K/Akt resulted in suppression of F. novicida–induced cytokine production through the inhibition of NFκB. Consistently, macrophages lacking SHIP displayed enhanced NFκB-driven gene transcription, whereas overexpression of SHIP led to decreased NFκB activation. Thus, we propose that SHIP negatively regulates F. novicida–induced inflammatory cytokine response by antagonizing the PI3K/Akt pathway and suppressing NFκB-mediated gene transcription. A detailed analysis of phosphoinositide signaling may provide valuable clues for better understanding the pathogenesis of tularemia

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 50° 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

Raman spectra of silicon/germanium alloy thin films based on porous silicon

Regularities of composition changes of silicon/germanium alloy thin fi lms formed on a single-crystalline silicon substrate by electrochemical deposition of germanium into a porous silicon matrix with subsequent rapid thermal annealing (RTA) at temperatures of 750–950 °C are studied. An analysis of the samples by Raman spectroscopy showed that an increase of the RTA temperature leads to a decrease in the germanium concentration in the formed fi lm. A decrease of the RTA duration at a given temperature makes it possible to obtain fi lms with a higher germanium concentration and to control the composition of thin silicon/germanium alloy fi lms formed by changing the RTA temperature and duration. The obtained results on controlling the composition of silicon/germanium alloy fi lms can be used to create functional electronic devices, thermoelectric power converters, and optoelectronic devices

ЛАБОРАТОРНЫЕ ИССЛЕДОВАНИЯ АНТИПАРАЗИТАРНОЙ АКТИВНОСТИ ЛЕВАМИЗОЛА ПРИ ФИЛОМЕТРОИДОЗЕ КАРПА (Cyprinus carpio Linnaeus, 1758)

Objective of research:  studies of efficacy of levamisole used against philometroidosis in carp in laboratory conditions.  Materials and methods:   Experiments were conducted on scaly carps with the body mass 300 g. spontaneously infected with  Philometra lusiana.  In carp the clinical signs of  philometroidosis have been detected. The intensity of infection before the experiment was 10–20 parasites/fish.  Carps were divided into 6 groups by  10  fish in each group.   Levamisole was  injected through the catheter to fishes of 1, 2, 3, 4 and 5 group at the doses of 100, 50, 25, 15 and 5 mg/kg, respectively with the use of 2% starch gel.  Fish of the 6th group did not receive the preparation and served as controls.  The efficacy of preparation was evaluated  7 days later by most-mortem examination to determine females  Ph. lusiana  in the scale pockets and males between  the air  bladder walls.  Scrapes from the air bladder walls were investigated under a microscope at the 56 times magnification; the intensity and extensity of invasion were determined.  Results and discussion: Levamisole is highly effective against philometroidosis in carp. The drug used at the dose 100–15 mg/kg causes death of females and males Ph. lusiana. Levamisole  at the dose 5 mg/kg   is not effective,  at the dose 100 mg/kg may reduce the feeding activity in fish.Цель исследования  –  изучение эффективности левамизола при филометроидозе карпа в лабораторных условиях. Материалы и методы. Опыт проводили на чешуйчатых карпах массой тела 300 г, спонтанно инвазированных  Philometra lusiana. У карпа отмечали клинические признаки филометроидоза. Интенсивность инвазии составила до опыта 10–20 экз./особь. Карпов разделили на 6 групп по 10 особей в группе. Рыбе 1, 2, 3, 4 и 5-й групп вводили через катетер левамизол в дозе соответственно 100, 50, 25, 15 и 5 мг/кг в составе 2%-ного крахмального геля. Рыба 6-й группы препарат не получала и служила контролем. Эффективность препарата учитывали через 7 суток путем вскрытия рыбы для обнаружения самок Ph.  lusiana  в чешуйных кармашках и самцов между оболочками плавательных пузырей. Соскобы оболочки пузыря исследовали под микроскопом при увеличении в 56 раз и определяли экстенсивность и интенсивность инвазии. Результаты  и обсуждение.  Левамизол высокоэффективен при филометроидозе карпов. Препарат приводит к гибели самок и самцов  Ph. lusiana  в дозах 100–15 мг/кг. В дозе 5 мг/кг левамизол не эффективен, в дозе 100 мг/кг вызывает снижение пищевой активности рыб.

A new approach for producing of film structures based on Si1-xGex

In this work, we propose a new, previously unpresented in the literature, approach to the formation of Si1-xGex films. This approach includes electrochemical processes of the formation of porous silicon, electrochemical deposition of low-melting metals and Ge. Post-heat treatment is made possible to synthesize film structures based on Si1-xGex solid solutions. Using this approach an alloy of the composition Si0.4Ge0.6 has been obtained at a lower formation temperature than predicted by the phase diagram for the Si-Ge system