Engineering Commons^™

Transient Electrochemical Surface-Enhanced Raman Spectroscopic Study In Electrochemical Reduction Of P-Nitrothiophenol, Yun Ling, Jing Tang, Guo-Kun Liu, Cheng Zong

Journal of Electrochemistry

P-nitrothiophenol (PNTP) is one of the most common probe molecules studied by surface-enhanced Raman spectroscopy (SERS). The research in electrochemical reduction behavior of PNTP will help understanding the mechanism for the nitrobenzene reduction. In this paper, we used transient electrochemical surface-enhanced Raman spectroscopy (TEC-SERS) to study the SERS of PNTP with cyclic voltammetry and chronoamperometry on gold electrodes. The results show that the TEC-SERS provide a time resolution that equals the transient electrochemical methods, and we concluded that the reaction was so quick that we did not observe the spectral information of intermediate species described in the literatures with a …

Quantitative Detection Of Levofloxacin Hydrochloride By Differential Pulse Stripping Voltammetry With Electrodeposited Bismuth Film Electrodes, Zi-Ying Guo, Zuo-Peng Li, Jiang Li, Jian-Guo Zhao, Feng Feng

Journal of Electrochemistry

In this study, differential pulse stripping voltammetry was developed for the quantitative detection of levofloxacin hydrochloride indirectly. Levofloxacin hydrochloride contains organic amine, which can be precipitated upon interaction with Zn(SCN)₄^2-. By means of differential pulse stripping voltammetry, the concentration of Zn²⁺ can be determined using an in-situ formed bismuth film electrode, which allows determining indirectly the amount of levofloxacine hydrochloride. The linearity equation, I = 1.1401c - 0.5309 with the correlative coefficient R = 0.9979, was presented in the experiment. The results showed that this approach is very sensitive, having a limitation of detection of 3.18 …

Polyaniline Coated Hollow Sulfur Prepared Using Sublimate 2,4,6-Tri(Propan-2-Yl)-1,3,5-Trioxane As Template For Sulfur Electrode, Zhang-Feng Li, Xiao-Rui Wang, Wen-Sheng Tian, Jin-Ze Yang, Ping Zhang, Li-Ping Ma, Yang Chen, Xiao-Li Cui, Zhi-Yu Jiang

Journal of Electrochemistry

An advance method for preparing polyaniline-coated hollow sulfur material using sublimate material ADD(2,4,6-tri(propan-2-yl)-1,3,5-trioxane) as a template was developed for lithium-sulfur battery. At first, the smashed ADD particles were coated by a sulfur layer through the reaction of Na₂S₂O₃ with diluted HCl. Then polyaniline layer was coated again on the surface of sulfur layer through the reaction of aniline with (NH₄)₂S₂O₈. After being dried at 60 ^oC for 12 h, the ADD in such a composite evaporated totally, and resulted in the formation of polyaniline-coated hollow sulfur …

Electrochemical Determination Of Trace Copper Ions In Drinking Water Source, Jing-Ji Peng, Hong Zheng, Yi-Song Zou, Guo-Kun Liu, Dong-Xing Yuan

Journal of Electrochemistry

Aiming at the on-site and quick safety evaluation of the dissolved trace copper ions (Cu²⁺) in drinking water source, an electrochemical detection platform was developed on the basis of the square wave anodic stripping voltammetry using the gold nanoparticles (Au NPs) modified glassy carbon electrode, where Au NPs were deposited via electrochemical cyclic voltammetry. The proposed method displayed the limit of detection as low as 1.3 μg·L^-1 in the linear range of 2 ~ 50 μg·L^-1. The proposed method was applied to the determination of Cu²⁺ in the midstream of Minjiang River, one of …

Bipolar-Membrane Electrodialysis Method To Treat Industrial High Saline Perfume Wastewater, Jian Zhang, Dong-Fang Niu, Shuo-Zhen Hu, Xin-Sheng Zhang

Journal of Electrochemistry

Large amount of organic saline wastewater is generated from various chemical industries. The contents of organic saline wastewater are more and more complicated as they are created from different types of industries. Directly discharging the organic saline wastewater without pre-treatment can generate severe environmental problem and waste useful resources. It is necessary to use an economical method to treat the organic saline wastewater and recover the salt into useful materials to achieve resource reuse. Bipolar-membrane electrodialysis (BMED) is one of the methods that can remove salt from the wastewater and convert it into certain acid and base with higher value …

Study On Electro-Sorption Of Heavy Metals And Sulfamethoxazole On Activated Carbon Fibers, Wen-Jun Zhao, Bing-Xin Jia, Ya-Nan Zhang, Jiu-Nian Guan, Jiao Qu, Ying Lu

Journal of Electrochemistry

To study the optimal removal condition, adsorption mechanism and comparative analysis of the three typical cationic pollutants, i.e., Zn(II), anionic pollutant Cr(VI) and molecular pollutant sulfamethoxazole (SMX), using self-made upflowed electro-sorption device for adsorptions of above three pollutants by modified activated carbon fiber were researched. The activated carbon fiber (ACF) was modified by hydrochloric acid. The ACF morphology and structure before and after modification were characterized by SEM, BET and FTIR. The characterization results show that the modified ACF had fewer surface impurities than the modified surface and the gully is more obvious, the specific surface area was increased by …

Electrochemical Sensor Based On Magnetic Electrode Modified With Magnetic Molecularly Imprinted Nanoparticles Immobilized Hemoglobin For Determination Of Hydrogen Peroxide, Yang Yuan, Jia-Xin Wang, Yu-Hua Cao

Journal of Electrochemistry

In this work, the surface-imprinted technique was used to prepare magnetic hemoglobin (Hb) imprinted nanoparticles, using Fe₃O₄@SiO₂ NPs as the carrier, Hb as the template molecule, and tetraethyl orthosilicate (TEOS) as the imprinted polymer monomer. The nanoparticles had a core-shell structure, with magnetic Fe₃O₄ NPs as the core and Hb imprinted polymers as the shell. Therefore, Hb could be concentrated and fixed on the surface of the magnetic imprinted nanoparticles (MMIPs NPs). Furthermore, MMIPs NPs were immobilized with chitosan (CS) on the surface of a magnetic electrode to constitute Hb enzyme-like biosensor …

Ionic Liquid Assisted Synthesis Of Porous Carbons From Rice Husk For Supercapacitors, Han-Fang Zhang, Feng Wei, Jian Sun, Meng-Ying Jing, Xiao-Jun He

Journal of Electrochemistry

It is still a challenge to prepare carbon materials with high specific surface area at low cost from renewable resources. Herein, the authors report an efficient approach to synthesize porous carbons (PCs) from rice husk with ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF₆)) as a template and an activation agent. The as-made PCs featured the high specific surface area up to 1438 m²·g^-1. As electrodes for supercapacitors, PCs showed a high specific capacitance of 256 F·g^-1 at 0.05 A·g^-1 in 6 mol·L^-1 KOH aqueous electrolyte and a good rate performance of 211 F·g …

Electrochemical Properties Of Sulfur In Different Carbon Support Materials, Bo Zhang, Jia Liu, Xiao-Chen Liu, De-Jun Li

Journal of Electrochemistry

In order to investigate the effect of carbon structure on electrochemical performance of sulfur/carbon composite in lithium-sulfur battery, in this paper, sublimation sulfur was incorporated into three types of carbon materials, namely, graphene, carbon black and porous carbon. The three sulfur/carbon composites were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD) techniques, and their electrochemical performances were also studied. The results showed that the sulfur/porous carbon composite offered an initial discharge capacity of 1623.2 mA·h·g^-1 and remained 845 mA·h·g^-1 after 100 cycles. Compared with graphene and carbon black, the mesopores and micropores in porous …

Electrochemical Behaviors Of Azopurine On Gold Electrodes, Ming-Xue Li, Hang Shi, Jia Liu, Meng Zhang, Jian-Zhang Zhou, De-Yin Wu, Zhong-Qun Tian

Journal of Electrochemistry

In this paper, we studied the electrochemical behaviors of azopurine on polished gold electrodes with cyclic voltammetry (CV). On the basis of analyzing scan rate and peak current, it was supposed that the redox process belonged to a reversible process controlled by adsorption in 0.2 mol·L^-1 PBS (pH = 4.0 ~ 10.0) solutions. The potentials of redox peaks moved more negatively with increasing pH value. This proved that the H⁺ proton has participcted in the electrochemical reaction. The further data analysis and the calculation of surface adsorption excess demonstrated that the reaction was a two-proton and two-electron process. …

Morphology Controlled Preparations And Electrochemical Properties Of Znco2O4 Electrode Materials For Supercapacitors, Yue-Shen Zhou, Meng Li, Shuang Wu, Zhao-Lei Li, Yan-Min Gao

Journal of Electrochemistry

In this work, hydrothermal reaction and high temperature were used to grow ZnCo₂O₄ active materials on Ni foam. The crystal stuctures and surface morphlogies of four samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The electrochemical performances were characterized by cyclic voltammetry (CV)、galvanostatic charge/discharge (GCD) testing and electrochemical impedance spectroscopy (EIS) on an electrochemical station. It can be seen that active materials tended to form denser stuctures with an increasing amount of NH₄F in the solution system and four different morphologies of ZnCo₂O …

Zif-67-Derived Ag/Co-Embedded N-Enriched Mesoporous Carbon For Oxygen Reduction Reaction, Zheng-Ling Di, Jing Zhu, Lei Dai, Wei Meng, Yue-Hua Li, Zhang-Xing He, Ling Wang

Journal of Electrochemistry

Nitrogen-doped porous carbon materials are considered as one of the most promising catalysts for oxygen reduction reaction (ORR). Herein, in order to further improve the activity of the nitrogen-doped porous carbon, Ag/Co bimetal is embedded into nitrogendoped porous carbon to form Ag/Co-embedded nitrogen-doped porous carbon material (AgCo@NC). The AgCo@NC was derived by the wet impregnation of Ag+ into ZIF-67 precursor, followed by chemical reduction and a subsequent pyrolysis process under Ar atmosphere at different temperatures (500 ℃, 600 ℃, 700 ℃). The morphologic characterization shows that the Ag/Co nanoparticles were successfully embedded in the mesoporous carbon framework with abundant nitrogen …

Electrochemical Cycling Stability Of Polyaniline Films In Different Color Ranges, Kun Xu, Kai-Ling Zhou, Hao Wang, Jing-Bing Liu, Hui Yan

Journal of Electrochemistry

The electrochromic behaviors of polyaniline films were investigated by potential step and cyclic voltammetry coupled with UV viscosity photometer. The polyaniline films show colorful changes from pale yellow to green and then to blue. Electrochromic stability, electrochemical behavior, coloring performance, optical properties and surface formations of the produced films were studied in detail. The working electrode was the flexible PANI electrode, and the counter electrode and the reference electrode were a platinum sheet and Ag/AgCl, respectively. The in situ optical transmittance of the PANI film at 650 nm was measured using an ultraviolet-visible-near-infrared spectrophotometer (Shimadzu UV-3101PC) combining with a square …

Protein And Polysaccharide-Based Magnetic Composite Materials For Medical Applications., Elizabeth J Bealer, Kyril Kavetsky, Sierra Dutko, Samuel Lofland, Xiao Hu

Faculty Scholarship for the College of Science & Mathematics

The combination of protein and polysaccharides with magnetic materials has been implemented in biomedical applications for decades. Proteins such as silk, collagen, and elastin and polysaccharides such as chitosan, cellulose, and alginate have been heavily used in composite biomaterials. The wide diversity in the structure of the materials including their primary monomer/amino acid sequences allow for tunable properties. Various types of these composites are highly regarded due to their biocompatible, thermal, and mechanical properties while retaining their biological characteristics. This review provides information on protein and polysaccharide materials combined with magnetic elements in the biomedical space showcasing the materials used, …

Quantitative Peel Test For Thin Films/Layers Based On A Coupled Parametric And Statistical Study, Maysam Rezaee, Li Chih Tsai, Muhammad Istiaque Haider, Armin Yazdi, Ehsan Sanatizadeh, Nathan P. Salowitz

Mechanical Engineering Faculty Articles

The adhesion strength of thin films is critical to the durability of micro and nanofabricated devices. However, current testing methods are imprecise and do not produce quantitative results necessary for design specifications. The most common testing methods involve the manual application and removal of unspecified tape. This overcome many of the challenges of connecting to thin films to test their adhesion properties but different tapes, variation in manual application, and poorly controlled removal of tape can result in wide variation in resultant forces. Furthermore, the most common tests result in a qualitative ranking of film survival, not a measurement with …

150 Years Since The Development Of The Periodic System Of Chemical Elements By D.I. Mendeleev, Yu. Ts. Oganesyan, Yu. E. Penionzhkevich

Eurasian Journal of Physics and Functional Materials

The year 2019 has been declared by UNESCO as the year of the Periodic Table of Elements. 150 years ago, an outstanding Russian scientist D.I. Mendeleev systematized the chemical elements known at that time by chemical properties and created a table of elements. Since then, almost 60 chemical elements have been added to those known 150 years ago. Now the table has 118 chemical elements, most of which were synthesized artificially, in particular, on charged particle accelerators. Especially vigorous growth in the synthesis and research of new heavy transfermium elements was observed during the last 20 years, when about 20 …

The Effect Of Cupc Nanostructures On The Photo And Electrophysical Characteristics Of The Active Layer P3ht/Pcbm, A. K. Aimukhanov, B. R. Ilyassov, A. K. Zeinidenov, A. V. Zavgorodniy

Eurasian Journal of Physics and Functional Materials

The paper presents the results of a study of the influence of copper phthalocyanine (CuPc) nanostructures on the generation and transfer of charge carriers in the photoactive P3HT/PCBM layer. It was shown that the observed broadening and the shift in the maxima of the absorption spectra of P3HT/PCBM upon the addition of nanostructures to the polymer are associated with an increase in the degree of crystallization of the film. Using the method of impedance spectroscopy, it was found that CuPc nanostructures enhance the rate of recombination of charge carriers, which is probably due to the formation of surface defects. These …

Methods Of Calculation Of Radiation Protection For Operational Safety Optimization At Working With Radionuclide Photon Radiation Sources, D. S. Kim

Eurasian Journal of Physics and Functional Materials

Operational dosimetry solves the problem of implementing the principle of optimizing radiation safety, which is closely related to regulation and justification and implies a realistic achievable reduction in the dose load on a person when using ionizing radiation sources by reducing operating time, increasing the distance to radioactive material and shielding for attenuation of ionization flux. The article describes two ways of determining the thickness of shielding under necessity of making operational decision to protect a person from radionuclide source of known activity or the dose rate created by it. Based on the required multiplicity of its attenuation, which allows …

Md And Tem Evaluation Of Swift Xe Ion Induced Latent Tracks In Si3n4, R. A. Rymzhanov, A. Zhalmagambetova, A. Ibrayeva, A. Janse Van Vuuren, J. H. O’Connell, V. A. Skuratov

Eurasian Journal of Physics and Functional Materials

As known silicon nitride ceramics is considered as a candidate material for inert matrix fuel hosts used for transmutation of minor actinides. Unfortunately, by now very limited data is devoted to investigate of its stability under high energy heavy ion irradiation simulating fission fragment impact. Aim of our present study is a comparative analysis of parameters of latent tracks induced with swift Xe ion irradiation in polycrystalline Si₃N₄ using molecular dynamic (MD) simulation and high resolution transmission electron microscopy (TEM). Silicon nitride samples were irradiated with 220 MeV xenon ions at room temperature to fluence 5 × …

Detailed Study Of Rf And No Isotopes Radioactive Decay Properties, M. S. Tezekbayeva, A. V. Yeremin, O. N. Malyshev, M. L. Chelnokov, V. I. Chepigin, A. V. Isaev, A. V. Karpov, A. A. Kuznetsova, A. G. Popeko, Yu. A. Popov, A. I. Svirikhin, E. A. Sokol, A. Lopez-Martens, K. Hauschild, O. Dorvaux, B. Gall, P. Mosat, B. S. Sailaubekov

Eurasian Journal of Physics and Functional Materials

The experiments of detailed study of No and Rf isotopes radioactive decay properties in complete fusion reactions⁵⁰Ti+²⁰⁸Pb and⁴⁸Ca+^208,206,204Pb with subsequent neutron evaporation from the excited compound nucleus at the kinematic separator SHELS were performed in FLNR JINR. The data of the²⁵⁶Rf decay properties and preliminary data of²⁵⁰No decay properties are presented.

An Analysis Of Cross Sections Of 9be + 28si Interaction In The Framework Of The Double Folding Model, A. M. Kabyshev, K. A. Kuterbekov, A. K. Azhibekov, K. Zh. Bekmyrza, A. M. Mukhambetzhan, M. K. Kenzhebek, Ye. K. Sovetkhanov, Zh. A. Yeltay

Eurasian Journal of Physics and Functional Materials

In this paper the experimental data on the differential cross sections for elastic scattering of⁹Be ions on²⁸Si nucleus at the energies of the incident nucleus ranging from 12 to 201.6 MeV were analyzed in the framework of the double folding model using the Paris NN-potential CDM3Y. A good agreement with the experimental angular distributions of differential cross sections for elastic scattering was obtained and the values of the total reaction cross sections were calculated. When the double folding potential was used as real and imaginary parts, no manifestation of the threshold anomaly was detected. The reason …

Electron Hole Capture Centers In An Irradiated K2so4-Cu Crystal, T. N. Nurakhmetov, Zh. M. Salikhodzha, R. Z. Bakhtizin, A. M. Zhunusbekov, A. Zh. Kainarbay, D. H. Daurenbekov, B. M. Sadykova, K. B. Zhangylyssov, B. N. Yussupbekova

Eurasian Journal of Physics and Functional Materials

The methods of vacuum ultraviolet and thermal activation spectroscopy were used to measure the excitation spectra of impurity radiation in the fundamental absorption band of K₂SO₄-Cu crystals at 15 K and 300 K. An energy transfer was detected from the base to Cu⁺ impurities. The band gap of crystals K₂SO₄ was estimated. In K₂SO₄-Cu crystals, recombination radiation bands were detected at 2.95 ÷ 3.0 eV corresponding to electron hole capture centers.

Surface Modification Of Steel Mark 2 Electrolytic Plasma Exposure, Y. Y. Tabiyeva, B. K. Rakhadilov, G. K. Uazyrkhanova, L. G. Zhurerova, A. Maulit, D. Baizhan

Eurasian Journal of Physics and Functional Materials

This work is devoted to the research of the influence of the technological parameters of electrolytic plasma surface hardening on the structure and tribological properties of the surface of samples of the retaining steel mark 2. In the electrolytic plasma surface hardening was carried out in an electrolyte from an aqueous solution of 20% urea and 20% sodium carbonate. According to the result of metallographic and X-ray diffraction analysis, it was determined that the phase composition of steel mark 2 after processing varies, and fine martensite with a small amount of troostite and iron oxide is formed on the surface …

Shell Model Calculations For Deformed Li Isotopes, A. K. Azhibekov, V. V. Samarin, K. A. Kuterbekov, M. A. Naumenko

Eurasian Journal of Physics and Functional Materials

The nuclear shell model and its application to studying the structure of nuclei with deformed and spherical shapes are discussed. Calculations of level energies and wave functions in the shell model of deformed and spherical nuclei are performed for^7,8,11Li nuclei. A detailed calculation scheme for solving theradial Schrödinger equation is presented.

Assessing Magnetic Iron Oxide Nanoparticles Properties Under Different Thermal Treatments, Erick S. Vasquez, Evan M. Prehn, Keisha B. Walters

Chemical and Materials Engineering Faculty Publications

Magnetic nanoparticle structures have been examined as potential carrier vehicles and substrates in a wide range of applications where they undergo mechanical, chemical and/or thermal manipulation to allow for their modification, conjugation and transport. For safe and effective use, it is imperative to not only measure the initial physicochemical and structural properties of nanomaterials, but also identify and quantify any property changes related to a loss of chemical and/or physical integrity during processing and usage conditions. In this study an assessment of iron oxide magnetic nanoparticle thermal stability using modulated differential scanning calorimetry (mDSC) and a controlled-heating system is conducted …

Strengthening Of Corroded Steel Structures Using Cfrp – An Experimental Review, Ghada El-Mahdy Ph.D., P.Eng, Abdallah H. Yassin, Abdel El Rahman Khaled

Civil Engineering

Fibre reinforced polymers (FRP) have been widely used to strengthen reinforced concrete structures, however, nowadays their use to strengthen steel structures is under investigation. In particular, the need to strengthen corroded steel structures found in aggressive environments, such as marine environments, which have undergone a reduction in cross-sectional area and hence a reduction in their load-carrying capacity is in need of studying. The main problems that arise when using carbon fibre reinforced polymer (CFRP) sheets to strengthen steel structures is the weakness in the interfacial bond between the CFRP and the steel surface, the thinness of CFRP sheet, and the …

High-Pressure Studies On The Transition From Red Phosphorus To Black Phosphorus, Heng Xiang

Electronic Thesis and Dissertation Repository

Black phosphorus (BP) is a promising material in many research fields. However, the transition process from amorphous red phosphorus (ARP) is elusive and hence hinders large scale synthesis and applications. This work describes the application of the high-pressure method to study the transition process from ARP to BP.

In this thesis, the following three objectives were achieved: (1) to understand the mechanism of the transition, (2) to facilitate the synthesis of BP by taking the advantage of less pure ARP, (3) to propose new methods of synthesizing BP-based materials, such as the moderately oxidized BP and the black phosphorus/ amorphous …

Design Of Efficient Carbon-Based Adsorbents For The Removal Of Organic And Inorganic Water Contaminants, Sayedeh Soroosh Mortazavian Dehkordi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Granular activated carbon (AC) and biochar (BC) are two carbon-based adsorbents commonly used for water and wastewater treatment. However, these adsorbents have drawbacks that suppress their aqueous contaminants removal efficiency. Their major disadvantages are that AC has low selectivity and reusability potential, and BC has a hydrophobic nature.

The scope of this dissertation is to enhance the performance of commonly-used carbon-based adsorbents for the removal of organic and inorganic water contaminants and to understand the interactive mechanism of contaminants’ ions/molecules with adsorbents. Hexavalent chromium (Cr(VI)) and trichloroethylene (TCE) are two types of inorganic and organic water contaminants, respectively, which are …

Pressure Driven Electronic Band Gap Engineering In Tin(Iv)-O,N Compounds, Daniel Thomas Sneed

UNLV Theses, Dissertations, Professional Papers, and Capstones

The intrinsic link between long-range order, coordination geometry, and the electronic properties of a system must be understood in order to tailor function-specific materials. Although material properties are typically tailored using chemical dopants, such methods can cause irreversible changes to the structure, limiting the range of functionality. The application of high pressure may provide an alternative “clean” method to tune the electronic properties of semiconducting materials by tailoring their defect density and structure.

We have explored a number of optoelectronic relevant materials with promising characteristics, specifically Sn-(O,N) compounds which have been predicted to undergo pressure-mediated opening of their optical band …

Retrofit Of Corroded Corrugated Metal Culverts Using Gfrp Slip-Liner, Rahulreddy Chennareddy

Civil Engineering ETDs

Culverts are water conveyance structures, typically used to allow water flow and maintain a balance between the flow streams without interrupting structures such as highways and bridges. Corrugated metal pipes (CMPs) have been used as culverts in North America since the 1950s because of their low cost and simple construction method. Today, the corrosion of CMPs is a major problem faced by all U.S. Departments of Transportation. There is an urgent need to provide an efficient solution, one that is corrosion-resistant, to retrofit thousands of corroded CMPs across the country. High specific strength, high strength to weight ratio, corrosion resistance, …