Engineering Commons^™

Study Of The Influence Of B2o3 Oxide On The Physical And Technical Properties Of Ground Enamel Obtained Based On Local Raw Material Components, Shoxrux B. Naimov, Mastura Kh. Aripova

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of the study was to obtain ground enamel based on local raw materials and to study the effect of boron oxide. The selection of local raw materials for producing ground enamel showed that the resulting glass compositions are in the SiO₂–Al₂O₃–Na₂O–K₂O–CaO–B₂O₃ system. To adjust the properties, additives of nickel oxide and cobalt oxide were used. The properties of the developed compositions of primer enamels meet the requirements of GOST 24405-80. It has been determined that the addition of boron and an increase in its amount …

Formation Of Luminescent Coatings With The Use Of Low Melting Glass, Eygeniy N. Poddenezhny, Ekaterina E. Trusova, Andrei A. Boiko, Ekaterina R. Kravcova, Olga V. Davydova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the present research is to develop compounds and technologies for applying the luminous vitrocrystalline compounds to smooth and ribbed glass substrates in LED lamp structure with a remote photoconverter that contains oxide low melting glass as the base and nanostructured cerium–doped yttrium–aluminum garnet powder as the luminophore. The luminescent coatings based on nanostructured cerium doped yttrium-aluminum garnet powder and low melting glass of composition BaO-Bi₂O₃-B₂O₃-K₂O-SiO₂ where prepared. YAG:Ce³⁺ powder was synthesized by the method of thermochemical reaction. Silica glass powder was introduced into the composition …

Anomalous Of Resistance And Magnetic Susceptibility At 280-310 K And Ambient Pressure In Bismuth Cuprates Synthesized By Solar Energy, Dilbara Dj. Gulamova, Elyor B. Eshonkulov, Valeriya R. Li, Grigor I. Mamniashvili, Timur I. Gulamov

CHEMISTRY AND CHEMICAL ENGINEERING

In order to obtain the full content of high-temperature superconducting phases using the “Super Fast Alloys Quenching” technology in the Large Solar Furnace (Parkent), precursors of bismuth cuprates of the series Bi_1,7Pb_0,3Sr₂Ca_(n-1)Cu_nO_y, n=3-30 were synthesized. Methods for study the properties of precursors are presented. The oriented nano-sized microstructure and layered structure of nanocrystalline nuclei are shown. The phase composition of the precursors at the beginning of the series (n=3-5) is represented by X-ray amorphous and crystalline phases. An increase in the content of CaO and CuO destabilizes the …

Waste Utilization In Korean Cement Plants, Geun-Seong Lee, Zebo Abdullaevna Babakhanova, Mastura Khikmatovna Aripova

CHEMISTRY AND CHEMICAL ENGINEERING

The kiln process in cement plant has the advantage of completely and effectively destroying and burning all organic substances due to high temperature and long residence time, oxygen atmosphere and excellent mixing effect, alkaline conditions of raw materials, and incorporation of trace metals into clinker, and plays a role as a pollutant emission barrier during waste utilization. Waste utilization technology is now proven and successful in cement plants. The waste utilization in Korean cement plants are greatly expanding in the view of energy and material recoveries, and economics as well as environmental preservation. Research on waste utilization in the Korean …

Study Of Reactive Distillation Equipment For Eterification Process, Abbos Elmanov, Abdulaziz Bakhtiyorov, Adham Norkobilov, Olimjon Maksudov, Zarif Oripov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this work is to study the chemical technological processes for eterification processes, and the reactive distillation unit, which carries out the reaction and separation process in one device, was chosen as the object of research. А reаctive distillаtion system is exаmined to produce for the production of Ethyl Acetate (EtAc) viа eterificаtion of acetic acid (HAc) with ethаnol. Optimizаtion methods using sensitivity analysis аre аlso conducted. Cаlculаtion of vаpor liquid equilibrium of the mixture system is done using UNIFАC model. Heat integration from the distillate stream of the column to the acid feed stream and from bottom …

Numerical Calculation Of The Flame Spreading Over A Methane Hydrate Surface, Otabek Nigmatov, Oksana Ismailova

CHEMISTRY AND CHEMICAL ENGINEERING

The Methane Hydrate is expected as an energy source and is being as a medium distance transport means of natural gas alternative of LNG (Liquefied Natural Gas). During the natural gas transportation, fire accidents are concerned. In the present study, the flame spreading over a methane hydrate surface has been studied numerically as a function of hydrate surface temperature, T_s. When T_s = 173 K (-100℃), lower than the dissociation temperature (T_d = 183 K (-90℃)), the flame spreading speed is around 6.5 mm/s, while the flame spreading speed at T_s = 193 K (-80℃), …

Dft Study Of Quantum Chemical Parameters Of 4-Amino-2-Mercaptobenzimidazole And Their Tautomeric Forms, Dilnoza Rahmonova, Alisher Eshimbetov, Lobar Gapurova, Zuhra Ch. Kadirova, Shakhnoza Kadirova

CHEMISTRY AND CHEMICAL ENGINEERING

Coordination competing donor centers, electronic and geometric structures of the 4-amino-2-mercaptobenzimidazole ligand molecule were studied using quantum chemical calculation by the DFT / 6-31G method (d, p). It was shown that during the formation of the metal complex, the ligand is coordinated through the localized nitrogen atom of the imidazole ring. In this study, the total energies (Etot) of 4-amino-2-mercaptobenzimidazole (1) and its tautomeric forms (2 and 3) were calculated. And also, the energies of boundary molecular orbitals, the energy gap between boundary MOs (ΔE) and the distribution of the total charge on atoms and boundary orbitals were determined. In …

The Effect Of Hydrogen Peroxide And Potassium Amylxanthate On The Surface Properties Of Chalcocite And Enargite, Berdakh T. Daniyarov, Hajime Miki, Daminbek A. Ziyatov, Shahlo Daminova

CHEMISTRY AND CHEMICAL ENGINEERING

The effect on the surface properties and floatability of chalcocite and enargite after oxidative treatment with hydrogen peroxide (H₂O₂) in the presence and absence of potassium amylxanthate (PAX) as a collector was studied. In this research, flotation tests were carried out on mixed and individual minerals. Oxidative treatment with hydrogen peroxide had a negative effect on the floatability of chalcocite and enargite. PAX adsorption analysis shows that enargite adsorbs PAX faster than chalcocite. Moreover, Fourier transform infrared spectroscopy analysis shows that PAX was adsorbed in the form of copper amylxanthate on chalcocite and enargite surfaces. In …

Influence Of The Amount Of Monoethanolamine On The Physicochemical Properties Of Aminolysis Products, Soxibjon A. Egamberdiyev, Muzaffar G. Alimukhamedov, Juraev Asror, Ravshan Adilov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this paper is to investigate the process of aminolysis of secondary polyethylene terephthalate with monoethanolamine at low ratio. The effect of the amount of monoethanolamine on the physical and chemical properties of the aminolysis product of secondary polyethylene terephthalate was studied. With an increase of 1-4 moles of monoethanolamine obtained for synthesis (without the presence of a catalyst), it was observed that the number of amines in the aminolysis product increased from 324 to 503 mgKON/g, and the number of hydroxyls increased from 298 to 491 mgKON/g. The structure of the resulting bis(2-hydroxyethylene)terephthalamide was studied using IR …

Study Of The Structure Of Glass Ionomer Cements Developed Based On Glass System Sio2-Al2o3-Cao-Zno-P2o5-Caf2, Tatyana O. Nam, Mastura X. Aripova, Ripsime V. Mkrtchyan

CHEMISTRY AND CHEMICAL ENGINEERING

The goal was to study the structure of glass ionomer cements (GIC) developed on the basis of glasses of the SiO₂-Al₂O₃-CaO-ZnO-P₂O5-CaF₂ system. Glass powders with sizes less than 50 μm were sealed with a 40% solution of polyacrylic acid and after 72 hours, electron microscopic examination was carried out on a JSM-IT200 scanning microscope (JEOL, Japan). All samples demonstrate a cellular structure consisting of glass particles surrounded by glass elements that have entered into an acid-ion interaction with polyacrylic acid in a polymer matrix. GIC-4 and GIC-6 show the most …

Impact Of Sulfurization On Sputtered Bivo4 Thin Films, Shukur P. Gofurov, Dilbar T. Bozorova, Zuhra Ch, Kadirova, Oksana Ismailova

CHEMISTRY AND CHEMICAL ENGINEERING

The sulfurization method has been used to decrease the band gap of the BiVO₄ structure, reduce the recombination of electrons and holes, and increase the photoelectrochemical performance of this material. It has been observed that incorporation of sulfur into stoichiometric and V_rich BiVO₄ is variously affected changing of properties of the structure. Sulfurization can modify V_rich BiVO₄ structure rather than stoichiometric BiVO₄.

Development Of Clinker And Portland Cement Composition Based On Surkhondaryo Raw Materials, Salohiddin Ramazanov, Abdumalik Nabiyev, Mastura Aripova

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this research work is to develop clinker and Portland cement compositions based on Surkhandarya raw materials for the planned construction of a cement plant, as well as to study their physical and chemical properties. The compositions of clinkers, including limestone, clay from the Yolgizbulok deposit and slag from the Almalyk mining and metallurgical plant, were studied. The optimal clinker composition was selected, on the basis of which Portland cement was obtained. The optimal amount of gypsum addition was determined to achieve a cement stone strength of 43,5 MPa. The developed clinker composition will provide the planned enterprise …

Antibacterial Cerium-Containing Glazes For Ceramic Tiles, Ivan Levitskiy, Mastura Aripova, Mihail Dyadenko, Dar’Ya Kucherova, Artem Golub

CHEMISTRY AND CHEMICAL ENGINEERING

The results of research on the production of semi-fritted cerium-containing glazes used for ceramic tiles are presented.

A multicomponent raw material mixture based on dolomite, cerium dioxide CeO₂, aluminosilicate multicalcium frit and permanent components including feldspar, alumina and clay components (kaolin and refractory clay) is used to produce glazes.

The characteristics of the obtained coatings were studied: appearance, technological and physico-chemical properties, including antibacterial properties in relation to the strains of Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538. The influence of temperature parameters on the formation of glaze coatings, as well as their structure and phase …

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …

Globular Protein For Surface Modification Of Cellulosecontaining Materials, Nodira Saydaliyeva

Technical science and innovation

The purpose of this work is the chemical modification of cotton fabrics with natural globular protein. Modification was carried out in the process of finishing cotton fabrics, after decoction and bleaching in a continuous mode. The effect of modification on the strength, protein content and functional groups of cotton fabric has been studied. According to the results obtained using the AUTOGRAPH AGS-N machine, it was found that the modification of cotton fabrics with a solution of globular protein increases the strength of the treated fabrics, depending on the concentration of the modifier and the temperature regime. Treatment with a highly …

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul

Makara Journal of Science

Ancient potteries offer valuable information regarding technological advancements, life dynamics, cultural diversity, and trade routes in the past. Earthenware, stoneware, and porcelain from Southeast Asia have been characterized using several analytical techniques, as reviewed in this article. Fluorescent and diffracted X-rays give rise to elemental and phase compositions, respectively. Examination of molecular bonds requires vibrational spectroscopy, which is useful for the identification of organic materials in ancient potteries. With the advent of portable X-ray fluorescence and Raman spectrometry, on-site analysis of archeological ceramics is now possible. For in-depth analysis, synchrotron light sources can provide new insights into artifacts through X-ray …

Recent Advances In Solar Photo(Electro)Catalytic Nitrogen Fixation, Jun-Bo Ma, Sheng Lin, Zhiqun Lin, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Ammonia (NH₃) is an essential chemical in modern society. It is currently produced in industry by the Haber-Bosch process using H₂ and N₂ as reactants in the presence of iron-based catalysts at high-temperature (400–600 ^oC) and extremely highpressure (20–40 MPa) conditions. However, its efficiency is limited to 10% to 15%. At the same time, a large amount of energy is consumed, and CO₂ emission is inevitably. The development of a sustainable, clean, and environmentally friendly energy system represents a key strategy to address energy crisis and environmental pollution, ultimately aiming to achieve carbon neutrality. …

Micropatterning And Functionalization Of Single Layer Graphene: Tuning Its Electron Transport Properties, Miao-Miao Cui, Lian-Huan Han, Lan-Ping Zeng, Jia-Yao Guo, Wei-Ying Song, Chuan Liu, Yuan-Fei Wu, Shi-Yi Luo, Yun-Hua Liu, Dong-Ping Zhan

Journal of Electrochemistry

As a promising 2D material, graphene exhibits excellent physical properties including single-atom-scale thickness and remarkably high charge carrier mobility. However, its semi-metallic nature with a zero bandgap poses challenges for its application in high-performance field-effect transistors (FETs). In order to overcome these limitations, various approaches have been explored to modulate graphene's bandgap, including nanoscale confinement, external field induction, doping, and chemical micropatterning. Nevertheless, the stability and controllability still need to be improved. In this study, we propose a feasible method that combines electrochemical bromination and photolithography to precisely tune the electron transport properties of single layer graphene (SLG). Through this …

Automated Workflow For Redox Potentials And Acidity Constants Calculations From Machine Learning Molecular Dynamics, Feng Wang, Jun Cheng

Journal of Electrochemistry

Redox potentials and acidity constants are key properties for evaluating the performance of energy materials. To achieve computational design of new generation of energy materials with higher performances, computing redox potentials and acidity constants with computational chemistry have attracted lots of attention. However, many works are done by using implicit solvation models, which is difficult to be applied to complex solvation environments due to hard parameterization. Recently, ab initio molecular dynamics (AIMD) has been applied to investigate real electrolytes with complex solvation. Furthermore, AIMD based free energy calculation methods have been established to calculate these physical chemical properties accurately. However, …

Joint Time-Frequency Analysis: Taking Charge Penetration Depth And Current Spatial Distribution In The Single Pore As An Example, Nan Wang, Qiu-An Huang, Wei-Heng Li, Yu-Xuan Bai, Jiu-Jun Zhang

Journal of Electrochemistry

In recent years, joint time-frequency analysis has once again become a research hotspot. Supercapacitors have high power density and long service life, however, in order to balance between power density and energy density, two key factors need to be considered: (i) the specific surface area of the porous matrix; (ii) the electrolyte accessibility to the intra-pore space of porous carbon matrix. Electrochemical impedance spectra are extensively used to investigate charge penetration ratio and charge storage mechanism in the porous electrode for capacitance energy storage. Furthermore, similar results could be obtained by different methods such as stable-state analysis in the frequency …

The Top Ten Scientific Questions In Electrochemistry, Chinese Society Of Electrochemistry

Journal of Electrochemistry

No abstract provided.

Rational Design Of Heterostructured Nanomaterials For Accelerating Electrocatalytic Hydrogen Evolution Reaction Kinetics In Alkaline Media, Hai-Bin Ma, Xiao-Yan Zhou, Jia-Yi Li, Hong-Fei Cheng, Ji-Wei Ma

Journal of Electrochemistry

Owing to the merits of high energy density, as well as clean and sustainable properties, hydrogen has been deemed to be a prominent alternative energy to traditional fossil fuels. Electrocatalytic hydrogen evolution reaction (HER) has been considered to be mostly promising for achieving green hydrogen production, and has been widely studied in acidic and alkaline solutions. In particular, HER in alkaline media has high potential to achieve large-scale hydrogen production because of the increased durability of electrode materials. However, for the currently most prominent catalyst Pt, its HER kinetics in an alkaline solution is generally 2–3 orders lower than that …

Stability Of A Solid Oxide Cell Stack Under Direct Internal-Reforming Of Hydrogen-Blended Methane, Ya-Fei Tang, An-Qi Wu, Bei-Bei Han, Hua Liu, Shan-Jun Bao, Wang-Lin Lin, Ming Chen, Wan-Bing Guan, Subhash C. Singhal

Journal of Electrochemistry

In this work, the long-term stability and degradation mechanism of a direct internal-reforming solid oxide fuel cell stack (IR-SOFC stack) using hydrogen-blended methane steam reforming were investigated. An overall degradation rate of 2.3%·kh^–1 was found after the stack was operated for 3000 hours, indicating a good long-term stability. However, the voltages of the two cells in the stack were increased at the rates of 3.38 mV·kh^–1 and 3.78 mV·kh^–1, while the area specific resistances of the three metal interconnects in the stack were increased to 0.276 Ω·cm², 0.254 Ω·cm² and 0.249 Ω·cm^{2 …}

Kinetic Applications Of Smart Materials In Architecture: A Descriptive Analysis, Youssef Elkhayat

Journal of Engineering Research

In recent years, many smart materials for architectural applications have been invented. Some smart materials can adapt and interact with the surrounding environment and its variants, whether temperature, humidity, daylight or electric current. Smart material changes its shape without any need for assistance, and it can return to its original state without any significant deformation in shape with the end of the external influence. The invention of smart materials stimulated several architects and facade designers to consider using them in various architectural applications such as sun shading, sun breakers, and windows, significantly impacting the concept and technology of movement in …

The Effect Of Fine Recycled Concrete Aggregates On The Mechanical And Durability Properties Of Concrete, Abbas Chour, Jamal Khatib

BAU Journal - Science and Technology

The fast increase of construction and demolition (C&D) operations has resulted in the creation of massive amounts of garbage, which must be cleared. Reusing C&D waste is of significant importance for environmental conservation and resource utilization. One such alternative for structural concrete is recycled concrete aggregate obtained from building and demolition debris. In this context, the present study aims to comprehensively review the current state of the art in fine recycled concrete materials (fRCA), including their physical properties, technological advantages, mechanical properties, and durability characteristics. The study establishes a paradigm for evaluating the quality of fRCA, whether created in a …

Application Of Quantum Algorithms In The Synthesis Of Dynamic Objects, Noilakhon Yakubova

Chemical Technology, Control and Management

Around the world, the food industry is focusing on achieving energy and resource efficiency. One of the main challenges in the field of process automation is the creation of effective control systems using intelligent technologies to improve the quality of processes and achieve the production of high-quality products with less energy and resources. Therefore, it is necessary to work with a large amount of data. Particular attention is paid to the development of computational algorithms for automated high-speed computational analysis systems for processing this data at high speed. Therefore, the article discusses the use of quantum computing methods in controlling …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Electrochemical Performance Of Porous Ceramic Supported Tubular Solid Oxide Electrolysis Cell, Heng-Ji Wang, Wen-Guo Chen, Zhou-Yi Quan, Kai Zhao, Yi-Fei Sun, Min Chen, Ogenko Volodymyr

Journal of Electrochemistry

Solid oxide electrolysis cell (SOEC) is an efficient and clean energy conversion technology that can utilize electricity obtained from renewable resources, such as solar, wind, and geothermal energy to electrolyze water and produce hydrogen. The conversion of abundant intermittent energy to hydrogen energy would facilitate the efficient utilization of energy resources. SOEC is an all-ceramic electrochemical cell that operates in the intermediate to high temperature range of 500–750 ℃. Compared with traditional low temperature electrolysis technology (e.g., alkaline or proton exchange membrane cells operating at ~100 ℃), the high-temperature SOEC can increase the electrolysis efficiency from 80% to ~100%, providing …

Nitrogen-Doped Graphite Felt On The Performance Of Aqueous Quinone-Based Redox Flow Batteries, Heng Zhang, Li-Xing Xia, Shan Jiang, Fu-Zhi Wang, Zhan-Ao Tan

Journal of Electrochemistry

Modification of electrode is vitally important for achieving high energy efficiency in aqueous quinone-based redox flow batteries (AQRFBs). The modification of graphite felt (GF) was carried out by means of urea hydrothermal reaction, and simultaneously, the effects of hydrothermal reaction time on the functional groups and surface structure of nitrogen-doped graphite felt were studied. The surface morphology and defect, element content and surface chemical state of the modified electrode were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) test, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the modified electrodes was evaluated by cyclic voltammetry, electrochemical impedance …

An In-Situ Raman Spectroscopic Study On The Interfacial Process Of Carbonate-Based Electrolyte On Nanostructured Silver Electrode, Yu Gu, Yuan-Fei Hu, Wei-Wei Wang, En-Ming You, Shuai Tang, Jian-Jia Su, Jun Yi, Jia-Wei Yan, Zhong-Qun Tian, Bing-Wei Mao

Journal of Electrochemistry

The solid-electrolyte interphase (SEI) plays a key role in anodes for rechargeable lithium-based battery technologies. However, a thorough understanding in the mechanisms of SEI formation and evolution remains a major challenge, hindering the rapid development and wide applications of Li-based batteries. Here, we devise a borrowing surface-enhanced Raman scattering (SERS) activity strategy by utilizing a size optimized Ag nanosubstrate to in-situ monitor the formation and evolution of SEI, as well as its structure and chemistry in an ethylene carbonate-based electrolyte. To ensure a reliable in-situ SERS investigation, we designed a strict air-tight Raman cell with a three-electrode configuration. Based on …