Utilization Coefficient Research Articles

Исследование характеристик комбинированных устройств глубокого охлаждения дымовых газов на водогрейных котлах системы ЖКХ

One of the ways to increase the efficiency of hot water boilers of the housing and communal services system is the deep cooling of combustion products to temperatures below the dew point temperature. Currently, there are a number of studies on the use of condensation economizers and air heaters of various types to solve this problem. The use of such devices makes it possible to reduce the temperature of combustion products and, thus, increase the heat utilization coefficient, reduce fuel consumption. The use of combined flue gas cooling devices seems particularly promising, but the parameters of their operation have not yet been studied. In this regard, the development and study of the parameters of such devices are relevant. Using the techniques to design heat exchangers, a set of thermal calculations has been performed to study the characteristics of a combined deep cooling system for combustion products after a hot water boiler of the housing and communal services system, represented by an air heater and a condensation economizer. It is considered that one part of the flue gases after the air heater is sent to the economizer, and the other part goes through the bypass, bypassing the economizer, and then meets the combustion products coming out of it. The distribution of the combustion product flow before the economizer is based on the need to ensure the temperature of the mixed flow after the economizer at 70 °C. For the most common hot water boiler in the housing and communal services system of the TVG-8M type, the authors have been established the dependence of the heat transfer coefficients, the surface area of the heat exchangers and other parameters of the deep cooling system of the exhaust gases on the set value of the temperature of the combustion products after the air heater. It has been established that the proposed scheme of a combined deep cooling system for combustion products makes it possible to improve the technical and economic performance of the boiler by reducing fuel consumption. It is proved that the smoke temperature after the air heater for this type of the boiler should not be very low (not lower than 115–130 °C), since it dramatically increases the heat flow with a decrease in the average logarithmic temperature difference and leads to an increase not only in the temperature of the heated air, but also in the surface area of the air heater.

Increasing the efficiency of operation and management of railroad transport infrastructure based on maximum levels of fault tolerance

This paper considers the optimization of parameters for a railroad transport system. The maximum level of technological reliability and the average time spent by trains on the route are used as optimization criteria. The purpose of the study is to establish the optimal parameters for the operational process of railroad transport systems according to the criterion of the maximum level of technological reliability and the minimum time of trains on the route. Methods of technological reliability research have been proposed. Taking into account that the entire technological process is a sequential set of technological elements, a simulation model of the technological process of the transit transport-technological line along a route direction has been built. A population of agents that simulates the operation of railroad sections of the rotation of train locomotives and is a key subsystem of the simulation model has been developed and configured. The simulation model makes it possible to optimize the parameters of multi-section railroad lines. This approach is provided owing to the agent approach. As a result of the experiments, the optimal parameters of the functioning of railroad lines were established when organizing the passage of transit trains. The coefficient of utilization of the locomotive fleet fluctuates within the optimal range (0.55–0.65), which indicates the sufficiency of traction resources in the railroad system. The optimal parameters of the railroad transport system were established experimentally using the example of a train flow of 85 pairs of trains on a two-track route with five sections. The problem of "abandoned trains" has a solution but, to this end, it is necessary to increase the fleet of train locomotives by 150–200 % relative to existing standards. At the same time, even with an unlimited fleet of train locomotives, there is a fairly high probability (up to 30–50 %) of technological failures

Applicability of attribution methods for identifying runoff changes in changing environments

Under the dual impacts of global climate change and human activities, how to accurately and quantitatively assess and identify changes in watershed runoff is crucial to the rational development and utilization of water resources. Different methods of identifying runoff change attribution are applicable to different environments. In this study, we used five different methods, including the double mass curve (DMC), the soil and water assessment tool (SWAT), and the three Budyko hypotheses based on Fu, Choudhury‒Yang, and Milly‒Zhang formulas to explore the impact of human activities and climate change on runoff change in the Jinghe River basin (JRB). The results show that annual runoff of the JRB decreased considerably, and human activities accounted for more than 90%. Specifically, the results of the SWAT model and the three Budyko hypotheses are highly consistent except for the DMC method, which is not recommended in basins with significant changes in factors other than precipitation. More importantly, the Budyko hypothesis based on the Milly‒Zhang formula uses the vegetation water utilization coefficient to consider the impact of vegetation change on runoff, which is most consistent with the simulation results of the SWAT model and is recommended for the attribution analysis of changes in the Loess Plateau represented by the JRB.

Joint guarantee rate index assessment of the contribution of agricultural water-saving measures to river ecological flow in water shortage areas

Reconciling higher ecological water demands and economic purposes with finite freshwater resources remains one of the great management dilemmas. Low water efficiency and large water consumption in agricultural irrigation hinder the protection of river ecological flow in the water shortage areas of Northwest China. By analyzing the surplus and shortage of river ecological protection targets, the intensity guarantee rate index is innovatively proposed to quantitatively evaluate the important contribution of improved water-saving measures for river flow restoration. It compensates for the shortcomings of the duration guarantee rate index in evaluation that may mask ecological problems. Considering ecological baseflow, fish species, and landscape water demand, the ecological flow interval (6.00–12.42 m3/s) was determined. Three scenarios are highlighted for different typical years and irrigation regimes in combination with planting structure adjustment and irrigation water utilization coefficient. In 75 %, 90 %, and 95 % typical years, the maximum total annual water-savings (Scenario 3) are 57.3, 57.1, and 87.2 million m3 (sufficient irrigation); 32.2, 33.9, and 35.5 million m3 (deficit irrigation) respectively. The guarantee degree of river ecological flow under both irrigation regimes increased from the previous 65.6 % to a maximum of 91.7 % and 81.2 %. The increase in the daily guarantee rate and decrease in the intensity guarantee rate under the aforementioned three scenarios indicate a reduction of damage depth and duration of ecological flow. By using a quantitative study, it is pointed out that improving agricultural water-saving is a reasonable and necessary way to protect the river flow.

PRINCIPLES OF SIMULATION OF ENERGY-EFFICIENT GRANULATION PROCESSES IN A FLUIDIZED BED

The principles of physical and mathematical modeling of inhomogeneous jet-pulsating fluidization in the self-oscillating mode considering the movement of solid granulated particles on the working surfaces of the gas distributing device are investigated. The research tasks include substantiating the method of interaction between the gas phase and granular solids to ensure the implementation of heterogeneous jet-pulsating fluidization in the self-oscillating mode, experimentally determining hydrodynamic parameters to minimize the risk of stagnant zones on the working surface of the gas distributing device and formulating principles for introducing flat gas jets into orthogonal planes through a gas distribution device. The physical model focuses on creating heterogeneous jet-pulsating fluidization which is based on the formation of heterogeneous porosity in the bed of solids within the apparatus chamber. The study highlights the importance of rationally organizing the interaction mode between the gas phase and solids to ensure active circulation of granular material between 3 main technological zones: humidification, active heat exchange and relaxation. This organization enables sufficient mass transfer along the height of the bed and getting a product with the desired properties. Implementing the proposed modeling principles in equipment development will allow increasing the heat utilization coefficient by more than 60 % and will facilitate the implementation of innovative technology. The research contributes to the development of fluidization technology and its application in granulation at temperatures exceeding the melting point of thermolabile components, ensuring efficient use of resources and energy, and enhancing the environmental safety of technological processes. Bibl. 22, Fig. 11.

Sintering enhancement process based on fluidity and bonding phase strength

The sintering process is influenced by complex low-grade ores. This study used seven types of imported iron ore, A–F and domestically produced iron ore, G, as raw materials to study their chemical composition, as well as the liquid fluidity and bonding strength of the mixed ore after single and optimised ore blending. The high-temperature characteristic test values of mixed ores are positively correlated with the weighted calculated values of individual ores. Under the sintering cup conditions, the optimal ore mixing includes a 9% increase in liquid fluidity and a 6% increase in bonding strength. The latter significantly improved the sintering yield and drum strength, reaching 75.89% and 65.67%, respectively. In addition, the consumption of solid fuel has slightly decreased by 0.06 kg·t−1, and the utilisation coefficient has slightly increased. In addition, the sintering yield and quality indicators of the scheme have been comprehensively improved. Compared with the benchmark scheme, through liquid fluidity optimisation, an increase in magnetite phase, a decrease in haematite, and a significant decrease in acicular calcium ferrite were observed, interwoven with magnetite. The silicate-bounding iron oxide also showed an increase in this optimisation. In the optimisation of bonding strength, the corrosive structure interwoven with magnetite and needle shaped ferrite significantly increases, while the iron oxide bound with silicate decreases. The improvement effect of liquid phase fluidity and bonding phase strength optimisation on sintering process and mineralisation behaviour was verified through sintering cup test and mineral phase analysis.

Research and application of the method of measuring the effective utilization coefficient of irrigation water on farmland

Abstract Under the guidance of the new water management idea of “water conservation priority, spatial balance, system management, and two-handed effort,” the National Water Conservation Action Plan released in 2019 puts forward the key task requirements of “double control of total intensity,” in which the effective utilization coefficient of irrigation water in farmland is one of the indicators of water intensity control. The effective utilization coefficient of irrigation water is one of the water intensity control indicators. At present, there are practical difficulties in measuring the effective utilization coefficient of irrigation water in farmland, such as the low measurement rate of water consumption in the current irrigation area, the high input equipment and manpower requirements, and the difficulty in accurately measuring the net irrigation water absorbed by crops. Therefore, this paper proposed the method of “field monitoring - remote sensing inversion - a comprehensive analysis of data.” The method of “field monitoring - remote sensing inversion - econometric model construction - comprehensive analysis” was proposed in this paper, which can obtain gross irrigation water utilizing field monitoring, overcome the difficulty of accurate monitoring of net irrigation water using remote sensing, and carried out a comprehensive analysis, to realize the scientific, effective and rapid calculation of effective utilization coefficient of irrigation water. This method was applied to the Meixian District, Guangdong Province, and the research results show that it not only generates reliable measurement data but also alleviates workload. Furthermore, it offers scientific measurement techniques for water use efficiency indicators, facilitating the achievement of “dual control over total volume and intensity.” This paper provides an important technical basis for the rational allocation of water consumption and scientific approval of water use plans and supports the assessment of the effectiveness of water-saving irrigation development and the reasonable evaluation of the water-saving potential of farmland irrigation, thus providing a basis for local government departments at all levels to make planning, scientific decision-making, and macro-management.

Определение величин кормового коэффициента и коэффициента использования кормовой базы рыбами-планктонофагами в нижнем течении реки Вычегды

This paper presents the results of studies of the aquatic ecosystem components of the lower reaches of the Vychegda River. During 2022 growing season we found 234 species of various microalgae belonging to 8 departments. The phytoplankton community is diatom-green with small forms of organisms from other departments. 45 taxonomic units represented the zooplankton community over the entire period of research. We identified 20 taxa of Cladocera, 11 taxa of Copepoda, and 14 taxa of Rotatoria. Widespread Palearctic organisms formed the community. According to the results of control catches, six species of fish were identified: roach, perch, bream, ruff, silver bream and walleye. Perch and roach dominated the catches (87.7% of the catch). Material on 150 larvae and fry of bleak and ruff was obtained. The coefficient of feed utilization (KE) for phytoplankton averaged 0.033, for zooplankton – 0.11. The coefficient of assimilated food by zooplankton (K3) corresponded to an average of 0.348 (34.8%), the same indicator for planktonophagous fish was not above 0.3 (30%). The feeding coefficients of phytoplankton and zooplankton for the lower reaches of the Vychegda River averaged 30 and 9, respectively. Thus, the obtained feeding coefficients in 2022 growing season are close to the zonal ones for the Northern Fisheries Basin. The research results can be used to develop measures for the conservation of aquatic biological resources and their habitat.

Evaluation of the nutritional value of freeze-dried hydrolysates obtained from fish skin

Protein hydrolysates have a wide range of applications in the food industry. The additives obtained by enzymolysis of collagen-containing secondary fish waste (fish skin) have been freeze-dried. The following protein content is established in freeze-dried protein additives: 95.4/100 g (in pollock skin hydrolysates); 94.8 (cod skin); 92.5 g/100 g (pike-perch skin). The amino acid composition of the additives includes glycine, proline, valine, lysine, and arginine. Comparison of the amino acid composition with the reference protein demonstrates a high degree of satisfaction of the daily requirement for amino acids. The utility coefficient of the amino acid composition indicates a balance of amino acids, which determines the biological value of additives from pollock skin (88.67 %), cod (86.65 %), and pike-perch (79.68 %). Protein additives contain low-molecular peptides with biologically active properties. The assessment of the harmlessness index has been carried out using the simplest organisms: growth, reproduction and absence of death of the cells of the Tetrachymena pyriformis ciliate indicate the harmlessness and high biological value of the protein of protein supplements. The obtained food supplements are proposed to be used in the production of sports nutrition products.

A Study on the Bearing Performance of an RC Axial Compression Shear Wall Strengthened by a Replacement Method Using Local Reinforcement with an Unsupported Roof

When compared with conventional replacement reinforcement methods, the method of replacement using a local reinforcement with an unsupported roof has the advantages of shortening the reinforcement cycle and reducing material loss, and many scholars have carried out useful explorations thereof. At present, the formula for the bearing capacity of reinforcement by replacing concrete in the Code does not consider the effect of stress hysteresis on the parts of the reinforcement; so when the initial stress level is greater than 0.4, the Code’s strength utilization coefficient of 0.8 for the new concrete in the replaced area is on the side of insecurity. In this study, we are trying to improve and supplement the formula in the Code through the following work. Firstly, 18 groups of shear wall models were constructed using a VFEAP finite element analysis program to analyze the bearing performances of the shear walls after the replacement. The results showed that the replacement concrete strength, the initial stress level and the size of the replaced area had a significant influence on the bearing capacity of the shear wall after the replacement. Secondly, utilizing the replacement concrete strength, the initial stress level and the size of the replacement area as key parameters, then introducing the strength improvement coefficient considering the constraints of the stirrups, the modified strength utilization coefficient of new concrete in the replaced area was formulated. Finally, based on the modified strength utilization coefficient, the replacement bearing capacity formulas for the one-batch, two-batch, and three-batch replacements were derived, and an N-batch replacement bearing capacity formula was regressed and fitted on the basis of these equations, which are less discrete and more secure than the Code’s formula.

The functional state of athletes who have undergone coronavirus infection (COVID-19)

This study aimed to investigate the energy supply of athletes, who had a mild form of coronavirus infection (COVID-19) under cycling ergometric load (CEL) to substantiate the timing of recovery, as well as to determine the volume and intensity of physical activity. Eighty-seven athletes aged from 18 to 28 years old, involved in cyclic sports, were examined. Group I consisted of 52 athletes with COVID-19, and group II consisted of 37 healthy self-isolating athletes. In addition to the comprehensive examination, the tested athletes underwent special examinations: the study of diagnostic material using methods of nucleic acid amplification, spirography and spiroergometry, electrocardiography (ECG), and CEL. The results of athletes from both groups did not differ significantly (p ​> ​0.5) in the 1st, 2nd, and 3rd examinations. The second examination revealed a discrepancy between functional reserves and the load performed, as evidenced by the difference in the recovery rate of most indicators, the results of the third examination in the long-term period (6 months) showed that the athletes of the first group did not have any violations of the parameters of the respiratory function (RF) and cardiovascular system at rest, after performing CEL, as well as in the recovery period. The results suggest that the full resumption of training loads and participation in competitions are possible only with the complete normalization of the functional state of the cardiorespiratory system. The most informative indicators are: minute ventilation (V˙E), heart rate (HR), oxygen pulse (OP), and coefficient of oxygen utilization (COU).

Adding Yaw System to Improve Wind Energy Utilization of Offshore Wind Turbines

In wind power generation, the wind energy loss caused by yaw and other factors is as high as 50%, which directly leads to the difficulty of greatly improving The efficiency of wind power generating in producing electricity. The development of yaw control system restricts the progress of wind energy utilization, The purpose of this study is to investigate the application and influence of automatic steering of offshore wind turbines in practice. This paper proposes that the automatic yaw system of offshore wind turbine can improve the efficiency of wind power generation. The outcomes of the experiment demonstrate that the wind resources can be fully utilized and the power generation efficiency of the offshore fan can be improved by enabling the offshore fan to automatically turn according to the wind direction. The research has a certain value for the development of new energy power generation technology. In this paper, the method of Simulink simulation experiment is used to demonstrate that the yaw system can improve the wind energy utilization coefficient of offshore fan.

Innovative approaches to optimized cutting planning in the garment industry

The garment industry is responsible for large amounts of waste. The current line of making the industry sustainable imposes rethinking of all stages, from design to assembling. The research starts from the observation that the optimization of the cutting plan is resourceful regarding the reduction of waste. The paper proposes an original software dedicated to the planning of cutting. The markers for a given product, onto which are arranged one to four sizes are characterized by four parameters: coefficient of utility of fabric, total length of the fabric, number of layers and length of the marker. The use of the software is demonstrated for the product coat, to which the best marker is established. Numerical results show how variable the coefficient of utility can be, thus how important is the optimization of markers before cutting the fabric. For the product coat, whose patterns are long (the dimension along the length of the fabric is significantly bigger than the dimension along the width) the utility coefficient is optimized from 57% to 78%. Several observations (applying to all markers) are noticed regarding the shape of the patterns and the number of sizes on a marker. The software should be of interest to companies which assemble garment pieces. The mathematical model and logic applied within the software are validated using an experimental study on the product's dress and coat, to which the practical coefficients of utility are 75% and 87% respectively.

Value of people - human capital in Serbia through the prism of educational attainment of young population

Human capital is an important determinant of individual and overall socio-economic development. In addition to economic parameters, human capital is significantly influenced by the level of formal and informal education attained. Previous research in this area has focused on formal education and the skills acquired concerning better positioning in the labor market. Accordingly, the main objective of the conducted research is to determine the state and level of educational attainment as prerequisite for the developm ent of human capital in Serbia. This analysis is based on a set of indicators that represent the achieved educational attainment with special focus on the young population. It is conducted for the territory of Serbia, on municipal level, which enabled the categorization of municipalities according to educational attainment. Most municipalities in Serbia are characterized by insufficient educational attainment in the local context, or in general. For the purpose of the regional disparities identification, the coefficient of human capital utilization was created, in order to identify the mismatch between education attainment and labor market demand. The research shows that it is crucial to change the general perception of demographic problems and challenges, which will allow the development of applicable and more realistic public policies in the future.

Availability of behavioral health crisis care and associated changes in emergency department utilization.

To determine whether availability of behavioral health crisis care services is associated with changes in emergency department (ED) utilization. We used longitudinal panel data (2016-2021) on ED utilization from the Healthcare Cost and Utilization Project's State ED Databases and a novel dataset on crisis care services compiled using information from the Substance Abuse and Mental Health Services Administration's National Directories of Mental Health Treatment Facilities. A total of 1002 unique zip codes from Arizona, Florida, Kentucky, Maryland, and Wisconsin were included in our analyses. To estimate the effect of crisis care availability on ED utilization, we used a linear regression model with zip code and year fixed effects and standard errors accounting for clustering at the zip code-level. ED utilization related to mental, behavioral, and neurodevelopmental (MBD) disorders served as our primary outcome. We also examined pregnancy-related ED utilization as a nonequivalent dependent variable to assess residual bias in effect estimates. We extracted data on crisis care services offered by mental health treatment facilities (n = 14,726 facility-years) from the National Directories. MBD-related ED utilization was assessed by applying the Clinical Classification Software Refined from the Healthcare Cost and Utilization Project to the primary ICD-10-CM diagnosis code on each ED encounter (n = 101,360,483). All data were aggregated to the zip code-level (n = 6012 zip-years). The overall rate of MBD-related ED visits between 2016 and 2021 was 1610 annual visits per 100,000 population. Walk-in crisis stabilization services were associated with reduced MBD-related ED utilization (coefficient = -0.028, p = 0.009), but were not significantly associated with changes in pregnancy-related ED utilization. Walk-in crisis stabilization services were associated with reductions in MBD-related ED utilization. Decision-makers looking to reduce MBD-related ED utilization should consider increasing access to this promising alternative model.

Unravelling Elements of Value of Healthcare and Assessing their Importance Using Evidence from Two Discrete-Choice Experiments in England.

Health systems are moving towards value-based care, implementing new care models that allegedly aim beyond patient outcomes. Therefore, a policy and academic debate is underway regarding the definition of value in healthcare, the inclusion of costs in value metrics, and the importance of each value element. This study aimed to define healthcare value elements and assess their relative importance (RI) to the public in England. Using data from 26 semi-structured interviews and a literature review, and applying decision-theory axioms, we selected a comprehensive and applicable set of value-based elements. Their RI was determined using two discrete choice experiments (DCEs) based on Bayesian D-efficient DCE designs, with one DCE incorporating healthcare costs expressed as income tax rise. Respondent preferences were analysed using mixed logit models. Six value elements were identified: additional life-years, health-related quality of life, patient experience, target population size, equity, and cost. The DCE surveys were completed by 402 participants. All utility coefficients had the expected signs and were statistically significant (p<0.05). Additional life-years (25.3%; 95% confidence interval [CI] 22.5-28.6%) and patient experience (25.2%; 95% CI 21.6-28.9%) received the highest RI, followed by target population size (22.4%; 95% CI 19.1-25.6%) and quality of life (17.6%; 95% CI 15.0-20.3%). Equity had the lowest RI (9.6%; 95% CI 6.4-12.1%), decreasing by 8.8 percentage points with cost inclusion. A similar reduction was observed in the RI of quality of life when cost was included. The public prioritizes value elements not captured by conventional metrics, such as quality-adjusted life-years. Although cost inclusion did not alter the preference ranking, its inclusion in the value metric warrants careful consideration.

Improved digestibility of black gram leaf meal based diets for rohu (Labeo rohita) with supplementation of exogenous enzyme cocktail

Leaf meal is currently the most cost-effective source of protein and energy for use as a supplement in fish feed. The drawback associated with integrating it into the fish diet pertains to the presence of anti-nutritional elements that must be eliminated through a viable approach such as the addition of exogenous enzymes for achieving optimal fish production. Consequently, a 60-day feeding trial was conducted to evaluate the black gram leaf meal (BGLM) as a potential ingredient to replace de-oiled rice bran (DORB) in the diet of Labeo rohita juveniles and reported for the first time. Three hundred acclimatized juveniles (average weight 11 ± 0.09 g) were allocated randomly into ten treatment groups in triplicate. Ten iso-nitrogenous (32 %) and iso-lipidic (6 %) diets were made with varying degrees of BGLM inclusion by gradually replacing DORB without or with exogenous enzyme mixture (E) of protease, xylanase, and phytase at a ratio of 1:1:1 viz. Control (40 % DORB, 0 % BGLM), BG10 (30 % DORB, 10 % BGLM), BG20 (20 % DORB, 20 % BGLM), BG30 (10 % DORB, 30 % BGLM), BG40 (0 % DORB, 40 % BGLM) & CE (C + 0.1 % E), BG10E (BG10 + 0.1 % E), BG20E (BG20 + 0.1 % E), BG30E (BG30 + 0.1 % E), BG40E (BG40 + 0.1 % E) were prepared. Fish fed with BG20E diet exhibited maximum growth rates, nutrient utilization and digestibility co-efficient of the diet (P<0.05) however these were similar in C+E treatment (P>0.05). Inclusion of 20 % or more BGLM without enzyme cocktail significantly (P<0.05) decreased the nutrient utilization and growth performance of L. rohita. The dry matter and nutrient digestibility of the experimental diet were significantly decreased (P<0.05) with the inclusion of 20 % or more BGLM in place of DORB, however supplementation of exogenous enzyme cocktail significantly increase (P<0.05) the digestibility and highest was recorded in BG20E. The present study concluded that supplementation of exogenous enzyme cocktail (protease, xylanase, and phytase) increase the digestibility of BGLM and increases its inclusion level up to 30 % in the diet of L. rohita, however, 20 % BGLM supplemented with enzyme cocktail registered the best growth, nutrient utilization and digestibility coefficient of the diet.

Study on the Appropriate Degree of Water-Saving Measures in Arid Irrigated Areas Considering Groundwater Level

Irrigated areas are major vectors of agricultural development and components of ecosystems. The groundwater level maintains the irrigated areas’ ecology safety and sustainable development. Under the influence of irrational irrigation practices—such as flood irrigation or extreme water saving without consideration of ecological impact—different areas within an irrigation district may experience anomalies in groundwater levels (either too deep or too shallow). It is of great significance to carry out research on water resource allocation and future water-saving strategies, taking into consideration groundwater depths. In this study, a method for the optimal allocation of irrigation water resources that considered groundwater level was used to regulate irrational irrigation practices and to reveal the future direction of water saving. Helan County in Ningxia province, an ecologically fragile and arid irrigated area, was selected as a case study. Multiple scenarios of different water use and different degrees of water-saving were analyzed. The results showed that non-engineering water-saving measures (such as adjusting the planting structure and controlling the amount of irrigation for rice) had better benefits compared to engineering measures (such as efficient water-saving irrigation and channel lining). When implementing only one water-saving measure, the strategy of replacing 75% of the rice area with corn yielded the best results. This approach can reduce the irrigation water shortage rate to 11% and increase by 4.58% the acreage where the groundwater level is reasonable. When multiple water-saving measures are implemented together, the most effective strategy for future water-saving efforts involves the joint implementation of several measures: replacing 75% of the rice area with corn, limiting irrigation for rice to no more than 11.85 thousand m3/ha, adopting high-efficiency water-saving irrigation in 90% of the pump-diverted water irrigation region and 40% of the channel-diverted water irrigation region, and maintaining the channel’s water utilization coefficient at 0.62. This strategy can keep the irrigation water shortage below 3.66% and increase the acreage where the groundwater level is reasonable, by 4.58% per year. The conclusions and research approaches can provide references for the formulation of water-saving measures for irrigated areas’ sustainable development.

EFFECTS OF FERTILIZATION REGIMENS ON THE FRUIT YIELD AND QUALITY OF CUCUMBER CULTIVAR ‘DZHERELO’

Abstract. This is research relevant because the effects of different fertilization regimens on the fruit yield and quality of cucumber cv. ‘Dzherelo’ grown in an irrigated vegetable–forage rotation in the Left–Bank Forest–Steppe of Ukraine have been studied. Purpose: to evaluate the effects of different ways of optimizing nutrition regimens on the fruit yield and quality of cucumber cv. ‘Dzherelo’. Methods. Field, computational and statistical. Results. The effects of different fertilization regimens have been studied: mineral, organic, organic–mineral, resource–saving (local mineral fertilization), and complex with a calculated dose of mineral fertilizers and trace elements (foliar fertilizing with Reakom – R – cucumbers). The most effective fertilization regimens increasing the fruit yield and quality of cucumber cv. ‘Dzherelo’ grown in an irrigated vegetable–forage rotation have been selected. The nitrate content in cucumbers was shown to increase to 89.0–93.4 mg/kg of fresh weight after mineral fertilization, which was higher than the nitrate content after the other tested fertilization regimens but did not exceed the maximum permissible level of nitrates in outdoor–grown fresh cucumbers (MPL = 150 mg/kg). Conclusions. It was found that N, P and K from fertilizers were the most effectively absorbed by cucumber plants with broadcast mineral fertilizer at N90P60K60. In this variant, the utilization coefficients were as follows: nitrogen – 54%, phosphorus – 18.8%, and potassium – 51.8%. High yields (20.3 and 18.3 t/ha), marketability (87.7 and 88.0%) and fruit quality (dry matter content = 4.32–4.66%; total sugar content = 2.28–2 .35%; vitamin C content = 11.93–12.47 mg/100 g; nitrate content = 82.6–89.0 mg/kg) were recorded when cucumber cv. ‘Dzherelo’ was fertilized with broadcast mineral fertilizers at N200P210K200 with additional foliar fertilization with Reakom – R – cucumbers complex fertilizer or fertilized with organic–mineral fertilizers (66 t/ha of manure + broadcast N90P60K60), respectively.

Исследование математической модели объемного гидропривода с релейным управлением применительно к грузовой лебедке крана

The known variants of volumetric hydraulic drives of lifting and technological mechanisms are considered and analyzed. The areas of application of pumping and accumulator hydraulic drives, with various types of regulation, and options for their implementation as drives of a cargo winch of a bridge crane are considered. It is shown that the operation of the volumetric hydraulic drives of the cargo winch, along with volumetric and throttle control, can be performed by a relay method. It is noted that the cyclical operation of lifting mechanisms during lifting and lowering of cargo allows for mechanical and hydraulic energy recovery within the working cycle, which is a promising way to significantly increase the efficiency of their work. The analysis of the existing designs of hydraulic drives of technological machines, allowing to recover the potential energy of working bodies with cargo, is carried out. It is proposed as an alternative to the known hydraulic drives of the cargo winch of the bridge crane, a hydraulic drive with relay control. The efficiency of such a drive is shown, according to the indicators of the nominal pressure utilization coefficient and the energy intensity of the working fluid, in the case of the implementation of mechanical and hydraulic energy recovery in the working cycle in it. The mechanical and hydraulic circuits of such a drive are examined. An algorithm of mathematical model of its operation with consideration of different phases of cargo movement is proposed and its investigation is carried out. The possibility of fulfilling the safety conditions of operation of a hydraulic drive with relay control, in terms of ensuring the requirements for the uniformity of cargo movement, is analyzed.