Semiempirical Molecular Modeling Analyses For Graphene/Nickel Oxide Nanocomposite,
2020
Nanotechnology Research Centre (NTRC), The British University in Egypt (BUE), Suez Desert Road, El-Sherouk City, Cairo, 11837, Egypt
Semiempirical Molecular Modeling Analyses For Graphene/Nickel Oxide Nanocomposite, Islam Gomaa, Medhat A. Ibrahim, Hanan Elhaes
Nanotechnology Research Centre
Graphene metal oxide composite show applications in many areas according to their excellent electronic properties. Accordingly, graphene was subjected to interaction with NiO as adsorbing and a complex state. Semiempirical quantum mechanical calculations at PM6 was used to study the total energy, the final heat of formation, ionization energy, total dipole moment as well the charge distribution of the surface of graphene metal oxide composite. Calculated data indicated that graphene symmetry is changed into the C1 point group, forming stable composites with NiO that the complex composites were more stable compared with adsorb state composites. The change in the partial …
Molecular Dynamics Simulations Of Phase Behaviour And Structural Studies Of Guanidinium Triflate Ionic Liquid And Its Mixture With Water And N-Methyldiethanolamine For Carbon Dioxide Removal,
2020
Universiti Malaya
Molecular Dynamics Simulations Of Phase Behaviour And Structural Studies Of Guanidinium Triflate Ionic Liquid And Its Mixture With Water And N-Methyldiethanolamine For Carbon Dioxide Removal, Naimah Haron
Student Works (2020-2029)
Molecular dynamics (MDs) simulations with an all-atom force field have been carried out to understand the phase equilibrium behaviour of aqueous guanidinium triflate [gua][OTf] ionic liquid (IL) (binary system) at 440.15 K, as well as the phase equilibrium behaviour of N-methyl diethanolamine (MDEA) with aqueous [gua][OTf] IL (ternary system) at 298.15 K. This work further elaborated the understanding of absorption mechanism of carbon dioxide (CO2) into ternary system at 298.15 K. For binary system, the simulations measured changes in different physical properties such as density, structural, bonding properties (radial distribution function (RDF)), water clustering and hydrogen bonding) and dynamic property …
Computational Modeling As A Tool For Designing Ligands And Receptors,
2019
University at Albany, State University of New York
Computational Modeling As A Tool For Designing Ligands And Receptors, Waqas S. Awan
Legacy Theses & Dissertations (2009 - 2024)
Computational methods can be used for a wide range of applications, especially regarding DNA and RNA. Interactions such as sugar torsions, receptor-ligand interactions, ligand docking/drug docking, receptor modeling, and drug design are excellent candidates for computational analysis and in silico experiments. The use of molecular dynamics software (GROMACS) coupled with molecular design software (MOE) produce insights that may have been otherwise difficult to assess. All these problems are academic in nature but have practical uses outside of academia. Understanding alternate linkages can lead to antibiotic assays to address potential superbug epidemics. Modeling DNA superstructures can provide insight into how large …
Tools For Understanding Static Structure Factors And Their Application To Simulations Of Liquids,
2019
Northern Illinois University
Tools For Understanding Static Structure Factors And Their Application To Simulations Of Liquids, Travis Mackoy
Graduate Research Theses & Dissertations
Molecular dynamics (MD) simulations can be used to compute static structure factors (��(��)) and provide an interpretation of the underlying periodic atomic ordering. MD simulations complement experimentally measured ��(��) by allowing qualitative assignment of peaks to various ordering, such as cation-anion ordering in ionic liquids, via decomposition of ��(��) into partial ��(��). Here we present a method for classifying interatomic distances that allows for quantitative peak assignment and visualization of atoms that contribute most to each peak in calculated ��(��) for soft materials. The method is illustrated by investigating ��(��) for the ionic liquid 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide (C4C1pyrrTFSI), which shows two …
Simulation Of Fractal Growth On Metal Wire Electrode,
2018
Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology, Taiyuan 030008, Shanxi, China;
Simulation Of Fractal Growth On Metal Wire Electrode, Li-Feng Ding, Pei-Yuan Mao, Jun Cheng, Yu-Lan Niu, Yu-Hao Wen, Wei Chen
Journal of Electrochemistry
During processes of metal electrodepostion, there exist many complex morphological forms such as dendritic growing in the cathode deposited metal edge, which will seriously affect the quality of the electrodeposited product and current efficiency during machining. Investigations on dendritic crystal growing process and morphology could help controlling growth of electrolysis precipitate. In this work, Python and Matlab softwares were used, and the model of parallel electrode electrodeposition was established based on the diffusion-limited aggregation (DLA) model. By analyzing the law of fractal growth at different conditions of the particles number, probability, electrode spacing, the movement step length and orientation drift, …
Dft Study Of Water Assisted Hydrogen Dissociation On Gold Nanoparticles,
2018
Department of Chemistry,College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, Fujian, China;
Dft Study Of Water Assisted Hydrogen Dissociation On Gold Nanoparticles, Jia-Li Chen, Xia-Guang Zhang, De-Yin Wu, Zhong-Qun Tian
Journal of Electrochemistry
The gold nanoparticles (GNPs) show special activity toward hydrogen (H2) dissociation, comparing with bulk gold. Such activity is significantly affected by the existence of water. To inspect the influence of water on GNPs catalyzed H2 dissociation, we carried out density functional theory (DFT) calculations along the reaction paths for water clusters (H2O)m (m = 1, 2, 3, 7) assisted H2 dissociation on gold clusters (Aunδ, n = 3 ~ 5; δ = 0, 1). Our calculated results show that water benefits to the H2 dissociation. The dissociation mechanism varies …
Simulation Analysis In Dynamic Performance Of Proton Exchange Membrane Fuel Cell Under Starting Condition,
2018
School of Mechanical Engineering, Chongqing University of Technology, Chongqing 400054, China;
Simulation Analysis In Dynamic Performance Of Proton Exchange Membrane Fuel Cell Under Starting Condition, Yan Xiao, Ying-Jie Chang, Wei Zhang, Qiu-Hong Jia
Journal of Electrochemistry
Based on the equivalent circuit model, by considering both the dynamic gas pressure model and the dynamic heat transfer model, a lumped parameter model is developed. The start process of the fuel cell is simulated by using SIMULINK software. The undershoot of the voltage is observed from the simulation results, and the response time of the voltage is basically the same as that of the fuel cell temperature, which indicates that the temperature has great influence on the dynamic performance of the fuel cell. From the perspective of the temperature, the dynamic responses of the thermodynamic potential, the activation overvoltage, …
Numerical Simulation Of Output Performance In Pemfc,
2018
School of Mechanical Engineering, Shenyang Jianzhu University, Shenyang 110168, Liaoning China
Numerical Simulation Of Output Performance In Pemfc, Xin Luo, Shi-Zhong Chen, Yu-Hou Wu
Journal of Electrochemistry
The COMSOL software was used to analyze the output performances in proton exchange membrane fuel cell(PEMFC) under three kinds of flow fields. Under the same operating conditions, the performance differences among single serpentine flow field, interdigitated flow field and mixed flow field are compared, and the causes of the differences in the output performances of PEMFC under three kinds of flow fields were analyzed. The simulation results showed that the output performance of the mixed flow field was the best, the output performance of the interdigitated flow field the second and the output performance of single serpentine flow field the …
Electrostatic Interactions Of Water In External Electric Field: Molecular Dynamics Simulations,
2017
Electrostatic Interactions of Water in External Electric Field: Molecular Dynamics Simulations;
Electrostatic Interactions Of Water In External Electric Field: Molecular Dynamics Simulations, Qiang Zhu, Zigui Kan, Jing Ma
Journal of Electrochemistry
A series of molecular dynamics simulations with or without external electric field have been carried out for a bulk water with periodic boundary condition. The difference in radial distribution function of interatomic O…O distance is subtle, with and without external electric field, except for the orientation of dipole moments of water molecules. Without the applied external electric field, distribution of the orientation angle of dipole moments is rather broad. The induced local electric field is analyzed as a function of altitude in direction of electric field. The variation of the local induced electric field is increased as the increase of …
Surface Chemical Properties Of Mo2C, W2C, Mo2N And W2N Probed With Co, Co2 And O2 Adsorption: A Dft Analysis,
2017
Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA;
Surface Chemical Properties Of Mo2C, W2C, Mo2N And W2N Probed With Co, Co2 And O2 Adsorption: A Dft Analysis, Jingyun Ye, Tianyu Zhang, Lingyun Xu, Shuxia Yin, Krishanthi Weerasinghe, Pamela Ubaldo, Ping He, Qingfeng Ge
Journal of Electrochemistry
Transition metal carbides and nitrides are attractive materials for electrodes in many electrochemical energy storage and conversion applications. In the present study, we use density functional theory slab calculations to characterize the surface chemical properties of molybdenum (Mo) and tungsten (W) carbides and nitrides, namely, Mo2C, W2C, Mo2N and W2N with the adsorption of CO, CO2 and O2. These probing molecules provide measures of in both acidity/basicity and redox property of for the surfaces of these carbides and nitrides. Our results show that Lewis basic sites were responsible for CO2 …
Dynamic Simulation Of Oxygen Reduction Reaction In Pt/C Electrode For Proton Exchange Membrane Fuel Cells,
2016
State Key Laboratory of Advanced Technology for Materials Synthesis and Progressing, Hubei Fuel Cell Key Laboratory, Wuhan University of Technology, Wuhan 430070,China;
Dynamic Simulation Of Oxygen Reduction Reaction In Pt/C Electrode For Proton Exchange Membrane Fuel Cells, Shang Li, Fen Zhou, Lei Chen, Mu Pan
Journal of Electrochemistry
It is an urgent need to reduce the Pt loading in electrode for practical fuel cell applications worldwide. Herein, we theoretically investigate the oxygen distribution, generated current, and minimum Pt loading of Pt/C electrode for practical applications based on kinetic model of oxygen reduction reaction. The results indicate that with increasing electrode effective thickness to 40 mm, serious concentration polarization is expected for Pt/C electrode. To generate a power density of 1.4 W⋅cm-2 (2.1A⋅cm-2@0.67 V) for fuel cell, the cathode catalyst layer thickness in PEMFC should be as thin as 3 mm. The minimum Pt loading will …
A Molecular Docking Study On Alphavirus Nsp3 Macrodomains,
2016
University of Alabama in Huntsville
A Molecular Docking Study On Alphavirus Nsp3 Macrodomains, B. Danger Davies
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Electrochemical Catalysis: A Dft Study,
2014
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China;
Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei
Journal of Electrochemistry
In this review, we focus on achievements in electro-catalysis based on the density function theory study. The relationships among the electrode potential, electronic structure of catalysts and electro-catalytic activity are summarized in three parts: the adsorption and desorption of species, electron transfer, and stability of catalysts. The electrode potential and the electronic structure (d-band center or Fermi (HOMO) energy) of catalysts significantly influence the formation, adsorption and desorption of surface species on electrode. The electro-catalytic activity can be improved by modulating the electrode potential and electronic structure of catalysts.
Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface,
2014
College of Chemistry and Chemical Engineering, Hunan University of Arts and Science, Changde 415000, Hunan, China;College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen
Journal of Electrochemistry
DFT calculation is used to study various possible steps in the oxygen reduction reaction (ORR), including the adsorption and dissociation process of O2 and the serial protonation process of dissociated products to form H2O on the Pt(111) surface. By using slabs of different sizes, and different numbers of pre-adsorbed oxygen atoms, the coverage effects on the pathways are investigated. The calculated results using different hydrated proton models are also compared. It is shown that the initial step of the ORR is the formation of a protonated end-on chemisorbed state of OOH*, which can transform to an unprotonated …
A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction,
2013
College of Chemistry and Chemical Engineering, Hunan University of Arts and Science, Changde 415000, Hunan, China
A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction, Li-Hui Ou, Sheng-Li Chen
Journal of Electrochemistry
Developing Pt-lean catalysts for oxygen reduction reaction (ORR) is the key for large-scale application of proton exchange membrane fuel cell (PEMFC). In this paper, we have proposed a multiple-descriptor strategy for screening efficient and durable ORR alloy catalysts of low Pt content. We argue that an ideal Pt-based bimetallic alloy catalyst for ORR should possess simultaneously negative alloy formation energy, negative surface segregation energy of Pt and a lower oxygen binding ability than pure Pt. By performing detailed DFT calculations on the thermodynamics, surface chemistry and electronic properties of various Pt-M alloys (M refers to non-precious transition metals in the …
A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space,
2012
State Key Lab of A nalytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008, China;
A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space, Jianwei Zhao, Lili Chen, Yingqiang Fu, Shaohong Li, Tiannan Chen, Shijie Zhang
Journal of Electrochemistry
Research on diffusion behaviors is of significant value in that it is closely related to transport phenomena in micro-chemistry. However, the effects of variables on diffusion are still unclear. Here, we developed and programmed a simulation methodology along with data analysis, which was capable to simulate the diffusion of a particle within twodimensional heterogeneous space in large timescale; the effects of periodically arranged impenetrable barriers of specific shape and lateral drifting velocity on diffusion behavior were studied. As well as standard mean square displacement analysis, a new method, the appearance probability distribution method, was introduced, which revealed whether the particle …
Identification Of Persistent Long Range Interactions In GA95 And GB95 Through Thermal Unfolding Simulations,
2012
Old Dominion University
Identification Of Persistent Long Range Interactions In GA95 And GB95 Through Thermal Unfolding Simulations, Milen Redai Tesfamariam
Chemistry & Biochemistry Theses & Dissertations
For over five decades, different experiments have been performed to research how proteins attain their native three dimensional structures. However, the folding problem continues to be a puzzle in modern science. The design of two proteins that have maximal sequence identity but different folds and functions is one method that is being used to study the relationship between protein structure and amino acid sequence. In particular, mutant proteins of Streptococcus protein G, GA and GB, have 95% sequence identity and a 3a helix fold and β4/a fold, respectively. Molecular dynamics simulations of GA95 …
Application Of First Principles Calculations In Anode Materials For Lithium Ion Batteries,
2012
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Nankai University, Tianjin 300071,China
Application Of First Principles Calculations In Anode Materials For Lithium Ion Batteries, Tian-Ran Zhang, Dai-Xin Li, Si-Qi Yang, Zhan-Liang Tao, Jun Chen
Journal of Electrochemistry
First principles calculations play an important role in the study and development of new materials for lithium batteries. In this paper, we review the application of first principles calculations in the design of anode materials, including the modeling of the interaction of lithium in the anode materials, capacity, voltage, electrochemical reaction process, diffusion, rate capability, the relationship between the structure and properties, and the experimental phenomena interpreting. Based on the discussions, we emphasize on the importance of first principles calculations and demonstrate their requirement for further development.
Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus,
2012
Indiana State University
Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus, Unknown Unknown
Symposium 2012
Community associated Staphylococcus aureus (strain MSSA476) is a gram positive cocci capable of infecting many different parts of the body and known to cause serious infections that can be fatal, such as bacterial arthritis and acute endocarditis. To find effective ways of fighting against CA-MRSA strains we must learn more about their ability to infect. The focus of this study was cloning and characterization of a protein referred to as SAS0754. The size of SAS0754 is 340 amino acids and the gene sequence is 1023 nucleotides. The hypothetical function of this protein is that it is an extracellular matrix binding …
A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid,
2012
Indiana State University
A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid, Chase Buchanan, Richard W. Fitch
Symposium 2012
In our synthetic efforts toward the alkaloid phantasmidine, we required a convenient source of the title compound. Herein, we describe a short synthesis of 2,6-dichlorohomonicotinic acid by direct allylation of 2,6-dichloropyridine with LDA/allyl chloride, followed by permanganate oxidation of the side chain [figure1]. Yields for the allylation are high, while permanganate oxidation required more adjustment. Successful conditions require the modest acidification of the mixture with acetic acid and cleanup by acid base workup. No chromatography is needed.
