221 results match your criteria: "National University of Uzbekistan[Affiliation]"

Polyurethane (PUR), as an engineering polymer, is widely used in many sectors of industries. However, the high fire risks associated with PUR, including the smoke density, a high heat release rate, and the toxicity of combustion products limit its applications in many fields. This paper presents the influence of silsesquioxane fillers, alone and in a synergistic system with halogen-free flame-retardant compounds, on reducing the fire hazard of polyurethane foams.

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Two novel chitosan derivatives (water soluble and acid soluble) modified with thiocarbohydrazide were produced by a quick and easy technique using formaldehyde as links. The novel compounds were synthesized and then characterized by thermogravimetric analysis, elemental analysis, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Their surface morphologies were examined using scanning electron microscopy.

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Parallel texts dataset for Uzbek-Kazakh machine translation.

Data Brief

April 2024

National University of Uzbekistan named after Mirzo Ulugbek, Universitet Street, 4, Olmazor district, 100174, Tashkent city, Uzbekistan.

This paper presents a parallel corpus of raw texts between the Uzbek and Kazakh languages as a dataset for machine translation applications, focusing on the data collection process, dataset description, and its potential for reuse. The dataset-building process includes three separate stages, starting with a tiny portion of already available parallel data, then some more compiled from openly available resources like literature books, and web news texts, which were aligned using the sentence alignment method, encompassing a wide range of topics and genres. Finally, the majority of the dataset was taken from a raw text corpus in Uzbek and manually translated into Kazakh by a group of experts who are fluent in both languages.

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A novel application of the gall extract as an environmentally friendly corrosion inhibitor is reported in this study. The major phytochemicals present in the gall extract, namely pistagremic acid, β-sitosterol, pistiphloroglucinyl ether, pistaciaphenyl ester, naringenin, and 5,7-dihydroxy-2-(4-hydroxyphenyl)-2,3-dihydrochromen-4-one, play key roles in its anticorrosive behavior on steel in aggressive media. Several approaches were used to study the corrosion prevention activity of steel in 1 M HSO, including weight loss analysis, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and density functional theory (DFT).

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Exploring biodiversity and ethnobotanical significance of species in Uzbekistan: unveiling the cultural wealth and ethnopharmacological uses.

Front Pharmacol

January 2024

Centre d'Ecologie Fonctionnelle et Evolutive, Centre National de Recherche Scientifique, Ecole Pratique des Hautes Etudes, Institut pour la Recherche et le Développement, University of Montpellier, Montpellier, France.

Despite its millennial existence and empirical documentation, the ethnological knowledge of herbs is a more recent phenomenon. The knowledge of their historical uses as food, medicine, source of income and small-scale businesses, and the sociological impacts are threatened due to the slow ethnobotanical research drive. Species of the genus have long been extensively used in folk medicine to treat various illnesses of humans since the dawn of civilization.

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2-Amino-benzoxazole-oxalic acid (2/1).

IUCrdata

January 2024

Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, M. Ulugbek, Str, 83, Tashkent, 100125, Uzbekistan.

In the title compound, 2CHNO·CO , proton transfer from oxalic acid to the N atom of the heterocycle has occurred to form a 2:1 molecular salt. In the extended structure, N-H⋯O hydrogen bonds link the components into [100] chains, which feature (8) and (14) loops.

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A novel -phenyl-enedi-amine (opda)-based cadmium complex, bis-(benzene-1,2-di-amine-κ ,')bis-(benzene-1,2-di-amine-κ)cadmium(II) naphthalene-1,5-di-sulfonate, [Cd(CHN)](CHOS), was synthesized. The complex salt crystallizes in the monoclinic space group 2/. The Cd atom occupies a special position and coordinates six nitro-gen atoms from four -phenyl-enedi-amine mol-ecules, two as chelating ligands and two as monodentate ligands.

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Nanoceramic-based coatings for corrosion protection: a review on synthesis, mechanisms, and applications.

Environ Sci Pollut Res Int

January 2024

Laboratory of Sciences and Professions of the Engineer, Materials and Processes Department, ENSAM-Meknes Marjane II, Moulay Ismail University, El Mansour Meknes P.O. Box 15290, Morocco.

Corrosion is a pervasive issue with significant economic and safety implications across various industries. Nanoceramic-based coatings have emerged as a promising solution for corrosion protection due to their unique properties and mechanisms. This review aims to comprehensively examine the synthesis, mechanisms, and applications of nanoceramic-based coatings for corrosion protection.

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Cotton ( spp.) is the most important natural fiber source in the world. The genetic potential of cotton can be successfully and efficiently exploited by identifying and solving the complex fundamental problems of systematics, evolution, and phylogeny, based on interspecific hybridization of cotton.

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Membrane technology has been embraced as a feasible and suitable substitute for conventional time- and energy-intensive biodiesel synthesis processes. It is ecofriendly, easier to run and regulate, and requires less energy than conventional approaches, with excellent stability. Therefore, the present study involved the synthesis and application of a highly reactive and recyclable Titania-based heterogeneous nanocatalyst (TiO) for biodiesel production from nonedible seed oil via a membrane reactor, since is easily and widely accessible and has a rich oil content (39% /).

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Micrometer insights into Nepeta genus: Pollen micromorphology unveiled.

Micron

February 2024

Department of Medicinal Plants, Tashkent State Agrarian University, 2 A., Universitet Str., 100700, Uzbekistan.

This study provides a comprehensive pollen micromorphology within the Nepeta genus, revealing intricate details about the pollen grains' structure and characteristics. The findings shed light on the evolutionary and taxonomical aspects of this plant genus, offering valuable insights for botanists and researchers studying Nepeta species. The pollen grains of 18 Nepeta species were studied using scanning electron microscopy (SEM) and light microscopy (LM) in Northern Pakistan.

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Hybrid epoxy/Br inhibitor in corrosion protection of steel: experimental and theoretical investigations.

Environ Sci Pollut Res Int

January 2024

Laboratory of Organic Chemistry, Catalysis and Environment, Department of Chemistry, Faculty of Sciences, University Ibn Tofail, BP 242, 14000, Kenitra, Morocco.

The corrosion of carbon steel infrastructure in acidic environments poses significant economic and safety challenges. Traditional inhibitors such as chromates are being phased out due to toxicity concerns. Thus, there is a need to develop effective and sustainable green alternatives.

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Inorganic polyphosphate regulates functions of thymocytes via activation of P2X purinoreceptors.

Biochim Biophys Acta Gen Subj

January 2024

Laboratory of Experimental Biophysics, Centre for Advanced Technologies, Tashkent, Uzbekistan; Department of Biophysics, Faculty of Biology, National University of Uzbekistan, Tashkent, Uzbekistan. Electronic address:

Inorganic polyphosphate (polyP) is an ancient polymer, which was proven to be a signalling molecule in the mammalian brain, mediating the communication between astrocytes via activation of P2Y purinoreceptors and modulating the activity of neurons. There is very limited information regarding the ability of polyP to transmit the information as an agonist of purinoreceptors in other cells and tissues. Here, we show that application of polyP to the suspension of primary thymocytes increases the concentration of intracellular calcium.

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We studied and reconstructed a severe Central Asian dust storm of November 4, 2021, through high-resolution TROPOMI UVAI spaceborne observations, ground-based aerosol measurements, and Lagrangian particle modeling. The dust storm was caused by the front part of a cold polar anticyclone front from the Ural-Volga regions, which struck the central and eastern parts of Uzbekistan under favorable atmospheric conditions. Two plumes spread out, causing a thick haze to blanket the region.

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The present study provides an overview of scientific developments made in the last decade in the field of green adsorbents focusing on the modifications in natural polymers and their applications such as, wastewater treatment, and ion exchange. For this purpose, an introduction to the various methods of modifying natural polymers is first given, and then the properties, application, and future priorities of green adsorbents are also discussed. Methods of modification of natural polymers under homogeneous and heterogeneous conditions using modifiers with different properties are also described.

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Article Synopsis
  • Researchers achieved the first asymmetric synthesis of large chiral macrocycles containing chiral sulfur atoms.
  • They utilized disulfonimidoyl fluorides and disulfonimidoyl-nitrophenolates as efficient building blocks to create novel S-O bonds through stereospecific SuFEx and SuPhenEx click chemistries.
  • The process resulted in the one-step synthesis of rings with 21-58 members and successful characterization of both enantiomers using techniques like X-ray crystallography.
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In this study, we explored the electronic and thermoelectric (TE) properties of the Na-based Quaternary Heusler Alloys (QHAs) NaHfXGe (X = Co, Rh, Ir) using density functional theory (DFT). We performed the spin-polarized DFT calculations at the general gradient approximation (GGA) level and confirmed the ground state non-magnetic configuration of NaHfXGe. The mechanical and thermodynamical stabilities are analyzed and discussed to validate the stability by calculating the elastic constant and phonon dispersion curve.

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Effects of Synthetic Tetronamides and Methylated Denigrins on Bacterial Quorum Sensing and Biofilm Formation.

ACS Omega

October 2023

Department of Chemistry, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG CEP 31270-901, Brazil.

Detrimental biofilms of bacterial pathogens cause chronic infections with a high-level tolerance to antibiotics. To identify new control agents, we synthesized and tested a total of 14 tetronamides (including 5 new compounds) and 6 denigrin intermediates on the model species . At a concentration of 50 μg/mL, two tetronamides and two methylated denigrins exhibited significant inhibitory effects against biofilm formation of RP437, e.

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Cell volume regulation (CVR) is a prerequisite for animal cells to survive and fulfill their functions. CVR dysfunction is essentially involved in the induction of cell death. In fact, sustained normotonic cell swelling and shrinkage are associated with necrosis and apoptosis, and thus called the necrotic volume increase (NVI) and the apoptotic volume decrease (AVD), respectively.

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In this work, the null controllability problem for a linear system in is considered, where the matrix of a linear operator describing the system is an infinite matrix with on the main diagonal and 1s above it. We show that the system is asymptotically stable if and only if ≤- 1, which shows the fine difference between the finite and the infinite-dimensional systems. When ≤- 1 we also show that the system is null controllable in large.

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A first coordination compound of 2-amino-benzoxazole (), namely, bis-(2-amino-benzoxazole-κ )bis-(acetato-κ ,')cadmium(II), [Cd(CHCOO)()], has been synthesized from ethanol solutions of Cd(CH(COO) and . In the monoclinic crystals with the space group 2/, the cadmium ions coordinate two neutral mol-ecules in a monodentate fashion through the oxazole N atom, while two acetate ligands are coordinated through the O atoms in a bidentate manner. The coordination polyhedron of the central ion is substanti-ally distorted octa-hedral.

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Synthesis and Characterisation of Chickpea Peptides-Zinc Chelates Having ACE2 Inhibitory Activity.

Protein J

October 2023

State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, and the Key Laboratory of Chemistry of Plant Resources in Arid Regions, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, PR China.

Tryptic hydrolysates of protein fractions obtained by the Osborne method from chickpea (Cicer arietinum L.) seeds interacted with zinc ions and the results of chelation were monitored by the Energy Dispersive X-Ray (EDX) technique. The glutelin hydrolysate (GluHyd) reacted with zinc ions and depicted a relatively higher zinc content.

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Purpose: Salinity is a main factor in decreasing seed germination, plant growth and yield. Salinity stress is a major problem for economic crops, as it can reduce crop yields and quality. Salinity stress occurs when the soil or water in which a crop is grown has a high salt content.

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Industrial wastewater often consists of toxic chemicals and pollutants, which are extremely harmful to the environment. Heavy metals are toxic chemicals and considered one of the major hazards to the aquatic ecosystem. Analytical techniques, such as potentiometric methods, are some of the methods to detect heavy metals in wastewaters.

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