https://khorezmscience.uz/ August - KhorezmScience.uz true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2434-thermionic-emission-properties-of-oxidized-hafnium-zirconium-titanium-and-niobium-in-a-barium-atom-flux.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, August Mon, 03 Aug 2026 22:13:00 +0500

THERMIONIC EMISSION PROPERTIES OF OXIDIZED HAFNIUM, ZIRCONIUM, TITANIUM, AND NIOBIUM IN A BARIUM ATOM FLUX

This paper investigates the thermionic emission and adsorption properties of oxidized transition metals (Hf, Zr, Ti, and Nb) exposed to a flux of barium atoms. The surface cleanliness and oxidation kinetics were monitored using Auger electron spectroscopy under ultra-high vacuum conditions. The experimental findings reveal that despite similar initial work functions of the clean metals, their interaction with oxygen and barium is fundamentally governed by the substrate crystal lattice symmetry. In metals with a hexagonal close-packed (hcp) crystal lattice (Hf, Zr, Ti), three-dimensional interstitial suboxides are formed, where oxygen is strongly bound within the bulk lattice, resulting in weak barium adsorption on the surface. Consequently, the work functions of the Hf–O–Ba and Zr–O–Ba systems remain significantly high at 3.10–3.20 eV, thereby suppressing the thermionic emission current density by roughly 10⁴ times comparedtouncoateddispenser cathodes. In contrast, for body-centered cubic (bcc) niobium, oxygen localizes at the surface, increasing the dipole moment and markedly lowering the work function. Based on these insights, thin films of hafnium and zirconium are recommended as highly efficient anti-emission coatings operating at 1100–1300 K.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2433-investigation-of-plasma-characteristics-produced-on-a-binary-sodium-chloride-surface.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, August Mon, 03 Aug 2026 22:12:00 +0500

INVESTIGATION OF PLASMA CHARACTERISTICS PRODUCED ON A BINARY SODIUM CHLORIDE SURFACE

The present study examines the plasma produced when a solid NaCl sample is exposed to pulsed Nd:YAG laser radiation. Measurements were performed at a vacuum pressure of 10⁻² Torr with a 1064 nmlaser pulselasting20ns. Emission spectral were used to evaluate two principal plasma quantities: electron density and electron temperature. The electron density was obtained from Stark broadening of selected spectral lines, whereas the temperature was derived from a Boltzmann plot. The resulting values were subsequently used to estimate several additional plasma characteristics.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2432-nonthermal-plasma-application-to-hydrogen-production.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, August Mon, 03 Aug 2026 22:11:00 +0500

NONTHERMAL PLASMA APPLICATION TO HYDROGEN PRODUCTION

Nonthermal plasma (NTP) is being investigated as an electrically driven route for hydrogen production because energetic electrons can activate methane, water vapour and carbon dioxide without requiring the entire gas phase to reach thermochemical equilibrium. This article compares dielectric barrier discharge (DBD), gliding arc and microwave plasma systems, with particular attention to methane conversion, hydrogen yield and electrical energy demand. Published experimental results were evaluated using a common set of indicators: feed conversion, H₂ yield/selectivity, specific energy input and hydrogenenergyyield. The literature shows that reactor type and operating regime strongly determine performance. DBD is attractive for plasma-catalyst integration, gliding arc can provide high conversion at relatively favourable energy input, and microwave systems have demonstrated high-throughput hydrogen production. Catalyst addition can enhance conversion, but the gain in methane conversion does not necessarily translate proportionally into H₂ yield. The analysisthereforeidentifies energy efficiency, plasma-catalyst interaction, scale-up and product separation as the principal engineering constraints. The most promising development route is the integration of optimized discharge conditions, selective catalysts and low-carbon electricity.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2431-investigation-of-scattering-ne-and-ar-ions-from-black-phosphorine-at-the-glancing-incidence.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, August Mon, 03 Aug 2026 22:10:00 +0500

INVESTIGATION OF SCATTERING Ne+ AND Ar+ IONS FROM BLACK PHOSPHORINE AT THE GLANCING INCIDENCE

In this paper, the scattering process of Ne+ and Ar+ ions bombarding the surface of black phosphorene at grazing (small) angles is computer-simulated using the binary collision approximation method. The characteristic trajectories and energy spectra of the Ne+ and Ar+ ions scattered from this surface are calculated. The trajectories of the scattered ions revealed the presence of an armchair-like semichannel on the black phosphorene surface. Two intense peaks were initially observed in the obtained energy spectra; they were found to correspond to the ions scattered from the surface atomic layer and the bottom of the semichannel. An increase in the angle of incidence led to ion scattering from neighboring semichannels, and peaks with low intensity corresponding to them were observed. The obtained results allow for the characterization of the surface layer and its structure.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2430-analysis-of-fluid-temperature-changes-during-discharge-in-heat-accumulators-and-validation-of-the-mathematical-model.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, August Mon, 03 Aug 2026 22:09:00 +0500

ANALYSIS OF FLUID TEMPERATURE CHANGES DURING DISCHARGE IN HEAT ACCUMULATORS AND VALIDATION OF THE MATHEMATICAL MODEL

Among heat accumulators, hot water storage tanks are the most widely used due to their low cost, simplicity, and ease of operation, as well as their low environmental impact. The temperature distribution within a hot water storage tank is a key factor governing the thermal behavior and hot water delivery performance of the system. This distribution is influenced by a number of operating and design parameters. These include the water inlet flow rate, inlet temperature, initial temperature of the water inside the storage tank, tank geometry, the tank diameter-to-height ratio, and the locations and arrangement of the inlet and outlet pipes. Variations in these parameters can significantly affect the temperature stratification and, consequently, the thermal performance of the hot water storage tank. The dependence of the efficiency of hot water storage tanks on many such parameters increases the importance of using mathematical modeling and numerical simulations. In the present study, a one-dimensional mathematical model was established to describe the thermal behavior of a hot water storage tank and subsequently validated against experimental data. The comparison between the numerical predictions and experimental measurements yielded anRMSEof1.85 °C, while the coefficient of determination was calculated as ܴ²=0.94, demonstrating a strong agreement between the model results and experimental observations. The analysis also showed that the storage tank could be completely discharged within 1980 s, equivalent to 33 min.

]]> true https://khorezmscience.uz/actual-problems-of-mathematics-physics-and-mecanics/2429-a-comprehensive-study-of-the-structure-morphology-and-work-function-of-moo-thin-films-depositedbymagnetronsputtering.html Bunyod Actual problems of Mathematics, Physics and Mecanics, 2026, August Mon, 03 Aug 2026 22:08:00 +0500

A COMPREHENSIVE STUDY OF THE STRUCTURE, MORPHOLOGY, AND WORK FUNCTION OF MoO₃ THIN FILMS DEPOSITEDBYMAGNETRONSPUTTERING

In this study, the phase composition, surface morphology, and work function of molybdenum oxide (MoO₃) thin films deposited on siliconsubstratesby magnetron sputtering were comprehensively investigated. X-ray diffraction (XRD) analysis revealed that the films exhibited an amorphous structure. The film thickness was independently verified using two methods: a quartz crystal microbalance and reflectometry in the 2θ/θ geometry. Atomic force microscopy (AFM) demonstrated that the films formed a continuous coating over an area of 5×5 μm, with a surface roughness not exceeding 2 nm. Ultraviolet photoelectron spectroscopy (UPS) measurements showed that the work function was 5.8±0.2eV,remaining nearly unchanged for films with thicknesses of 10, 30, and150nm. Theobtained results indicate that amorphous, smooth MoO₃ films withahighworkfunction are promising as hole-injection layers in organic electronic devices.

]]> true https://khorezmscience.uz/actual-problems-in-modern-agriculture/2428-effect-of-mineral-fertilizer-rates-on-the-growth-grain-yield-and-economic-efficiency-of-sorghum.html Bunyod Actual problems in modern agriculture, 2026, August Mon, 03 Aug 2026 22:07:00 +0500

EFFECT OF MINERAL FERTILIZER RATES ON THE GROWTH, GRAIN YIELD, AND ECONOMIC EFFICIENCY OF SORGHUM

This study evaluated the effects of mineral fertilizer rates on the leaf area index, grain yield, and economic efficiency of the “Daulet” sorghum cultivar. The highest leaf area index of 5.21 m²/m² was recorded with N240P140K120 kg/ha. However, the highest grain yield of 6.12 t/ha, net profit of 18 131 380 UZS/ha, and profitability of 108.12% were obtained with N200P120K100 kg/ha. Therefore, this fertilizer rate was identified as the most agronomically and economically efficient treatment.

]]> true https://khorezmscience.uz/actual-problems-of-natural-sciences/2427-synthesis-and-single-crystal-x-ray-diffraction-study-of-a-copperii-complex-with-2-amino-5-ethylthio-134-thiadiazole-and-110-phenanthroline.html Bunyod Actual problems of Natural Sciences, 2026, August Mon, 03 Aug 2026 22:06:00 +0500

SYNTHESIS AND SINGLE-CRYSTAL X-RAY DIFFRACTION STUDY OF A COPPER(II) COMPLEX WITH 2-AMINO-5-ETHYLTHIO-1,3,4-THIADIAZOLE AND 1,10-PHENANTHROLINE

This paper presents the results on the synthesis and study of the structure of a new mononuclear complex of copper nitrate with 2-amino-5-ethylthio-1,3,4-thiadiazole and 1,10-phenanthroline. Using the method X-ray diffraction analysis, the structure of the complex was studied. It was shown that copper (II) nitrate forms a five-coordinated complex with a distorted tetragonal pyramidal structure with 2-amino-5-ethylthio-1,3,4-thiadiazole and 1,10-phenanthroline molecules, in the inner sphere of which three thiadiazole ligands and an 1,10-phenanthroline molecules are coordinated to the complexing agent; thiadiazole ligands are bonded as a monodentate through endocyclic nitrogen, the 1,10-phenanthroline is bonded as a bidentate, the nitrate anions are located in the outer sphere forming a cationic complex.

]]> true https://khorezmscience.uz/actual-problems-of-history-philosophy-and-sociology/2426-transformation-of-print-media-in-navoi-region-historical-stages-and-development-trends-1992-2025.html Bunyod Actual problems of history, philosophy and sociology, 2026, August Mon, 03 Aug 2026 22:05:00 +0500

TRANSFORMATION OF PRINT MEDIA IN NAVOI REGION: HISTORICAL STAGES AND DEVELOPMENT TRENDS (1992-2025)

This article examines the historical transformation of print media in Navoi Region between 1992 and 2025. Drawing on archival materials, localperiodicals, statistical data, and relevant historical sources, the study identifies the main stages in the development of the regional press. Particular attention is paid to changes in the number and circulation of print publications, their institutional development, material and technical modernization, and adaptation to changing socio-economic conditions. The article also analyzes the impact of digital technologies on local newspapers and highlights the gradual integration of print and digital forms of media within the regional information environment.

]]> true https://khorezmscience.uz/actual-problems-of-history-philosophy-and-sociology/2425-the-philosophy-of-intellectualism-a-philosophical-interpretation-of-reason-knowledge-and-human-perfection.html Bunyod Actual problems of history, philosophy and sociology, 2026, August Mon, 03 Aug 2026 22:04:00 +0500

THE PHILOSOPHY OF INTELLECTUALISM: A PHILOSOPHICAL INTERPRETATION OF REASON, KNOWLEDGE AND HUMAN PERFECTION

The article interprets intellectualism as a philosophical position that gives reason and knowledge the leading place in the human comprehension of being, and traces its formation, its conceptual structure and its present-day meaning. The problem is posed in a situation where cognition suffers from the excess of information rather than its scarcity, so that what matters philosophically is not how much a person knows but how knowledge is appropriated, examined and used. The study draws on the primary texts of Plato, Aristotle, al-Farabi, Ibn Sina, Descartes, Leibniz, Kant and Popper, using historical-philosophical reconstruction, comparative analysis, conceptual delimitation and hermeneutic interpretation. It is established that intellectualism is not erudition: it consists in the conscious assimilation of knowledge, the demand for grounds, critical examination and readiness to revise conclusions.

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