- Все статьи 5660
Статьи журнала - Бюллетень науки и практики
Все статьи: 5660
Description of women in Jawahir ul-ajaib
Статья научная
The article provides information on the first memoir devoted to women Jawahir ul-ajaib by Fakhriy Hiraviy, and the manuscript copies of the memoir stored in libraries around the world. You can find out about the quantity of art forms in the Jawahir ul-ajaib as well as the number of women and their work.
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Design and analysis of antireflection layer on the surface of crystalline silicon solar cell
Статья научная
With the positive development of photovoltaic technology, improving efficiency and reducing cost has become a global problem facing the solar industry. The development of solar cell anti-reflection film can significantly reduce the reflection of sunlight on the surface of the battery, increase the flux of light entering the battery, and create more photo-generated carriers, which is the most economical and effective way to improve the efficiency of the battery. More photo-generated carriers are produced, which is the most economical and effective way to improve the efficiency of batteries. Therefore, it’s of great value to explore a performance-matched antireflective film material for solar cells and its preparation process. The plasma enhanced chemical vapor deposition of silicon nitride antireflective coatings has been widely used in photovoltaic industry. The aim is to form an antireflection film on the surface of crystalline silicon solar cells and achieve good passivation effect. The thickness and refractive index of the antireflective film have an important influence on the performance of the battery. It is of great significance to explore the optimum technological conditions for preparing the optimum thin films. Considering the optical properties, stability, preparation process and production cost of antireflective film materials, the influence of antireflective film on the output characteristics of solar cells was studied by using PC1D simulation software.
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Design and analysis of heat pipe heat exchanger efficiency
Статья научная
The heat pipe has a high thermal conductivity, and its basic working principle is to transfer heat through evaporation and condensation through the working medium inside the pipe. Heat pipe has good thermal conductivity, isotherm and other characteristics, and the heat transfer area at both ends can be changed at will, control the temperature and other advantages. Therefore, the heat pipe heat exchanger has the advantages of high heat transfer efficiency, compact structure, small fluid resistance loss, and beneficial to control dew point corrosion. At present, it has been widely used in metallurgy, chemical industry, oil refining, boiler, ceramics, transportation, light textile, machinery and other industries, as energy saving equipment for waste heat recovery and heat energy utilization in the process and has achieved remarkable economic benefits. The design of the heat pipe heat exchanger on the development of the current situation, development trend, application, design principle and design process of a simple description, while focusing on the discussion of the heat pipe heat exchanger design process. The main content of the heat exchanger thermodynamic calculation, structural design and material selection. The model of heat pipe heat exchanger is established according to the actual situation and the calculated data.
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Design of PFC converter based on interleave boost
Статья научная
Based on the principle of stagger boost PFC, this paper expounds the application value of stagger PFC theory by developing a scientific and feasible scheme and using Matlab simulation. According to the subject requirements, the use of UCC28070 to achieve PFC control function. And learn IC functions. Based on the theory of interlaced PFC, the most suitable electronic device is selected to adjust each part of the circuit. Finally, Solidworks and Protel software were used to draw the radiator and PCB boards, then the prototype was made and debugged, and the final result was obtained.
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Статья научная
The subject of the research is designing a regenerative heat exchanger to heat hot water. Qualitative and quantitative analysis of relevant physical parameters to optimize heat exchanger models. The purpose of this study is to simulate realizing the goal of heating hot water with 25 kW and optimize the model to optimize the heat exchange efficiency in practical work. As a result of the research, Amplitude-frequency response of the circuit increases linearly as speed of rotation. When the speed is constant, the less of water mass is, the value of Amplitude great. The phase frequency response of the circuit increases overall as the speed increases. The greater the mass, the greater, and the rate of increase gradually decreases. we know that increasing the water volume can improve the heat transfer efficiency, but when the water volume (G) increases to 1.6, the rate of increasing the heat transfer efficiency begins to decline, so this should be taken into account in the design process. With the heating time increases, the heat transfer efficiency will also improve. It should be noted that when the heating time increases, the rate of increase of heat transfer efficiency decreases and specific heat capacity (KF) decreases.
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Design of a liquid cooler for a 100 kW semiconductor power converter
Статья научная
He focus of this research in this paper is to design a 100 kW power liquid cooler, semiconductor converter liquid cooler, thus using pulsed thermal medium circulation to increase the capacity of the cooling system on the surface of the power semiconductor device. Based on comparing the parameters of conventional and pulsed coolant circulation mode, the liquid cooling system of power semiconductor converter is studied by physical method. In laboratory testing, experiments are planned according to the order and frequency of changing device operating modes. Finally, the experimental research results are processed, and the relationship between the discharge heat power and the temperature drop and the coolant flow is established by using the mathematical statistics method. Result: Depending on the exhaust heat power and the coolant flow in the range of 3-1.5 L/min, the pulsating heat transfer enhancement in the liquid cooling system of the power semiconductor converter can increase the thermal capacity and the current load of the power semiconductor converter by a factor of almost 2.5 times, respectively. At the same time, the circulation of the coolant in the inner circuit is carried out by a hydraulic powered film pump.
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Design of dangerous driving behavior detection system based on STM32
Статья научная
With the rapid development of China’s economy and the continuous improvement of the living standards of the people, cars have gradually become an indispensable tool for travel. At the same time as the number of cars increases rapidly, the accident rate of road traffic is also increasing. Traffic accidents caused by dangerous driving behavior account for a large part of the accident rate. In order to reduce the road traffic accident rate, a vehicle dangerous driving behavior detection system using STM32 single-chip microcomputer is designed from the vehicle itself, which mainly detects the speed and weight of the vehicle. When the vehicle is in the starting state, the detection system detects the weight and speed of the vehicle in real time through the sensor and the motor speed. In this system, the STM32 is used as a core MCU. When the speed or weight of the vehicle exceeds the threshold, the MCU performs an alarm and subsequent operations. This design introduces the overall design of the system in detail, from the test of each module to the use of the overall connection test, the interface module and STM32 interface circuit as well as the system hardware circuit and related peripheral circuits are given, and finally the measurement data is displayed through the OLED. The design is simple in structure and can be applied to various vehicles.
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Design of heat pipe air preheater for 10 t/h gas-steam boiler
Статья научная
This design is aimed at energy -saving and designed a heat pipe air preheat to recover 10 t/h steam gas boiler flue heat waste heat, thereby increasing the efficiency of the boiler and reducing gas consumption. This article first introduces the thermal pipe, heat pipe heat exchange, and boiler thermal system, and then focus on the design and optimization of the heat pipe air heater. This design optimizes the thermal pipe specifications of the heat pipe air heater and the parameters of the fins. At the same time, the sealing structure, the fixed structure, and the airport structure are optimized. Subsequently, the UG software created a three-dimensional physical model model and rendering model, and finally proposed corresponding countermeasures on equipment corrosion, thermal pipe life and tube vibration problems. This design uses Excel software to make design calculation tables. Through input parameters, the results of the results of the number of thermal pipes can be obtained.
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Статья научная
As a new type of heat exchanger with compact structure and efficient performance, microchannel heat exchangers have good application prospects in industries with strict requirements such as energy and power, petrochemical, aerospace, and other industries. Therefore, exploring the performance and heat transfer characteristics of microchannel heat exchangers is of great significance. This article designs a performance testing system that can simultaneously explore the enhanced heat transfer inside the pipeline of water water and carbon dioxide compressed air microchannel heat exchangers. The variable working fluid circuit design is used to analyze the factors that affect the enhanced heat transfer. The Control variates is used to control the heat transfer conditions, explore the difference of heat transfer performance between different working fluids under different flow rates, inlet temperatures and other conditions, and analyze the heat transfer performance of different channel types by comparison method. The results indicate that when the hot water flow rate range is 2.063×10-5~2.556×10-5m3/s, Re-5~2.556 ×10-5m3/s, the Reynolds number and Nusselt number in the pipeline increase with the increase of inlet flow. In the carbon dioxide compressed air heat transfer experiment, when the flow rate range is 2.810×10-4~3.182×10-4m3/s, the Nusselt number and convective heat transfer coefficient of the 3.6mm inner diameter microchannel are always greater than the Nusselt number and convective heat transfer coefficient of 6.6mm. When the pipe diameter is the same, the water water microchannel heat exchanger has better heat transfer performance and smaller pressure drop compared to the carbon dioxide compressed air microchannel heat exchanger.
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Designing a cooler with natural cold for a 100 kW semiconductor power converter
Статья научная
The subject of the study is the design of a cooler with natural cooling capacity for a 100 kW semiconductor power converter. The purpose of this thesis is to design a cooler with natural cooling capability for a 100 kW semiconductor power converter and to evaluate its practical effects. We summarize the demand for power semiconductor devices for new applications in power electronics in recent years. During the study and testing of the cooler for the 100 kW semiconductor power converter, the parameters that became the basis for mathematical modeling were determined. In this paper, we summarize the key issues and the current state of research on power semiconductor modules, including module thermal design and thermal modeling issues. The degree of realization is complete. In the process of developing the experimental device, reduction of energy consumption losses and reduction of explosion and fire hazards in industrial production facilities was achieved, which in turn will increase the efficiency of the invention and reduce its production costs. Development of efficiency - reduction of power consumption losses, reduction of explosion and fire hazards in industrial production facilities due to overheating of power semiconductors.
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Статья научная
As in the Republic of Azerbaijan, appropriate measures are being taken in the Guba district in the field of environmental policy, environmental security, and efficient use of natural resources that meet the needs of society and require environmental protection in order to achieve sustainable socio-economic development. Therefore, the interaction of society with nature, the optimization of the impact of these relations, and the search for solutions are considered as one of the important issues. In this case, the main attention should be paid to the organization of the designing the industrial zones Phin the Guba district. Because the correct designing of industrial zones helps to organize work, protect the environment, and achieve sustainable socio-economic benefits. The article presented as a result of research in this area examines the volume of industrial products produced in the Guba district, the retail trade turnover of local production and export products, design of industrial zones, and environmental problems during production.
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Designing of a cavitation heat generator for heating water with a capacity of 10 kW
Статья научная
This article establishes a three-dimensional model of the design circuit of a water heating cavitation device and simulates it in Hysys software. The relationship between temperature, pressure and flow rate of cavitation generator in pulsed heating water circulation unit is studied by using control variables. The dependence of pressure and temperature difference on flow rate was studied. The dependence of pressure and temperature difference on the thermal power of the cavitation device was studied. The dependence of pressure and temperature differences on pipeline diameter was investigated. Explored the differences in pressure and temperature through water flow methods in pulse and stationary modes. The following conclusions can be drawn: 1) When the flow rate and output thermal power remain constant, the pipe diameter is inversely proportional to the pressure; 2) When the pipe diameter and output thermal power remain constant, the flow rate is proportional to the pressure; 3) When the total output power is 10 kW, the outlet temperature of the system gradually rises to a relatively stable state after 1000 seconds for different power cavitator schemes; 4) When the total output power is basically equal, the more times the parallel connection is made, the smaller the voltage drop, and the higher the system efficiency; 5) When the pipe diameter and output heat power are constant, the larger the flow rate, the smaller the temperature after the cavitator and the temperature difference between the front and back become smaller. When the pipe diameter and flow rate are constant, the smaller the output thermal power, the smaller the temperature after the cavitator and the temperature difference between the front and back become smaller.
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Designing of a liquid cooler with a phase transition with a power of 5 kW
Статья научная
A diagram and installation of a prototype of a two-flow heat pipe with the ability to regulate the parameters of the working environment have been developed. The installation allows the heat pipe to operate in both normal and pulsed cooling modes. Data were obtained that made it possible to obtain the dependence of the heat transfer coefficient on the heater power, and the heat transfer coefficients in stationary and pulsed modes were determined. In this article, the Aspen Hysys software package is selected as the software and circuit simulation. As a result of theoretical studies, it was established that the heat transfer coefficient of a heat pipe in pulsed mode is 12% higher than in stationary mode with the same initial coolant parameters. Based on the results of the work, it is proposed to use the method of pulsed supply of liquid coolant as one of the ways to increase the heat transfer of a heat pipe.
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Статья научная
The article presents the research results on the microbiological activity of some Passiflora genus species, first introduced in Azerbaijan. Phytochemical compounds were analyzed in vitro in ethanolic extracts of Passiflora incarnata L. , P. edulis Sims, P. caerulea L. leaves and fruits to determine the antimicrobial activity against six pathogenic bacteria. The activity indicators of ethanolic extracts from leaves and fruits of all three species were compared. Leaf extracts were found to have higher antibacterial activity compared to fruit extracts. Ethanolic extracts of Passiflora edulis Sims were more active than extracts from P. incarnata L. and P. caerulea L. The results of the study may contribute to the development of new medications against pathogenic microbes and the progress of the pharmaceutical industry in the future.
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Developing of management: choice and implementation of new tools
Статья научная
The research presented in this article shows the experience of implementing new Managerial tools in context of management and employees’ development which is carried out in the large vehicle manufacturing company GM Uzbekistan. The paper describes the details of some new management techniques implementation and evaluated the results of implementation. Analysis of the results of innovation activity, questionnaire survey and special interview reveals of main influenced factors. Result of the research illustrates the importance of in-company culture and managerial style, empowerment and involvement of personnel, top management support and managerial stress, education and training programs. The management of the JVC General Motors Uzbekistan has actively tried to induce new managerial tools and techniques as Continuous Improvement activity through Employee’s Suggestion System, Quality circle, 5S, TPM and others and MBO - Management by Objectives as tools for activation personnel potential and establishing self-managed teams within company employees...
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Статья научная
The research works were carried out in the years 2021-2023 in farms located in the Guba district of Azerbaijan (41°04ʹ27ʺ N 48°36ʹ32ʺ E). During the research, as the apple fruit eater hibernates both in the caterpillar and pupal stages, their coming out of hibernation in the spring season of the next year coincides with different times. It is for this reason that this pest can be found in agrocenosis from spring to autumn. Because the development of generations is mixed together and creates a complex phenological calendar. Apple fruit borer produce 2 complete generations in the study areas. The third generation hibernates in different stages (caterpillar and pupa).
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Development of Beta zeolite template free synthesis method
Статья научная
The development of new methods for the synthesis of zeolites and the improvement of existing methods for the synthesis of zeolites in order to reduce their cost and improve the quality of the final product is an important task of modern chemistry and chemical technology. Existing methods for the synthesis of zeolites, including hydrothermal synthesis methods, are extremely time-consuming and expensive due to the widespread use of structure-forming agents. At the same time, traditional methods for solving the above problems by increasing the rate of hydrothermal synthesis by increasing the temperature are not optimal, due to the possibility of the formation of additional inorganic phases at high temperatures. Zeolite BETA is one of the most commonly used aluminosilicates both as a catalyst and as a material for creating inorganic membranes for various purposes, while the synthesis of the above zeolite is extremely long and takes from 5 to 10 days. The presented article presents the results of the development of a method for obtaining BETA zeolite by a hydrothermal method under the influence of ultrasound. A study of the influence of temperature and the ratio of silicon to aluminum in the reaction medium on the yield of zeolite is also given. It has been established that an increase in the temperature of hydrothermal synthesis from 80° C to 120 °C contributes to an increase in the yield of zeolite up to 97%. An increase in the molar ratio of silicon to aluminum, on the contrary, leads to a decrease in the zeolite yield to 15%. It is shown that the synthesis under conditions of ultrasonic treatment with a power of 6 mW/cm2 contributes to an increase in the yield of the target product by 2-4 times, and an increase in the rate of formation of BETA zeolite by 2-8 times.
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Development of a model for the analysis of the socio-economic security of a complex system
Статья научная
The effectiveness of the use of mathematical methods of data analysis to the results of experimental studies is justified by a formalized representation of the quality of the objects of the studied array in numerical format. At the same time, depending on the individuality of the field of study there is an opportunity to meet a number of problems. As a rule, the socio-economic area of the probabilities of formalization of the quality of the objects is located at the stage between difficult and easy) formalization. The difficulty of formalization, first of all, is that it is impossible not to take into account the social component in the formal description of social and economic systems. But if earlier the formalization of the social element in principle was not likely due to the undeveloped apparatus, then it was not remembered. All modelling was limited to the analogy with technical systems or statistical data processing. However, at the moment on the basis of interdisciplinary approaches there is a real probability to address the formalization of society - a difficult field of study.
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Development of automobile industry and business in Uzbekistan
Статья научная
In this paper looked through several aspects of the sustainable development of the automotive business and industry in Uzbekistan. We analyzed the legal and regulatory framework, directed investment target program for the development of the automotive business, the main socio-economic indicators and the results of the JSC “Uzavtosanoat”, which is the top of the organization and the main coordinator of the sector in Uzbekistan. In the process, information obtained that year by year, an increasing number of localized sets of component, parts for cars, trucks and agricultural machinery. In addition, in 2015, because of 8 AK “Uzavtosanoat” system projects in the republic created 220 new jobs and spent more than 42 billion soums of domestic investment. As results of 6 foreign direct investment projects assimilated more than 7 million US dollars and created over 100 new jobs in the system of JSC “Uzavtosanoat”. In 2013-2015 years increased production of trucks and heavy machinery was almost 270 percent, batteries 126.7 percent, in turn decreased the production of passenger cars by 25 percent, 68 per cent of the buses. This data indicates that gradual changes in the world and in the internal conditions of vehicles market is saturated domestic market of buses and cars. Increased domestic demand for trucks due to the prosperity of various types of civil and housing construction in the country, a gradual upgrade of Trucks Park in the enterprises, the acquisition of new trucks and special vehicles from the side of small business and private entrepreneurship.
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Development of effective forms of the entrepreneurship on the silkworm seed system
Статья научная
The article describes the role and importance of sericulture in the national economy, as well as the stages of the development of greening production. The proposals and recommendations on the organization of an effective form of entrepreneurship in the delivery of green to subjects involved in breeding silkworms are given. A scheme showing the steps of operation. It is recommended to study the experience of foreign countries in reproduction and distribution of silkworm seeds, and then they can be used in our republic. Particular attention should be paid to work experience in India. The Republic of India is the second largest silkworm seed and cocoon cultivator, but it is the world’s leading producer of raw silk. The Indian government is paying more attention to public-private partnerships for the production of silkworm seeds. That is, the production of silkworm seeds is based on the specific requirements of the state, so the government will make silkworm seeds at the expense of the lowest costs.
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