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The quality of the fiber in the lines of medium staple cotton in 2018-2020 was assessed. in Tashkent, Fergana and Kashkadarya regions of the Republic of Uzbekistan. 10 lines of different genetic origin were tested. The influence of the genotype and the environment on the manifestation of the qualitative parameters of the fiber (length, specific breaking load, micronaire) was studied. As a result of three years of experiments, it was found that the length of the fiber is equally affected by both the genotype and the environment (up to 40%). The genotype significantly affects the specific breaking load of the fiber (68%). The variability of the micronaire fiber was more dependent on the genotype from 35 to 48.4%, the contribution of the environment was from 2.6 to 16%.

The article presents the results of many years of research with the aim of creating eggplant varieties and hybrids with early valuable economic traits and traits resistant to root-knot nematode. In the breeding nursery, 3 second-generation eggplant hybrids (F2), obtained as a result of generational research in 2005-2013, were studied. The lines were characterized by growth period, early ripening, fruit weight, shape, color, plant type, etc. At the end of the growing season, the lines were dug up, assessed for damage by root nematodes and selected for the root system. As a result of the research, 16 early ripening lines were identified with high productivity and quality of fruits, resistant to nematodes and other economically valuable traits. In particular, the early, high-yielding, nematode-resistant line L-32-3 was transferred to the State Variety Test in 2021 under the name Globus variety.

Reference evapotranspiration is one of the main geophysical parameters, the reliable assessment of which is important in irrigation water management, planning, distribution and regulation of water resources. The Food and Agriculture Organization of the United Nations recommends using the Penman-Monteith formula to estimate ETo. However, its’ application by end-users is limited since the formula requires several parameters which are often missing. In such cases, it recommends the Hagreaves-Samani formula. In this study, the reference evapotranspiration is estimated as the case study for Uzbekistan applying both, the Penman - Monteith and the Hargreaves - Samani methods. Data used is taken from 13 state climate stations of Uzbekistan. The results of the study indicate that under data-scarce conditions, the Hargreaves – Samani formula, can be recommended for end-user applications, after the adjustment to local conditions, in order to determine the water requirements of crops and irrigation scheduling.

As urbanization accelerates, it is crucial to assess how green spaces contribute to ecological balance and sustainability. This study aims to quantify the impact of urban green spaces on local biodiversity and ecosystem functions. By evaluating various green space types and their contributions to urban ecosystems, we seek to provide actionable insights for sustainable urban planning. We conducted a comprehensive analysis of urban green spaces across several cities, employing a combination of field surveys, remote sensing data, and ecological modeling. Metrics such as species diversity, habitat quality, and ecosystem services were assessed to determine the effectiveness of different green space configurations. Our findings indicate that diverse green space types, including parks, green roofs, and urban forests, significantly enhance biodiversity and ecosystem functions. Key metrics showed increased species richness and improved ecological services such as air purification and temperature regulation. Quantitative data revealed that larger and more varied green spaces tend to have more substantial ecological benefits. The study underscores the importance of integrating diverse and well-planned green spaces into urban environments to promote biodiversity and support essential ecosystem functions. These findings highlight the need for urban planners to prioritize green space development as a strategy for sustainable urban growth and environmental resilience.

This scientific article examines the problem of calculating an elementary section of a gas pipeline operating in a periodic mode, with mass flow at the inlet and pressure at the outlet. The relationship between changes in gas mass flow in the receiver and pipeline according to boundary conditions has been developed; the receiver is installed at the entrance to the pipeline. When modeling the system under study, we use linearized quasione-dimensional equations of state of real gas in a gas pipeline. In the works of I.A. Charny, a similar condition was constructed, but at the outlet of the gas pipeline, and the problem itself was formulated in relation to pressure. In our case, the problem will be formulated with respect to mass flow. For the problem under consideration, a system of equations regarding gas mass flow was used. The solution to the problem is sought in the form of a sum of stationary and periodic parts. Thus, a solution to the problem of propagation of a unit amplitude of the input disturbance of the gas mass flow rate relative to the mass flow rate has been obtained.

One of the reasons hindering potato farming development on Uzbekistan's farms is the low supply of inexpensive mini-production equipment for harvesting potatoes. The use of high-performance potato harvesters in small areas is uneconomical. The authors proposed a potato digger with a digging working body of the "Paraplaw" type. The study aims to develop a potato digger with working bodies of the "Paraplaw" type. A prototype of a mini potato harvester was made, and its economic tests were carried out. The basic principles and methods of classical mechanics, mathematical analysis, and statistics were used in this study. The developed digging work part is made in the form of rippers with inclined racks installed towards each other, and their chisels are equipped with ripping elements in the form of rods. The results of the digger tests have been given. It was found that during the operation of the improved potato digger, tuber losses were reduced by 2.9%, and productivity increased by 13.2% compared to the serial one.

The process of digging potatoes is characterized by high energy costs due to the interaction of the potato digger's plowshares with the tuber-bearing soil layer. The study aims to substantiate the parameters of potato digger's lattice plowshare. In the proposed potato digger, the plowshare is made latticed and equipped with oscillating rods. This potato digger has a mechanism for transmitting torque to oscillating rods. The experiments were carried out using a special laboratory-field installation. Various lattice plowshares were manufactured, and single-factor experiments were carried out. During the experiments, the degree of damage and loss of the tuber and the traction resistance potato digger were taken as evaluation criteria. The results of experimental studies to determine the parameters of plowshare are presented. It is established that the optimal design scheme for a potato digger consists of torque transmission mechanisms, lattice plowshares, and forcibly oscillating rods. As a result, theoretical studies, analytical dependencies, and mathematical models were obtained to determine the parameters of a lattice plowshare. Studies have established that to destroy the tuber formation to the required extent with minimal damage and loss of tuber, as well as energy costs, the width lattice plowshare should be 55 cm, the angle plowshare installation relative to the horizon is 22°, the length plowshare is 38 cm, and the width gap between the bars is 3 cm.

The main content of this article is the reduction of safety problems and risks in civil engineering from the point of view of science in civil engineering. The technology of protecting buildings and structures from corrosion and thermal effects on metal structures requires an increase in the corrosion resistance of structures.

Currently, potato diggers used in agricultural production in Uzbekistan have a number serious drawbacks. In particular, they have a high material and energy capacity, and their use in small farms and personal subsidiary farms is considered less effective. The purpose study is to substantiate the parameters vibrating rods potato digger ploughshare. The authors proposed a potato digger with lattice ploughshares equipped with vibrating rods. Swinging rods are attached to the main ploughshares, the oscillation which is carried out from the tractor power take-off shaft. A diagram a ploughshare with vibrating rods and a mechanism for transmitting motion is given. The laws theoretical mechanics are used in the research. In the experiments, losses and damage to potatoes, as well as traction resistance, were taken as a criterion for evaluating the performance potato digger. As a result theoretical studies carried out, analytical dependencies and mathematical models were obtained that allow determining the parameters rods. It is proved that the length bars the potato digger ploughshare should be 25 cm, the number bars is 14 pieces, the distance between the bars is 3 cm, the diameter the bars is 1 cm.

This article analyzes the issue of organizing students' self-study, which is one of the urgent problems of the credit-modular system. The student independently discusses in detail what to pay attention to in order to solve an engineering problem using information and communication technologies using differential equations with special derivatives of hyperbolic type. It is stated that the initial-boundary value problem of the process is solved by the Fourier method. The construction of a decision graph using the Maple system is explained. The student's attention is focused on the analysis of the results based on the nature of the considered engineering problem.

High-frequency limiting rectifier diodes are used in power sources for rectifying alternating current, in protective elements of radio-electronic equipment, and in switching devices. They are the basis of energy-saving devices, meeting the high requirements for power limit and performance. The main task in the manufacturing process of high-frequency diodes is to ensure the low leakage current and the optimum value of the forward voltage drop which can be compared with the contact potential difference of the p–n junction. This paper is devoted to studying the effect of radiation exposure and subsequent heat treatment on the current-voltage and capacitance characteristics of high-frequency silicon diodes.The authors studied p+–p–n–n+ diodes made of n-type KEF-4 (КЭФ-4) silicon wafers with an initial thickness of 235 μm. Radiation processing was performed using an ELU-6 (ЭЛУ-6) linear electron accelerator. The integral flux of "fast" electrons ranged from 1,0·1015 to 2,6·1017 cm–2, energy was 1.5 MeV, density was 1,7·1011 — 5,5·1013 cm–2·s–1. Heat treatment was performed for 5 hours at a temperature of 90°C in a special chamber. The studies have shown that heat treatment lead to a shift of the forward current-voltage characteristic to a region of lower voltages (i.e., a given current can be reached at a lower voltage); at low current values, however, the voltage drop may increase after heat treatment. Reverse current decreased fivefold, resulting in a decrease in power output. At the same time, the temporal characteristics of the diode could also be improved by reducing the capacitance (to one order of magnitude).

The study examines possible water savings by replacing alfalfa with winter wheat in the Fergana Valley, located upstream of the Syrdarya River in Central Asia. Agricultural reforms since the 1990s have promoted this change in cropping patterns in the Central Asian states to enhance food security and social benefits. The water use of alfalfa, winter wheat/fallow, and winter wheat/green gram (double cropping) systems is compared for high-deficit, low-deficit, and full irrigation scenarios using hydrological modeling with the HYDRUS-1D software package. Modeling results indicate that replacing alfalfa with winter wheat in the Fergana Valley released significant water resources, mainly by reducing productive crop transpiration when abandoning alfalfa in favor of alternative cropping systems. However, the winter wheat/fallow cropping system caused high evaporation losses from fallow land after harvesting of winter wheat. Double cropping (i.e., the cultivation of green gram as a short duration summer crop after winter wheat harvesting) reduced evaporation losses, enhanced crop output and hence food security, while generating water savings that make more water available for other productive uses. Beyond water savings, this paper also discusses the economic and social gains that double cropping produces for the public within a broader developmental context.

The work is devoted to the study of physical features of electronic processes taking place in the space charge region and in the base region of arsenide-gallium three-barrier photodiode structures with the effect of locking two adjacent transitions. The structures have high photosensitivity in the «impurity» region of the spectrum at both inclusion polarities. The obtained results suggest that such structures can be used in optical communication systems. The study allowed showing that a three-barrier photodiode m1—p-GaAs—n-GaAs—m2-structure with a high quantum efficiency can exceed 8 times the photosensitivity of a photodiode as compared to a photodiode with a single p—n junction. In the m1—p-GaAs—n-GaAs—m2 photodiode structure, the maximum photosensitivity is achieved in the impurity region of the spectrum (above 1.0 μm) when excitation of nonequilibrium current carriers through the barrier to the semiconductor, in contrast to the intrinsic spectral region (0.86 μm). It has been shown experimentally that the photosensitivity of the structure in the direct-displacement mode of the p-n junction is larger, compared with the locking mode, and the maximum photosensitivity is achieved in the impurity region of the spectrum. That is, the impurity levels of oxygen present in the base region take part in the separation of the photocarriers. The dependence of the current on the voltage is described by a power function with an exponent of 0.5 corresponding to the generation-recombination process in the space-charge region of the p-n junction.

The article presents an economic analysis of the state of municipal waste generation, utilization and recycling in the countries of the European Union and the Russian Federation. As a basis for the analysis, we used data on the 20 most representative countries that make a significant contribution to the formation of the main macroeconomic indicators of the EU. The results of the implementation of the EU environmental policy, the degree of reflection on the volume of trade in secondary raw materials, private investment in this sector, employment in the processing and recycling sectors, etc. are considered. In addition, a correlation analysis was carried out, which allowed us to determine the degree of dependence of waste disposal and recycling on various indicators, to identify the most significant of them and the main factor affecting the effectiveness of the country’s environmental policy.

In recent years, transmission and reception systems of optical signals are widely used. Receiving the optical signal in such systems is carried by photoreceiving modules based on a photodetector, which defines the quality of the received signal, the range and speed of the entire system. However, hitherto used p–i–n- and avalanche photodiodes do not fully meet the growing demands. The present work is devoted to investigate the photovoltaic characteristics of semiconductor thin base transistor structure based on germanium, which is superior the silicon counterparts by speed and gain. Investigated p+–n–p-structures were obtained by diffusion of antimony onto the substrate of p-type germanium to a depth of 1 micron and alloying of indium to the part of its surface which creates diffusion layer of ?+-type and with thickness of 0,5 microns. Experiments have shown that the reverse biasing of a single p+-n-emitter-base junction leads to a smooth increase in reverse current, at the same time when it is connected in series to forward biased collector p-n-junction there is a sharp increase in the current by voltage, giving properties of voltage surge suppressor. This behavior of the current-voltage characteristics can be explained by the punch-through effect when the space charge regions of the emitter junction and the space charge region of collector junction touch each other and the conditions are realized for double carrier injection into a fully depleted region of the transistor. At the same time giving small fixed voltages 0,1—0,15 V to the collector-base junction the output static characteristics can be received with an operating voltage of 3—3,5 V. A characteristic feature of the investigated transistor is that when the base region under illumination by integrated light intensity (50 and 3000 lux) light current appears, whose magnitude with the increase of operating voltage (up to 1.7 V) increases nonlinearly, resulting in increased current photosensitivity up to 17 µA/lux, which is one and a half orders of magnitude greater than photosensitivity of germanium phototransistor “OOA-5”.

Methyl groups are ubiquitous in natural products and biologically active compounds, but methods for their selective transformation in such structures are limited. For example, terpenoids contain many methyl groups, due to their biosynthetic pathways, but few reactions of these groups in such structures have been reported. We demonstrate that the combination of methyl C-H silylation and oxidation proximal to native hydroxyl or carbonyl groups occurs in a range of terpenoids and show that the installed hydroxyl group serves as a toehold to enable substitution, elimination, or integration of the methyl carbon into the terpenoid skeleton by the cleavage of C-C bonds. In one case, substitution of the entire methyl group occurs by further oxidation and decarboxylative coupling. In a second, substitution of the methyl group with hydrogen occurs by photochemical hydrodecarboxylation or epimerization by retro-Claisen condensation. In a third, photocatalytic decarboxyolefination formally eliminates methane from the starting structure to generate a terminal olefin for further transformations. Finally, a Dowd-Beckwith-type rearrangement cleaves a nearby C-C bond and integrates the methyl group into a ring, forming derivatives with unusual and difficult-to-access expanded rings. This strategy to transform a methyl group into a synthon marks a distinct approach to restructuring the skeletons of complex architectures and adding functional groups relevant to medicinal chemistry.

The authors propose the evaluation of the level of development of waste management and the factors associated with effectiveness of waste management in the world. Scientific novelty consists in new principle of the selection of factors. This principle based on the balance between the rate of waste generation and the efficiency of utilization, depending on income level in the countries. As a result, the factors affecting the effectiveness of waste management selected and classified by the method of expert evaluation. The algorithms has been proposed for calculate of the indicators of the intensity of waste generation, of the efficiency of utilization, of the balance of waste, of the overall efficiency of waste management. The evaluation of the effectiveness of waste management was applied by method of score of 217 countries of the world for 2018. The study found a correlation between the effectiveness of waste management and the country’s per capita income. This evaluation allows classifying countries on the level of per capita income and by the types of balance between the intensity of waste generation and the efficiency of waste utilization. On this basis the authors proposed to form a balanced policy of waste management.

Products of the polymer industry today are everywhere. They have penetrated both our daily life and the development of high-tech industries. In the current reality, new technologies are developing at a rapid pace and pose new challenges to the polymer industry. However, with the growth of production and consumption of plastics, the problem of recycling waste from the polymer industry has gradually become more acute. This article analyzes the production of plastics, their utilization and assesses the prospects for further development of the industry in developed countries. Separately, the issues of solving these problems in Europe are studied as a model of managing the recycling process and possible borrowing the experience for the Russian economy.

The results of the study of the composition and characteristics of high-ash brown coal of the Angren deposit, used in the power industry of the Republic of Uzbekistan are presented. A feature of this coal is the presence in the composition of the fuel of various clay rocks that fall during mechanized mining from the surrounding rocks. Dependencies have been determined showing the effect of the composition of the fuel and the parameters of its characteristics on mechanical, chemical and thermal processes, as well as on the chemical composition of brown coal ash.

Chronobiology and chronomedicine is a special part of biomedical sciences studying rhythmical patterns in physiological and pathological processes. In order to analyse probability of some pathology and to make forecasts concerning possibility of some diseases based on the signs of rhythmicity disorders it is necessary to perform continuous monitoring of different physiological functions for a certain period of time. Since 1984 until now we have had an excellent opportunity of studying biological rhythms and their disorders in animals using the method of radio-telemetric monitoring. A huge amount of continuous data obtained in telemetric monitoring could be used for mathematical modeling of different pathological processes on the basis of rhythmic patterns. In this work we have presented some preliminary results of the chronobiological study in which the effects of bright light on blood pressure and heart rate were investigated. The experiment was carried out on male rats of genetic strains: Wistar-Kyoto – normotensive rats and SHR – spontaneously hypertensive rats. The animals were exposed to 1 hour exposure of ∼ 10000 lux white LED light from 10.00 to 11.00 a.m. For the analysis of daily profiles of blood pressure and heart rate we used the method of radio-telemetric monitoring of blood pressure and heart rate. It was shown that systolic blood pressure significantly increased in both Wistar-Kyoto and SHR rats under the action of bright during the time of bright light exposure (from 10.00 to 11.00 a.m.) and within the whole daytime period. For SHR rats an increase in diastolic blood pressure during the period of bright light action was also typical. But there were no significant changes in heart rate in the animals of either strain. These results require further and more detailed chronobiological studies to provide additional evidence. However traditional statistical methods seem to be important but not sufficient for further investigations. Moreover we could lose a considerable part of data without using contemporary methods of computer and mathematical modeling.