Experimental Study on Out-of-Plane Seismic Performance of New Type Masonry System

The authors developed two types of block systems, consisting only of main and key blocks, without joint mortar, to improve the in- and out-of-plane seismic performances and enhance the workability. Two types of block systems have different key block shapes. One is the peanuts shape, and the other is the H shape. The proposed block systems have a half-height difference between the main and key blocks, to significantly improve seismic performance in in- and out-of-plane directions, compared to typical masonry wall with joint mortar. In this study, in order to evaluate the out-of-plane seismic performance of the proposed block systems, two types of block walls are experimentally investigated, including the typical block wall. Firstly, the shaking table tests are carried out to investigate the fundamental out-of-plane behaviors of three specimens. Next, four-point bending tests are planned to evaluate the out-of-plane seismic performance, since all specimens do not occur the out-of-plane collapse in the shaking table tests from the preliminary calculation. In this paper, the development of predominant period, profiles of acceleration and displacement, and maximum tensile strength of each specimen are discussed in detail. As a result, the maximum loads of the proposed block walls were about three to four times that of the typical block wall. This result means that the proposed block system has significantly improved seismic performance in the out-of-plane direction.

About nitrogen metabolism with a lacto-vegetable diet

In one of our reports, we were able to show that a milk diet, which does not satisfy the energy needs of scarlet fever patients, leads to a negative nitrogen balance. Since in the milk diet, along with a moderate content of protein and fat, there were extremely few carbohydrates, it was natural to assume that an increase in the amount of the latter could have a significant effect on protein metabolism. To replenish food with carbohydrates, we included in the diet, in addition to milk, vegetable purees, cereals, jelly. The menu was composed in such a way that for breakfast and dinner, patients were given porridge with milk, and for lunch, vegetable puree and cranberry jelly. In addition, children received 200 grams twice a day. milk as a drink. The well-known schematization of dishes was carried out in order to facilitate the technical conditions of work. According to a preliminary calculation, the total caloric value of our lacto-vegetable diet was 2086 calories, with a content of 56 grams in food. squirrel, 294 gr. carbohydrates and 70 gr. fat. Of the 10 children put on this menu, only one 12-year-old patient with a mild form of scarlet fever ate the whole food offered to him, while the rest of the children were content with more or less of the dishes they were given. Patients aged 4-5 years drank an average of 600-700 grams. milk and ate 150-300 gr. porridge, 75-150 gr. mashed potatoes and 150-200 gr. jelly; older children ate 400-500 grams. porridge, 150-300 gr. puree, 250-300 gr. jelly and about 800 gr. milk.

CALCULATION OF THE CONSTRUCTION OF THE SEWERAGE COLLECTOR DURING ITS REPAIR AND RESTORATION IN AN OPEN WAY

A significant part of sewerage networks in cities in the country are reinforced concrete pipelines with a diameter of 500 to 1500 mm, which lie at a small depth. In many cases, they transport wastewater to treatment plants through areas free of traffic and pedestrians. These factors allow you to effectively perform repair and restoration work in an open way. Corrosion processes that occur in the surface part of the collectors lead to the destruction of the basement. The tray part of the collectors, which is constantly filled with wastewater, remains intact. As studies have shown, the preserved tray part can be successfully used as a fixed formwork and support element in the restoration of the basement of the collector. In this case, to create a new basement part of the collector, in place of the destroyed, it is advisable to use a monolithic structure of polymer concrete reinforced with composite reinforcement. These works are performed using pneumatic and inventory formwork. To implement the proposed structure, it is necessary to perform a preliminary calculation of its load-bearing capacity, provided that it rests on the preserved tray part. As a result of this work it is possible to receive economy in comparison with use for repair and restoration works of polyethylene and fiberglass pipes of necessary diameter. During the calculation, a model of the collector was considered, consisting of a preserved tray part of the collector made of concrete class C12 / 15, the upper part of the collector made of concrete class C20 / 25. The calculation proved the possibility of using polymer concrete structures for repair and restoration of sewers in an open way, provided that the new basement rests on the preserved tray part. The proposed open method allows to significantly reduce the cost of repair and restoration work in comparison with the use of polyethylene and fiberglass pipes.

The concept of the auxiliary propulsion system of the III stage of the Soyuz launch vehicle

The paper introduces a concept of creating an auxiliary propulsion system for the III stage of the Soyuz launch vehicle. The concept is aimed at reducing the cost of launching a payload into low Earth orbit. The study describes the auxiliary propulsion system and its constituent elements and gives the results of a preliminary calculation of the main characteristics of a low-thrust engine. Within the research, we developed a sketch layout of the auxiliary propulsion system integrated into the 14D23 liquid propellant rocket engine and analyzed the mass characteristics of the constituent elements and the greatest contribution to the total mass of the propulsion system. The proposed propulsion system is distinguished by electric drives for the power supply system pumps used instead of the turbine drive. This auxiliary propulsion system, combined with a 14D23 liquid propellant rocket engine, powered by oxygen-naphthyl propellants, is proposed for use in the III stage of the Soyuz-2-1b launch vehicle.

Knowledge, attitudes and practices in relation to smoking among Burkinabé people residents of Dakar (Senegal) on World No Tobacco Day 2020

Introduction: The study focused on knowledge attitudes and practices vis-à-vis smoking. It was carried out by the 2020 executive office of the Collective of Burkinabé Students in Health in Senegal on World No Tobacco Day 2020. The objective was initially to assess attitudes and practices in relation to smoking smoked by industrial cigarettes and shisha then knowledge of the anti-smoking law and the possibilities of weaning that exist in Senegal and finally to know the best attitude to fight against smoking. Methods: This was a descriptive cross-sectional study for analytical purposes. The sampling technique was voluntary and data collection was self-administered and took place from Monday May 25th to Saturday May 30th, 2020 via electronic questionnaires. The self-administered data collection technique reduced prevarication and social desirability bias. However, the lack of preliminary calculation of a sample size makes inferences in the general population difficult. The sampling technique that was voluntary exposes itself to self-selection biases. Nevertheless, the study does suggest some very important aspects of smoking among young people. Results: This study shows that shisha is increasingly becoming the gateway to smoking among young people. It reveals that the health warnings on industrial cigarette packages are less and less dissuasive. It also shows that our study population believes that the two priority actions to be carried out to fight effectively against smoking in Senegal are on the one hand "to improve the offer of help for smoking cessation" and on the other hand " rigorously apply the punitive aspects of the anti-smoking law”. Conclusion: Smoking is a global epidemic that increasingly affects young people. Tobacco control is multidimensional and requires perfect synchronization of the different actors and continuous assessment of the effectiveness of control and prevention methods. Keywords: Cigarette, Shisha, Youth, Anti-tobacco control, Senegal

Rational design for a friction unit of a disc-shoe brake

In this study, we develop a rational design for a friction unit provided that restrictions are imposed on the fly-wheel masses of rotating elements and the onset of a thermal stabilization state. The input calculation data were the braking torque, specific pressure in the friction pair, angular velocity and the diameter of the brake disc hub. The geometric programming method was used at the preliminary stage to calculate the design and operational parameters of a discshoe brake. Further, the parameters were refined based on the conditions of mutually exclusive factors (energy intensity and braking time) and the stress-strain state. On the basis of the proposed rational design for a friction unit, a software application for calculating in the DELPHI programming language was developed. The ranges of design parameters were determined at the preliminary design stage: a brake disc diameter from 0.237 to 0.37 m; the width of working surfaces from 0.0335 to 0.1 m; and the thickness of half-discs from 0.012 to 0.026 m. The final result of the rational design method was the specified ranges of design parameters: diameter from 0.31 to 0.324 m; width from 0.041 to 0.0485 m; and thickness from 0.0148 to 0.0151 m. The developed method of rational design reduces the diameter ranges of the designed brake disc in comparison with the preliminary calculation by 9.5 times, while the ranges of the width of the working surfaces are reduced by 8.9 times, and the thickness range – by 46.6 times. At the final stage, the secondary design and operational parameters of the friction unit were determined: the areas of the working and non-working surfaces of the friction pairs and the coefficient of their mutual overlap. The proposed method of rational design reduces the selected range of design parameters, which will provide a more rational choice of compliance with their specified performance characteristics.

ANALYSIS OF THE EFFICIENCY OF ELECTRIC POWER TRANSMISSION IN THE SYSTEM OF WIRELESS CHARGING OF THE ELECTRIC VEHICLE'S BATTERY

Theoretical researches of efficiency of electric energy transfer in the wireless charger of inductive type with serial resonance in circles of transmitting and receiving coils are carried out. It is shown that this efficiency depends on the parameter (the product of the magnetic coupling coefficient and the Q- factor of the coils) and the ratio of the active resistances of the battery and the coil. It is shown that there is an optimal value of this ratio, at which the efficiency of the device is maximum (when ) and its value increases monotonically with increasing parameter . Moreover, to achieve an efficiency greater than 0.8, it is necessary to have a system of coils with a value of 10. The graphical dependences that determine the value of this efficiency as a function of these two parameters and set the allowable interval for changing the resistance ratio in terms of high energy efficiency. Numerical calculation of the high-frequency magnetic field (with an operating frequency of 100 kHz) generated by the coils was performed, in two cases - in the absence of shielding and in the presence of aluminum electromagnetic screens and showed high efficiency of such screens. The peculiarity of the calculation is that to determine the values of complex currents in both coils, which depend on the mode of operation of the whole device, use their preliminary calculation based on the created Simulink-model of the device. References 14, figures 5, table 2.

Plastic Shaping of Concentrator-Waveguide Tip for Ultrasound Endovascular Ablation

One of the most effective methods of treating intravascular formations at present is the use of stepped ultrasonic waveguide systems of a tubular type (concentrators-waveguides) with a hollow spherical tip, the presence of which makesit possible to supply liquid media to the dislocation zone of an intravascular formation with the aim of additional cavitation effect and as efficiently as possible. destroy intravascular formations due to vibration impact. Based on the results of the analysis on the features of the existing shaping methods for obtaining a hollow spherical tip of the concentrator-waveguide, it is advisable to use methods of plastic deformation – expansion and crimping. The paper presents results of preliminary calculations, numerical modeling and experimental studies of tip shaping processes of the concentrator-waveguide by distribution and crimping. On the basis of the finite element method in the environment of the ABAQUS software package, modeling of the expansion and crimping of a pipe billet was carried out, which has made it possible to: evaluate the stress-strain state of the deformable conical section of the billet, the change in wall thickness during the forming process and calculate the length of the billet for the design of the conical section; to establish the patterns of the influence of geometric parameters on the power modes of the distribution process; to set the parameters of the modes of forming the tip of the concentrator-waveguide by the method of distribution and crimping, which ensure the formation of the required geometry. The obtained results of preliminary calculation, numerical modeling and experimental studies of tip shaping processes of the concentrator-waveguide by distribution and crimping have similar values, which confirms the correctness of using both the method of preliminary calculation and numerical modeling in the development of the technology for manufacturing the concentrator-waveguide.

Influence of technological process parameters on equipment dynamic factor

Technological equipment of the metallurgical industry operates in difficult conditions in terms of dynamic loads. On the other hand, special requirements are imposed on their mechanisms - they must be reliable in operation and allow easy regulation, and in the event of breakdowns, allow quick replacement or repair of units and parts, and at the same time must meet the conditions for the accuracy of reproduction of the given technological opera-tions.In modern rolling shops, technological operations are carried out according to the continuous and continuous principles of creating new rolling equipment and the operation of complex machines requires the use of achievements in various fields of science and technology. Scissors, straightening machines, coilers, uncoilers, tilters, manipulators, pushers, conveyors are built into the flow technological working lines. And the performance of the technological line as a whole depends on the coordinated work of these mechanisms.The issues of dynamic loads from the point of view of the interaction of the rolling stands of the continuous broadband mill 1680 have been considered rather thoroughly, while the effect of changing the technological modes of rolling on the equipment of the current line, in particular the coiler, is not covered.In order to reduce equipment downtime due to emergency failures associated with an increase in dynamic loads from incorrectly selected technological modes, the task was set to analytically study the effect of a change in the rolling process on the dynamism coefficient using the example of roller coilers of rolling mills.To analyze the forced vibrations arising in the drive of the reel drum of the mill 1680, a two-mass torsion system is considered, to which external moments are applied - the moment of the technological resistance of the working body, reduced to the motor shaft, and the nominal torque of the electric motor.On the basis of the considered calculation scheme, a functional equation of motion was compiled through which the relationship between the change in the parameters of the technological process and the coefficient of dynamism was established.The solution of the functional equation of motion makes it possible to establish the value of the moment of elastic forces as a function of time, which is used in calculating the dynamic coefficient, which in turn characterizes the dynamic loads on the nodes of technological equipment. Its preliminary calculation allows avoiding emergencies associated with equipment failure in case of incorrect selection of the technological process modes.