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Full-Text Articles in Physical Sciences and Mathematics

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.


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.


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 …


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 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 …


Biogeochemistry And Contaminant Geochemistry Of Marine And Estuarine Sediments, New Haven, Connecticut (Usa), Michael A. Kruge, Gaboury Benoit Nov 2000

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 …


Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise Oct 2000

Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise

Chemistry & Biochemistry Theses & Dissertations

As early as 1950, Raman spectroscopy was proposed as a method to determine aromatics and olefins in hydrocarbon mixtures. Until recently, extensive use of Raman spectroscopy in the characterization of hydrocarbons has not been practical due to several limitations. One early limitation to Raman analysis was the absence of a high intensity and stable excitation source. This problem has been overcome with the advent of lasers. Another limitation was the presence of fluorescence in hydrocarbon fuels when excited by visible lasers. However, the development of Fourier-transform Raman spectrometers now allows Raman spectra to be collected using near-IR lasers (e.g …


The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo Aug 2000

The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo

Journal of Electrochemistry

A linear polarization method was applied to measure corrosion rate of reinforcing bar of concrete in situ. Generally in the experiment, the area and shape of the reinforcing bar as a working electrode can be changed and adjusted according to our needs. But polarization area cannot be defined when reinforcing bar is polarized in situ, so that a real R p can't be obtained. Thus the purpose of present work is to improve the measurement system. We used the double_ring auxiliary electrodes made by ourselves. The size of the double_ring auxiliary electrodes was adjusted repeatedly until the real polarization area …


Pulse Potential Modulated Electrochemical Gas Sensors, Zhong Bai Zhou, Liang Dong Feng, Wen Jun Liu Aug 2000

Pulse Potential Modulated Electrochemical Gas Sensors, Zhong Bai Zhou, Liang Dong Feng, Wen Jun Liu

Journal of Electrochemistry

The current popular electrochemical gas sensors are mostly stable with regard to their operating states. As a result, the further improvement of sensor charcateristics is restricted by such a "steady state" . Based on the transient electrochemistry principle, a kind of all new transient electrochemical multi component gas sensors— "pulse potential modulated electrochemical gas sensors" was established by combining computer controlled fast modulated potential technique with microelectrode method.This novel approach provided a real time and dynamic sensor technique integrated with acquisition, treatment and display of signals for rapid simultaneous detecion of multicomponent gases, as illustrated by the case of monitoring …


Cyclodextrin Inclusion Complexes Of Betamethasone-Related Steroids Studied Using Hplc, Keith Gerald Flood Aug 2000

Cyclodextrin Inclusion Complexes Of Betamethasone-Related Steroids Studied Using Hplc, Keith Gerald Flood

Seton Hall University Dissertations and Theses (ETDs)

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Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten Jul 2000

Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten

Theses and Dissertations in Biomedical Sciences

The major objective of this research is to examine ion mobility spectrometry as a rapid screening tool for specific application to clinical chemistry research and laboratory use. Methodology was developed for target analytes representing several classes of physiologically active substances, including anesthetics, illicit drugs, and their metabolites. The IMS characteristics of animal tissues and other compounds such as amino acids and proteins were determined. Quality assurance and control procedures were developed for specific quality data objectives. Criteria were established relating to use of IMS for assessing the precision and accuracy of data, qualitative screening, and semi-quantitative analyses.

It was found …


Study Of The Cathod Of The Amperometric Glucose Sensor, Xiu-Juan Yu, Ding Zhou May 2000

Study Of The Cathod Of The Amperometric Glucose Sensor, Xiu-Juan Yu, Ding Zhou

Journal of Electrochemistry

The possibility for several kinds of conducting materials used as the cathode of glucose sensor was studied by the cathode polarization curves. It was shown that the titanium coated by RuO 2/TiO 2 is stable to the electrochemical corrosion and it could promote the generation of hydrogen. H 2O 2 could be detected in the electrochemical system constructed by the anode of graphite powder and epoxy resin composite and the cathode of titanium coated by RuO 2/TiO 2 in the potential range of 0.6V~0.8 V. It can be used as the cathode of glucose sensor instead of Pt. The response …


A Study For The Data Analysis Of Electrochemical Noise With Wavelet Analysis, Hong-Bo Ding, Bao-Yun Xia, Zhong-Xiao Pan, Chang-Jian Lin May 2000

A Study For The Data Analysis Of Electrochemical Noise With Wavelet Analysis, Hong-Bo Ding, Bao-Yun Xia, Zhong-Xiao Pan, Chang-Jian Lin

Journal of Electrochemistry

In the process of electrochemical dynamics system,the phenomenon of the random fluctuations of electrochemical parameters(electrode potential,cell current,etc.)is called “Electrochemical Noise”(ECN).Wavelets analysis is one new data analysis technique which has undergone a breakthrough in the area of mathematics and singnal processing in recent years.In this paper,the technique of continuous wavelet transform has been employed to investigate electrochemical noise data,and the chaotic nature of corrosion process has been manifested.


Retention Of Ionizable Compounds In Hplc, Rosario Lobrutto May 2000

Retention Of Ionizable Compounds In Hplc, Rosario Lobrutto

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.


The Vaporization Enthalpies Of Some Crown And Polyethers By Correlation Gas Chromatography, Gary Nichols, Jennifer Orf, Sarah M. Reiter, James Chickos, George W. Gokel Feb 2000

The Vaporization Enthalpies Of Some Crown And Polyethers By Correlation Gas Chromatography, Gary Nichols, Jennifer Orf, Sarah M. Reiter, James Chickos, George W. Gokel

James Chickos

No abstract provided.


Determination Of Diclofenac In Voltalin Tablets By Differential Pulse Voltammetry, Gui-Fen Wang, Yuan-Zhe Piao Feb 2000

Determination Of Diclofenac In Voltalin Tablets By Differential Pulse Voltammetry, Gui-Fen Wang, Yuan-Zhe Piao

Journal of Electrochemistry

Diclofenac,dissolved in a base solution of chlorhydric acid,showed a sensitive oxidation peak at 0.91 V(vs.SCE) when the solution was cyclically swept from +0.6 to +1 2 V(vs.SCE) by differential pulse voltammetry at GCE.There was a good linear relationship between the differential pulse peak current and the concentraion of diclofenac in the range from 5.0×10 -7 to 6.0×10 -6 mol/L,and the relative standard deviation is 3.5%(n=10).When determining the content of diclofenac in voltalin tablets, we have got the same results by this method as ultraviolet spectrophotometry.


Heavily Fluorinated Sugar Analogs, Stephen G. Dimagno Jan 2000

Heavily Fluorinated Sugar Analogs, Stephen G. Dimagno

Chemistry Department: Faculty Publications

Heavily fluorinated Sugar analogs of formula

wherein R1 is selected from alkyl, alkenyl, aryl, CH2OH, -CH2-O-alkyl, -CH2-O-aryl, -CH2OPO3H, -CH2-O-carbohydrate, -CH2-NH-peptide, or -CH2-O-peptide; wherein R2 is selected from hydroxy, -O-carbohydrate, -NH-peptide,

wherein R3 is selected from H, halogen, lower alkyl, lower alkenyl, lower haloalkyl, lower haloalkenyl, amino, mono- or di-lower alkylamino; wherein R4 is Selected from amino, hydroxy, alkoxy, or halogen; and wherein R5 is H or amino. The compounds of formula (I) are useful as antiviral and antineoplastic agents …


Octafluoro-Meso Tetraarylporphyrins And Methods For Making These Compounds, Stephen G. Dimagno Jan 2000

Octafluoro-Meso Tetraarylporphyrins And Methods For Making These Compounds, Stephen G. Dimagno

Chemistry Department: Faculty Publications

The novel compounds of the present invention are f-octafluoro-meso-tetraarylporphyrins of formula (I) and their metallic complexes of formula (II):

B-octafluoro-meso-tetraaryl porphyrins are Synthesized by reacting 3,4-difluoropyrrole with an aromatic aldehyde in the presence of boron trifluoride etherate, followed by oxidation. The difluoropyrrole used in this reaction is pro duced by reacting 3,3,4,4-tetrafluoropyrroline or its corre sponding Salt, 3,3,4,4-tetrafluoropyrrolidinium Salt, with a base Such as potassium tert-butoxide. The metalloporphyrins of the present invention are Synthesized by deprontonating B-octafluoro-meso-tetraarylporphyrin ligands and treating Said ligands with metal ions.


Determination Of Thermal Maturity And Organic Matter Type By Principal Components Analysis Of The Distributions Of Polycyclic Aromatic Compounds, Michael A. Kruge Jan 2000

Determination Of Thermal Maturity And Organic Matter Type By Principal Components Analysis Of The Distributions Of Polycyclic Aromatic Compounds, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The thermal maturity and organofacies sensitivity of polycyclic aromatic compound (PAC) distributions was explored by examination of the aromatic fractions of solvent extracts from a diverse set of 53 shales, coals and kerogen macerals which have undergone either natural or artificial maturation and which represent all three principal sedimentary organic matter (OM) types. Systematic changes with maturation were observed in the following groups of isomers: tri- and tetramethylnaphthalenes, methyl- and dimethylphenanthrenes, methyl- and dimethyldibenzothiophenes, methylpyrenes, and methylchrysenes. The maturity differences were quantified by mathematical ratios of the relative concentrations of the more thermally stable isomers to the less stable, on …