Tea Polyphenol-Assisted Green Synthesis Of Silver Nanoparticle-Boron-Doped Diamond Nanoparticles For Theophylline Electrochemical Detection, Prastika Krisma Jiwanti, Adira Ainun Tsalsabilla, Angellita Wijaya Gunawan, Siti Wafiroh, Mohammad Kalimanjaro, Mai Tomisaki

Makara Journal of Science

Drug theophylline is a bronchodilator used to treat asthma and chronic obstructive pulmonary disease (COPD), but precise monitoring is required to avoid side effects. Therefore, this study aimed to develop a screen-printed electrode (SPE) modified with a composite of green-synthesized silver nanoparticles and boron-doped diamond nanoparticles using tea polyphenols (Ag-BDDTP/SPE) for detecting theophylline. Formation of AgNPs was confirmed by UV-Vis spectroscopy, which showed a localized surface plasmon resonance peak at ~450 nm. Transmission electron microscopy revealed polydisperse nanoparticles with an average diameter of 39.94 nm. During the electrochemical detection of theophylline, square-wave voltammetry (SWV) was employed to evaluate signal-to-background (S/B) …

Lafe0.925ti0.075o3 Perovskite Coated With Ethyl Cellulose: A High-Stability, Low-Hysteresis Platform For Advanced Humidity Sensing, Akhmad Futukhillah Fataba Alaih, Djoko Triyono, Rifqi Almusawi Rafsanjani

Makara Journal of Science

Humidity sensors are pivotal in numerous sectors, such as environmental monitoring, industrial automation, and health-care. This study presents the fabrication and detailed evaluation of an advanced humidity sensor using ethyl cellulose (EC)-coated LaFe_0.925Ti_0.075O₃ (LFTO) perovskite nanoparticles synthesized via the sol-gel method. The LFTO nanopar-ticles exhibited a mesoporous structure with an enhanced surface area, which significantly improved their moisture adsorption capabilities. The innovative application of EC coating addresses critical substrate adhesion issues, enhancing mechanical stability without compromising sensor sensitivity. Comprehensive performance evaluations revealed minimal hysteresis (

Effect Of Heat Treatments On The Corrosion Resistance Of A Trip Steel And Its Evaluation By Non-Destructive Testing, Karla Ivette Vega-Nava, Ariosto Medina-Flores, Marco Antonio Espinosa-Medina, José Sergio Pacheco-Cedeño, Héctor Guillermo Carreón-Garcidueñas, Francisco Fernando Curiel-López, Jose Jaime Taha-Tijerina

Mechanical Engineering Faculty Publications

The development of advanced high-strength steels (AHSS) for the automotive industry requires optimizing the balance between mechanical properties and durability in aggressive environments. This study investigates the effects of two heat treatment routes on the microstructure and corrosion resistance of a transformation-induced plasticity (TRIP) steel (Fe-0.2C-1.75Mn-0.5Si-1Al). Route A includes a full austenitizing step at 1000 °C prior to intercritical annealing, whereas Route B omits this step and begins directly with intercritical annealing at 800 °C. Microstructural characterization (SEM/XRD), electrochemical assays, and eddy current tests were employed. The results revealed that Route A yields a homogeneous microstructure with 12.7% retained austenite, …

Review On Capacity Degradation Mechanisms And Lifetime Prediction Of Energy Storage Li-Ion Battery, Ma Yue, Chen Yanqiao, Wang Chu, Wang Xianwen, Liu Hui, Chen Yifei, Chen Lai, Yan Kang, Su Yuefeng

Dianchi(Changsha)

No abstract provided.

Opportunities And Challenges Of Cross-Border E-Commerce In Li-Ion Batteries, Ma Jingjing, Chen Xianyi

Dianchi(Changsha)

No abstract provided.

Strengthening The Properties Of Clay Soil With Crushed Oysters, Hadeel Ammar Mohammed, Najwa Wasif Jassim, Hanan Adnan Hassan Afaj, Mohammed Yousif Fattah, Noor S. Al-Hassnawi

HBRC Journal

When problematic clayey soils are used for engineering purposes without treatment, they can lead to structural cracks in roads, buildings, and underground infrastructure. The use of oyster shell powder in geotechnical applications has been the subject of little research, which is why this study looked into it. Examining the stabilization of different percentages (6, 9, 12, 15, 18, and 21 percent) of oyster shell (OS) treatment of clayey soil is the aim of this study. Compaction, strength, CBR, and Atterberg tests are among the experiments used in this study. The study's importance lies in turning oyster shell waste into a …

Numerical Evaluation Of Constitutive Soil Models For Cyclic Soil–Structure Interaction In Integral Abutment Bridges, Walaa Sayed Said, Sherif Adel Akl, Abdullah Galaa, Mohamed El-Khouly

HBRC Journal

The accurate representation of backfill soil behaviour is a critical step in Finite Element (FE) analysis of Integral Abutment Bridges (IABs) subjected to thermally induced cyclic loading. This paper focuses on the evaluation and selection of a constitutive model, out of those commonly available in geotechnical FE packages, suitable for this purpose. Hardin–Drnevich (HD), General Quadratic/Hyperbolic Shear (GQHS), Hardening Soil (HS) including its extension to consider the small-strain stiffness (HSS), and the University of British Columbia (UBC) sand model were first assessed through simulating drained cyclic simple shear element tests. The results indicated that the UBC model captured key aspects …

Patterns Of Alcolysis Of Secondary Polyethylene Terephthalate With Diethylene Glycol, Juraev B. Juraev, Murafar G. Alimuhamedov, Ravshan I. Adilov, Bobir B. Aykhodjaev, Olga S. Kukurina

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work was to study the process of alcoholysis of recycled polyethylene terephthalate with diethylene glycol, as well as the structure and physicochemical properties of the final product. IR and PMR spectroscopy were used to study the structure and identify the structure of the products of RPET alcoholysis with diethylene glycol. As a result of  studies of the alcoholysis of polyethylene terephthalate-containing waste with diethylene glycol, a wide range of hydroxyl-containing oligoesters was synthesized. The possibility of changing their physicochemical properties by adjusting the process parameters was demonstrated. This makes it possible to synthesize hydroxyl-containing oligoesters with …

Synthesis And Infrared-Spectroscopic Study Of Complexes Of Selected 3d-Metals With 2-(2-Pyridyl)-Benzimidazole, Farangiz A. Khujayeva, Hakima A. Alikulova, Shahzoda G. Allamurodova, Mushtariybonu M. Sunnatillayeva, Shahlo Sh. Daminova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this study was to synthesize and systematically investigate the coordination compounds of several 3d metals with 2-(2-pyridyl)benzimidazole (2-PBI) using infrared (IR) spectroscopy. Complexes of copper(II), nickel(II), and cobalt(II) with the general formula [M(2-PBI)3](ClO₄)₂were successfully synthesized. Based on the analysis of the IR spectra, it was established that the 2-PBI ligand coordinates to the metal ion in a bidentate manner through the nitrogen atoms of the benzimidazole and pyridyl rings. The shifts of the ν(C=N) and ν(C–N) stretching vibration bands, as well as the appearance of new bands in the 623–485 cm⁻№ region corresponding to ν(M–N) and vibrations, …

Production Of Organo-Mineral Fertilizing Ameliorants Based On Phosphogypsum, Central Kyzylkum Phosphorites And Biohumus, Temur A. Ospanov, Axmed M. Reymov, Rashid K. Kurbaniyazov, Jaxanger M. Bisenbaev

CHEMISTRY AND CHEMICAL ENGINEERING

Phosphogypsum, a large-scale industrial by-product generated during phosphoric acid production, poses significant environmental challenges due to its accumulation and potential ecological impact. This study investigates the utilization of phosphogypsum as a raw material for producing fertilizing ameliorants in combination with Central Kyzylkum phosphorites and biohumus. Composite mixtures were prepared and granulated using a 30% ammonium sulfate solution as a binding agent. The chemical composition, phase structure (XRD), and microstructure (SEM–EDS) of the obtained materials were analyzed. The results demonstrate the formation of calcium phosphate and sulfate phases, including CaHPO4·2H2O, β-Ca3(PO4)2, and CaSO4·2H2O, which contribute to both fast- and slow-release nutrient …

Processing Of Wc–Co Waste With Selective Extraction Of Co3o4 By Oxidative Fusion In Nano3 Melt, Ilyos A. Bozorov, Aziz B. Ibragimov, Odiljon E. Abdurakhmonov, Mastura Kh. Aripova, Sherzod E. Abdurakhmonov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this study was to develop and experimentally validate a selective method for producing high-purity cobalt oxide from WC–Co hard alloy waste using oxidative fusion in a sodium nitrate (NaNO₃) melt, followed by combined aqueous and acidic purification of the solid residue. Cemented carbide scrap and waste containing 6–12 wt.% Co were used as feedstock, without prior grinding. It was found that, during heat treatment in the range of 650–900 °C, tungsten predominantly converts into soluble sodium tungstates, while cobalt concentrates in the solid residue as an oxide phase. Optimal process conditions, such as 850°C and …

Temperature-Dependent Electrocatalytic Activity Of Mxene For Hydrogen Evolution Reaction., Javlonbek I. Mamanazirov, Shavkat I. Mamatkulov

CHEMISTRY AND CHEMICAL ENGINEERING

This study represents the synthesis technology of MXene catalyst for hydrogen evolution reaction (HER) and investigates the temperature-dependent electrocatalytic activity of MXene-based catalysts in alkaline media. Using a three-electrode configuration in 1M KOH, the electrochemical performance was systematically evaluated across a temperature range of 25 °C to 40 °C. Linear sweep voltammetry (LSV) results demonstrate a significant enhancement in catalytic efficiency at elevated temperatures, evidenced by a consistent shift in polarization curves toward lower potentials. Specifically, the overpotential required to achieve a current density of 10 mA/cmІ decreased from 257 mV at 25 °C to 203 mV at 40°C, marking …

Features Of Formation Of The Structure And Properties Nonfritted Glazes For Sanitary Ceramic Products, Ivan A. Levitskii, Mihail V. Dyadenko, Valery G. Luhin

CHEMISTRY AND CHEMICAL ENGINEERING

The results of research on the formation of nonfritted glass-ceramic coatings for sanitary ceramic products are presented. The synthesis was carried out in a multicomponent raw material mixture including pegmatite, chalk, quartz sand with a constant content of zirconium silicate, talc, wollastonite, zinc whitewash, refractory clay and kaolin. Glazes were obtained by single firing at a temperature of 1200±5 °C for a duration of 20 hours. Samples of coatings were obtained, the processes of glaze formation were studied, the fusibility of glazes was assessed, and their physico-chemical properties were studied in relation to the features of the formation of the …

Fiber-Optic Products Based On Borosilicate Glasses, Mihail V. Dyadenko

CHEMISTRY AND CHEMICAL ENGINEERING

The research results of the development of glass compositions for a light-guiding core, reflective and protective coats of optical fiber using a stack method are presented. The optimal ratio of glass-forming oxides and modifications in their compositions has been determined, which ensures the resistance of glasses to crystallization during the manufacture of optical fiber, its thermomechanical strength, the required geometry of optical fibers and the light transmission of fiber-optic products, amounting to 60–75%.

The influence of the chemical composition of the glasses of the light-guiding core and the light-reflecting coats on their refractive index, which determines the magnitude of the …

Synthesis Of Nanostructured Yttrium Oxide Luminescent Powders Activated By Terbium Ions, Eygeniy N. Poddenezhny, Andrei A. Boiko, Olga S. Nevzorova, Ekaterina E. Trusova, Vladimir S. Urbanovich

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to synthesize nanostructured luminescent powders of yttrium oxide doped with terbium ions. Y₂О₃:Tb³⁺ powders were obtained by thermochemical synthesis (combustion). The sources for the synthesis were nitric acid salts of yttrium and terbium. Organic acids, citric acid and acetic acid, were used as reducing agents and combustible components. It has been established that large porous aggregates with sizes up to 200 microns are formed with citric acid during combustion, and nanostructured finely dispersed powders consisting of nanocrystalline particles with sizes of 39±5 nm are formed with …

Magnetic Cellulose Nanocrystal Composites: Synthesis, Properties, Applications, And Opportunities, Mohammad Jahid Hasan, Kishore Chand, Esteban E. Ureña-Benavides, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

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Magnetic Cellulose Nanocrystal Composites: Synthesis, Properties, Applications, and Opportunities

Rheological Protocol To Assess And Optimize Latex Coagulation Dynamics For The Thin Glove Coagulant Dipping Process, Monday U. Okoronkwo, Kok Kong Ng, Wolfram Franke, Gaurav Sant

Chemical and Biochemical Engineering Faculty Research & Creative Works

Many products that directly impact the quality of human life today — gloves, catheters, condoms, and baby bottle teats — are made through the latex-dipping technology. While a variety of methods have been developed – e.g., particle counting, turbidimetry, microscopy, and light scattering – which are suitable for studying the coagulation of latex at very low concentrations, much less work has focused on methods suitable for in-situ characterization of latex coagulation in concentrated solutions (e.g., as relevant to the dipping process). This paper presents a process-relevant rheological protocol for assessing and optimizing latex coagulation dynamics for the thin glove coagulant …

Centrifugally Spun Silica Fibers For Lithium-Ion Battery Anodes: Structure And Cycling Stability, Alejandra Guerrero, Valeria Tirado, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

Introduction: Silicon dioxide (SiO2) fiber structures have attracted attention as alternative anode materials for lithium-ion batteries because of their ability to improve cycling stability compared to commercial silicon particles.

Materials and methods: SiO2 composite fibers were prepared by centrifugal spinning of polyvinylpyrrolidone (PVP)/SiO2 precursor solutions followed by calcination at 500–700 ◦C for different holding times to produce short-fiber composites and micro-belt SiO2 fiber structures. The morphology and crystal structure of the SiO2 short fibers and micro-belts were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS). Electrochemical performance was evaluated using CR2032 half-cells.

Results: The …

Optimizing Graphene Oxide In Self-Compacting Concrete: A Sustainable Nano-Material Strategy For Enhanced Durability And Structural Performance, Mohammed Shakeebulla Khan, Vijaya G. S

Journal of Sustainable Construction Materials and Technologies

In order to reduce the environmental impact of the constructed world, advanced and sustainable construction materials are needed. This work is a summary of the comprehensive study on a novel self-compacting concrete with nano-engineered material (graphene oxide) modified self-compacting concrete (GO-SCC). The optimum dosage of GO was determined using Taguchi method, Analysis of Variance (ANOVA) and Response Surface Methodology (RSM) multi-objective statistical optimization method, and was found to be 0.10% by weight of cement (bwoc). This dosage of 0.10% GO led to the overall desirability score of 0.87, which confirmed that this was the optimum dosage for six response variables …

Comparative Analysis Of Random Forest And Artificial Neural Networks For Predicting In-Situ Soil Density, Eng. Jinan Ali Abd Al-Kareem Al-Maliki, Dr Ammar Salman Dawood, Dr. Ihsan Al-Abboodi

HBRC Journal

This study suggests that RF and ANN are proven to be robust algorithms in predicting in-situ soil density, which is considered a significant geotechnical parameter. The research is based on 86 soil samples and focuses on five main input parameters: Gravel Percentage (G%), Plastic Limit (PL%), Sand Percentage (S%), Fines Percentage (F%), and Liquid Limit (LL%). The models developed here utilize five commonly recorded index properties (G%, S%, F%, LL, and PL) for all field samples taken from the Basra-Faw Road project. The influence of moisture content and compressive energy was ignored, as all field samples acquired the same moisture …