Physical Sciences and Mathematics Commons^™

Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei

Journal of Electrochemistry

β-Amino acids have a wide range of applications in the field of pharmaceuticals. Utilizing a combination strategy of nickel catalysis and paired electrolysis, a catalytic α-arylation protocol of carbonyl compounds has been developed. This protocol affords various a-aryl-a-cyanoacetates, which can be reduced to high-value-added α-aryl-β-amino acids. The cross-coupling reaction of electron-deficient aryl bromides with a-cyanoacetates achieves the expected products with good yields and functional group compatibility under mild conditions. Excessive electron-richness in initial aryl bromides facilitates the self-coupling of desired products. DFT calculations confirm that the presence of electron-rich aryl substitutions decreases the …

Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan

Journal of Materials Exploration and Findings

Metal matrix composite (MMC) with 7xxx aluminum matrix is potential for ballistic applications due to the combination of strength, toughness, and light weight. Previous study successfully produced aluminum-based composites with SiC particles which were able to stop type III bullet, however cracks remained on back of the plate. Therefore, in this research, SiC was replaced by zirconia (ZrO₂) due to its high fracture toughness. Ti-B grain refiner was added to further improve toughness through grain boundary strengthening mechanism. This research developed 5 vol.% ZrO₂ strengthened Al-10Zn-6Mg-2Si composite with addition of Al-5Ti-1B grain refiner produced through squeeze casting …

Integration Of The Ashby Technique And Pahl-Beitz Quantitative Ranking For Railway Axle Material Selection, Helya Chafshoh Nafisah, Jaka Fajar Fatriansyah, Siti Norasmah Surip

Journal of Materials Exploration and Findings

Railway axle serves as a vital connection between the train's wheels and its body. However, cyclic loading and high speed can induce fatigue in railway axle, which potentially leads to damage human safety. Therefore, it is important to find materials that have good mechanical properties with the lowest weight and cost. In this paper, a comprehensive method using Ashby chart has been performed to select candidate materials of railway axle. The methods begin with analyzing function by determining the problem, objective function, and constraints. After that, the results obtained are ranked using Pahl and Beitz quantitative weighting method. The results …

Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani

Journal of Materials Exploration and Findings

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand …

An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The process of generating chlorine gas using electrolysis in aqueous systems is well established. However, a new process requires chlorine to be generated at high temperatures using molten salt. This harsh environment requires a new study of anode materials for the chlorine evolution reaction. Anode materials can be compared by their kinetic parameters, the transfer coefficient α and the exchange current i0. The basic theory of these properties as they relate to the chlorine evolution reaction has been detailed and an analysis method for finding these effective parameters has been shown and demonstrated.

Review Of Cyclic Voltammetry Measurements For Uranium In Flinak Molten Salt, Jackson Ivory

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The electrochemical behavior of uranium FLiNaK molten salts is explored, focusing on cyclic voltammetry (CV) as a powerful tool for redox characterization and diffusion studies. Through a comprehensive review of recent research, the study highlights the significance of CV in understanding electrode kinetics, material compatibility, and process optimization in molten salt environments. The findings underscore the potential of FLiNaK molten salt reactors in advancing nuclear energy technologies, fuel processing, and waste management strategies. Collaborative interdisciplinary efforts are emphasized to address challenges and accelerate innovation in electrochemical methods for nuclear applications.

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, …

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 …

High Energy Approximation For Monte Carlo Event Generator, A. N. Ismailova, Yu. L. Parfenova, P. G. Sharov, D. M. Janseitov

Eurasian Journal of Physics and Functional Materials

Analysis of the nuclear physics experiment often requires Monte Carlo simulation of the detector setup. Such kind of simulations often requires a quite advanced model of nuclear interaction. In this work we describe application of Monte Carlo simulation in the nuclear physic experiment, and discuss on example of elastic scattering how to apply well known High Energy Approximation (or Glauber model) to Monte Carlo simulation of the experimental setup.

Determination Of Phase Boundaries And Diffusion Coefficients Of Copper In Spinel Cucr2se4 And Delafossite Cucrse2 By Galvanostatic Intermittent Titration Technique (Gitt), A. O. Onishenko, E. A. Suslov, M. S. Postnikov, A. S. Shkvarin, A. N. Titov, A. I. Merentsov

Eurasian Journal of Physics and Functional Materials

Cux CrSe2 materials can exist in the form of delafossite with a layered structure and exhibit multiferroic properties, or in the form of spinel and exhibit ferromagnetic properties, depending on the copper concentration. The stability of both forms of Cux CrSe2 has been studied with regards to defectivity in the copper sublattice. The boundaries of the Cux CrSe2 homogeneity regions for the delafossite- like structure and for the cubic spinel CuCr2Se4 were determined by coulometric titration at room temperature. Analysis of the time dependence of cell polarization allowed us to estimate the diffusion coefficients in these materials

Concentration Polarization And Ionic Conductivity Of Nanocomposite Thermoelectric Materials K0.01cu1.94s, K0.02cu1.94s, K0.03cu1.94s, M. M. Kubenova, M. Kh. Balapanov, K. A. Kuterbekov, B. Akhmetgaliev, R. Kh. Ishembetov, R. F. Almukhametov, M. Zeleev, A. M. Kabyshev, K. Zh. Bekmyrza, R. Alina, R. E. Kondakirov, M. K. Kenzhebek

Eurasian Journal of Physics and Functional Materials

The paper presents experimental results of concentration polarization and ionic conductivity of nanocom- posite thermoelectric materials K0.01Cu1.94S , K0.02Cu1.94S , K0.03Cu1.94S . According to X-ray phase analysis, the synthesized samples are monoclinic jarleite Cu1.93÷1.97S with an admixture of oxygen ox- ide Cu2S and monoclinic chalcocyte. High values of total ionic conductivity are observed, ranging from 0.86 to 1.5 Cm/cm. The lowest ionic conductivity (0.86 Cm/cm at 355 ◦ C) is observed for alloy K0.02Cu1.94S . In addition, it was found that with an increase in the concentration of potassium in the studied materials, ionic conductivity tends to decrease, activation energy …

Study Of The Effect Of Combined Reinforcement And Modification Of Epoxy Resin With Rubbers On The Impact Strength Of Carbon Fiber-Reinforced Plastic, M. N. Meiirbekov, M. B. Ismailov, A. K. Kenzhegulov, L. M. Mustafa, I. B. Tashmukhanbetova

Eurasian Journal of Physics and Functional Materials

The effect of modified epoxy resin with polyurethane, silicone, and butadiene rubber and combined reinforcement with fiberglass and Kevlar on the strength properties of carbon fiber-reinforced plastic was studied. It was found that when rubber is introduced into the composition of the epoxy resin, polyurethane, and combined reinforcement according to the carbon fiber/Kevlar scheme in a ratio of 10:10 leads to an increase in impact strength by 42% to 273 kJ/m2 and compressive strength increases by 35% to 575 MPa

Luminescence And Creation Of Electron-Hole Trapping Centers In Alkali Metal Sulfates Activated By Pb2+ Impurity, T. N. Nurakhmetov, R. K. Shamieva, Zh. M. Salikhodzha, N. I. Temirkulova, T. T. Alibay, B. M. Sadykova, B. N. Yussupbekova, A. A. Kabdulkak

Eurasian Journal of Physics and Functional Materials

The nature of the impurity emission and the process of creating intrinsic and impurity electron-hole trapping centers were studied by spectroscopic and thermal activation methods in Na2SO4 - Pb and K2SO4 - Pb phosphors. The combined radiative electronic state is formed from intrinsic SO3− 4 - SO− 4 and impurity Pb+ - SO− 4 electron-hole trapping centers in UV-irradiated phosphors with a photon en- ergy of 6.2 eV at 80 K. Emissions of 3.2 eV and 3.6 eV resulting from irradiation with photons with an energy of 6.2 eV are associated with intracenter transitions of 3p1 - 1s0 in Pb2+ …

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 …

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, …

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 …}

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 …

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 …

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 …

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, Datu Rizal Asral, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Hydrocarbon releases might result in serious consequences in various aspects. In addition to the contribution to environmental pollution, repetitive leakages need high repair costs. This study aim is to minimize potential repetitive leakage for other typical 3-phase piping systems. We conducted the risk assessment by adopting Risk Based Inspection (RBI) API 581 to identify risk level, calculating piping lifetime, recommended inspection plan and mitigations. The most relevant root causes can be obtained through quantitative Fault Tree Analysis (FTA). Observation and investigation was taken from eight 3-phase piping systems that experienced repetitive leakages. It has been found that the risk level …

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj

Journal of Materials Exploration and Findings

The production of metal and alloy products requires the use of heat treatment, when during the heat treatment process, quenching is a crucial step. The quenching medium can be anything from water, a salt bath, oil, air and gas. In a vacuum furnace, pressurized gas, most frequently nitrogen (N₂) gas, serves as one of the quenching mediums. One of the drawbacks of the quenching process is the distortion and dimensional change of the parts. This paper aims to investigate the influence of nitrogen gas quenching pressure on the distortion and dimensional change of aerospace actuator gear planet parts …

Stability Of Non-Centrosymmetric Phases In Tetra-Coordinated Of Ldtm Intercalates, A. S. Shkvarin, M.S. Postnikov, S. V. Pryanichnikov, A. N. Titov

Eurasian Journal of Physics and Functional Materials

On the basis of comparison of temperature dependences of lattice parameters of CuCrSe₂ and Cu_0.5ZrSe₂ in the temperature region including transition between phases with centrosymmetric and noncentrosymmetric distribution of copper on positions tetrahedrally coordinated by selenium. It is concluded that the critical factor that ensures the stability of the non- centrosymmetric copper distribution is the covalent interaction between copper and selenium sublattices. This effect is not related to the anisotropy of the elastic constants of the lattice and can be observed in other layered structures with copper tetrahedrally coordinated by chalcogen.

Production Of Zno Thin Films Used In Solar Cell With A Sol-Gel Homemade Dip Coater Technique And Investigated Of Their Structural, Morphological And Optical Properties, Z. Gã¼Ltekin, C. Akay, N. A. Gã¼Ltekin, M. Alper

Eurasian Journal of Physics and Functional Materials

We designed a homemade dip coater controlled by an Arduino microcontroller to produce semiconductor metal oxide films such as ZnO, CoO, and NiO. The developed device was successfully used to deposit ZnO film on a glass substrate. The structural, surface, and optical properties of the film were investigated. XRD patterns showed that the film is predominantly a hexagonal wurtzite crystalline structure. Scanning electron microscopy (SEM) images showed that the ZnO film was uniformly and homogeneously coated on the glass substrate. EDX analysis confirmed the presence of Zn and O in the film structure. Optical characterization by UV-visible spectrometry showed that …

Scanning Tunneling Spectroscopy Of Homooligonucleotides, T. Sharipov, R. Garafutdinov, A. Mishra, S. Santer, R. Shaikhitdinov, M. Balapanov, R. Bakhtizin

Eurasian Journal of Physics and Functional Materials

Short single-stranded DNA molecules of two types, consisting of dC nucleotides only or dA nucleotides only, were immobilized onto the surface of mica and silver substrates and studied by scanning probe microscopy methods. Geometric dimensions of the studied objects were determined. The currentvoltage curves of d(A)12 and d(C)12 oligonucleotides were measured. Their differential electrical resistances were estimated and compared with each other.

Characterization And Luminescence Dynamics Of Mgf2:W Ceramics, A.V. Strelkova, V. M. Lisitsyn, L. A. Lisitsyna, T.A. Koketai, D. A. Mussakhanov, Zh.T. Karipbayev, A. M. Zhunusbekov

Eurasian Journal of Physics and Functional Materials

This study delves into the synthesis and characterization of luminescent ceramics based on tungstenactivated magnesium fluoride (MgF₂) complemented with varying concentrations of lithium hydroxide (LiOH). Utilizing a distinctive sintering process conducted in an open-air milieu under robust radiation conditions, we successfully synthesized a series of tungsten-activated ceramics. Study revealed that the resultant ceramics prominently display luminescent properties, which can be excited by UV radiation in the spectrum of 200-300 nm, as well as by high-energy electron fluxes. The spectral characteristics of these ceramics, in terms of band position, half-width, and excitation spectra, are strikingly analogous to those observed …