July - KhorezmScience.uz

DEPENDENCE OF SELF-HEATING AND SHORT-CHANNEL EFFECTS ON OXIDE MATERIALS IN A 2D MoS2 CHANNEL-BASED MOSFET

Bunyod — Fri, 03 Jul 2026 22:14:00 +0500

This study presents a comprehensive numerical investigation of the influence of gate oxide and buried oxide (BOX) materials on the electrothermal performance of two-dimensional MoS2-based metal–oxide–semiconductor (MOS) transistors. Particular attention is devoted to the analysis of the selfheating effect (SHE), subthreshold slope (SS), and drain-induced barrier lowering (DIBL), which are among the key performance-limiting factors in nanoscale devices. Al2O3 and HfO2 are considered as gate dielectric materials, while SiO2 and HfO2 are employed as buried oxide (BOX) materials. The dependences of the subthreshold slope and the lattice temperature at the channel center on the gate length are systematically evaluated for different combinations of gate oxide and BOX materials. A device structure with the channel fully covered by the gate dielectric is considered throughout the study. The simulation results demonstrate that the combination of an Al2O3 gate dielectric and a SiO2 BOX provides the lowest subthreshold slope, indicating superior electrostatic gate control. In contrast, employing HfO2 as both the gate dielectric and the BOX significantly mitigates the self-heating effect by improving thermal dissipation, thereby enhancing the thermal stability and reliability of the device. These findings provide valuable insights into dielectric engineering for the optimization of highperformance, low-power, and thermally reliable MoS2-based MOS transistors intended for future nanoelectronic applications.

OPTICAL AND ELECTRICAL ANALYSIS OF CIGS SOLAR CELLS ENHANCED WITH METALLIC NANORODS

Bunyod — Fri, 03 Jul 2026 22:13:00 +0500

In this study, we present a two-dimensional numerical analysis of thinfilm CIGS solar cells enhanced with surface-integrated metallic nanorods. Employing ANSYS Lumerical’s FDTD and CHARGE solvers, we evaluated the optical and electrical characteristics of cells with copper (Cu), gold (Au), and silver (Ag) nanorods relative to an un-patterned baseline. The device structure comprises an Al emitter (cathode), a ZnO transparent conducting oxide layer, a CdS buffer layer, a CIGS absorber layer, and an Al back contact (anode). The simulations demonstrate that plasmonic light scattering from the nanorods significantly enhances optical absorption and charge collection. Specifically, Cu nanorods outperformed all other designs, yielding a short-circuit current density of 17.4 mA/cm² and a power conversion efficiency of 17.8%, compared to baseline values of 7.2 mA/cm² and 7.4%. Consequently, surface-integrated plasmonic nanostructures demonstrate strong potential for advancing thin-film solar energy conversion.

SYNTHESIS AND STRUCTURE OF MIXED LIGAND COMPLEXES BASED ON AMIDE DERIVATIVES AND METAHYDROXOBENZOATE

Bunyod — Fri, 03 Jul 2026 22:12:00 +0500

In this work, the synthesis, structure, quantum chemical analysis, and spectroscopic properties of complex compounds [Co(C7H5O3)2(L1,2,3)2] (where L1-nicotinamide, L2-thiocarbamide, L3-acetamide) obtained on the basis of the divalent cobalt (Co(II)) ion with amide derivatives were studied. Mhydroxobenzoic acid (mgb) was used as the initial ligand. Quantum-chemical calculations of the complex compounds were analyzed, IR spectra were compared, and changes in the vibration frequencies of the ligands' functional groups were recorded.

METHODS FOR PROTEIN EXTRACTION FROM ARTEMIA BIOMASS AND THEIR PRACTICAL SIGNIFICANCE: A LITERATURE-BASED REVIEW

Bunyod — Fri, 03 Jul 2026 22:11:00 +0500

The brine shrimp Artemia (Anostraca, Branchiopoda) is the primary live and dry feed source used in more than 85% of world aquaculture, and its nutritional value is determined chiefly by its high protein content (30-80% of dry matter) and balanced amino acid profile. Based on more than thirty scientific sources published between 1969 and 2023, this article systematizes the classical (Kjeldahl, Biuret) and modern (Lowry, BCA, HPLC amino acid analysis, electrophoresis, CsCl isopycnic centrifugation) methods used for extracting, quantifying, and evaluating the quality of protein from Artemia cysts, decapsulated cysts, nauplii, and adult individuals. It also analyzes the key factors affecting protein content and quality - diet composition, enrichment, salinity and temperature stress, sex and developmental stage, and geographic strain. The practical applications of the resulting protein product - feeding aquaculture and ornamental fish larvae, poultry feed, functional bio-feed and bioencapsulation, and biomedical and molecular-biology research - are reviewed. The findings show that the efficiency of protein recovery from Artemia varies considerably depending on culture conditions, processing technology, and the analytical method chosen, indicating the need for an integrated approach for targeted application.

HISTORICAL PROCESSES THAT TOOK PLACE IN THE TASHKENT OASIS

Bunyod — Fri, 03 Jul 2026 22:10:00 +0500

This article analyzes the ethnic processes that occurred in the Tashkent Oasis, with particular emphasis on the influence of economic factors and the cultural and economic characteristics of the region.

EFFECTIVE DEVELOPMENT OF THE SYSTEM FOR TRAINING PROMISING YOUNG LEADERS IN UZBEKISTAN: INSTITUTIONAL PROBLEMS AND SOCIOLOGICAL MECHANISMS

Bunyod — Fri, 03 Jul 2026 22:09:00 +0500

This article examines the improvement of the system for selecting, training, professionally developing, and ensuring the career advancement of promising young leaders in the civil service of Uzbekistan through sociological and institutional approaches. The empirical basis of the study consisted of semistructured interviews conducted with 50 experts drawn from the civil service, the hokimiyat system, youth policy, leadership training programs, education, and research. The data were processed using thematic coding, content analysis, and comparative interpretation. The findings show that the need for promising young leaders is primarily qualitative rather than quantitative. Experts identified strategic and analytical thinking, decision-making, team management, communication, emotional intelligence, digital literacy, an innovative approach, and ethical responsibility as the key competencies of a modern leader.

ANALYSIS OF THE DETERMINANT APPROACH IN MATERNAL AND CHILD HEALTH PROTECTION POLICY

Bunyod — Fri, 03 Jul 2026 22:08:00 +0500

This article analyzes the determinant approach to maternal and child health protection policy. It examines how maternal and child health policy embodies the responsibility for promoting the well-being of society and explores the development of the determinant approach in line with socio-economic development trends. The study also analyzes measures and initiatives aimed at promoting maternal and child health and development.

BUILDING IDEOLOGICAL RESILIENCE IN THE AGE OF GLOBALIZATION: PHILOSOPHICAL FOUNDATIONS OF THE “UZBEKISTAN-2030” DEVELOPMENT STRATEGY

Bunyod — Fri, 03 Jul 2026 22:07:00 +0500

This article examines the socio-philosophical dimensions of building ideological resilience within the framework of the “Uzbekistan-2030” development strategy, situating the analysis in the broader context of globalization-driven transformations. By synthesizing contemporary Western philosophical theories with indigenous intellectual heritage – including the Kul Tigin inscription and the classical treatise of Khoja Samandar Termiziy – the study articulates a structural-functional model of ideological resilience. The author argues that the philosophical coherence between the strategic vision of Uzbekistan-2030, the traditions of Central Asian thought, and the modern discourse of open society and responsibility ethics constitutes a distinctive national paradigm of ideological development suited to the challenges of the twenty-first century.

HYDROMETALLURGICAL EXTRACTION OF MARGANESE FROM LOW AND MIDDLE-SIZE MARGANESE ORES

Bunyod — Fri, 03 Jul 2026 22:06:00 +0500

In Uzbekistan, a significant portion of manganese ores is of low and medium composition and is distributed across the Dautash, Kyzylbayrak, Takhtakarachin, Alisai, and Karatau regions. Existing geological data indicate that Dautash and Kyzylbayrak are volcanogenic-sedimentary, while Alisai belongs to the exfiltration type, with 8–35% manganese in the ores and 5–43% MnO2 in Alisai. This article analyzes sulfuric acid hydrometallurgical schemes for extracting manganese from this raw material, recommending a reducing smelting scheme for oxide ores and a phased smelting-purification-deposition scheme for mixed oxide-carbonate ores. Based on similar scientific research, a comparison was made between the Fe (0), biomass-based reducing agents, and the FeS2 and HNO3–glucose systems; the scheme for obtaining products in the form of H2SO4 + reducing solution + solution purification + MnCO3 or MnSO4 was selected as the most industrial and acceptable from a reagent-logistics perspective. Due to the lack of local field test and pilot results in the uploaded file, some indicators were assessed as inaccurate data, while the economic block was covered as a sensitivity analysis based on the no specific constraint condition.

WORLD PRACTICE AND MODERN TECHNOLOGICAL APPROACHES TO EXTRACTING MARGANES FROM MARGANES-CONTAINING RAW MATERIALS

Bunyod — Fri, 03 Jul 2026 22:05:00 +0500

This review article analyzes global practices for extracting manganese from manganese-containing ores, ferroalloy dust, electrolytic manganese residues, and battery raw materials. Pyrometallurgy, sulfate hydrometallurgy, reduction smelting with oxalate and other organic reducing agents, reduction roasting and subsequent smelting, bioleaching, pyro-hydro combined approaches, as well as deep refining of solutions based on solvent extraction, ion exchange, electrolysis and auxiliary purification processes are compared. The results of the review show that, alongside the traditional manganese market for steel, the production of high-purity manganese sulfate suitable for batteries is becoming a key driver of today’s technological shift. For low- and medium-grade manganese objects in Uzbekistan, hydrometallurgical or combined pyro-hydro schemes combining enrichment, selective reductive sulfate leaching, and step-by-step solution purification are recommended as a priority.