Advances in Physical Chemistry最新文献_第2页

Electrochemical Investigation of Catechol at Poly(niacinamide) Modified Carbon Paste Electrode: A Voltammetric Study 邻苯二酚在聚烟酰胺修饰碳糊电极上的电化学研究:伏安法研究

Advances in Physical Chemistry Pub Date : 2016-11-07 DOI: 10.1155/2016/8092860

Amit B. Teradale, S. D. Lamani, B. Swamy, P. Ganesh, Swastika N. Das

{"title":"Electrochemical Investigation of Catechol at Poly(niacinamide) Modified Carbon Paste Electrode: A Voltammetric Study","authors":"Amit B. Teradale, S. D. Lamani, B. Swamy, P. Ganesh, Swastika N. Das","doi":"10.1155/2016/8092860","DOIUrl":"https://doi.org/10.1155/2016/8092860","url":null,"abstract":"A polymeric thin film modified electrode, that is, poly(niacinamide) modified carbon paste electrode (MCPE), was developed for the electrochemical determination of catechol (CC) by using cyclic voltammetric technique. Compared to bare carbon paste electrode (BCPE), the poly(niacinamide) MCPE shows good electrocatalytic activity towards the oxidation of catechol in phosphate buffer solution (PBS) of physiological pH 7.4. All experimental parameters were optimized. Poly(niacinamide) modified carbon paste electrode gave a linear response between concentration of CC and its anodic peak current in the range within 20.6–229.0 μM. The limit of detection (3S/M) and limit of quantification (10S/M) were 1.497 μM and 4.99 μM, respectively. From the study of scan rate variation, the electrode process was found to be adsorption-controlled. The involvement of protons and electrons in the oxidation of CC was found to be equal. The probable electropolymerisation mechanism of niacinamide was proposed. Finally, this method can be used in development of a sensor for sensitive determination of CC.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80320765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Theoretical Studies of the Stone-Wales Defect in C36 Fullerene Embedded inside Zigzag Carbon Nanotube 之字形碳纳米管嵌套C36富勒烯Stone-Wales缺陷的理论研究

Advances in Physical Chemistry Pub Date : 2016-11-01 DOI: 10.1155/2016/1862959

K. Grishakov, K. Katin, M. Maslov

引用次数: 8

Remediation of Rhodamine B Dye from Aqueous Solution Using Casuarina equisetifolia Cone Powder as a Low-Cost Adsorbent 木麻黄球果粉作为低成本吸附剂对水溶液中罗丹明B染料的修复

Advances in Physical Chemistry Pub Date : 2016-10-17 DOI: 10.1155/2016/9497378

M. K. Dahri, M. R. R. Kooh, L. Lim

引用次数: 32

General Randić, Sum-Connectivity, Hyper-Zagreb and Harmonic Indices, and Harmonic Polynomial of Molecular Graphs 分子图的一般randiki，和连通性，Hyper-Zagreb和调和指数，调和多项式

Advances in Physical Chemistry Pub Date : 2016-09-25 DOI: 10.1155/2016/2315949

M. Farahani, Wei Gao, M. Kanna, R. P. Kumar, Jia-bao Liu

引用次数: 7

Removal of Phosphate Using Red Mud: An Environmentally Hazardous Waste By-Product of Alumina Industry 氧化铝工业副产物赤泥脱除磷酸盐对环境有害

Advances in Physical Chemistry Pub Date : 2016-08-29 DOI: 10.1155/2016/9075206

S. Prajapati, P. A. Najar, V. Tangde

{"title":"Removal of Phosphate Using Red Mud: An Environmentally Hazardous Waste By-Product of Alumina Industry","authors":"S. Prajapati, P. A. Najar, V. Tangde","doi":"10.1155/2016/9075206","DOIUrl":"https://doi.org/10.1155/2016/9075206","url":null,"abstract":"The industrial waste, bauxite residue generated in the Bayer chemical process of alumina production, commonly known as red mud (RM) has been used as the adsorbent for selective removal of phosphate in aqueous solutions. RM collected from the storage area of alumina industry was characterized by chemical analysis and physical methods such as BET surface area, Scanning Electron Microscopy (SEM), particle size analysis, and X-ray diffraction (XRD) methods. Among the various red mud samples (0.2–200 μ) studied, the samples treated with 1 M HCl for 2 h were found better for the selective adsorption of phosphate in comparison with untreated and heat treated RM samples. The presence of phosphate in the aqueous samples collected after adsorption studies with red mud was determined by standard spectrophotometric procedure using ammonium molybdate and ascorbic acid in nitrate medium at 880 nm. The studies reported significant adsorption of phosphate on acid treated red mud in comparison with adsorption of phosphate on untreated and heat treated red mud, respectively. The adsorption of phosphate on raw red mud and activated red mud was further investigated with respect to stirring time, pH of the solution, dose of adsorbent, and varying phosphate concentration. Acid treated RM is observed as an efficient and cost-effective adsorbent for selective removal of phosphate in aqueous solutions.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90859670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Kinetics and Mechanistic Study of Permanganate Oxidation of Fluorenone Hydrazone in Alkaline Medium 高锰酸盐在碱性介质中氧化芴酮腙的动力学及机理研究

Advances in Physical Chemistry Pub Date : 2016-07-25 DOI: 10.1155/2016/4526578

A. Fawzy, Saleh A. Ahmed, I. Althagafi, M. Morad, K. Khairou

{"title":"Kinetics and Mechanistic Study of Permanganate Oxidation of Fluorenone Hydrazone in Alkaline Medium","authors":"A. Fawzy, Saleh A. Ahmed, I. Althagafi, M. Morad, K. Khairou","doi":"10.1155/2016/4526578","DOIUrl":"https://doi.org/10.1155/2016/4526578","url":null,"abstract":"The oxidation kinetics of fluorenone hydrazone (FH) using potassium permanganate in alkaline medium were measured at a constant ionic strength of 0.1 mol dm−3 and at 25°C using UV/VIS spectrophotometer. A first-order kinetics has been monitored in the reaction of FH with respect to [permanganate]. Less-than-unit order dependence of the reaction on [FH] and [OH−] was revealed. No pronounced effect on the reaction rate by increasing ionic strength was recorded. Intervention of free radicals was observed in the reaction. The reaction mechanism describing the kinetic results was illustrated which involves formation of 1 : 1 intermediate complex between fluorenone hydrazones and the active species of permanganate. 9H-Fluorenone as the corresponding ketone was found to be the final oxidation product of fluorenone hydrazone as confirmed by GC/MS analysis and FT-IR spectroscopy. The expression rate law for the oxidation reaction was deduced. The reaction constants and mechanism have been evaluated. The activation parameters associated with the rate-limiting step of the reaction, along with the thermodynamic quantities of the equilibrium constants, have been calculated and discussed.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89343821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Energy Landscape of Pentapeptides in a Higher-Order Conformational Subspace 高阶构象子空间中五肽的能量格局

Advances in Physical Chemistry Pub Date : 2016-05-16 DOI: 10.1155/2016/3240674

K. ElSawy

{"title":"Energy Landscape of Pentapeptides in a Higher-Order Conformational Subspace","authors":"K. ElSawy","doi":"10.1155/2016/3240674","DOIUrl":"https://doi.org/10.1155/2016/3240674","url":null,"abstract":"The potential energy landscape of pentapeptides was mapped in a collective coordinate principal conformational subspace derived from principal component analysis of a nonredundant representative set of protein structures from the PDB. Three pentapeptide sequences that are known to be distinct in terms of their secondary structure characteristics, (Ala)5, (Gly)5, and Val.Asn.Thr.Phe.Val, were considered. Partitioning the landscapes into different energy valleys allowed for calculation of the relative propensities of the peptide secondary structures in a statistical mechanical framework. The distribution of the observed conformations of pentapeptide data showed good correspondence to the topology of the energy landscape of the (Ala)5 sequence where, in accord with reported trends, the α-helix showed a predominant propensity at 298 K. The topography of the landscapes indicates that the stabilization of the α-helix in the (Ala)5 sequence is enthalpic in nature while entropic factors are important for stabilization of the β-sheet in the Val.Asn.Thr.Phe.Val sequence. The results indicate that local interactions within small pentapeptide segments can lead to conformational preference of one secondary structure over the other where account of conformational entropy is important in order to reveal such preference. The method, therefore, can provide critical structural information for ab initio protein folding methods.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89470923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Corrigendum to “(Photo)electrochemical Methods for the Determination of the Band Edge Positions of TiO2-Based Nanomaterials” “(照片)测定tio2基纳米材料能带边缘位置的电化学方法”的勘误表

Advances in Physical Chemistry Pub Date : 2016-04-28 DOI: 10.1155/2016/8235954

R. Beranek

引用次数: 4

Simulation of Ni-MH Batteries via an Equivalent Circuit Model for Energy Storage Applications 基于等效电路模型的镍氢电池储能仿真

Advances in Physical Chemistry Pub Date : 2016-03-16 DOI: 10.1155/2016/4584781

Y. Zhu, Wenhua H. Zhu, Zenda Davis, B. Tatarchuk

{"title":"Simulation of Ni-MH Batteries via an Equivalent Circuit Model for Energy Storage Applications","authors":"Y. Zhu, Wenhua H. Zhu, Zenda Davis, B. Tatarchuk","doi":"10.1155/2016/4584781","DOIUrl":"https://doi.org/10.1155/2016/4584781","url":null,"abstract":"Impedance measurement was conducted at the entire cell level for studying of the Ni-MH rechargeable batteries. An improved equivalent circuit model considering diffusion process is proposed for simulation of battery impedance data at different charge input levels. The cell capacity decay was diagnosed by analyzing the ohmic resistance, activation resistance, and mass transfer resistance of the Ni-MH cells with degraded capacity. The capacity deterioration of this type, Ni-MH cell, is considered in relation to the change of activation resistance of the nickel positive electrodes. Based on the report and surface analysis obtained from the energy dispersive X-ray spectroscopy, the composition formula of metal-hydride electrodes can be closely documented as the AB5 type alloy and the “A” elements are recognized as lanthanum (La) and cerium (Ce). The capacity decay of the Ni-MH cell is potentially initiated due to starved electrolyte for the electrochemical reaction of active materials inside the Ni-MH battery, and the discharge product of Ni(OH)2 at low state-of-charge level is anticipated to have more impeding effects on electrode kinetic process for higher power output and efficient energy delivery.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90094434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Calculating Heat of Formation Values of Energetic Compounds: A Comparative Study 含能化合物生成热值计算的比较研究

Advances in Physical Chemistry Pub Date : 2016-03-14 DOI: 10.1155/2016/5082084

Michael S. Elioff, J. Hoy, J. Bumpus

{"title":"Calculating Heat of Formation Values of Energetic Compounds: A Comparative Study","authors":"Michael S. Elioff, J. Hoy, J. Bumpus","doi":"10.1155/2016/5082084","DOIUrl":"https://doi.org/10.1155/2016/5082084","url":null,"abstract":"Heat of formation is one of several important parameters used to assess the performance of energetic compounds. We evaluated the ability of six different methods to accurately calculate gas-phase heat of formation () values for a test set of 45 nitrogen-containing energetic compounds. Density functional theory coupled with the use of isodesmic or other balanced equations yielded calculated results in which 82% (37 of 45) of the values were within ±2.0 kcal/mol of the most recently recommended experimental/reference values available. This was compared to a procedure using density functional theory (DFT) coupled with an atom and group contribution method in which 51% (23 of 45) of the values were within ±2.0 kcal/mol of these values. The T1 procedure and Benson’s group additivity method yielded results in which 51% (23 of 45) and 64% (23 of 36) of the values, respectively, were within ±2.0 kcal/mol of these values. We also compared two relatively new semiempirical approaches (PM7 and RM1) with regard to their ability to accurately calculate . Although semiempirical methods continue to improve, they were found to be less accurate than the other approaches for the test set used in this investigation.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87073067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13