https://khorezmscience.uz/ June - KhorezmScience.uz true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2379-impact-of-geometric-scaling-on-self-heating-effects-in-gaas-based-gate-all-around-field-effect-transistors.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, June Wed, 03 Jun 2026 22:13:00 +0500

IMPACT OF GEOMETRIC SCALING ON SELF-HEATING EFFECTS IN GaAs-BASED GATE-ALL-AROUND FIELD-EFFECT TRANSISTORS

As gate-all-around field-effect transistors (GAAFETs) are scaled toward sub-10 nm gate lengths and nanowire diameters, self-heating effects (SHE) become an increasingly dominant reliability and performance concern, particularly for high-mobility III–V channel materials such as GaAs whose thermal conductivity is roughly three times lower than that of silicon. This paper reviews recent literature on self-heating in GAAFET architectures, presents the device structure and the coupled electro-thermal simulation methodology used to analyze a GaAs-channel nanowire GAAFET, and discusses the qualitative and analytical trends of temperature rise as a function of gate length, nanowire diameter, and the number of vertically stacked channels. The results indicate that geometric scaling, while beneficial for electrostatic control and short-channel immunity, systematically increases the thermal resistance of the device and therefore the magnitude of self-heating, an effect that is significantly more pronounced in GaAs than in Si.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2378-change-in-the-width-of-the-volume-charge-field-of-pn-junction-diodes-under-the-influence-of-a-magnetic-field.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, June Wed, 03 Jun 2026 22:12:00 +0500

CHANGE IN THE WIDTH OF THE VOLUME CHARGE FIELD OF P–N JUNCTION DIODES UNDER THE INFLUENCE OF A MAGNETIC FIELD

In this article, the volt-ampere characteristic of p–n junction diodes under the influence of a magnetic field and the change in the volume charge field parameters were theoretically studied. That is, the effect of the electromotive force (EMF), the Lorentz force, and the change in the distribution of charge carriers generated under the influence of a magnetic field on the width of the volume charge field, diffusion current, diffusion capacitance, and volume capacitance of the p–n junction was analyzed based on a mathematical model. The calculation results showed that the mobility of charge carriers increased under the influence of a temperature gradient, and the Lorentz force changed their direction and spatial distribution under the influence of a magnetic field, resulting in a change in the diffusion and volume capacitances depending on the magnetic induction. Also, these processes were analyzed comparatively for homogeneous and heterogeneous semiconductors, and the importance of the magnetic field in controlling the electrical parameters of p–n junction diodes was theoretically substantiated.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2377-existence-and-uniqueness-of-solutions-to-a-first-boundary-value-problem-for-a-loaded-fractional-diffusion-equation.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, June Wed, 03 Jun 2026 22:11:00 +0500

EXISTENCE AND UNIQUENESS OF SOLUTIONS TO A FIRST BOUNDARY VALUE PROBLEM FOR A LOADED FRACTIONAL DIFFUSION EQUATION

The paper studies a first boundary value problem for a loaded diffusion equation involving the Riemann–Liouville fractional derivative. A loaded term depending on the integral of the unknown solution with respect to xxx is added to the right-hand side of the diffusion equation. Using the Green function, the problem is reduced to a Volterra–Fredholm type integral equation, and the solution is represented by the method of successive approximations.

]]> true https://khorezmscience.uz/actual-problems-in-modern-agriculture/2376-prospects-for-camel-wool-production-worldwide-and-uzbekistans-opportunities-in-this-sector.html Bunyod Actual problems in modern agriculture, 2026, June Wed, 03 Jun 2026 22:10:00 +0500

PROSPECTS FOR CAMEL WOOL PRODUCTION WORLDWIDE AND UZBEKISTAN’S OPPORTUNITIES IN THIS SECTOR

This article examines the current state of camel wool production and processing worldwide and evaluates the development potential of this sector in Uzbekistan. Camel wool is recognized as one of the most valuable natural fibers due to its excellent thermal insulation, softness, durability, lightweight structure, and hypoallergenic properties. As global demand for environmentally friendly textile materials continues to grow, camel wool has become an increasingly important raw material for the textile industry. The article analyzes the experience of leading camel wool-producing countries, including Mongolia, China, Kazakhstan, and Iran, with particular attention to production technologies, processing systems, and export opportunities. The research applies comparative analysis, statistical evaluation, and a review of scientific literature to assess the current situation and identify development prospects. The findings indicate that Uzbekistan possesses favorable climatic conditions, traditional camel breeding practices, and sufficient natural resources to expand camel wool production and establish value-added processing industries. The study concludes that improving processing technologies, increasing investment, and strengthening exportoriented production can significantly enhance the competitiveness of Uzbekistan’s textile sector and contribute to sustainable rural development.

]]> true https://khorezmscience.uz/actual-problems-in-modern-agriculture/2375-integrating-emi-multi-sensor-remote-sensing-and-machine-learning-for-high-resolution-diagnostics-of-soil-salinity-in-the-amu-darya-river-delta.html Bunyod Actual problems in modern agriculture, 2026, June Wed, 03 Jun 2026 22:09:00 +0500

INTEGRATING EMI, MULTI-SENSOR REMOTE SENSING, AND MACHINE LEARNING FOR HIGH-RESOLUTION DIAGNOSTICS OF SOIL SALINITY IN THE AMU DARYA RIVER DELTA

Soil salinity is a pervasive environmental stressor triggering land degradation in irrigated areas of arid regions, notably in the Aral Sea Basin of Central Asia. This study presents a high-resolution diagnostic approach to map soil apparent electrical conductivity (ECa) by integrating proximal Electromagnetic Induction (EMI) surveys with multi-sensor satellite imagery within the Google Earth Engine (GEE) platform. Using an EM38-MK2 sensor, we collected 21,396 in-situ ECa measurements across 526.4 ha of agricultural fields in the Khorezm region of Uzbekistan. These measurements were combined with multi-temporal Sentinel-2 (NDVI, NDWI, EVI), Sentinel-1 (VV, VH), and ALOS-2 PALSAR-2 (HH, HV) composites from the 2024 irrigation season. A Random Forest (RF) regression model was trained to predict ECa, with robust validation performance (R² = 0.925, RMSE = 4.27 dS/m). According to the analysis NDVI during critical crop growth stages and Sentinel-1 VH backscatter were found out as the most influential predictors, underlining the synergy between crop water stress and soil salinity. The classification of the resulting 20m resolution salinity map revealed that 69.3% of the studied area is affected by high to extreme salinity while 18.4% (96.4 ha) of the lands fall into the severe salinity category. Our findings demonstrate that the integration of multi-sensor remote sensing with dense EMI surveys provides a scalable, cost-effective framework for precise assessment of soil salinity, providing essential insights for sustainable land management in irrigated croplands.

]]> true https://khorezmscience.uz/actual-problems-of-natural-sciences/2374-synthesis-structural-characterization-and-analysis-of-the-coii-complex-with-2-hydroxybenzamide-and-monoethanolamine.html Bunyod Actual problems of Natural Sciences, 2026, June Wed, 03 Jun 2026 22:08:00 +0500

SYNTHESIS, STRUCTURAL CHARACTERIZATION, AND ANALYSIS OF THE Co(II) COMPLEX WITH 2-HYDROXYBENZAMIDE AND MONOETHANOLAMINE

This article presents the synthesis and physicochemical characterization of a mixed-ligand Co(II) complex with salicylamide and monoethanolamine (MEA) ligands. The complex was synthesized in an alcohol–water medium using a GT SONIC-D3 professional ultrasonic cleaner operating at a frequency of 40 kHz. The obtained product was characterized by Fouriertransform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), while its elemental composition was determined by X-ray fluorescence (XRF) analysis. FTIR results indicated that coordination to the Co(II) ion occurs through the oxygen and nitrogen donor atoms of the ligands. SEM analysis revealed a needle-like crystal morphology of the synthesized complex. XRF analysis confirmed the presence of cobalt in the complex structure. The obtained results demonstrate the formation of a stable mixed-ligand complex in the Co(II)–salicylamide–MEA system.

]]> true https://khorezmscience.uz/actual-problems-of-history-philosophy-and-sociology/2373-the-main-sectors-of-the-economy-of-the-khiva-khanate.html Bunyod Actual problems of history, philosophy and sociology, 2026, June Wed, 03 Jun 2026 22:07:00 +0500

THE MAIN SECTORS OF THE ECONOMY OF THE KHIVA KHANATE

In the history of Uzbek statehood and in the history of the Khiva Khanate at the end of the 18th and beginning of the 20th centuries, the role of trade and economic relations in the Khiva Khanate was incomparable and was considered a symbol of the power and antiquity of the khanate. The political and economic processes that took place in the history of the Khiva Khanate are the historical roots of today's economic developments. During the reign of the Kungrat dynasty, which came to power in the Khiva Khanate at the beginning of the 19th century, economic processes and relations were especially developed in the oasis.

]]> true https://khorezmscience.uz/actual-problems-in-modern-technical-sciences/2372-the-effect-of-grid-bar-grate-parameters-on-cotton-flow-dynamics-and-the-efficiency-of-large-impurity-separation.html Bunyod Actual problems in modern technical sciences, 2026, June Wed, 03 Jun 2026 22:06:00 +0500

THE EFFECT OF GRID BAR GRATE PARAMETERS ON COTTON FLOW DYNAMICS AND THE EFFICIENCY OF LARGE IMPURITY SEPARATION

This paper presents a theoretical investigation of the dynamics of a cotton tuft moving between a saw-toothed drum and a grid bar grate, as well as the process of large impurity separation. Analytical equations describing the velocity and travel distance of the cotton tuft along the surface of the grid bars were derived by considering the effects of gravitational, frictional, and periodic elastic forces. The influence of grid bar diameter, spacing between adjacent grid bars, contact wrap angle, and grate surface geometry on the cotton flow velocity was evaluated based on the law of conservation of mass. A mathematical model describing the variation of centrifugal force and impurity concentration along the grate arc was also developed. The calculation results show that increasing the wrap angle and the grid bar diameter reduces the cotton flow velocity, whereas increasing the spacing between the grid bars enhances the impact force. Although a smaller grid bar diameter increases the impact intensity and improves impurity removal, it also raises the risk of fiber damage. Conversely, a larger diameter provides a wider contact surface but reduces the impact effect. Based on the theoretical analysis, a grate configuration with a 15 mm grid bar diameter and30 mm spacing between adjacent grid bars was theoretically substantiated as the rational design, ensuring stable cotton flow, efficient separation of large impurities, and preservation of fiber quality.

]]> true https://khorezmscience.uz/actual-problems-in-modern-technical-sciences/2371-status-and-prospects-of-mineral-fertilizer-production-in-uzbekistan.html Bunyod Actual problems in modern technical sciences, 2026, June Wed, 03 Jun 2026 22:05:00 +0500

STATUS AND PROSPECTS OF MINERAL FERTILIZER PRODUCTION IN UZBEKISTAN

This article outlines the current condition of mineral fertilizers production in Uzbekistan, the demand for mineral fertilizers, and especially the role of local raw materials in the production of phosphorus fertilizers from the Central Kyzylkum Phosphorite.Especially, mineral fertilizers have the necessary characteristics in agriculture to obtain plenty of crops. In particular, it is necessary to produce complex fertilizers containing fresh phosphorus to meet the need for phosphorus fertilizers.

]]> true https://khorezmscience.uz/actual-problems-in-modern-technical-sciences/2370-parametric-study-of-cutting-speed-feed-rate-and-depth-of-cut-on-material-removal-rate-in-mild-steel-turning-operations.html Bunyod Actual problems in modern technical sciences, 2026, June Wed, 03 Jun 2026 22:04:00 +0500

PARAMETRIC STUDY OF CUTTING SPEED, FEED RATE, AND DEPTH OF CUT ON MATERIAL REMOVAL RATE IN MILD STEEL TURNING OPERATIONS

Metal cutting constitutes a cornerstone of modern manufacturing, and the systematic optimisation of cutting parameters is essential to ensure continuous advancement in the quality of engineered and fabricated products. The present work seeks to quantify the effects of key machining parameters — namely cutting speed, depth of cut, and feed rate — on the metal removal rate in mild steel cylindrical turning. Statistical analysis of the experimental data produced a mean value of 4.26 and a standard deviation of 2.31. The experimental data demonstrated that the metal removal rate exhibited considerable variability, directly attributable to the combined influence of the applied cutting parameters. The most significant variation in metal removal rate was induced by feed rate, which drove a steady and marked increase in material removal as its magnitude was progressively raised. A notable decline in MRR was subsequently observed, directly linked to the deterioration of the cutting tool edge during machining.

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