Physical Sciences and Mathematics Commons^™

Copolymerization Of Methylacrylate And Acrylic Acid, N Y. Bozorov, V. O. Kudishkin

Scientific journal of the Fergana State University

Linear copolymers of methylacrylate and acrylic acid with different content of monomer units have been synthesized by classical radical copolymerization in dioxane solution and in the block. The composition of copolymers was determined. The relative activities of the monomers calculated by the methods of Fineman - Ross and Kelen -Tudos. It is shown that the activity of acrylic acid can vary depending on the medium in which copolymerization is carried out.

Defining The Antioxsidants Quantity In Certification Of The Chicken Meat, B. N. Sattarova, I. R. Asqarov, Sh. X. Abdulloev

Scientific journal of the Fergana State University

The article presents an analysis of the results obtained by chromatography-mass-spectrometric studies to determine the mass fractions of certain antioxidants in chicken meat, the excessive amount of which seriously threatens human health. The advantages of this method in the certification of meat products are substantiated. It has been established that the content of alpha-tocopherol in chicken meat imported from some foreign countries is several times higher than that produced in local poultry farms.

Solution Of Cancerogen Asbestos Problems In Obtaining Harmless Fibre Products, M. A. Axmadaliev, I. R. Asqarov

Scientific journal of the Fergana State University

The article presents the ways of obtaining ecologic harmless composite materials based on mineral fibers in the replacement of asbestos containing goods

Formation Of Stochastic Competence In Mathematics Lessons, A. Yusupova, Z. Mukimova, Kh. Ibrokhimova

Scientific journal of the Fergana State University

This article presents methods for the formation of student stochastic competence.

Solving Differential Matrix Equations For Surface With Respect To Action Of Group Of Lorence, U. Bekbayeva, K. Muminov

Scientific journal of the Fergana State University

In The artlcle a description is given for the system of differential matrix equations, the solutions of which regenerate the class of surfaces in 4 – dimensional space, which are equivalent with respect to the action of group - O(3,1).

Copolymerization Of Methylacrylate And Acrylic Acid, N Y. Bozorov, V. O. Kudishkin

Scientific journal of the Fergana State University

Linear copolymers of methylacrylate and acrylic acid with different content of monomer units have been synthesized by classical radical copolymerization in dioxane solution and in the block. The composition of copolymers was determined. The relative activities of the monomers calculated by the methods of Fineman - Ross and Kelen -Tudos. It is shown that the activity of acrylic acid can vary depending on the medium in which copolymerization is carried out.

Tricomi Type Problem For Mixed Type Equation With Sub-Diffusion And Wave Equation, E. Karimov, S. Kerbal

Scientific journal of the Fergana State University

In this paper, we have considered a Tricomi type problem for mixed type equation with Hilfer’s double order derivative sub-diffusion equation and classical wave equation in a composite domain. Main methods of the investigation are a method of integral equations and energy integrals’ method.

Sorption Of Copper (Ii), Nickel (Ii) And Cobalt (Ii) Ions Into The Ionite Modified By Polyphinylchloride And Polyethylene Polyamine, Kh Ismoilova, D Bekchanov, Sh Khasanov, M Baltaeva

Scientific journal of the Fergana State University

IPolyphinylchloride was modified by polyethylene polyamine, and the ionites were studied in static conditions by the artificial solution of copper (II), nickel (II) and cobalt (II) ions. In static conditions, factors affecting the sorption process, such as time, temperature and concentration dependence were investigated. The results of the inquiry process were studied by IR analysis

Defining The Antioxsidants Quantity In Certification Of The Chicken Meat, B. N. Sattarova, I. R. Asqarov, Sh. X. Abdulloev

Scientific journal of the Fergana State University

The article presents an analysis of the results obtained by chromatography-mass-spectrometric studies to determine the mass fractions of certain antioxidants in chicken meat, the excessive amount of which seriously threatens human health. The advantages of this method in the certification of meat products are substantiated. It has been established that the content of alpha-tocopherol in chicken meat imported from some foreign countries is several times higher than that produced in local poultry farms.

Solution Of Cancerogen Asbestos Problems In Obtaining Harmless Fibre Products, M. A. Axmadaliev, I. R. Asqarov

Scientific journal of the Fergana State University

The article presents the ways of obtaining ecologic harmless composite materials based on mineral fibers in the replacement of asbestos containing goods

Formation Of Stochastic Competence In Mathematics Lessons, A. Yusupova, Z. Mukimova, Kh. Ibrokhimova

Scientific journal of the Fergana State University

This article presents methods for the formation of student stochastic competence.

Sea Surface Roughness Observed By High Resolution Radar, Atsushi G. Fujimura, Susanne Lehner, Alexander Soloviev, Xiaofeng Li

Marine & Environmental Sciences Faculty Articles

Changes in the sea surface roughness are usually associated with a change in the sea surface wind field. This interaction has been exploited to measure the sea surface wind speed by scatterometry. A number of features on the sea surface associated with changes in roughness can be observed by synthetic aperture radar (SAR) because of the change in Bragg backscatter of the radar signal by damping of the resonant ocean capillary waves. With various radar frequencies, resolutions, and modes of polarization, sea surface features have been analyzed in numerous campaigns, bringing various datasets together, thus allowing for new insights in …

Organic/Inorganic Interfacial Interactions Affecting Metal Reactivity: Water Treatment And Sensor Applications, Mohamed Nabil Shaikh

Civil Engineering ETDs

The aim of this dissertation was to investigate the interactions occurring at the organic – inorganic interface between solid media and aqueous contaminants for water treatment and sensor applications. The gaps in current literature on these interfacial organic-inorganic interactions must be bridged in order to develop advanced water treatment and monitoring technologies for improving water quality and thus, restore and protect the contaminated water resources. As a part of this dissertation, manganese oxides-based composites and electrospun polymer mats were developed and investigated for gaining mechanistic insights of organic (bisphenol A and acetaminophen) and inorganic (uranium) contaminants removal, respectively. These reactions …

Reaction Induced Morphology Changes Of Tetracene And Pentacene Surfaces, Feifei Li, Jacob W. Ciszek

Chemistry: Faculty Publications and Other Works

Morphology plays a critical role in determining the properties of solid-state molecular materials, yet fluctuates wildly as these materials undergo reaction. A prototypical system, a vapor–solid Diels–Alder reaction of tetracene and pentacene thin-films, is used to observe the evolution of morphology features as the reaction transitions from surface to bulk. The initial stages of reaction display little topographical change as measured by atomic force microscopy (AFM) and scanning electron microscopy (SEM), and substrates are coated with a uniform layer of product 1–2 molecules thick, as determined by energy-dispersive X-ray (EDX) spectroscopy. The highly textured surfaces of late stage reactions are …

Statuses, Challenges And Strategies In The Development Of Low-Temperature Carbon Dioxide Electroreduction Technology, Xu-Rui Zhang, Xiao-Lin Shao, Jin Yi, Yu-Yu Liu, Jiu-Jun Zhang

Journal of Electrochemistry

Low-temperature carbon dioxide (CO₂) electrochemical reduction technology is a hotspot for research and development in recent years as a way to reduce the negative impact of CO₂ on the environment and to generate energy storage through converting electricity to low-carbon fuels. Although basic research on catalyst activity, product selectivity, and reaction mechanism has been widely reported, the design and practicality of catalytic stability and corresponding electrochemical reactor systems have not been given sufficient attention and systematic development. In this paper, two important factors affecting the development of CO₂ electrochemical reduction technology in low temperature aqueous solution …

Odu Launches Open Seas Technology Innovation Hub, News @ Odu

News Items

No abstract provided.

Preface To Special Issue Of Electrochemical Reduction Of Carbon Dioxide, Qing Li, Min Liu

Journal of Electrochemistry

No abstract provided.

Copper-Based Compounds For Electrochemical Reduction Of Carbon Dioxide, Fan Yang, Pei-Lin Deng, You-Jia Han, Pan Jing, Bao-Yu Xia

Journal of Electrochemistry

The electrochemical reduction of carbon dioxide (CO₂) to useful chemicals and fuels has attracted enormous interest since the deteriorating global warming and energy shortage problems resulted from ever-increasing CO₂ emission. Designing efficient catalysts is of capital significance to realize the efficient and selective conversion of CO₂. Among various catalysts explored, copper-based compounds have promising potentials with acceptable efficiency for hydrocarbon production. Herein, recent advances on copper-based materials are summarized for electrochemical CO₂ conversion. We intend to include the dimensional structure, different forms (alloy, oxide) and molecular catalysts in copper-based catalysts. Moreover, the reaction mechanisms …

Recent Advances In Bismuth-Based Co2 Reduction Electrocatalysts, Rui Zhou, Na Han, Yan-Guang Li

Journal of Electrochemistry

Carbon dioxide (CO₂) is an economical, secure and sustainable carbon resource around us. Its effective capture and recycling have been the focus of our entire society. Using the electrochemical method, CO₂ can be reduced to different value-added chemicals or fuels. This approach not only would mitigate CO₂ accumulation in the atmosphere, but also would help alleviate our dependence on fossil fuel. In this article, the basic principle and process of electrochemical CO₂ reduction are first introduced. The recent development in bismuth-based catalysts for electrocatalytic CO₂ reduction is reviewed with an emphasis on their preparation, …

Electrocatalytic Reduction Of Carbon Dioxide To Carbon Monoxide Using Cobalt Nitride, Chen Ma, Peng-Fei Hou, Peng Kang

Journal of Electrochemistry

Electrocatalytic reduction of carbon dioxide (CO₂) is a promising method to alleviate global warming issues, although it still faces many challenges. Herein, we report cobalt nitride for electrocatalytic reduction of CO₂ to carbon monoxide (CO) in an aqueous electrolyte. A comparison of catalysts with different preparation temperatures and atmospheres suggests that nitrogen doping is critical to improve catalytic activity. For the most active catalyst of 700-Co_5.47N/C, the CO current density reached 9.78 mA·cm^-2 at potential of -0.7 V vs. RHE. In addition, the CO/H₂ ratio could be adjusted from 1:3 to 3:2 by …

Regulation Of Copper Surface Via Redox Reactions For Enhancing Carbon Dioxide Electroreduction, Bao-Hua Hang, Jin-Tao Zhang

Journal of Electrochemistry

A large-scale application of fossil fuels has led to excessive emission of carbon dioxide (CO₂), resulting in serious environmental issues. A promising path to reducing CO₂ emissions is recycling CO₂ into valuable chemicals and fuels through an electrochemical process. Herein, the redox reactions between copper (Cu) and ferric chloride (FeCl₃) have been utilized to regulate the Cu surface composition and structure, aimed to improve the electrocatalytic activity toward CO₂ reduction. Typically, a series of samples (named Cu-1h, Cu-2h, Cu-3h and Cu-4h) were prepared via the redox reactions for various time from 1 to …

Electrochemical Detection Of 4-Nitrophenol Based On Glassy Carbon Electrode Modified By Tio2Nps/Rgo Composite, Lin-Na Jiu, Yong-Qiang Cheng

Journal of Electrochemistry

4-nitrophenol (4-NP) has become factitious pollution, and presented a serious threat to the nature and human health. It is necessary to develop a convenient and fast detection method. In this work, the glassy carbon electrode modified by titanium dioxide nanoparticles (TiO₂NPs)/reduced graphene oxide (RGO) composite as an electrochemical sensor was studied for the trace detection of 4-NP. The morphology of the composite was characterized by scanning electron microscopy (SEM). The homogeneous mixing of titanium dioxide nanoparticles and reduced graphene oxide increased the specific surface area of the composite, and facilitated the electrochemical reaction of 4-NP. The electrochemical characteristics …

Preparations And Electrocatalytic Properties Of Cu-Bipy-Btc-Derived Carbon-Based Catalyst For Oxygen Reduction Reaction, Li-Hua Zhang, Jun-Feng Chen, Wan-Tang Huang, Yong-You Hu, Jian-Hua Cheng, Yuan-Cai Chen

Journal of Electrochemistry

Efficient and low-cost oxygen reduction reaction (ORR) electrocatalyst plays a key role for fuel cells. In this paper, ORR active metal organic framework (MOF: Cu-bipy-BTC, bipy = 2,2?-bipyridine, BTC = 1,3,5-tricarboxylate) was prepared using hydrothermal method, and then carbon-based material MOF-800 was obtained from pyrolyzing Cu-bipy-BTC at 800 °C. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption isotherm and X-ray photolectron spectroscopy (XPS) were used to characterize the morphologies and structures of the catalysts. Linear sweep voltammetry (LSV) and current-time curve (i-t) were adopted to evaluate the electrocatalytic properties of the catalysts. …

Single-Layer Oxygen Deficiency Δ-Mno2 For Electrochemical Co2 Reduction, Yue-Feng Zhang, Jian-Jun Liu, Zeng-Xi Wei, Xin-Xin Tian, Jian-Min Ma

Journal of Electrochemistry

Manganese dioxide (MnO₂) has been widely used in catalysis. In addition, since the defect engineering can change the electronic properties of the catalyst, here we have systematically studied electrocatalytic carbon dioxide reduction reaction (CO₂RR) on δ-MnO₂ with and without oxygen deficiency, denoted as Ov-MnO₂ and MnO₂, respectively. We calculate the electronic properties and the intermediate of free energy for MnO₂ and Ov-MnO₂ with the help of spin-polarized density functional theory. By analyzing this result, we can find that the introduction of defects change the δ-MnO₂ from semiconducting properties …

Modifications Of The Cztse/Mo Back-Contact Interface By Plasma Treatments, Wenjin Chen, Teoman Taskesen, David Nowak, Ulf Mikolajczak, Mohamed H. Sayed, Devendra Pareek, Jorg Ohland, Thomas Schnabel, Erik Ahlswede, Dirk Hauschild, Lothar Weinhardt, Clemens Heske, Jurgen Parisi, Levent Gutay

Chemistry and Biochemistry Faculty Research

Molybdenum (Mo) is the most commonly used back-contact material for copper zinc tin selenide (CZTSe)-based thin-film solar cells. For most fabrication methods, an interfacial molybdenum diselenide (MoSe2) layer with an uncontrolled thickness is formed, ranging from a few tens of nm up to ≈1 μm. In order to improve the control of the back-contact interface in CZTSe solar cells, the formation of a MoSe2 layer with a homogeneous and defined thickness is necessary. In this study, we use plasma treatments on the as-grown Mo surface prior to the CZTSe absorber formation, which consists of the deposition of stacked metallic layers …

Recent Progress In Copper-Based Catalysts For Electrochemical Co2 Reduction, Wen Lei, Wei-Ping Xiao, De-Li Wang

Journal of Electrochemistry

As the situation of energy crisis and environmental pollution become more and more serious, the electrochemical reduction of carbon dioxide (CO₂) has attracted lots of attention because of its multiple meanings such as environment, resources and economic benefits. In this paper, the state of the art electrochemical reduction of CO₂ in aqueous solution is reviewed, and the latest research progress in Cu-based catalysts with different structures and morphologies is summarized. In the end, the application prospects, opportunities and challenges of Cu-based materials are briefly presented to provide an outlook for future research directions.

Effect Of Morphology Of Fe-N Codoped Carbon Nanomaterial On Electrochemical Reduction Reactions, Er-Ling Li, Fa Yang, Ming-Bo Ruan, Ping Song, Wei-Lin Xu

Journal of Electrochemistry

Graphene nanosheets (GS) and carbon nanotubes have been considered as good catalysts candidates for applications in energy conversion and storage. However, hybrids of GS and carbon nanotubes are always formed in transition metal-based nitrogen-doped system, making the system quite complex for exploring the structure-activity relationship. To prepare the catalysts with desired species controllably, we try to adjust the outcomes with the effect of nitrogen on the growth of carbon nanotubes. In this work, a series of Fe-N co-doped carbon hybrid catalysts containing N-doped GS or hybrids of GS/bamboo carbon nanotubes (BCNTs) or BCNTs were obtained with one-step pyrolyzed method. To …

"Being Mindful" And Becoming A "Harmony Worker" During Unsettling Times.Docx

Carroy U "Cuf" Ferguson, Ph.D.

The Optimum Tilt Angle And Orientation For Solar Panels, Eman Mohammed, Journal Port Science Research

port Science Research

Tunneling Anisotropic Magnetoresistance In Ferroelectric Tunnel Junctions, Artem Alexandrov, M. Ye. Zhuravlev, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Using a simple quantum-mechanical model, we explore a tunneling anisotropic magnetoresistance (TAMR) effect in ferroelectric tunnel junctions (FTJs) with a ferromagnetic electrode and a ferroelectric barrier layer, where spontaneous polarization gives rise to the Rashba and Dresselhaus spin-orbit coupling (SOC). For realistic parameters of the model, we predict sizable TAMR measurable experimentally. For asymmetric FTJs, whose electrodes have different work functions, the built-in electric field affects the SOC parameters and leads to TAMR being dependent on the ferroelectric polarization direction. The SOC change with polarization switching affects tunneling conductance, revealing an alternative mechanism of tunneling electroresistance. These results demonstrate alternative …