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Nanosensors For The Detection Of Nerve Agents And Explosives, Deepak Kumar Thimmaraju

Masters Theses

The central hypothesis of this research was development of a novel nanosensor for the detection of nerve agents and explosives. The nanosensor assembly comprises a bottom up approach with nanoparticle (N), monomer (M), nanomolecule (N) and a receptor (R) as moieties of a NMNR assembly. My research was focused on evaluating receptors for their efficiency towards the target analytes such as nerve agents and explosives. Pi electron rich receptor 2-Phenyl-2-Propanol and its fluorinated analog 1,1,1,3,3,3-Hexafluoro-2-Phenyl-2-Propanol were investigated for their ability to detect nerve agents such as DCP, its analogs DMMP and HCl along with the explosives mono, di, and trinitrotoluene. …

Weak Ferromagnetism In Fe₁₋ₓcoₓsb₂, Rongwei Hu, Raphäel P. Hermann, Fernande Grandjean, Yong Jae Lee, John B. Warren, Vesna F. Mitrovic, Cedomir Petrovic

Chemistry Faculty Research & Creative Works

Weak ferromagnetism in Fe_1-xCo_xSb₂ is studied by magnetization and Mössbauer measurements. A small spontaneous magnetic moment of the order of ~ 10^-3µ_B appears along the b axis for 0.2 ≤ x ≤ 0.4. Based on a structural analysis, we argue against extrinsic sources of weak ferromagnetism. We discuss our results in the framework of the nearly magnetic electronic structure of the parent compound FeSb₂.

A Modified Route To Cyclopenta[C]Thophenes Via Grignard Reagents, Amber Bell

Masters Theses & Specialist Projects

The synthesis of cyclopenta[c]thiophenes is sparsely found in literature due to the several difficulties of their synthesis. Our research has shown that we could modify a previously known route to 1,3-disubstituted cyclopenta[c]thiophenes using traditional Grignard chemistry. Along the way we discovered the synthetic route we were using had several omissions. Therefore, we were required to completely fill in missing experimentals in order to obtain each cyclopenta[c]thiophene intermediate, in high purity and good yield. In addition, we were able to fully characterize via NMR, our intermediates which was found in the literature. Finally, we were able to show using 'H 13 …

Shake & Bake: Dual-Use Chemicals, Contexts, And The Illegality Of American White Phosphorus Attacks In Iraq, Joseph D. Tessier

The University of New Hampshire Law Review

[Excerpt] “On November 29, 2005, in a Department of Defense press conference with Secretary of Defense Donald Rumsfeld and Gen. Peter Pace, Chairman of the Joint Chiefs of Staff, General Pace stated that white phosphorus “is a legitimate tool of the military,” and can be used for illumination, smoke, and incendiary purposes. Incredibly, the Department of Defense released an addendum to the press conference clarifying that white phosphorus was not used as an incendiary weapon. According to General Pace, “it was well within the law of war to use white phosphorus . . . for marking and screening.” This was …

Synthesis, Study Of Self-Assembly, And Trivalent Lanthanide Metal Ion Recognition Characteristics Of Amphiphilic Acylpyrazolones And Amphiphilic Acylisoxazolones, Venkat Reddy Guduru

Dissertations

This research project focused on the separation of trivalent lanthanide metal ions by HPLC using amphiphilic acylpyrazolones and amphiphilic acylisoxazolones. The central hypothesis of our research project is that the nanoscale self-assembly nature of amphiphilic ligands (chelating lingads) can influence their metal ion recognition and separation. To test the central hypothesis, we have synthesized a family of novel amphiphilic ligands and employed them as model systems for the separation of trivalent lanthanide metal ions. Several novel intermediates such as 4-acylated. N -acylated, O -acylated pyrazolones and isoxazolones, have been efficiently synthesized and fully characterized.*

The trivalent lanthanide metal ion recognition …

Synthesis And Characterization Of Stilbenoids And Their Aza-Analogs As Photoluminescent Materials For The Detection Of Nerve Agent Mimics, Chun Wang

Dissertations

A novel series of stilbenoids and their aza analogs were synthesized, characterized and used as photoluminescent components in the detection of nerve agents. Their structure-property relationship was elucidated through UV-visible and fluorescence spectroscopy. The research in this thesis is driven by the hypothesis that the two-block sensor system consisting of a receptor incorporated ruthenium complex and a fluorescent signal molecule of stilbenoids, is capable of detecting chemical warfare agents. The sensor anchored onto nanoparticles and subsequently the nanoparticles were arranged through mediated self-assembly. While photo-induced electron transfer is a well-known mechanism for sensor design, the described system showed that photo-induced …

Electrochemical Oxidization Of Herring Sperm Dna And Its Interaction With Histone, Juan Xu, Gui-Ping Huang, Hong Li, Wei Zhu

Journal of Electrochemistry

The voltammetric behavior of herring sperm DNA at glassy carbon electrode and its interaction with histone have been investigated by using cyclic voltammetry,differential pulse voltammetry,and fluorescence measurement.In the potential range of 0.20 V to 1.25 V,it is found that an irreversible oxidative peak is exhibited in acid solution,but in the neutral or alkaline solution two oxidative peaks are observed.Oxidative peak potential values show a negative shift with increasing pH via a slope of-57 mV·pH-1 and a linear relation with DNA concentration in the range of 0.45 to 8.20 mmol·L-1.In the presence of histone,the oxidative peak current of DNA and the …

Eiectro-Oxidation Of Methanol On Pdnio/C Catalyst In Alkaline Medium, Mei-Li Wang, Lin Sang, Cheng-De Huang

Journal of Electrochemistry

The electro-oxidation of methanol in alkaline electrolyte at in-house synthesized PdNiO/C and Pd/C catalysts and the effect of heat treatment on the structure and performance of catalysts were studied by cyclic voltammetry,chronoamperometry,chronopotentiometry and X-ray diffraction methods.It is shown that when the reduction temperature is 70℃ and the ratio between Pd and Ni is 8∶2,The PdNiO/C catalyst presents a highest activity for methanol electrooxidation.Calcining can increase the particle size and crystallinity of catalysts,but decrease the dispersion and activity of catalysts, too.Besides,the NiO is disengaged from Pd lattice by heat-treatment.The optimal PdNiO/C catalyst shows higher catalytic activity and much better poisoning resistance …

Study On Electrochemical Impedance Spectroscopy Of Carbon Steel Eroded In Methyldiethanolamine Solution, Dong-Ping Wei, Rong-Zong Hu, Dan-Mei Pan, Wei-Xiong Huang, Rui Dong

Journal of Electrochemistry

Corrosion behavior of carbon steel in methyldiethanolamine(MDEA) solution was investigated by Electrochemical Impedance Spectroscopy(EIS).The results were showed that the corrosion rate of carbon steel in solution containing dissolved oxygen is higher than that in solution removed of dissolved oxygen before cathodic activation.They were reversed after cathodic activation.The corrosion rate is increased at first and then decreased when the concentration of MDEA is increased in the blank solutions.In the simulated solutions containing quantities of!heat-stable salts(HSS),the corrosion rate is decreased monotonously with increase of the MDEA concentration.As anodic polarization potential is increased,the EIS of carbon steel in HSS simulated solution showed characteristics …

Molten Salt Systems And The New Developments For The Application Of Molten Salts, Peng Liu, Ye-Xiang Tong, Qi-Qin Yang

Journal of Electrochemistry

The general situation of molten salt systems since 21 century are presented.The development of room temperature molten salts are emphasized.Applications of molten salts to the areas of preparating alloys and functional materials;batteries and capacitors;analysis and separation;use as reaction media and catalyzers;environmental protection have good prospect.In order to continually develop the molten salt system,it is necessary further to know the properties of molten salts and relevant theories,as well as exploiting the new methods and novel systems of synthesizing molten salts.

Electrochemical Behavior Of Zinc Alloy Anode In Ca(Oh)_2 Solutions Of Different Ph, Peng-Ying Ren, Ji-Quan He

Journal of Electrochemistry

The polarization curves of zinc alloy anodes in Ca(OH)2 solutions have been measured by potentiodynamic method,and the composition of corrosion products were examined by X-ray-diffraction(XRD).The experimental results indicated that not only the electrochemical behavior of zinc alloy anodes were absolutely different in every alkaline solutions,but also many electrochemical parameters were determined,such as zero current potential(E0),the density of corrosion current(icorr),passive current density(ip),breakdown potential(Eb),and so on.There were three zero current potential when zinc alloy anodes in some Ca(OH)2 solutions which made passive state unstable.The graphs of E-pH about zinc alloy anodes dipped in different Ca(OH)2 solutions were drawn,and compared with the potential-pH …

Electrochemical Behavior Of Dill Pipe In 31%(By Mass)Nacl Solution Based New Type Inhibitor, Fu-Guo Liu, Min Du, Qing-Zhang Wang

Journal of Electrochemistry

The inhibitive effect of compound inhibitor including emulsifier(P)、zinc sulfate、sodium polyphosphate、Glucose Gluconate was studied in 31% NaCl(bymass) solution.The inhibitory mechanism was analyzed by polarization curve and EIS.The results showed that the compound inhibitor was anodic-type inhibitor and its inhibitive effect on anodic and cathodal reaction was the most obvious at 200×10-6g·L-1.And the results of EIS revealed that the inhibition efficiency increased and the film formed on electrode surface was more and more compact with time.Inhibition mechanism was different with concentration of inhibitor.

A New Method To Reduce The Contact Resistance Between Metal Current Collector And Graphite Plate For Pemfc, Hao Sun, Ming Han, Meng-Kai Liu, Jun-Bo Jia, Yao-Tian Zhan

Journal of Electrochemistry

A new method to reduce the contact resistance between metal current collector and graphite plate for PEMFC has been proposed.It was found that the contact resistance between the stainless steel current collector and graphite plate after embedding a metal net-carbon polymer composition is effective by to eliminate,Fuel cell testing has presented that this new method can effectively reduce the internal resistance of PEMFC,and improve the performance of the PEM fuel cell.

Study On The Corrosion Of Chlorine Condenser By Electrochemical Method, Bin Xiang, Wen Chen, Wen-Zhang Huang, Shao-Hua Xing, Sheng-Tao Zhang

Journal of Electrochemistry

Corrosion of condenser is very seriously in chlorine-alkali industry,which could lead to fatal disaster.The most commonly used material in low pressure condenser includes steel of 16MnR,10#,and welding rod of J507.Electrochemical analysis of the three materials in 29.9%(by mass) calcium chloride(CaCl2) solution was carried out.The corrosion current density icorr and impedance parameters of the three materials in 29.9% CaCl2 solution were estimated separately.The result showed that in the tripartite phase regions where the 10# seamless tube and 16MnR armor plate were jointed by welding,the weld was firstly eroded and suggested that the chlorine condenser should be examined and repaired every year.

Electrochemical Behavor Of Zinc-Indium Alloy Electrodes In Concentrated Alkaline Solution, Zhi-Lin Wang, Xiao-Ge Zhang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The electrochemical behavior of zinc-indium alloy electrodes in 35%KOH solutions has been investigated by electrochemical methods including the potentiodynamic polarization and discharge measurements under constant current density.The results indicate that the anodic current density and passive current density increase after the indium addition.The discharge measurement shows that the addition of indium shortens the time to passive state for the Zn alloy compared to pure zinc at a large discharge conditions,that is the addition of indium may enhance the electrochemical activity of Zn alloy electrodes.It is found that the anodic dissolution of zinc-indium alloy electrodes in the concentrated KOH solution occurs …

Preparation And Properties Of High Capacity Lifepo_4, Jun Li, Gui-Tang Lai, Hui-Min Huang, Da-Guang Li, Xin-De Xia

Journal of Electrochemistry

Carbon-doped LiFePO4/C and pure phase LiFePO4 cathode materials were prepared by liquid-state precipitation reaction.The results of XRD,SEM,elemental analysis,FTIR and A.C.impedance tests show that the samples have had olivine structure and a 3.4V discharge platform.The tapped density of LiFePO4/C sample could reach 1.46g/cm3,the initiate discharge capacity is 144.6mAh/g at 0.1C,which remained capacity is 93.2% after 20 cycles.The first discharge capacity is 133.5mAh/g at 1C and the capacity decreased 8.76% after 20 cycles.

Research Of 2,2′-Dipyridine On Electroless Copper Plating Using Sodium Hypophosphite As Reductant, Bin Yang, Fang-Zu Yang, Ling Huang, Shu-Kai Xu, Guang-Hua Yao, Shao-Min Zhou

Journal of Electrochemistry

In the bath of the electroless copper plating using sodium hypophosphite as reductant,the effects of 2,2′-dipyridine on the deposition rate,anodic oxidation of sodium hypophosphite,cathodic reduction of copper ions,surface morphologies,structure and the existing status of the deposit components were examined.The results showed that,2,2′-dipyridine hindered the electroless deposition.Experiments of liner sweep voltammetry(LSV) indicated that,as the addition of 2,2′-dipyridine to the electrolyte,the oxidation peak potential of sodium hypophosphite shifted to a more negative value but the peak current decreased;the reducing peak potential of copper ions moved to a more negative value whereas the peak current increased.Scanning electron microscope(SEM)、energy dispersive spectroscopy(EDS)、X-ray diffraction(XRD) and X-ray …

Electrochemical Behavior And Determination Of Luteolin At A Glassy Carbon Electrode, Ai-Lin Liu, Shao-Bo Zhang, Xiao-Sha Wu, Li-Ping Li, Yang-Yuan Cao, Li-Ying Huang, Xin-Hua Lin

Journal of Electrochemistry

The electrochemical behavior of luteolin was studied by voltammetry at a glassy carbon electrode in phosphate buffer solution.The results exhibited that the well-defined redox peak of luteolin is observed and the electrode process is adsorption-controlled.The charge transfer coefficient(α) was calculated as 0.66 in phosphate buffer solution(pH 4.0).The relationships between oxidation peak current and the concentration of luteolin are linear in the range of 1.0×10-8 ～ 5.0×10-6 mol·L-1 by differential pulse voltammetric method.The detection limit had been estimated as 1.0×10-8 molL-1.This method can be used for the determination of luteolin with satisfactory results.

Selection Of Additions In The Process Of Electrochemical Synthesizing Of K_2feo_4, Wei-Hua Yang, Dong-Qin Bi, Yan Zhou, Hong-Hui Wang, Xin-Ren Lan

Journal of Electrochemistry

Some of different additions including KIO4 was added to the anodic electrolyte for electrochemical synthesizing of K2FeO4,the effects of these additions on current yield were investigated.XRD and SEM were used to characterize the structure and image of K2FeO4.The results show that KIO4 is a preferable addition.When the mass dosage of KIO4 is 0.02%,electrolysis time is 1 h,the current yield is enhanced by 31.6% and the corresponding purity of the product is improved by 3.85 %.

Construction Of Three-Dimensional Finite Element Model For Complicated Cathodic Protection System, Ai-Ping Wang, Min Du, Qing-Zhang Wang, Sheng-Shan Cao, Ji-Xing Sun

Journal of Electrochemistry

When condensers with carbon steel waterbox and titanium tube structure were protected by SACP in an ocean beach power plant,while seawater were used to be cooling water,carbon steel was under-protected and Titanium was over-protected,because their protective potential are less than-0.85V(vs.SCE) and more than-0.75V(vs.SCE) separately.In order to optimize the SACP design,potential distribution of two materials must be obtained during the SACP process.In the lab,carbon steel waterbox and Titanium tube model(Q235-Ti model) were set up.A series of electrochemical techniques(steady polarization,galvanostatic charge technique)were used to obtain reasonable boundary condition and surface form of two materials during the SACP process.The experiments were carried out …

Study On Metal|Solid Electrolyte|Gel Membrane Containing Water|Graphite System, Jing-Dong Liu

Journal of Electrochemistry

The characteristic of oxide layer formed on the surface of metal in Metal|Solid Electrolyte|Gel Membrane Containing Water|Graphite System was studied by using Point Defect Model and Barrier Layer/Porous Layer Model.Trace water in solid electrolyte helped to form porous layer at the surface of metal,The thickness of porous layer increased due to water molecule reacts with barrier layer continuously,which lowered the porosity and decreased the electromotive potential and current.Porosity influenced solubility behavior of oxide layer intensely.Like barrier layer,porous layer is also a semiconductor.

Preparation And Investigations On The Tio2nanotube Arrays For Cathodic Protection Of 316l Stainless Steel, Jing Li, Hong Yun, Chang-Jian Lin

Journal of Electrochemistry

A highly ordered TiO2nanotube layer was fabricated by potentiostatic anodization of pure titanium in fluorinated electrolyte solutions.The structure and composition of the as-prepared TiO2 nanotubes were characterized by SEM and XRD.The TiO2 nanotubes show a stronger absorption in the ultraviolet(UV) light range.The performances of photogenerated cathodic protection and the photoelectrochemical response for the TiO2 nanotube layers under illumination and dark conditions were evaluated through the electrochemical measurements.It is found that the open-circuit potentials of 316 SS coupled with the TiO2 nanotubes layers shift negatively under UV light irradiation(λ<380nm).It is indicated that the TiO2 nanotubes arrays are able to function effectively a photogenerated cathodic protection for metals under light illumination and keep the cathodic protection for a long time under dark conditions.

Voltammetric Behavior Of Rutin And Its Application, Zong-Yao Qian, Bing-Qi Li, Hong Liu, Xin-Fu Xia, Yin-Mei Wang, Ya-Ping Niu

Journal of Electrochemistry

In solution of 0.1mol/L Tris-HCl(pH=8.3),a sensitive reduction peak of rutin was obtained by liner sweep polarography.The peak potential was-1.10V(vs.Ag/AgCl).The peak current was proportional to the concentration of rutin over the range of 7×10-7～9.8×10-6mol/L.This method has been applied to the determination of the flavonoid in G.Uralensis.The results showed that the reduction process was irreversible with adsorption that studied by linear sweep and cyclic voltammetry.

Ion-Implanting Modification Of Layered Manganese Dioxide And Its Electrochemical Performance, He-Ning Huang, Dong-Ping Lv, Xing-Kang Huang, Qi-Wei Zhang, Yong Yang

Journal of Electrochemistry

Layered MnO2(δ-MnO2) was prepared by thermal decomposition of potassium permanganate.Ti was ion-implanted into such δ-MnO2 by physical techniques,forming a composite(δ-MnO2-Ti).These materials were characterized by XRD,SEM,XPS techniques and their electrochemical proprieties were investigated.The results showed that the layered structure of δ-MnO2 did not been destroyed after Ti ion implantation,and the implanted Ti element was mainly Ti4+ as indicated by XPS.Both of the first and the highest discharge specific capacities of the ion-implanted layered MnO2(δ-MnO2-Ti),compared to those of δ-MnO2,were improved significantly.

Determination Of Malathion Based On Carbon Nanotubes Modified Electrode Incorporating Acetylcholinesterase, Lu Zhang, Yao-Dong Zhang, Hong-Lan Qi

Journal of Electrochemistry

A biosensor for determination of organophosphorus pesticide based on the acetylcholinesterase and multi-wall carbon nanotubes modified electrode is fabricated.Under the optimal conditions,the chronoamperometric current at +0.70V(vs.SCE) increased linearly with the concentration of malathion in the range from 6.0×10-10 to 6.0×10-9 mol·L-1 with a detection limit of 1.0×10-10 mol·L-1.The recoveries of malathion in lake water is 97% to 105% determinated by this method.

Brief Account On The 4~(Th) Cse Conference(November 3,2007,Yangzhou)

Journal of Electrochemistry

No abstract provided.

A Circular On The 26~(Th) Ccs Congress(July 13~16,2008.Tianjin,China)

Journal of Electrochemistry

No abstract provided.

The Tropical Forest And Fire Emissions Experiment: Method Evaluation Of Volatile Organic Compound Emissions Measured By Ptr-Ms, Ftir, And Gc From Tropical Biomass Burning, T. G. Karl, Ted J. Christian, Robert J. Yokelson, Paulo Artaxo, Wei Min Hao, Alex Guenther

Chemistry and Biochemistry Faculty Publications

Volatile Organic Compound (VOC) emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS), Fourier Transform Infrared Spectroscopy (FTIR) and gas chromatography (GC) coupled to PTRMS (GC-PTR-MS). We investigated VOC emissions from 19 controlled laboratory fires at the USFS (United States Forest Service) Fire Sciences Laboratory and 16 fires during an intensive airborne field campaign during the peak of the burning season in Brazil in 2004. The VOC emissions were dominated by oxygenated VOCs (OVOC) (OVOC/NMHC similar to 4:1, NMHC: non-methane hydrocarbons) The specificity of the PTR-MS instrument, which measures the mass to charge ratio of …

Exploring The Role Of Calcium Ions In Biological Systems By Computational Prediction And Protein Engineering, Yubin Zhou

Chemistry Dissertations

Ca2+, a signal for death and life, is closely involved in the regulation of numerous important cellular events. Ca2+ carries out its function through its binding to Ca2+-receptors or Ca2+-binding proteins. The EF-hand protein, with a helix-loop-helix Ca2+-binding motif, constitutes one of the largest protein families. To facilitate our understanding of the role of Ca2+ in biological systems (denoted as calciomics) using genomic information, an improved pattern search method (http://www.chemistry.gsu.edu/faculty/Yang/Calciomics.htm) for the identification of EF-hand and EF-like Ca2+-binding proteins was developed. This fast and robust method allows us to analyze putative EF-hand proteins at the genome-wide level and further visualize …

Electrokinetic Modeling Of Free Solution Electrophoresis, Yao Xin

Chemistry Dissertations

Modeling electrophoresis of peptides, proteins, DNA, blood cells and colloids is based on classical electrokinetic theory. The coupled field equations-Poisson, Navier-Stokes or Brinkman, and ion transport equations are solved numerically to calculate the electrophoretic mobilities. First, free solution electrophoretic mobility expressions are derived for weakly charged rigid bead arrays. Variables include the number of beads (N), their size (radius), charge, distribution (configuration), salt type, and salt concentration. We apply these mobility expressions to rings, rigid rods, and wormlike chain models and then apply the approach to the electrophoretic mobilities and translational diffusion constants of weakly charged peptides. It is shown …