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Title: ELECTROCATALYTIC REDUCTION OF ACETYLENE BY MOLYBDENUM-CYSTEINE AND MOLYBDENUM-EDTA COMPLEXES.
Creator: LEAZENBEE, LOUIS O., Florida Atlantic University, Schultz, Franklin A., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: Binuclear oxo- and sulfide-bridged Mo(V)-cysteine and Mo(V)-EDTA complexes are chosen as model compounds for nitrogenase enzyme. Both groups of complexes undergo electrochemical reduction in a single four- electron step to Mo(III) dimers. The reduced binuclear Mo (III) units dissociate into catalytically active species capable of reducing the nitrogenase substrate, acetylene. Ease of dissociation increases as oxygen is replaced by sulfur in the bridging unit. Electrocatalytic reduction...
Show moreBinuclear oxo- and sulfide-bridged Mo(V)-cysteine and Mo(V)-EDTA complexes are chosen as model compounds for nitrogenase enzyme. Both groups of complexes undergo electrochemical reduction in a single four- electron step to Mo(III) dimers. The reduced binuclear Mo (III) units dissociate into catalytically active species capable of reducing the nitrogenase substrate, acetylene. Ease of dissociation increases as oxygen is replaced by sulfur in the bridging unit. Electrocatalytic reduction products of acetylene consist primarily of C2H4 and C2H6 at low partial pressures, but C4H6, C4H8, and higher hydrocarbons predominate at higher pressures. The reduction of substrate is believed to occur by a Mo(III) catalyst adsorbed on the electrode surface. A mechanism is proposed for the e lectrocatalysis, and its relationship to the enzymic catalysis is discussed.
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Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13880
Subject Headings: Electrochemical analysis, Enzymatic analysis
Format: Document (PDF)

Title: ELECTROCHEMICAL REDUCTION OF A BINUCLEAR OXO-BRIDGED IRON(III) COMPLEX WITH THE SCHIFF BASE LIGAND, N,N'-ETHYLENEBIS-(SALICYLIDENEIMINATE).
Creator: WENK, SANDRA E., Florida Atlantic University
Abstract/Description: The elect;rochemical reduction of Fe2(salen)2O at a platinum electrode in dimethylsulfoxide is investigated using the techniques of cyclic voltammetry, controlled potential coulometry and chronoamperometry. The effects of concentration and addition of a proton source on the reduction mechanisrn are investigated. The reduction proceeds by two related mechanisms. At short-times, Fe2(salen)2O is reduced by two sequential one-electron steps producing an Fe(III)Fe(II) dimer and an unstable Fe(II)...
Show moreThe elect;rochemical reduction of Fe2(salen)2O at a platinum electrode in dimethylsulfoxide is investigated using the techniques of cyclic voltammetry, controlled potential coulometry and chronoamperometry. The effects of concentration and addition of a proton source on the reduction mechanisrn are investigated. The reduction proceeds by two related mechanisms. At short-times, Fe2(salen)2O is reduced by two sequential one-electron steps producing an Fe(III)Fe(II) dimer and an unstable Fe(II) dimer. At long-times the mixed-valence dimer reacts leading to transfer of 1.5 electrons per Fe2 unit. Mechanisms consistent with the experimental data are proposed involving the formation of a tetrameric structure.
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Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13866
Subject Headings: Electrochemistry, Electrochemical analysis
Format: Document (PDF)

Title: Electrochemical behavior of carbon fiber cathode materials in organic electrolytes containing various lithium salts.
Creator: Durand, Severine Nathalie., Florida Atlantic University, Lipka, Stephen M.
Abstract/Description: The intercalation of anions into carbon fiber from organic electrolytes containing lithium salts was studied. The reversible intercalation of anions into carbon could lead to the possible substitution of conventional metal oxide cathode materials in lithium-ion cells. EWC300 was selected as the most suitable carbon fiber material based on data from preliminary tests. Experiments were performed with LiClO4 in EC/DMC and LiPF6 in EC/DMC electrolytes. Slow scan cyclic voltammetry (0.1 mV/s) and...
Show moreThe intercalation of anions into carbon fiber from organic electrolytes containing lithium salts was studied. The reversible intercalation of anions into carbon could lead to the possible substitution of conventional metal oxide cathode materials in lithium-ion cells. EWC300 was selected as the most suitable carbon fiber material based on data from preliminary tests. Experiments were performed with LiClO4 in EC/DMC and LiPF6 in EC/DMC electrolytes. Slow scan cyclic voltammetry (0.1 mV/s) and galvanostatic charge/discharge experiments at various C rates were used. Intercalation of PF6- occurred by staging and was highly dependent on the current density. High current density (20 mA/g) was necessary to reach potentials over 5 V vs Li to achieve intercalation capacities over 80 mAh/g. Powder x-ray diffraction revealed that carbon fibers became less crystalline after anions were intercalated into their structure. Scanning electron microscopy showed longitudinal cracking on the carbon fibers after 120 cycles indicating dimensional instability.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15624
Subject Headings: Anions, Carbon fibers, Lithium cells, Electrochemical analysis
Format: Document (PDF)

Title: Characterization of nickel electrodes for secondary batteries by means of electrochemical impedance spectroscopy.
Creator: Nenov, Krassimir Petrov., Florida Atlantic University, Lipka, Stephen M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: An automated procedure for integrated cycling and electrochemical impedance spectroscopy (EIS) testing of nickel sinter individualized pressure vessel electrodes for secondary nickel/hydrogen batteries was developed. Nickel electrodes from three major U.S. manufacturers were cycled under various conditions. The condition of the electrodes was monitored using both EIS and traditional electrochemical methods. In order to establish relationships between the status of the electrodes and the...
Show moreAn automated procedure for integrated cycling and electrochemical impedance spectroscopy (EIS) testing of nickel sinter individualized pressure vessel electrodes for secondary nickel/hydrogen batteries was developed. Nickel electrodes from three major U.S. manufacturers were cycled under various conditions. The condition of the electrodes was monitored using both EIS and traditional electrochemical methods. In order to establish relationships between the status of the electrodes and the acquired impedance spectra, various cycling and electrode parameters were analyzed and compared with the EIS data. Nonlinear least squares (NLS) regression was used for analysis of the impedance data. An equivalent circuit was developed which produced good correlation with the impedance data at all states-of-charge and discharge rates. Problems with the experimental procedure which limit the validity of EIS testing were discussed.
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Date Issued: 1991
PURL: http://purl.flvc.org/fcla/dt/14777
Subject Headings: Impedance spectroscopy, Electrochemical analysis, Electric batteries--Electrodes
Format: Document (PDF)

Title: 1,8-Naphthridine Based Receptors for Selective Monosaccharide Binding in Aqueous Media.
Creator: Addo-Mensah, Alfred Kwesi, Cudic, Predrag, Florida Atlantic University
Abstract/Description: In this dissertation the synthesis, characterization, and binding properties of carbohydrate receptors 34-38 was described. Macrocyclic receptor 34 and macrobicyclic receptor 35 bind monosaccharides in aqueous media through combination of hydrophobic, electrostatic and hydrogen bonding interactions. The dissociation constants (Kd) for the complexes between 1 ,8-naphthyridine receptors 34, and 35 with a variety of neutral and negatively charged monosaccharides in aqueous media were determined...
Show moreIn this dissertation the synthesis, characterization, and binding properties of carbohydrate receptors 34-38 was described. Macrocyclic receptor 34 and macrobicyclic receptor 35 bind monosaccharides in aqueous media through combination of hydrophobic, electrostatic and hydrogen bonding interactions. The dissociation constants (Kd) for the complexes between 1 ,8-naphthyridine receptors 34, and 35 with a variety of neutral and negatively charged monosaccharides in aqueous media were determined by fluorimetric and UV /vis titration. The observed values are in the range from ~0.3 to >10 mM, within the Kd range reported for lectin/monosaccharide complexes. However, among monosaccharide substrates tested receptor 34 showed the strongest affinity for sialic acid (Kd = ~0 . 3 mM), a monosaccharide that plays many important roles in a wide variety of physiological and pathological processes. Macrocyclic receptor 34 recognizes not only sialic acid in solution, but also binds selectively in vitro to human cancer cell surface carbohydrate antigens containing terminal sialic acid moieties. In addition, besides their binding selectivity, receptors 34 and 35 display also the ability to discriminate between closely related monosaccharide substrates by opposite variation of the fluorescence emission intensity. Structure-binding relationship study of receptor 34 revealed that H-bonding donor/acceptor pattern and presence of positive charge on receptor's side arms are crucial for selective monosaccharide binding in aqueous media.
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Date Issued: 2008
PURL: http://purl.flvc.org/fau/fd/FA00000844
Subject Headings: Monosaccharides--Synthesis, Sensory receptors--Testing, Organic compounds--Synthesis, Electrochemical analysis
Format: Document (PDF)

Title: Evaluation of corrosion behavior of ion vapor deposited aluminum related coating systems.
Creator: Hang, Ling., Florida Atlantic University, McIntyre, Jack F.
Abstract/Description: Experiments were conducted to investigate the effectiveness of ion vapor deposited (IVD) aluminum as a base coat for polyurethane topcoat systems in marine environments. Three test environments were used including marine atmospheric atmosphere, quiescent filtered seawater open to laboratory air and aerated seawater. Visual observation and electrochemical impedance spectroscopy techniques were primary testing methods; other characterizations included adhesion tape test, coating thickness...
Show moreExperiments were conducted to investigate the effectiveness of ion vapor deposited (IVD) aluminum as a base coat for polyurethane topcoat systems in marine environments. Three test environments were used including marine atmospheric atmosphere, quiescent filtered seawater open to laboratory air and aerated seawater. Visual observation and electrochemical impedance spectroscopy techniques were primary testing methods; other characterizations included adhesion tape test, coating thickness measurements, holiday detection, optical microscopy, open circuit potential measurements and potentiodynamic polarization. It was found that IVD aluminum was a good candidate for replacement of environmentally sensitive coatings on AA2219-T87 and AISI 4340 steel substrates, respectively. The IVD aluminum coating provided good sacrificial protection and served as a good base for polyurethane topcoat systems. Electrochemical impedance spectroscopy was a suitable method to predict coating performance in the early stages of exposure.
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Date Issued: 1993
PURL: http://purl.flvc.org/fcla/dt/14970
Subject Headings: Aluminum coating, Corrosion and anti-corrosives, Metals--Corrosion fatigue, Electrochemical analysis
Format: Document (PDF)

Title: Electrochemical impedance spectroscopy of nickel-hydrogen and silver oxide-metal hydride secondary batteries.
Creator: Nechev, Kamen S., Florida Atlantic University, Lipka, Stephen M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Full nickel-hydrogen (Ni-H2) boilerplate batteries were cycled and impedance measurements were made at different states-of-charge (SOC), electrolyte concentrations and charge/discharge rates. Experiments were conducted on cells containing new and cycled (11,000 cycles) electrodes. Additionally, an EIS study of Ni-H2 flightweight IPV satellite cells was performed. A number of experiments were conducted on silver oxide-metal hydride batteries. The interest was focused on both negative and...
Show moreFull nickel-hydrogen (Ni-H2) boilerplate batteries were cycled and impedance measurements were made at different states-of-charge (SOC), electrolyte concentrations and charge/discharge rates. Experiments were conducted on cells containing new and cycled (11,000 cycles) electrodes. Additionally, an EIS study of Ni-H2 flightweight IPV satellite cells was performed. A number of experiments were conducted on silver oxide-metal hydride batteries. The interest was focused on both negative and positive electrodes and upon the system itself. This work was preliminary and aided in describing the general performance of the battery. For analysis, the data was fitted to an equivalent electrical circuit using the Nonlinear Least Squares Method (NLSM). The correlation between theoretical and empirical data was sufficiently good.
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Date Issued: 1993
PURL: http://purl.flvc.org/fcla/dt/14958
Subject Headings: Nickel-hydrogen batteries, Electrodes, Nickel, Impedance spectroscopy, Electrochemical analysis, Electric batteries--Electrodes
Format: Document (PDF)

Electrochemical analysis (7)	+ -
Electric batteries--Electrodes (2)	+ -
Impedance spectroscopy (2)	+ -
Aluminum coating (1)	+ -
Anions (1)	+ -

Carbon fibers (1)	+ -
Corrosion and anti-corrosives (1)	+ -
Electrochemistry (1)	+ -
Electrodes, Nickel (1)	+ -
Enzymatic analysis (1)	+ -
Lithium cells (1)	+ -
Metals--Corrosion fatigue (1)	+ -
Monosaccharides--Synthesis (1)	+ -
Nickel-hydrogen batteries (1)	+ -
Organic compounds--Synthesis (1)	+ -
Sensory receptors--Testing (1)	+ -

Florida Atlantic University (7)	+ -
Lipka, Stephen M. (3)	+ -
College of Engineering and Computer Science (2)	+ -
Department of Ocean and Mechanical Engineering (2)	+ -
Addo-Mensah, Alfred Kwesi (1)	+ -

Charles E. Schmidt College of Science (1)	+ -
Cudic, Predrag (1)	+ -
Department of Chemistry and Biochemistry (1)	+ -
Durand, Severine Nathalie. (1)	+ -
Hang, Ling. (1)	+ -
LEAZENBEE, LOUIS O. (1)	+ -
McIntyre, Jack F. (1)	+ -
Nechev, Kamen S. (1)	+ -
Nenov, Krassimir Petrov. (1)	+ -
Schultz, Franklin A. (1)	+ -
WENK, SANDRA E. (1)	+ -

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