Physical Sciences and Mathematics Commons^™

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

Seton Hall University Dissertations and Theses (ETDs)

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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 …

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.

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

Journal of Electrochemistry

Polymers were prepared by oxidation of biphenyl and p terphenyl by consecutive cyclic voltammetry and at a constant potential in rigorously dried dichloromethane solutions. In situ studies on the polymerization properties and deposited polymer were also proceeded employing electrochemical quartz crystal micro balance, spectroelectrochemical measurements. The great mass deposition was observed as the biphenyl and p terphenyl monomers are oxidized indicating that polymers were formed by the oxidation of biphenyl and p terphenyl in the solution and then deposited on the platinum electrode surfaces. Polymerization can be further confirmed by the red shifts of spectra observed by spectroelectrochemical measurements. The …

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 CH 3CH 2OH was investigated by using cyclic voltammetry and in_situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH 3COO -,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 nm_Pt/GC electrode that gives rise to enhancement of …

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 MoO 4 2- 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 MoO 4 2- ,as an anodic inhibitor, formed passive film rapidly and impeded both anodic and cathodic procedures. Moreover, Na 2MoO 4 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 Na 2MoO 4 concentration.Some elements of alloy strengthened resistance to corrosion, shch as chromium and nickel, but aluminum promoted corrosion. …

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. LiNi 0.8 Co 0.2 O 2 prepared under the stream of oxygen gas showed a higher cycling capacity of (～190 mAhg 1 ).

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 mA·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.

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 LiMn 2O 4 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 LiMn 2O 4 are also reported.

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/cm 2 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 …

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 …

The Electrochemical Performance Of The Spinel Limn_2o_4, Shi Gang Lu, Yu Cheng Sun, Ren Min Liu, Wei-Hua Jin, Wen-Zhong Li, Cang Han

Journal of Electrochemistry

The cathode material spinel LiMn 2O 4 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 LiMn 2O 4 structure. It was found that the spinel LiMn 2O 4, treated with layer compound …

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 ,NO 3 and SO 4 2 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.

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 In x Ga 1 x As film were also studied.

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.

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 …

The Difference Of The Geometrical Thickness And The Electrochemical Apparent Effective Thickness Of Self-Assembled Monolayers, Xiao Cui, Li Li

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.

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.

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.

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.

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 …

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 …

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 …

6. Ichitaro Uematsu, Otto Vogl, Teiji Tsuruta, Yoshiko Uematsu

Otto Vogl

No abstract provided.

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.

Modeling Distinct Vertical Biogeochemical Structure Of The Black Sea: Dynamical Coupling Of The Oxic, Suboxic, And Anoxic Layers, T Oguz, Hw Ducklow, P Malanotte-Rizzoli

VIMS Articles

A one-dimensional, vertically resolved, physical-biogeochemical model is used to provide a unified representation of the dynamically coupled oxic-suboxic-anoxic system for the interior Black Sea. The model relates the annual cycle of plankton production in the form of a series of successive phytoplankton, mesozooplankton, and higher consumer blooms to organic matter generation and to the remineralization-ammonification-nitrification-dentrification chain of the nitrogen cycle as well as to anaerobic sulfide oxidation in the suboxic-anoxic interface zone. The simulations indicate that oxygen consumption during remineralixation and nitrification, together with a lack of ventilation of subsurface waters due to the presence of strong stratification, are the …

Biogeochemistry And Contaminant Geochemistry Of Marine And Estuarine Sediments, New Haven, Connecticut (Usa), Michael A. Kruge, Gaboury Benoit

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The urbanized shore areas of Long Island Sound in the vicinity of New Haven, Connecticut (USA) have a long history of exposure to point and non-point sources of pollution, New Haven having been one of the birthplaces of the industrial revolution. As an unintended consequence of such activities, the region's sedimentary systems have incorporated a complex mixture of organic and inorganic contaminants. With its long and varied pollution history and the multiplicity of sedimentary environments (fluvial, estuarine, intertidal, marsh, etc.) present in a compact geographical area, the region is ideal natural laboratory for field testing new contamination assessment techniques. The …

Detection Of Solid Pigment In Dermatoscopy Images Using Texture Analysis, Murali Anantha, William V. Stoecker, Randy Hays Moss

Chemistry Faculty Research & Creative Works

Background/aims: Epiluminescence microscopy (ELM), also known as dermoscopy or dermatoscopy, is a non-invasive, in vivo technique, that permits visualization of features of pigmented melanocytic neoplasms that are not discernable by examination with the naked eye. ELM offers a completely new range of visual features. One such feature is the solid pigment, also called the blotchy pigment or dark structureless area. Our goal was to automatically detect this feature and determine whether its presence is useful in distinguishing benign from malignant pigmented lesions.

Methods: Here, a texture-based algorithm is developed for the detection of solid pigment. The factors d and a …

Second-Harmonic And Sum-Frequency Imaging Of Organic Nanocrystals With Photon Scanning Tunneling Microscope, Yuzhen Shen, Jacek Swiatkiewicz, Jeffrey G. Winiarz, Przemyslaw P. Markowicz, Paras N. Prasad

Chemistry Faculty Research & Creative Works

Second-harmonic generation and sum-frequency generation with photon scanning tunneling microscopy and shear-force detection are used to map the nonlinear optical response and the surface topograph of N-(4-nitrophenyl)-(L)-prolinol crystals with a subdiffraction-limited resolution. The domain-size dependence of the spatial feature is obtained, which shows the local orientational distribution of the optical near field radiated by nonlinear nanocrystals and reveals the difference between nanoscopic and macroscopic second-order optical nonlinearities of molecular crystals.

Cerium Liii-Edge X-Ray Absorption Study Of The Ceₓfe4-YCoYSb₁₂ Skutterudites, Fernande Grandjean, Gary J. Long, Robert Cortès, Donald T. Morelli, Gregory P. Meisner

Chemistry Faculty Research & Creative Works

The cerium L_III-edge x-ray absorption near-edge spectra of the Ce_xFe_4-yCo_ySb₁₂ compounds have been obtained at 295 K and unambiguously indicate that cerium is in the 4f¹ electronic ground state for all values of 0.22≤x≤0.98 and 0.0≤y≤3.5. This stable trivalent state of cerium is in agreement with the proposed (CeFe₄Sb₁₂) _1-α(Co₄Sb₁₂)α, solid solution structure, in which the cerium atoms are always surrounded by twelve antimony first neighbors and six iron second neighbors, the observed magnetic properties of CeFe₄Sb₁₂ and …