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2000

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Articles 1 - 30 of 333

Full-Text Articles in Chemistry

Heavy Metals And Organic Pollutants In Sediments Of Dar Es Salaam Harbour Prior To Dredging In 1999, J F Machiwa Dec 2000

Heavy Metals And Organic Pollutants In Sediments Of Dar Es Salaam Harbour Prior To Dredging In 1999, J F Machiwa

Tanzania Journal of Science

Heavy metals and organic contaminants were analysed in the sediments of the inner area of the Dar es Salaam harbour. Complementary analytical parameters, such as, the organic carbon content and the silt/clay fraction of the sediments showed good positive correlation (r = 0.64). Stations that had high content of fine grain material in the sediment also indicated relatively high level of organic carbon and pollutants. The Florida criteria (MacDonald 1993) for assessment of pollution of tropical marine sediments was adopted in oredr to evaluate the extent of pollution in Dar es Salaam harbour sediments. The Florida criteria is one of …

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Composition And Anaerobic Digestion Of Single And Combined Organic Fractions Of Municipal Solid Waste Of Dar Es Salaam, A K Kivaisi, J Mukisa Dec 2000

Composition And Anaerobic Digestion Of Single And Combined Organic Fractions Of Municipal Solid Waste Of Dar Es Salaam, A K Kivaisi, J Mukisa

Tanzania Journal of Science

The composition of major categories of municipal solid waste (MSW) of Dar es salaam city was determined. Food remains and vegetable matter constituted 80-90% of the categories. Organic fractions of the individual categories contained 18-20 % total solid (TS), 30-50 % (dry weight) total fibre and 1-1.3 % nitrogen. The assorted organic fractions were tested for anaerobic conversion into biogas at 55°C in batch cultures for 14 days with a mixed population of microorganisms. At a substrate concentration of 6-8 g volatile solids per litre fermenter volume (g VS l-1 FV) individual fractions were degraded by 51-75% and gave methane …

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Nonlinear Effects Of Physisorption On Static Friction, G.T. Gao, Xiao Cheng Zeng, Dennis J. Diestler Dec 2000

Nonlinear Effects Of Physisorption On Static Friction, G.T. Gao, Xiao Cheng Zeng, Dennis J. Diestler

Xiao Cheng Zeng Publications

The effects of a physisorbed film on the force of static friction in a model contact (monatomic adsorbate confined between plane-parallel walls) were investigated by Monte Carlo simulation. At fixed coverage the friction curve (shear yield stress vs normal stress) exhibits a marked nonlinearity, which results from a competition between adsorbate–wall interactions that predominate at low loads and wall–wall interactions that set in beyond a threshold load, which increases with coverage. Previous proximal-probe and computer experiments, carried out at high coverages, see only the initial (low-load) linear portion of the friction curve.

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High-Performance Liquid Chromatographic Separation Of Enantiomers Of Synthetic Amino Acids On A Ristocetin A Chiral Stationary Phase, Antal Péter, Gabriella Török, Daniel W. Armstrong, Géza Tóth, Dirk Tourwé Dec 2000

High-Performance Liquid Chromatographic Separation Of Enantiomers Of Synthetic Amino Acids On A Ristocetin A Chiral Stationary Phase, Antal Péter, Gabriella Török, Daniel W. Armstrong, Géza Tóth, Dirk Tourwé

Chemistry Faculty Research & Creative Works

A macrocyclic glycopeptide, ristocetin A, was used as chiral stationary phase for the high-performance liquid chromatographic separation of enantiomers of 28 unnatural amino acids, such as analogues of phenylalanine, tyrosine and tryptophan, and analogues containing 1,2,3,4-tetrahydroisoquinoline, tetraline or 1,2,3,4-tetrahydro-2-carboline skeletons. Excellent resolutions were achieved for most of the investigated compounds by using reversed-phase or a new polar-organic mobile phase system. The conditions of separation were optimized by variation of the mobile phase composition, temperature and flowrate. Copyright (C) 2000 Elsevier Science B.V.

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Simplified Calculation Of The Stability Matrix For Semiclassical Propagation, Sophya Garashchuk, John C. Light Dec 2000

Simplified Calculation Of The Stability Matrix For Semiclassical Propagation, Sophya Garashchuk, John C. Light

Faculty Publications

We present a simple method of calculation of the stability (monodromy) matrix that enters the widely used semiclassical propagator of Herman and Kluk and almost all other semiclassical propagators. The method is based on the unitarity of classical propagation and does not involve any approximations. The number of auxiliary differential equations per trajectory scales linearly rather than quadratically with the system size. Just the first derivatives of the potential surface are needed. The method is illustrated on the collinear H[sub 3] system.

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Allosteric Tuning Of Ruthenium 2,2’-Bipyridyl Luminescent Sensor Systems, Daqing Gan Dec 2000

Allosteric Tuning Of Ruthenium 2,2’-Bipyridyl Luminescent Sensor Systems, Daqing Gan

Masters Theses

A series of new ruthenium bipyridyl crown supramolecular sensor systems containing two binding sites were synthesized. The crystal structure and photophysical properties of the developed sensor systems were thoroughly studied using x-ray, nuclear magnetic resonance and photoscopy methods. It turned out that the chelation of transition metal on the remote sites of the bipyridyl crown ligands greatly reduced the reactivity of the crown cavity. It is believed that the chelation of transition metal on the nitrogen atoms forces the bipyridyl function towards coplanarity and restricts the conformational freedom of the crown ring. The conformational rigidity in turn influences the binding …

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The Environmental Science Minor: A Disciplinary Approach To Interdisciplinary Studies With A Grounding In Undergraduate Research, Brian E. Bodenbender, Edward C. Hansen, Graham F. Peaslee, Jonathan W. Peterson Dec 2000

The Environmental Science Minor: A Disciplinary Approach To Interdisciplinary Studies With A Grounding In Undergraduate Research, Brian E. Bodenbender, Edward C. Hansen, Graham F. Peaslee, Jonathan W. Peterson

Faculty Publications

No abstract provided.

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Dendritic Polymers As Bonded Stationary Phases In Capillary Electrochromatography, Chiayu Helen Chao Dec 2000

Dendritic Polymers As Bonded Stationary Phases In Capillary Electrochromatography, Chiayu Helen Chao

Seton Hall University Dissertations and Theses (ETDs)

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Template Synthesis Of Nano-Structured Electrode Materials And Its Electrochemical Performance, Jian Zhao, Quan-Yong Gao, Yong Yang, Zu-Geng Lin Nov 2000

Template Synthesis Of Nano-Structured Electrode Materials And Its Electrochemical Performance, Jian Zhao, Quan-Yong Gao, Yong Yang, Zu-Geng Lin

Journal of Electrochemistry

In this letter, various nano structured materials such as spinel LiMn2O4 nanotubes/nanowires and carbon nanotubes have been prepared by using porous alumina template. The prepared template and materials have been characterized by AFM and TEM techniques. It is shown that size of the nanotubes can be conveniently controlled by using template method. Some preliminary results of cyclic voltammetry about nano structured LiMn2O4 are also reported.

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Electrochemical Hydrogen Storage Properties Of Carbon Nanotubes, Xue Qin, Xue-Ping Gao, Feng Wu, Hong Liu, Ying Lan, Hua-Tang Yuan, De-Ying Song, Pan-Wen Shen Nov 2000

Electrochemical Hydrogen Storage Properties Of Carbon Nanotubes, Xue Qin, Xue-Ping Gao, Feng Wu, Hong Liu, Ying Lan, Hua-Tang Yuan, De-Ying Song, Pan-Wen Shen

Journal of Electrochemistry

The electrochemical properties of carbon nanotubes (CNTs) electrode have been investigated in this paper. The high discharge capacity of 200 mAh·g-1 was measured for the CNTs Ni electrode at a discharge density of 200 mAh·g-1 . CNTs-Ni electrode, the high electrochemical activity and the long cycle life were observed. The electrochemical mechanism of hydrogen adsorption and oxidation at the CNTs Ni electrode was studied by cyclic voltammertry method.

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Fabrications And Characterizations Of Porous Silicon By Tow-Step Techniques I: Constant Current Application, Xuan Cheng, Feng-Ming Liu, Chang-Jian Lin, Zuo-Xin Wen, Zhong-Qun Tian, Ru Xue Nov 2000

Fabrications And Characterizations Of Porous Silicon By Tow-Step Techniques I: Constant Current Application, Xuan Cheng, Feng-Ming Liu, Chang-Jian Lin, Zuo-Xin Wen, Zhong-Qun Tian, Ru Xue

Journal of Electrochemistry

Porous silicon structures were formed by a two step technique consisting of electrochemical polarization and chemical oxidation processes in 1∶1 hydrofluoric acid and ethanol solutions. A constant current density of 0.03 A/cm2 was applied to p type silicon wafers, followed by chemical treatment in 20% nitric acid solutions. These samples were then carefully examined by scanning electron microscope (SEM) and Raman spectrometer to study their surface morphologies and optical properties. After a year storage in a desiccator, the aged porous silicon samples were re examined by SEM and Raman spectrometer before and after treated with styrene and decene(1) organic …

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A Study Of Monitoring Corrosion Of Metal Via An Optic Waveguide Sensing Method, Xue-Ming Li, Wei-Ming Chen, Shang-Lian Huang, Na Zhang, Zong-Qing Huang Nov 2000

A Study Of Monitoring Corrosion Of Metal Via An Optic Waveguide Sensing Method, Xue-Ming Li, Wei-Ming Chen, Shang-Lian Huang, Na Zhang, Zong-Qing Huang

Journal of Electrochemistry

An optical wave guide sensing method was proposed for monitoring corrosion of metal in outdoors steel structures. Replacing the cladding of wave-guide with metal film in a particular location, the method takes the metal film as the corrosion sensitive film. The experiment of waveguide sensor was carried out on a 721 colorimetric vessel, with which the soution is held in itself and the light is propagated in its sidewall. A Fe-C alloy film was electroplated onto the inner sied of vessel to form the corrosion sensitive film. The structure of the Fe-C alloy film was studied by XRD, EDX and …

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A Study Of The Adsorption Behaviors On The Surface Of Gold Electrode By In-Situ Electrochemical Raman Spectroscopy, Xia-Qin Wu, Xiao-Wei Cao, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang Nov 2000

A Study Of The Adsorption Behaviors On The Surface Of Gold Electrode By In-Situ Electrochemical Raman Spectroscopy, Xia-Qin Wu, Xiao-Wei Cao, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang

Journal of Electrochemistry

The results of in-situ measurements with Raman spectroelectrochemical thchnique on bare gold electrode and adenine modified gold electrode were reported. The adsorption behaviors of adenine and superoxide dismutase (SOD) and their interactions with gold electrode were analyed. The mechanism of promoted electron transfer process of SOD in the presence of adenine at gold electrode surface is discussed.

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Forming And Mechanism Of Chitosan Coating On Aluminum Cathode By Electrophoresis, Xi Zhang, Shao-Hui Wu, Ying-Chu Tao Nov 2000

Forming And Mechanism Of Chitosan Coating On Aluminum Cathode By Electrophoresis, Xi Zhang, Shao-Hui Wu, Ying-Chu Tao

Journal of Electrochemistry

The electrophoretic deposition behavior and the corresponding coating mechanism were investigated. The influencing factors, such as cell potential, CS concentration, pH value of solution, temperature and supporting electrolytes, on coating were researched. The coating morphology was characterized by XRD and SEM. The mechanism of electrophoretic deposition in CS solution was discussed.

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The Electrochemical Performance Of The Spinel Limn2O4, Shi-Gang Lu, Yu-Cheng Sun, Ren-Min Liu, Wei-Hua Jin, Wen-Zhong Li, Cang Han Nov 2000

The Electrochemical Performance Of The Spinel Limn2O4, Shi-Gang Lu, Yu-Cheng Sun, Ren-Min Liu, Wei-Hua Jin, Wen-Zhong Li, Cang Han

Journal of Electrochemistry

The cathode material spinel LiMn2O4 of lithium ion battery was synthesized by making use of solid state reaction at 750～850 ℃. The discharge capacity was 115～125 mAh·g-1 . It was observed that the capacity loss increase at the elvated 55 ℃ temperature. A little excess Li content and the Co doped spined could improved the cycle capability of the cathode material. The dissolution of the spined in the electrolyte was measured. The treatment method was used to stabilize the LiMn2O4 structure. It was found that the spinel LiMn2O4, treated …

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The Study Of Pretreatment For The Determination Of The Conventional Anion In Sea Water By Ic——The Method Of Electrolysing Argentine Electrode, Lei Guo, Wei Yang, Rong-Zong Hu Nov 2000

The Study Of Pretreatment For The Determination Of The Conventional Anion In Sea Water By Ic——The Method Of Electrolysing Argentine Electrode, Lei Guo, Wei Yang, Rong-Zong Hu

Journal of Electrochemistry

The method of pretreatment to determine trace amounts of Br-, NO3- and SO42- in sea water by ion chromatography was proposed, by which the electrolysing argentine electrode was used to minimize the disturbance of Cl-. The results indicate that the method is simple, convenient, quick and efficient with recovery rates over 95 percent.

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Study On Electrodeposition Of Ingaas Thin Film, Yu-Chun Li, Xi-Lian Wang, Jing-Ke Han, Ai-Zhen Han, Yuan-Kai Gao, Zhi-Wei Yang Nov 2000

Study On Electrodeposition Of Ingaas Thin Film, Yu-Chun Li, Xi-Lian Wang, Jing-Ke Han, Ai-Zhen Han, Yuan-Kai Gao, Zhi-Wei Yang

Journal of Electrochemistry

The principle and the experimental method of the electrodeposition are discribed in detail in this paper. InGaAs thin film was prepared by using optimized electrodeposited conditions. The radiative wave length of the film was between 1.3～1.5 μm, the composition of the film was analyzed by energy spectrometer and the transmission spectrum of the film was measured by spectrophotometer and monochromator. The V-I chractristic of the conductive type and the topography of the InxGa1-xAs film were also studied.

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Studies Of Electrochemical Impedance Spectroscopy On Coated Steel With Artificial Defect, Zhi-Gang Zhang, Zhi-Jun Gu, Yong-Gui Liao, Qi-Long Guo, Fang-Teng Su, Yan-Zhen Chen Nov 2000

Studies Of Electrochemical Impedance Spectroscopy On Coated Steel With Artificial Defect, Zhi-Gang Zhang, Zhi-Jun Gu, Yong-Gui Liao, Qi-Long Guo, Fang-Teng Su, Yan-Zhen Chen

Journal of Electrochemistry

Electrochemical Impedance Spectroscopy (EIS) was applied to rapidly evaluate the performance of organic coatings and the characterization of the protective properties of anticorrosive pigments in the presence of artificial defect in organic coatings. The results showed that artificial defect method can rapidly evaluate the performance of coatings and discriminate whether the pigments in the coatings have inhibitive.

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The Memory Effect Of Mh-Ni Battery, De-Ming Xie, Jian-Ming Wang, Jian-Qing Zhang, Chu-Nan Cao Nov 2000

The Memory Effect Of Mh-Ni Battery, De-Ming Xie, Jian-Ming Wang, Jian-Qing Zhang, Chu-Nan Cao

Journal of Electrochemistry

The memory effect of MH-Ni battery was investigated. The depth of discharge, discharge rate and cycle number influence the memory effect greatly. A few completely full charge/discharge cycles could eliminate it. The existence of the memory effect had nothing to do with zinc element. During the course of life cycling at low DOD (degree of discharge), the smaller the discharge current was, the lower was the maximum charge voltage. In addition, discharge voltage and discharge capacity drop fast at the beginning, gradually leveled off at about a value. If the discharge current was increased, the discharge capacity was obviously less …

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The Development Of Carbon Monoxide Tolerant Catalysts For Proton-Exchange Membrane Fuel Cell, Zhong-Jun Hou, Hong-Mei Yu, Bao-Lian Yi, Ming Han Nov 2000

The Development Of Carbon Monoxide Tolerant Catalysts For Proton-Exchange Membrane Fuel Cell, Zhong-Jun Hou, Hong-Mei Yu, Bao-Lian Yi, Ming Han

Journal of Electrochemistry

High over-potential of proton exchange membrane fuel cell (PEMFC) anode caused by carbon monnoxide poisoning when reformate or methanol is used as fuel is main obstacle to the high performance of PEMFCs. Using carbon monoxide tolerant catalysts is the most hopeful way to solve the CO problem. The CO poisoning problem is reviewed briefly in this paper, and the development of CO tolerant catalysts is introduced in details, including electrocatalysts activity, preparation method and mechanism of tolerance to CO.Mo and W can improve catalysts' CO tolerance. Multi-component catalysts are expected to be more tolerant to CO.

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The Difference Of The Geometrical Thickness And The Electrochemical Apparent Effective Thickness Of Self-Assembled Monolayers, Xiao-Li Cui, Jun-Xin Li, Ru-Ting Tong Nov 2000

The Difference Of The Geometrical Thickness And The Electrochemical Apparent Effective Thickness Of Self-Assembled Monolayers, Xiao-Li Cui, Jun-Xin Li, Ru-Ting Tong

Journal of Electrochemistry

The geometrical thickness, which was obtained from the capacitance of membrane, can be used to characterize the existence of membrane. The apparent effective thickness, which is analyzed from the electron transfer constant of transmembrane, can be used to determine the degree of “collapsed" of molecules. Though the two thicknesses were different in value, there was no contradiction. The influence on the geometrical thickness is little, but the effect to the apparent effective thickness is great from the small “collapsed" area in the membrane from the given calculation.

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Electrochemical Polymerization Of Biphenyl And P-Terphenyl In Organic Solvent, Sheng-Yun Cui Nov 2000

Electrochemical Polymerization Of Biphenyl And P-Terphenyl In Organic Solvent, Sheng-Yun Cui

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L-1 NaOH+0.1 mol·L-1 CH3CH2OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH3COO-, only very small amount of CH 3CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

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Effect Of High Concentration Lithium Bromide Solution On Electrochemical Behavior Of Low Alloy Steel At High Temperature, Jian-Wei Guo, Cheng-Hao Liang Nov 2000

Effect Of High Concentration Lithium Bromide Solution On Electrochemical Behavior Of Low Alloy Steel At High Temperature, Jian-Wei Guo, Cheng-Hao Liang

Journal of Electrochemistry

By electrochemical measurements and weight loss experiments, the effect of MoO42- on low alloy steel's electrochemical behaviors was investigated at high temperature in 55%LiBr+0.07 mol/L LiOH solution. The results showed that MoO42-, as an anodic inhibitor, formed passive film rapidly and impeded both anodic and cathodic procedures. Moreover, Na2MoO4 prevented corrosion effectively in 55%LiBr+0.07 mol/L LiOH solution when its concentration is more than 200 mg/L. The pitting potential increased accompanying to the arising of Na2MoO4 concentration. Some elements of alloy strengthened resistance to corrosion, shch as chromium and nickel, …

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Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I. Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou Nov 2000

Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I. Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L-1 NaOH+0.1 mol·L-1 CH3CH2OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH3COO-, only very small amount of CH 3CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

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Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing-Guo Liu Nov 2000

Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing-Guo Liu

Journal of Electrochemistry

The synthesis and electrochemical characteristics of lithium cobalt nickel oxide as cathode materials for rechargeable lithium batteries were investigated. It was clarified from these investigations that lithium cobalt nickel oxide has been produced from basic cobalt carbonate,basic nickel carbonate, lithium carbonate, and citrate. LiNi0.8Co 0.2O2 prepared under the stream of oxygen gas showed a higher cycling capacity of (～190 mAh·g-1).

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Magnetic Clusters On Single-Walled Carbon Nanotubes: The Kondo Effect In A One-Dimensional Host, Teri W. Odom, Jin-Lin Huang, Chin Li Cheung, Charles M. Lieber Nov 2000

Magnetic Clusters On Single-Walled Carbon Nanotubes: The Kondo Effect In A One-Dimensional Host, Teri W. Odom, Jin-Lin Huang, Chin Li Cheung, Charles M. Lieber

Barry Chin Li Cheung Publications

Single-walled carbon nanotubes are ideal systems for investigating fundamental properties and applications of one-dimensional electronic systems. The interaction of magnetic impurities with electrons confined in one dimension has been studied by spatially resolving the local electronic density of states of small cobalt clusters on metallic single-walled nanotubes with a low-temperature scanning tunneling microscope. Spectroscopic measurements performed on and near these clusters exhibit a narrow peak near the Fermi level that has been identified as a Kondo resonance. Using the scanning tunneling microscope to fabricate ultra-small magnetic nanostructures consisting of small cobalt clusters on short nanotube pieces, spectroscopic studies of this …

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Dynamics And Folding Of Single Two-Stranded Coiled-Coil Peptides Studied By Fluorescent Energy Transfer Confocal Microscopy, David Talaga, Wai Leung Lau, Heinrich Roder, Jianyong Tang, Yiwei Jia, William F. Degrado, Robin M. Hochstrasser Nov 2000

Dynamics And Folding Of Single Two-Stranded Coiled-Coil Peptides Studied By Fluorescent Energy Transfer Confocal Microscopy, David Talaga, Wai Leung Lau, Heinrich Roder, Jianyong Tang, Yiwei Jia, William F. Degrado, Robin M. Hochstrasser

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

We report single-molecule measurements on the folding and unfolding conformational equilibrium distributions and dynamics of a disulfide crosslinked version of the two-stranded coiled coil from GCN4. The peptide has a fluorescent donor and acceptor at the N termini of its two chains and a Cys disulfide near its C terminus. Thus, folding brings the two N termini of the two chains close together, resulting in an enhancement of fluorescent resonant energy transfer. End-to-end distance distributions have thus been characterized under conditions where the peptide is nearly fully folded (0 M urea), unfolded (7.4 M urea), and in dynamic exchange between …

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Enantioselective Reversed-Phase And Non-Aqueous Capillary Electrochromatography Using A Teicoplanin Chiral Stationary Phase, Charlotte Karlsson, Håkan Wikström, Daniel W. Armstrong, Paul K. Owens Nov 2000

Enantioselective Reversed-Phase And Non-Aqueous Capillary Electrochromatography Using A Teicoplanin Chiral Stationary Phase, Charlotte Karlsson, Håkan Wikström, Daniel W. Armstrong, Paul K. Owens

Chemistry Faculty Research & Creative Works

Enantiomeric separation of chiral pharmaceuticals is carried out in aqueous and non-aqueous packed capillary electrochromatography (CEC) using a teicoplanin chiral stationary phase (CSP). Capillaries were slurry packed with 5 μm 100-A porous silica particles modified with teicoplanin and initially evaluated using a non-aqueous polar organic mode system suitability test for the separation of metoprolol enantiomers (R(s)=2.3 and 53 000 plates m-1). A number of pharmaceutical drugs were subsequently screened with enantioselectivity obtained for 25 racemic solutes including examples of neutral, acidic and basic molecules such as coumachlor (R(s)=3.0 and 86 000 plates m-1) and alprenolol (R(s)=3.3 and 135 000 plates …

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Evaluation Of The Macrocyclic Glycopeptide A-40,926 As A High-Performance Liquid Chromatographic Chiral Selector And Comparison With Teicoplanin Chiral Stationary Phase, Alain Berthod, Timothy Yu, John P. Kullman, Daniel W. Armstrong, Francesco Gasparrini, Ilaria D'Acquarica, Domenico Misiti, Angelo Carotti Nov 2000

Evaluation Of The Macrocyclic Glycopeptide A-40,926 As A High-Performance Liquid Chromatographic Chiral Selector And Comparison With Teicoplanin Chiral Stationary Phase, Alain Berthod, Timothy Yu, John P. Kullman, Daniel W. Armstrong, Francesco Gasparrini, Ilaria D'Acquarica, Domenico Misiti, Angelo Carotti

Chemistry Faculty Research & Creative Works

A new macrocyclic antibiotic of the vancomycin family, referred to by its industrial designation as A-40,926, was bonded to 5 μm silica particles and utilized as a chiral stationary phase (CSP). Since A-40,926 is structurally related to teicoplanin, the A-40,926 CSP was compared to a commercially available teicoplanin CSP. A set of 28 chiral compounds, including amino-acids and related compounds, compounds with a ring containing the stereogenic centre, compounds bearing aromatic structures near their stereogenic centres and alcohols, was tested for enantioseparation on the two CSPs. The results are compared and discussed in terms of enantioselective Gibbs energy difference. The …

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Crystallization And Preliminary X-Ray Diffraction Studies On The Dna-Binding Domain Of The Multidrug Transporter Activation Protein (Mtan) From Bacillus Subtilis, M. H. Godsey, N. N. Baranova, A. A. Neyfakh, R. G. Brennan Nov 2000

Crystallization And Preliminary X-Ray Diffraction Studies On The Dna-Binding Domain Of The Multidrug Transporter Activation Protein (Mtan) From Bacillus Subtilis, M. H. Godsey, N. N. Baranova, A. A. Neyfakh, R. G. Brennan

CUP Faculty Research

The N-terminal DNA-binding domain of the multidrug transporter activation protein (MtaN) was crystallized by the hanging-drop vapour-diffusion method using lithium chloride as a precipitant. The crystals are orthorhombic and belong to the space group I212121, with unit-cell parameters a = 49.4, b = 67.8, c = 115.0 Å. Diffraction data have been collected at 100 K to 2.75 Å resolution at a synchrotron-radiation source.

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