Materials Science and Engineering Commons^™

Study Of Regularities Of Formation Of Hydroxyammonium Oligomers From Alkanolamine Of The Type Of Hexahydrosimtriazine And Epichlorohydrin, Nozima M. Ibragimova, Ravshan I. Adilov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is to study the patterns of formation of hydroxylammonium oligomers based on hexahydrosymtriazine with epichlorohydrin. The paper studies the interaction patterns of the alkanolamine hexahydrosimtriazine type - N, N', N'-tris (β-oxyethyl) hexahydro-S-triazine (THOHST)with epichlorohydrin (ECH). The reaction between TOEGT and ECH occurs at a noticeable rate, already at 0 ^oC. An increase in the reaction duration leads to a symbate increase in the molecular weight values, the concentration of hydrolyzed chlorine, a decrease in the content of epoxy groups, and the concentration of hydroxyl groups do not change within the experimental error. An increase …

O-Xloratsetiltimol Sintezi Va Uni Kimyoviy Modifikatsiyalash, Azimjon U. Choriev, Anvar K. Abdushukurov, Ilyos U. Normurodov, Sarvinoz K. Mirzayeva

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to develop a convenient method for the synthesis of O-chloroacetylthymol and to propose the mechanism of the O-chloroacetylation reaction. Thin-layer chromatography of chloroacetylation and nucleophilic substitution reaction products was studied and their composition was confirmed by reference substances. Nucleophilic exchange reactions of O-chloroacetylthymol with sodium oxalate, sodium tartrate, potassium rhodanides were studied. Favorable conditions for carrying out the nucleophilic exchange reaction were searched and 3 new substances unknown in the literature were synthesized. The structure of the synthesized substances was proved by IR and NMR spectra.

Study Of Crystallization Ability Of Glasses Synthesized In The Basalt-Quartz-Soda System, Eldor I. Ruzmatov, Mastura Kh. Aripova, Bahrom R. Ro'ziboyev

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is to study the crystallization capacity of glasses synthesized in the basalt-quartz-soda system. The crystallization capacity of glasses was studied by the method of mass crystallization in the range of 600 ^oC and 1050 ^oC. The stages of spontaneous crystallization were determined by the DTA method. The density, TCLE, refractive index, compressive strength and frost resistance were studied. The crystalline phases of crystallized glasses were determined by the X-ray phase method. The presence of diopside and anorthite was revealed.

Influence Of The Granulometric Composition Of Carbonate Rocks On Glass Formation Processes In Float Glass Technology, Sergey P. Grechuha, Yury G. Pavliukevich, Ludmila F. Pаpko, Olesya M. Mozhdzher, Aleksandr P. Kravchuk

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to study the influence of the granulometric composition of dolomite and limestone of 0.1–1.0 mm, 1.0–1.6 mm, 1.6–2.5 mm fractions on the rate of glass formation processes in the synthesis of float glass. The dependence of the degree of decarbonization of dolomite and limestone on the dispersion of particles and the time of heat treatment has been established. According to the study of the influence of the granulometric composition of carbonate rocks on the melting characteristic of float glass, it can be concluded that it is possible to use the 1.0–1.6 mm fraction of …

Antibacterial Semi-Fritted Glazes Containing Iron (Iii) And Manganese (Iv) Oxides, Ivan A. Levitskiy, Mihail V. Dyadenko, Ekaterina E. Trusova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this research work is production of colored antibacterial glaze coatings for ceramic products containing iron (III) and manganese (IV) oxides. The coatings are produced on the basis of multicalcium aluminoborosilicate frit, dolomite and iron or manganese oxides. The constant components in the raw mixture were feldspar, alumina, coal clay and kaolin. The coatings were obtained by finely grinding the components then applied to the dried semi-finished product and single fired at a temperature of 1200±5 °C for 60±2 minutes. The formation of the glaze layer, the decorative properties of coatings, and their physical and chemical and operational …

Synthesis Of Nanostructured Cerium-Doped Yttrium-Aluminum Garnets By Method Of Sol-Gel Burning In A Microwave Oven, Eygeniy N. Poddenezhny, Andrei A. Boiko, Ekaterina E. Trusova, Ekaterina R. Kravcova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of research is to study the new method of thermochemical synthesis of yttrium-aluminum garnet luminescent powder, cerium doped (Y₃Al₅O₁₂:Се³⁺, YAG:Ce) using the nitric acid salts of yttrium, aluminum and cerium, with the mixture of carbamide and hexamethylenetetramine used as fuel. Synthesis was performed in a microwave oven with the power of 800 W and frequency of 2450 MHz in a porcelain crucible closed with a perforated heat-resistant cover. The average size of coherent scattering region (CSR) of YAG:Ce particles (nominal diameter D) obtained in the crucible during the microwave heating …

Polyvinyl Alcohol–Red Cabbage Nanofibers As Ph-Responsive Freshness Sensors For Advanced Food Packaging Technology, Foliatini Foliatini, Singgih Wibowo, Henny Rochaeni, Suhartini Suhartini, Fachrurrazie Fachrurrazie, Arzzaq Imanda Prianditya, Pradnadia Putri Hadriansyah, Naura Athira Putri Siregar, Novi Nurpadilah, Putri Alfiani, Maudi Rahim, Endah Sriwahyuni

Makara Journal of Science

The development of innovative food packaging technologies, particularly those capable of monitoring freshness, has become increasingly important in the food industry. This research explores the development of a pH-responsive freshness sensor using polyvinyl alcohol–red cabbage (PVA/RC) nanofibers. The nanofibers are fabricated through the electrospinning technique and meticulously analyzed via scanning electron microscopy, Fourier-transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). The results underscore the fine structure of the nanofiber matrix, with an average diameter of ~68 nm. FTIR analysis substantiates the presence of anthocyanin compounds from RC within the PVA/RC nanofibers, which confirms the integration of beneficial components into …

Experimental Examination Of Enhanced Nanoceramic-Based Self-Cleaning Sprays For High-Efficiency Hydrophobic Photovoltaic Panels, Iman El-Mahallawi, Merna Abdrabo, Ahmed Elkaseer Prof., Engy Elshazly, Mohamed S. El-Deab

Renewable Mechanical Energy

Dust deposition poses a significant challenge in the implementation of photovoltaic panels (PV) especially in hot and dusty environments, such as the Middle East and North Africa (MENA) region. This issue leads to progressive degradation of PV efficiency and output power. In this context, this research work aims to improve PV performance by developing self-cleaning sprays as a preventative solution. Different concentrations of SnO2 and TiO2 nanoceramics were dispersed in isopropyl alcohol solvent to reduce the mixture’s viscosity and facilitate smooth spraying on solar panels, whose efficiency was continually assessed in outdoor conditions. Although less commonly used for this application, …

Mapping Of The Potential To Substitute Plastic In Food Packaging In Finnish Supermarkets, Taina Lahtinen, Kirsi Kataja, Jari Viitanen, Vinay Kumar, Jussi Lahtinen, Ali Harlin

Journal of Applied Packaging Research

Single-use plastics (SUP), which are extensively utilized in food packaging, are one notable cause for the constantly growing littering issue. This novel study is one of the first attempts to systemically analyze food packaging data to reveal the potential for plastic packaging material reduction or substitution by utilizing a primary packaging material summary of single items sold in Finnish supermarkets. The outcome of the study indicates considerable dissimilarities among product groups concerning used packaging materials, weight, share of plastic, and sales volume. The analysis identified sweets and ready-to-eat meals as product groups for which there is a clear need, but …

Performance-Tunable Thermal Barrier Coating For Carbon Fiber-Reinforced Plastic Composites Via Flame Spraying, Heejin Kim, Kandasamy Praveen, Min Wook Lee, Juhyeong Lee

Mechanical and Aerospace Engineering Faculty Publications

Thermal barrier coatings (TBCs) are essential for improving the heat resistance of materials operating in high-temperature environments. This paper proposes a new method for manufacturing double-layered TBC with graded porosity for carbon fiber-reinforced plastic (CFRP) composites. The TBC was created by a flame spraying process, consisting of relatively dense and porous layers: (1) a dense layer was produced by spraying yttria-stabilized zirconia (YSZ) particles directly onto neat carbon fabric substrate and (2) a porous layer was prepared by co-spraying YSZ particles with sacrificial polyetheretherketone (PEEK) particles. The porosity of the porous layer was controlled by varying a PEEK injection distance …

Nanofiber-Hydrogel Composite Scaffold Fabrication Methods For Peripheral Nerve Regeneration, Jacob Lee Carter

Theses and Dissertations

Nerve graft conduits (NGCs) are a rapidly advancing field for treating peripheral nerve injuries that aim to guide the growth of regenerating axons across damaged gaps. A more effective NGC can be manufactured by combining the use of nanofibers to act as guidewires within a 3-D hydrogel that imitates the extracellular matrix of nerve tissue. Several methods have been developed to embed aligned nanofibers in an ordered architecture within a hydrogel matrix. The first method involves layer-by-layer additive manufacturing to create NGCs with rows of polycaprolactone (PCL) nanofibers surrounded by a gelatin methacrylate (GelMe) hydrogel in a 3-D structure. A …

Luminescent Coupling In Perovskite Tandem Solar Cells: The Advantages Of Perovskite And Luminescent Coupling In Photovoltaics, Briana Dokken

Senior Seminars and Capstones

Multijunction or tandem solar cells are made of multiple semiconductor light absorbing layers. Having multiple absorber layers in a solar cell allows it to absorb a larger range of the solar spectrum. When electrons recombine (relax to a lower energy state) in the top layer of a tandem solar cell, they can emit luminescent photons that are absorbed by the bottom layer of the cell. This process is called luminescent coupling, and it can be used to enhance the performance of photovoltaic cells. Another strategy to increase solar cell performance is to use perovskite as the absorber layer material. Currently, …

Experimental Study Of Drag Characteristics And Dust Removal Performance Of A Hybrid Wet-Filter Precipitator, Hang Yi, Zifeng Yang, Deqiang Chang, Xinjiao Tian, Jingxian Liu

Mechanical and Materials Engineering Faculty Publications

With their advantages of high dust removal efficiency and low drag characteristics, hybrid wet-filter precipitators have great potential for dust control in coal mines, but the underlying mechanisms are not well understood. In this study, to help fill this knowledge gap, a hybrid wet-filter precipitator consisting of a 40-layer metal filter and a defogger device is designed and a prototype is constructed. Experiments are conducted to investigate its drag characteristics under wind velocities from 0.85 to 5.68 m/s and its dust removal performance under wind velocities of 2 and 4 m/s. On the basis of results with the initial design, …

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …

Response Of ¹¹B Enriched Zrb2 Ultra-High Temperature Ceramic To Neutron Irradiation At Elevated Temperatures, Yan Ru Lin, Takaaki Koyanagi, David J. Sprouster, Christian M. Petrie, William Fahrenholtz, Greg Hilmas, Yutai Katoh

Materials Science and Engineering Faculty Research & Creative Works

ZrB₂, an ultra-high temperature ceramic (UHTC) is being considered for use in fusion reactor first-wall structures, yet its response to irradiation remains poorly understood. This study employed scanning/transmission electron microscopy (S/TEM), synchrotron X-ray diffraction (XRD), finite element calculations, and thermal property measurements to thoroughly investigate the neutron-irradiation effects on ¹¹B-enriched ZrB₂. Neutron irradiations were conducted at 220 °C and 620 °C, with a neutron fluence of 2.2 x 1025 neutron/m2 (energy > 0.1 MeV), resulting in 3.9 dpa and 4200 appm He. The study revealed the unusual prevalence of prism loops and a > c anisotropic lattice …

Study Of The Structure Of Zn And Na Borophosphate Glasses Using X-Ray And Neutron Scattering Techniques, Uwe Hoppe, Parker T. Freudenberger, Richard K. Brow, Jozef Bednarčik, Alex C. Hannon

Materials Science and Engineering Faculty Research & Creative Works

The atomic structures of Zn and Na borophosphate glasses were studied using X-ray and neutron scattering techniques. Peaks assigned to the B−O, P−O, and O−O distances confirm that only BO₄ units co-exist with the PO₄ tetrahedra. The Zn−O and Na−O coordination numbers are found to be a little larger than four. The narrowest peaks of the Zn−O first-neighbor distances exist for the glasses along a line connecting the Zn (PO₃)₂ and BPO₄ compositions (50 mol% P₂O₅), which is explained by networks of ZnO₄, BO₄, and PO …

First-Principles Simulation Of The Interaction Between Dna Nucleotides And One-Dimensional Carbon Chain In Electrical Based Sequencing, Zeina Salman, Jin-Woo Kim, Steve Tung

Biological and Agricultural Engineering Faculty Publications and Presentations

Electrical DNA sequencing has attracted significant attention in recent years due to its simplified sequencing protocol, compact sequencing system, and relatively low sequencing cost. In the design and fabrication of the sequencing device, carbon-based nanomaterials such as graphene have been explored as a promising sensing material that provides an excellent combination of spatial resolution and base specificity. Using first-principles simulation, we determined the effect on the electrical conductivity of a one-dimensional carbon chain due to the presence of four DNA bases. The simulation results indicate that the interaction between the carbon chain and different DNA bases leads to different levels …

Analysis Of The Thermal Aging Kinetics Of Tallow, Chicken Oil, Lard, And Sheep Oil, Yun-Chuan Hsieh, Hao Ouyang, Yulin Zhang, Donyau Chiang, Fuqian Yang, Hsin-Lung Chen, Sanboh Lee

Chemical and Materials Engineering Faculty Publications

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid–base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 ◦C to 180 ◦C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics. The evolutions of the color centers, defects for dynamic viscosity, and electric dipoles follow second-order, first-order, and zero-order kinetics, respectively. …

Development Of Tissue-Engineered Model Of Fibrotic Scarring After Spinal Cord Injury To Study Astrocyte Activation And Neurite Outgrowth In Vitro, Nikolas Ala-Kokko, Inha Baek, Younghye Song

Biomedical Engineering Faculty Publications and Presentations

Traumatic spinal cord injuries (SCI) are debilitating injuries affecting twenty-seven million people worldwide and cause functional impairments. Despite decades of research and medical advancements, current treatment options for SCI remain limited, in part due to the complex pathophysiology of spinal cord lesions including cellular transformation and extracellular matrix (ECM) remodeling. Recent studies have increased focus on fibrotic scarring after SCI, and yet much remains unclear about the impact of fibrotic scarring on SCI lesion progression. Here, using collagen and decellularized spinal cord-based composite hydrogels, a three-dimensional (3D) cell culture model mimicking the fibrous core of spinal cord lesions was implemented …

Growth And Faceting Of Tungsten And Oxides In Scandate Cathode Particles During In Situ Heating In The Scanning Electron Microscope, Huanhuan Bai, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Tungsten-based scandate dispenser cathodes are promising next-generation thermionic electron sources for vacuum electron devices, due to their excellent emission performance at tempera- tures lower than those required for conventional cathodes. There has been a significant recent effort to understand scandate cathode performance and to characterize the tungsten and other materials on the emitting surface, primarily via the study of cathodes before and after emission testing. Moreover, these scandate cathodes have typically been characterized at room temperature only. In situ obser- vations of scandate cathodes is challenging, as these devices are thermionic emitters that operate in a high-vacuum environment, and because …

Effects Of External Pressure On Cycling Performance Of Silicon-Based Lithium-Ion Battery: Modelling And Experimental Validation, Kai Zhang, Yinan He, Junwu Zhou, Xinyang Wang, Yong Li, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Controlling the stress state of electrodes during electrochemical cycling can have a positive effect on the cycling performance of lithium-ion battery. In this work, we study the cycling performance of silicon-based lithium-ion half cells under the action of pressure in a range of 0.1 to 0.4 MPa. The cycling performance of the silicon-based lithium-ion half cells increases first with increasing the pressure to 0.2 MPa and then decreases with further increasing the pressure. The analysis of the surface morphologies of cycled electrodes reveals that applying a pressure of 0.2 MPa leads to the formation of fine electrode surface with the …

Electrified Membrane For Water Treatment And Resource Recovery: Advancing Multiscale Strategies In Gas-Involving Reactions, Jianan Gao

Dissertations

Multifunctional, modular, and scalable water treatment technologies that operate without chemical additives are crucial for addressing global water pollution challenges. While traditional membrane-based separation processes are crucial for ensuring clean water supplies, they primarily focus on pollutant removal rather than on the upcycling of pollutants into valuable resources. Electrified membrane filtration presents a robust alternative, utilizing minimal or no chemical additives and harnessing electrical power to directly reduce contaminants or produce reactive oxidants or reductants on-site.

This dissertation is dedicated to the development of innovative electrochemically reactive membranes designed to address three major challenges: (1) the engineering of electrocatalysts with …

Experimental Investigation And Evaluation Of Mechanical Properties And Microstructural Characterization On Chromium Molybdenum Steel Processed Through Laser Based Welding, Rakesh S

Theses and Dissertations

Creep Strength Enhanced Ferritic (CSEF) martensitic modified 9Cr-1Mo (P91) steel is extensively employed in fast breeder nuclear reactors and thermal power plants owing to its superior resistance to thermal fatigue and oxidation corrosion compared with other low-alloy steels. Despite its excellent high-temperature performance, the weldability of this steel remains a critical concern.

Conventional arc welding processes generate excessive heat input and complex thermal cycles, resulting in heterogeneous microstructures, retention of δ-ferrite, and subsequent degradation in service life. In contrast, high energy density beam welding techniques such as laser and electron beam welding offer precise thermal control and minimal heat-affected zones …

Improving Fatigue Characteristics Of Cold Formed Low Carbon Steel, Venkatesan D

Theses and Dissertations

EN353 is a low carbon alloy steel, predominantly used in the manufacturing of heavy-duty gears, shafts, and pinions, especially crown wheel and pinions. It is usually carburized, hardened, and tempered to produce a hard, wear-resistant case. Heat- treated EN353 steel exhibits enhancement in ductility, toughness, strength, and hardness as the internal stresses get relieved in the material. Spheroidizing of medium and high carbon steel is a method of prolonged heating at a temperature below the eutectoid temperature, where pearlite, the lowest energy arrangement of steel, gets converted to ferrite and cementite.

The graphite content of steel assumes a spheroidal shape, …

Thermomechanical Analysis Of Biomass Plastic Composite (Bpc), Solomon Chijioke Madu, Victor Sunday Aigbodion, Ikechukwu Ike-Eze

Makara Journal of Technology

High-performance electrical insulation material can be manufactured using biomass plastic composite (BPC), which is a new type of composite material that is either made up of one or a combination of natural plant fibers/particulates, such as bamboo, cellulose fiber, rice husks, or hemp, and thermoplastic granules. In this study, the BPC composite material that was developed comprised polyethylene (PE), rice husk, and oyster shell. The results of the study showed a significant optimal improvement in the morphological, thermodynamic, and mechanical properties during the addition of 20% to 30% biomass particulates (i.e., rice husk and oyster shell). The thermogravimetric analysis, storage …

Rate Law For Photoelectrochemical Water Splitting Over Cuo, Bo-Yuan Gao, Wen-Hua Leng

Journal of Electrochemistry

Photocatalytic splitting of water over p-type semiconductors is a promising strategy for production of hydrogen. However, the determination of rate law is rarely reported. To this purpose, copper oxide (CuO) is selected as a model photocathode in this study, and the photogenerated surface charge density, interfacial charge transfer rate constant and their relation to the water reduction rate (in terms of photocurrent) were investigated by a combination of (photo)electrochemical techniques. The results showed that the charge transfer rate constant is exponential-dependent on the surface charge density, and that the photocurrent equals to the product of the charge transfer rate constant …

Winning Works From Journal Of Electrochemistry: The 2Nd Xiamen University Short Video Abstract Contest For Science And Technology Journal Papers, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Recent Advances On Ruthenium-Based Electrocatalysts For Lithium-Oxygen Batteries, Yu-Zhe Wang, Zhuo-Liang Jiang, Bo Wen, Yao-Hui Huang, Fu-Jun Li

Journal of Electrochemistry

Rechargeable lithium-oxygen (Li-O₂) batteries have attracted wide attention due to their high energy density. However, the sluggish cathode kinetics results in high overvoltage and poor cycling performance. Ruthenium (Ru)-based electrocatalysts have been demonstrated to be promising cathode catalysts to promote oxygen evolution reaction (OER). It facilitates decomposition of lithium peroxide (Li₂O₂) by adjusting Li₂O₂ morphologies, which is due to the strong interaction between Ru-based catalyst and superoxide anion (O₂^–) intermediate. In this review, the design strategies of Ru-based electrocatalysts are introduced to enhance their OER catalytic kinetics in …

Numerical Analysis Of Explosion Characteristics Of Vent Gas From 18650 Lifepo4 Batteries With Different States Of Charge, Shi-Lin Wang, Xu Gong, Li-Na Liu, Yi-Tong Li, Chen-Yu Zhang, Le-Jun Xu, Xu-Ning Feng, Huai-Bin Wang

Journal of Electrochemistry

The combustion and explosion characteristics of lithium-ion battery vent gas is a key factor in determining the fire hazard of lithium-ion batteries. Investigating the combustion and explosion hazards of lithium-ion batteries vent gas can provide guidance for rescue and protection in explosion accidents in energy storage stations and new energy vehicles, thereby promoting the application and development of lithium-ion batteries. Based on this understanding and combined with previous research on gas production from lithium-ion batteries, this article conducted a study on the combustion and explosion risks of vent gas from thermal runaway of 18650 LFP batteries with different states of …

Winning Results Of The 2Nd Xiamen University Short Video Abstract Contest For Science And Technology Papers, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.