Utilization Coefficient Research Articles

Error analysis and realization of a phase-modulated diffraction grating used as a displacement sensor.

A grating-based interferometric cavity produces coherent diffraction light field in a compact size, serving as a promising candidate for displacement measurement by taking advantage of both high integration and high accuracy. Phase-modulated diffraction gratings (PMDGs) make use of a combination of diffractive optical elements, allowing for the diminishment of zeroth-order reflected beams and thus improving the energy utilization coefficient and sensitivity of grating-based displacement measurements. However, conventional PMDGs with submicron-scale features usually require demanding micromachining processes, posing a significant challenge to manufacturability. Involving a four-region PMDG, this paper establishes a hybrid error model including etching error and coating error, thus providing a quantitative analysis of the relation between the errors and optical responses. The hybrid error model and the designated process-tolerant grating are experimentally verified by micromachining and grating-based displacement measurements using an 850 nm laser, confirming the validity and effectiveness. It is found the PMDG achieves an energy utilization coefficient (the ratio of the peak-to-peak value of the ±1st order beams to the 0th-order beam) improvement of nearly 500% and a four-fold reduction in 0th-order beam intensity compared with the traditional amplitude grating. More importantly, this PMDG maintains very tolerant process requirements, and the etching error and coating error can be up to 0.5 µm and 0.6 µm, respectively. This offers attractive alternatives to the fabrication of PMDGs and grating-based devices with wide process compatibility. This work first systematically investigates the influence of fabrication errors and identifies the interplay between the errors and the optical response for PMDGs. The hybrid error model allows further avenues for the fabrication of diffraction elements with practical limitations of micromachining fabrication.

Comparative study of novel backfill coupled heat exchangers using different waste materials in underground stopes

Underground mines in China are rich in geothermal resources. Based on backfill mining technology, the collaborative development of deep mineral resources and geothermal resources can be realized. The key of this approach is to form artificial thermal reservoirs by heat storage backfill body and to extract geothermal energy as much as possible through the built-in pipe. It is important to investigate the backfill material and system parameter design to improve the heat storage and release performance of backfill body and enhance the extraction efficiency of geothermal energy in mine. In this paper, experimental and simulation studies of backfill coupled heat exchanger system with different backfill materials are carried out to make a comparative study. The backfill materials involved include traditional backfill material, natural flake graphite backfill material and paraffin RT28 backfill material. After comparing the heat storage and heat release behavior, liquid fraction variation and efficiency of different systems, the natural flake graphite backfill body which has better engineering value is selected to further conduct experiments to study the influence of surrounding rock temperature, initial temperature of backfill body and inlet water temperature on the thermal performance of the system. The results show that with the increase of surrounding rock temperature, initial temperature of backfill body, or the decrease of inlet water temperature, the total heat storage, heat release and energy utilization coefficient of the system all increase. When the initial temperature of backfill is 26 °C, surrounding rock temperature is 45 °C, inlet velocity and temperature are respectively 0.7 m/s and 18 °C, the energy utilization coefficient of the system is the highest, which is 81.4%. The research results are helpful to the design of heat storage backfill body and the improvement of thermal performance of the system.

Assessment of Availability and Utilization of Medical Equipment’s in Nekemte Specialized Hospital, August, 2021

Objectives: The aim of this study was to assess the availability and utilization of medical equipment in Nekemte Specialized Hospital (NSH). Methods and Materials: A retrospective cross-sectional study design was employed. Adapted and pre-tested structured English version checklist for availability and utilization of medical equipment, document review and an in-depth interview were used for data collection. Data were collected by observation of availability of the medical equipment and interviewing selected professionals for utilization of capital item medical equipment. Microsoft excel 2013 was used for data analysis. Descriptive analysis was made to determine the availability and functional status of medical devices and qualitative part were thematically analysed. Results: This finding showed that about 60.4% (209) of medical equipment are available from the total required quantity of 348 which account only 45 (37.2%) of them were items. Among the available 209 medical equipment’s about 84.67% of them are functional and 15.33% of them were non-functional during the assessment. Besides, the Donated equipment accounts 45%. From eight-capital item three of them were properly utilized with utilization coefficient of 81.4%, 100% and 100.0% while the rest five were underutilized with utilization coefficient of 2.5%, 5.77%, 9.2% and 0%. Conclusion and Recommendation: The hospital lacks valuable, advanced and specialized medical equipment that are needed for diagnosis and treatment. Medical equipment fails due to lack of training for user, infrastructure problem like power surge and hard water, and misuse. Training that improves skill of the user and technicians should be given.

Efficiency of Medical Equipment Utilization and Its Associated Factors at Public Referral Hospitals in East Wollega Zone, Oromia Regional State, Ethiopia.

The significance of effectively using medical equipment has received widespread public attention. Due to its complex effects on healthcare costs and quality, the relationship between hospital features and medical equipment consumption has drawn increased attention. Therefore, the study aimed to evaluate the efficiency of medical equipment utilization and its associated factors. The study was conducted at public referral hospitals in East Wollega, Oromia Regional National State, Ethiopia, in 2021. A cross-sectional study design was mixed with observation and document review. The study included approximately 192 pieces of equipment. Descriptive statistics and Pearson Chi-square (χ 2) were used to identify associations between each independent and dependent variable at p<0.05 to declare level of significance. Using 95% confidence interval (CI), the level of utilization coefficient was estimated to be 0.49 (0.44-0.55). As a result, 111 pieces of equipment (57.8%) were used efficiently, while 81 (42.2%) were underutilized. The form in which the hospitals received the equipment (χ 2=7.7.2; P=0.005), regular availability (χ 2=19.30; P=0.00), equipment breakdown (χ 2=11.57; P=0.001), the availability of trained staffs operating the equipment (χ 2=26.14; P=0.00), performing preventive maintenance (χ 2=91.54; P=0.00), the availability of spare parts (χ 2=32.36; P=0.00), and the availability of accessories (χ 2=43.91; P=0.00) were statistically significant factors affecting the medical equipment utilization. On average, the utilization coefficient of medical equipment in the study hospitals was low compared to other study findings, which indicated that 2 out of 5 pieces of medical equipment were under-utilized, which could be significantly affected by the form in which the hospital received the equipment, its regular availability, equipment breakdown, availability of trained staff operating the equipment, performing preventive maintenance, and availability of adequate spare parts and accessories. Every hospital should develop an appropriate strategic framework to manage and utilize the available medical diagnostic equipment based on its level and demand.

Performance Analysis of Multistage Thermoelectric Cooler with Water-Cooled

A finite time thermodynamic model of the multistage thermoelectric cooler with constant temperature heat source and water-cooled is established, and the calculation method of input power and coefficient of performance (COP) are given. The influence of key parameters on device performance under different working conditions is given. The effects of the working current and cross-sectional area of the thermoelectric unit on refrigerating capacity, COP, thermodynamic perfection, module utilization coefficient, and coordination performance coefficient are analyzed. The results show that there are optimal working currents and optimal cross-sectional area, which can make the performance of the device reach the best. The evaluation index also provides a reference for realizing different goals and optimization.

A Bi-Level Optimization Model for Virtual Power Plant Membership Selection Considering Load Time Series

In order to improve the level of new energy consumption and reduce the dependence of the power system on traditional fossil energy, this paper proposed a bi-level optimization model for virtual power plant member selection by means of coordination and complementarity among different power sources, aiming at optimizing system economy and clean energy consumption capacity and combining it with the time sequence of load power consumption. The method comprises the following steps: (1) The processing load, wind power, and photovoltaic data by using ordered clustering to reflect the time sequence correlation between new energy and load and (2) uses a double-layer optimization model, wherein the upper layer calculates the capacity configuration of thermal power and energy storage units in a virtual power plant and selects the new energy units to participate in dispatching by considering the utility coefficient of the new energy units and the environmental benefit of the thermal power units. The Latin hypercube sampling (LHS) method was used to generate a large number of subsequences and the mixed integer linear programming (MILP) algorithm was used to calculate the optimal operation scheme of the system. The simulation results showed that by reducing the combination of subsequences between units and establishing a reasonable unit capacity allocation model, the average daily VPP revenue increased by RMB 12,806 and the proportion of new energy generation increased by 1.8% on average, which verified the correctness of the proposed method.

Experimental study of air distribution and heating performances of deflection ventilation

Deflection ventilation uses a purposely-designed deflector to divert supply air jet into the occupied zone directly. A few numerical studies have shown good indoor air quality with deflection ventilation. However, there was a lack of research on thermal comfort, which is also important to ensure human wellbeing. This study conducted experimental measurements when deflection ventilation was operated for winter heating. Eleven cases with different supply air velocities, supply air temperatures and deflection angles were carried out in an office-layout experimental chamber. As a comparison, another case with mixing ventilation was also measured. The predicted mean vote (PMV), draft rate (DR), air diffusion performance index (ADPI) and energy utilization coefficient (EUC) were adopted to evaluate the heating performances. The results showed that the deflection angle played a decisive role on air distribution. An inclined deflector (deflection angle: 35° downward) could elevate air temperature in the lower occupied zone as compared with a horizontal deflector (deflection angle: 0°), which provided efficient air distribution for winter heating. The average PMV values were in the range of −0.7 – 0.5, and the values of DR and ADPI in the occupied zone were typically less than 20% and higher than 80%, respectively. According to ISO 7730 and ASHRAE 113, deflection ventilation achieved satisfactory indoor environment with regard to thermal comfort. The EUC was typically greater than unity, indicating high energy efficiency of deflection ventilation, especially for the cases with deflection angle of 35°. In comparison with mixing ventilation, deflection ventilation can provide better thermal comfort as well as energy efficiency.

Performance enhancement of an H‐Darrieus vertical axis wind turbine via moving surface boundary‐layer control

AbstractThe moving surface boundary‐layer control method (MSBC) is a kind of active flow control methods that overcomes the adverse pressure gradient and suppresses the flow separation by directly energizing the boundary layer near the moving surface. In this study, computational fluid dynamics simulations were performed to investigate the feasibility of using MSBC to improve the aerodynamic performance of a straight‐bladed H‐Darrieus vertical axis wind turbine (VAWT). In doing so, a segment of the original surface of the VAWT blade was then replaced with a moving surface. Influences of different geometric and motion parameters of moving surface, including location, length, velocity ratio, and groove depth on the net power coefficient of VAWT, were systematically studied. Moreover, the sensitivity of different parameters to the net power coefficient of VAWT at the optimal tip speed ratio was analyzed via the orthogonal design method. As a result, the optimal combination of moving surface parameters was able to be determined. The present results show that the maximum net power coefficient of VAWT having blades with partially moving surface can be increased by 22.8% compared with that of the baseline VAWT. In addition, the effectiveness of two active flow control methods, co‐flow jet and moving surface, in improving aerodynamic performance of a VAWT was also compared. It is found that MSBC method has the potential to achieve superior control performance and promote the energy utilization coefficient of the VAWT more effectively by using comparatively less external energy input.

Prospects for use of man-made disturbed lands in mining regions for the location of renewable energy sources facilities

This article describes the prospects for use of man-made disturbed lands of mining regions, which for a number of reasons are not subject to recultivation, in the context of the effective use of renewable energy sources. The use of renewable energy sources is considered, first of all, to satisfy energy needs, but taking into account their environmental value and renewability. It is shown the importance of decentralization of power supply sources for consumers, which can be achieved through the use of renewable energy sources. The article provides a brief structure of Ukraine's energy consumption. The main obstacles that stand in the way of the development of renewable energy sources and improvement of energy efficiency in Ukraine are analyzed. As one of the perspective directions for the introduction of renewable energy sources, the use of wind power plants is considered. The main advantages of wind energy are listed. Formulas for calculating the power of a wind power plant are provided. The gross potential, technical potential and economic potential of the implementation of wind power plants are considered. The coefficient of wind energy utilization, which depends on the wind speed, is given. The paper gives a comparative assessment of existing types of wind turbines – with a horizontal and a vertical axis of rotation. It has been proved that vertical axis wind power plans are more effective for implementation. The vertical axis wind power plans have their advantages. It is recommended to use vertical axis wind power plans with using of a magnetic levitation. This makes vertical axis wind turbines the most efficient. Due to the use of wind generators with a vertical axis of rotation of a turbine with a magnetic-levitating bearing, in the conditions of Kryvbas, vertical wind power plants can produce electricity more than 7 times more than traditional (horizontal) ones. It has been proven that the amount of generated electricity increases with the height of the wind turbine location. The article examines the ecological advantages of placing wind power plans on man-made disturbed lands of mining regions.

Performance Evaluation of Low-cost Grain Dryer

Paddy is India’s most significant agricultural crop, accounting for more than 40% of the nation’s overall production of food grains. The moisture content of 10.0 to 12.0 %, which is suitable for safe storage, must be achieved after the drying of paddy. Drying of materials having high moisture content is complicated process, involving simultaneous heat and mass transfer. In this study the performance of grain dryer was evaluated for paddy grains for two different paddy varieties, Rajshree weighed 372 kg and Rajendra Kasturi weighed 366 kg with Initial Moisture Content IMC of Rajshree 14.00 % w.b. (V1) and of Rajendra Kasturi 13.40 % w.b. (V2). Initial Moisture Content (all in w.b.) of variety V1 was 14.00 % and of variety V2 was 13.40 %. It was reduced to the Final Moisture Content (all in w.b.) of 10.10 % for variety V1 and 9.60 % for variety V2. It was found that 1000 grains weight of paddy grains was reduced due to loss of moisture. It is also observed that average length and average breadth of grains decreases with decrease in moisture content for both the varieties of paddy grains. It was found that the bulk density of paddy grains after drying was 578.9 kg/m 3 and 555.58 kg/m3 V1 and V2. Decrease in bulk density is natural phenomenon during drying which was also observed here. It was observed that percent moisture reduction was lower at initial stage of drying for variety V1, which became higher at later stage of drying. However, the percent moisture reduction was higher at initial stage of drying for variety V2, which became lower at later stage of drying. Paddy was dried up to 10.10 % and 9.60 % for variety V1 and V2 respectively during this time. The drying efficiency for both varieties V1 and V2 was found as 35.36 % and 36.85 % respectively. The heat utilization factor and coefficient of performance was found as 0.948 and 0.052 for variety V1 and 0.960 and 0.040 for V2. Grain dryer is capable of drying paddy grains within reasonable time. Temperature and moisture profiles during paddy drying are found well accepted for drying of paddy. The quality of dried paddy grains was reasonably good and acceptable. Considering the level of technology and the capacity, the dryer meets the requirements of paddy traders and farmers of Bihar.

Theoretical preconditions for determining the utilization coefficient of shift time when using planning machines

This article presents a set of works that must be performed to maintain the ecology of the soil in the process of planning by planning machines. The smoothness of the movement of agricultural machines is ensured by reducing the unevenness of the surface of the cultivated field. In these studies, it was noted that the utilization rate of the planning machine depends on the speed of the unit, the length of the field section, the time spent on eliminating technical malfunctions, etc. Taking into account the mathematical dependencies, the coefficient of utilization of the shift time in function depends on movement speed, working width and specific working conditions and the value of the actual productivity of the planner per hour of shift time. The capacity of the planner was calculated according to the equation proposed by the researchers of this article, and does not differ much from the unit performance obtained during field tests, and the percentage of difference is 5 ... 6%. Therefore, the results of this work can be used for preliminary design and kitting-up of machine-tractor units for planning works of pre-sowing background of irrigation agriculture.

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Purpose. Create a mathematical model that will make it possible to establish relationships between the main design parameters of a mobile energetic means of the type “Avtotractor” (MEM) and technological modules (TM) during the execution of the aggregation process. Methods. Used analytical methods and mathematical modeling of the process of operation of agricultural units, tractor and car theory. Numerical modeling was carried out using a personal computer. Results. A system of differential equations has been created, which allows simulating and analyzing the movement processes and modes of operation of the unit. In particular, by varying the weight of the vehicle, parameters of the running system (pressure in the tires of the wheels, dynamic rolling radius of the wheels, the number of driving axles), the resistance of the agricultural machine or equipment, the gear ratio of the transmission etc. Conclusions. A mathematical model of the movement process of the agricultural unit based on the MEM-115 “Avtotractor” was obtained, which makes it possible to describe the relationship between the main design parameters of the MEM and its operating modes. Keywords: equivalent dynamic model, system of differential equations, motion process, slip coefficient, weight utilization coefficient.

Human capital: valuation and management

The article considers approaches to the assessment of human capital taking into account the concept of value-oriented corporate management, which has become the methodological basis of the study. The tools of synthetic and analytical accounting in accordance with RAS and the tax legislation of the Russian Federation were used to disclose the content and comprehension of the studied financial notions. The methods of relative values of economic analysis, quantitative methods of evaluation, cost-based (property), revenue and market (comparative) approaches are used in relation to determining the value of human capital. A more specific definition of the human capital utilization coefficient and quantitative estimates of individual human capital, goodwill of human capital are proposed. A universal methodology has been developed for assessing human capital in proportion to the business qualities and labor contribution of employees to the capitalization of the enterprise and the increase in its value. The proposed methodology integrates revenue, cost-based (property) and market approaches. The quantitative relationship between the goodwill of individual human capital and the goodwill of the entire enterprise is revealed. For practitioners in the field of business valuation, researchers in the development of value-oriented corporate management, teachers and students of economics in the study of financial methods of corporate valuation.

Comparative characteristics of the amino acid composition of protein from traditional sources and entomoprotein: calculated data

The growth of the world population leads to an increase in demand for food consumption. Along with the projected reduction in demand for meat products, a search is underway for a new type of food ("novel food"), one of the promising options for which are insects. In 2023 the European Commission has registered flour made from house cricket (Acheta domesticus) as a "novel food" for human consumption. Currently, the amino acid composition of both new types of food and the diet that includes them is not regulated. Accordingly, the potential amino acid imbalance in the diet when entomoprotein is included need to be further investigated. The aim of the study was to characterize the amino acid composition of a simulated diet using protein obtained from house cricket. Material and methods. To assess the balance of diets in terms of amino acid composition, a comparative analysis was made of the actual diet containing protein from traditional foods (scenario 1) and the diet with the likely replacement of beef, pork and poultry with a product containing A. domesticus protein (entomoprotein) (scenario 2). The volume of food consumption has been calculated based on the results of the assessment of a sample survey of household budgets. The study included foods with an established value of annual consumption, that was calculated as daily consumption. The content of essential amino acids in food sources of protein, as well as in the domestic cricket protein, was evaluated using the data from relevant sources. Dietary balance was assessed by calculating its digestibility using data on amino acid scoring, the utility of essential amino acids, the excess content of individual essential amino acids, and the comparable excess content of essential amino acids. Results. We determined the daily consumption volumes of basic foods, formed consumption scenarios, including with the potential use of a protein product based on entomoprotein. Comparative analysis of the amino acid composition of the diet showed significantly higher content (from 1.4 up to 2.9 times) of amino acids in the diet in scenario 2. The results of calculating the amino acid score and utility coefficient showed that a diet using entomoprotein could provide a better usage of amino acids for protein synthesis compared to the «traditional» diet, however, the digestibility of protein from the traditional diet is higher compared to entomoprotein (96.8 vs 89.1%). Conclusion. Despite the fact that the utility of essential amino acids in the scenario of replacing meat products with a product containing A. domesticus entomoprotein is higher, while the digestibility of protein is lower, the differences identified are insignificant.

Investigation of the influence of the direction of the incoming flow relative to the plane of the three-cylinder rotor on the aerodynamic coefficients

Experiments have been carried out to study the influence of the direction of the incoming flow relative to the rotor plane on the values of the drag coefficient of a multi-blade rotor layout with power elements in the form of rotating cylinders of variable cross-section. It is shown that the drag force of the multipath depends on the Reynolds number, and practically remains constant in the range of Reynolds numbers (16-50)· 104 .According to the results of a series of experimental data, the dependences of the thrust coefficient of the multipath rotor on the Reynolds number and the installation angle of the airflow were also calculated and constructed. It is established that the coefficient of thrust of the rotor decreases with an increase in the Reynolds number. Keywords: rotor, Reynolds number, drag force coefficient, thrust force coefficient, WEUC (wind energy utilization coefficient).

Thermodynamic analysis of a novel solar photovoltaic thermal collector coupled with switchable air source heat pump system

Solar photovoltaic panel can only convert a small part of solar energy into electricity, and the remaining energy in the form of heat is discharged into the environment. In this paper, a novel solar photovoltaic thermal collector coupled with switchable air source heat pump system was introduced to improve the power generation of photovoltaic panels and effectively use the solar thermal energy, which can meet the requirements of the heating in winter and the cooling in summer. At first, the energy model and exergy model of the system were developed. Meanwhile, R134a, R290, R410A and R717 were selected as the candidate working fluids to remove the heat from the back of photovoltaic panel. Furthermore, a numerical simulation was implemented in MATLAB based on the energy and exergy models, and NIST REFPROP database was associated to obtain thermodynamic properties of the working fluids. And then, the thermodynamic performance of the system using different working fluids was investigated and compared. Finally, the optimal working fluid was determined based on the electrical efficiency, energy utilization coefficient, and exergy efficiency of the system. The results indicated that the electrical efficiency of cooled photovoltaic panel in the system was 4.1%-13.7% higher than that of uncooled photovoltaic panel in winter, and 1.1%∼10.6% in summer. The exergy destruction of the compressor and PVT collector accounts for a large percentage. Interestingly, R717 is the optimal working fluid of the proposed system, where the system has the highest annual energy utilization coefficient of 1.654 and the highest annual exergy efficiency of 0.251. Therefore, the application of the system has the potential for achieving the coupling of the annual photovoltaic cooling and the solar thermal energy utilization.

The Performances of Hybrid Grouper, Epinephelus fuscoguttatus × E. lanceolatus Fed with Defatted Soybean Meal-Based Feeds with Supplementation of Phytase

Fish meal is the primary protein ingredient in fish feed and this material is expensive and non-renewable. However, the use of plant protein in marine fish feed such as soybean meal products are limited due to anti-nutritional factor that hindered fish performances. Therefore, hybrid grouper, a cross between tiger grouper (Epinephelus fuscoguttatus) and giant grouper (E. lanceolatus) was evaluated using defatted soybean meal (DSM) based feed and phytase. DSM- based feeds (30% of protein replacement) with supplementation of phytase at 0 and 2000 FTU/kg dosages, as well as a control feed (CON) comprised completely of fish meal (FM) was given to the hybrid grouper with an initial body weight of 6.2±0.0g. Each experimental feed was formulated with 50% of crude protein and 12% of crude lipid. The fish were raised in 100L fiberglass tanks equipped with a flow-through water system for each triplicate treatment. The hybrid grouper was fed with the respective feeds twice a day until the perceived satiation level for 12 weeks. Hybrid grouper fed CON and DSM-based feed did not exhibit any significant difference in growth. However, hybrid grouper fed with DSM-based feed grew larger compared to that fed with CON. Hybrid grouper fed with DSM-based feed showed significantly higher feed intake, lower net protein utilization, hepatosomatic index, viscerosomatic index, and apparent digestibility coefficient (ADC) protein values (p&lt;0.05). The value of ADC of phosphorus was slightly higher in DSM-based feed supplemented with phytase at a dosage of 2000 FTU/kg. No significant effect was observed on body proximate composition, morphological condition of the intestine, and ADC of lipids in all the treatments. The results show that hybrid grouper can effectively consume 30% DSM-based feed and supplementing phytase did not affect the fish performances.

USE OF ENERGY-SAVING TECHNOLOGIES IN HIGHER EDUCATION INSTITUTIONS

The article examines the requirements for the creation of an autonomous university, considers alternative measures to solve energy saving problems, shows the effectiveness and necessity of conducting an energy audit of the institution, indicates the actions performed by Khmelnytskyi National University in the framework of energy saving. The methodology for evaluating the effectiveness of measures is similar to the calculation of current energy consumption and energy consumption for the previous representative period. The difference is that when evaluating energy-saving measures, it is necessary to predict how the situation will change after their implementation. This entails a change in many coefficients, such as the rate of energy consumption, the power utilization coefficient, the duration of equipment operation during the year. To save energy, Khmelnytskyi National University built its own boiler house with a capacity of 3,900 kW, which made it possible to disconnect several buildings from the city-wide heat supply network. Solar power plants were put into operation, solar panels were placed on the roofs of the buildings of the educational institution, educational and production bases, sports complex The implementation of the latest technologies for the production and consumption of energy resources, as well as technologies involving the use of alternative energy sources, is possible on the basis of a previously conducted comprehensive energy audit. The feasibility of building an autonomous heating system, which made it possible to disconnect the main buildings from the city-wide heat supply network, has been proven. Taking measures to insulate walls, replace the water supply system, and use heating points increases the energy efficiency of resource use. In addition, the introduction of alternative energy systems, the creation of own solar power plants and modern control systems for them allows you to optimize lighting costs per hectare, reduce costs for electricity needs, and even make money from sales using the “green tariff”. In this way, any higher educational institution can organize and conduct its own measures to increase the energy-efficient consumption of energy resources, conduct information campaigns, involving students and teachers. This will not only improve the energy situation at the university, but will also help save energy at home.

EVALUATION OF THE EFFICIENCY OF USING A MIXED SYSTEM OF MAINTENANCE AND REPAIR OF ROAD VEHICLES OF ROAD TRANSPORT

The article argues the relevance of determining the efficiency of the mixed system of maintenance and repair of road vehicles. Improving the system of maintenance and repair of road transport is one of the main ways to increase the efficiency of motor transport enterprises. This is due to the high growth rate of work performed, the significant complexity of the design of modern vehicles and the variety of implementation of new maintenance strategies and diagnostic methods. Significant complications in the design of components and units of modern road vehicles, increasing their functions, more busy modes of operation of components, units, etc. - significantly exacerbated the problem of traffic safety, which is largely due to the quality of maintenance and repair. The urgent need to improve the system of maintenance and repair is due to changes in the technical condition of automotive equipment and the requirements for maintaining the working condition of vehicles during operation. An analysis of existing maintenance and repair strategies has shown that each has its advantages and disadvantages. The combination of advantages of each strategy and elimination of shortcomings will lead to the creation of a mixed system of maintenance and repair, which along with high-quality staffing of repair companies and equipping them with modern diagnostic equipment will increase the readiness of road vehicles, technical efficiency and efficiency quality of operation, reduce maintenance and repair costs at a given level of reliability. © О. М. Рікунов, В. І. Кужелович, 2022 Keywords: road transport vehicles, maintenance and repair system, preventive maintenance system, average total duration of maintenance and repair, technical readiness coefficient, technical utilization coefficient, economic feasibility

Многовариантный расчет механизма подъема груза крана мостового типа на ЭВМ

The mechanism for lifting the load of bridge-type cranes, as a rule, is placed on a cargo trolley moving along the crane bridge. The weight of the cargo trolley and the weight of the load create a bending moment on the bridge. The bending moment is the main force factor in the calculation of the metal structure of the crane, that is, its value largely determines the metal capacity of the crane. Therefore, minimizing the weight and size parameters of the lifting mechanism is one of the most important tasks in the design of bridge cranes. In the classical methods of calculating the mechanism for lifting the load of a bridge type crane, the elements of the mechanism are selected on the basis of their sequential calculation, taking into account the corresponding safety factors. This approach does not imply variation in the parameters of the lifting mechanism and does not allow achieving its minimum weight and size indicators. Minimizing the weight and size parameters of the lifting mechanism of a bridge-type crane can be provided by comparing various variants of its layout schemes. This can be achieved on the basis of multivariate calculation. Obviously, the multivariate calculation of the lifting mechanism of a bridge-type crane increases the amount of calculations and is very time-consuming to implement manually. This determines the relevance of developing a methodology for multivariate calculation of the mechanism for lifting the load of a bridge type crane and a computer program that implements it. The paper presents a methodology for multivariate calculation of the load lifting mechanism, which allows varying the multiplicity of the cargo polispast, the displacement step according to the classification group of the operating mode of the drum diameter selection coefficient and the minimum rope utilization coefficient, as well as the computer program that implements this methodology.