Chemistry Commons^™

Evaluation Of A Naive Model For Square Wave Voltammetry At A Microelectrode, Patrick Enright, John Cassidy, Tony Betts

Articles

A square wave voltammetric waveform ( SWV) was applied to an inlaid microdisk electrode in a solution of K4[Fe(CN)6]. A simple model relying on the assumption of steady state current throughout the scan was used to model the current potential behaviour. However, experimental peak current magnitudes were between 30% and 50% greater than those predicted by the model. The model predicts an increase of peak current and peak width at half height with pulse height Esw and no effect of the parameters frequency, f and step height, ΔEs. Experimental peak current magnitudes and peak current magnitudes predicted by the model …

Imaging Of Metal Ion Dissolution And Electrodeposition By Anodic Stripping Voltammetry – Scanning Electrochemical Microscopy, Mario A. Alpuche-Aviles, John E. Baur, David O. Wipf

CAS Publications

We have developed a new imaging method for SECM employing fast scan anodic stripping voltammetry (ASV) to provide sensitive and selective imaging of multiple chemical species at interfaces immersed in solution. A rapid CV scan (100 V/s) is used along with a short preconcentration time (300-750 ms) to allow images to be acquired in a normal SECM time frame. A Hg-Pt film electrode is developed having an equivalent Hg thickness of 40 nm that has good sensitivity at short preconcentration times and also retains thin-film behavior with high-speed voltammetric stripping. Fast scan anodic stripping currents are shown to be linear …

Photofragmentation Of Sif4 Upon Si 2p And F 1s Core Excitation: Cation And Anion Yield Spectroscopy, Maria Novella Piancastelli, Wayne C. Stolte, Renaud Guillemin, A. Wolska, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We have studied the fragmentation dynamics of core-excited SiF₄ by means of soft-x-ray photoexcitation and partial positive and negative ion yield measurements around the Si L_2,3-shell and F K-shell ionization thresholds. All detectable ionic fragments are reported and we observe significant differences between the various partial ion yields near the Si 2p threshold. The differences are similar to our previous results from CH₃Cl showing more extended fragmentation in correspondence to transitions to Rydberg states. At variance with smaller systems, we observe negative ion production in the shape resonance region. This can be related …

Methods In Industrial Biotechnology For Chemical Engineers, Florentin Smarandache, W.B. Vasantha Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

Industrial Biotechnology is an interdisciplinary topic to which tools of modern biotechnology are applied for finding proper proportion of raw mix of chemicals, determination of set points, finding the flow rates etc., This study is significant as it results in better economy, quality product and control of pollution. The authors in this book have given only methods of industrial biotechnology mainly to help researchers, students and chemical engineers. Since biotechnology concerns practical and diverse applications including production of new drugs, clearing up pollution etc. we have in this book given methods to control pollution in chemical industries as it has …

Phosphorylation Of Muc1 By Met Modulates Interaction With P53 And Mmp1 Expression, Pankaj K. Singh, Michelle E. Behrens, John P. Eggers, Ronald Cerny, Jennifer M. Bailey, Kandavel Shanmugam, Sandra J. Gendler, Eric P. Bennett, Michael A. Hollingsworth

Ronald Cerny Publications

MUC1, a transmembrane mucin, is a key modulator of several signaling pathways that affect oncogenesis, motility, and cell morphology. The interaction of MUC1 cytoplasmic tail (MUC1CT) with signal transducers and its nuclear translocation and subsequent biological responses are believed to be regulated by phosphorylation status, but the precise mechanisms by which this occurs remain poorly defined. We detected a novel association between the Met receptor tyrosine kinase and the MUC1CT. Met catalyzed phosphorylation of tyrosine at YHPM in the MUC1CT. Stimulation of S2-013.MUC1F pancreatic cancer cells with hepatocyte growth factor facilitated nuclear localization of MUC1CT, as determined by real time …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Matrix, Spencer M. Steinberg, Gary Cerefice, David W. Emerson

Separations Campaign (TRP)

Observations related to the oxidation of iodide to iodine (I₂) or hypoiodic acid (HIO) by MnO₂ were continued. The formation of triiodide presumable involves the adsorption of iodide onto the MnO₂ surface (perhaps displacing a surface hydroxyl group). The iodide should be subsequently oxidized and released back into solution as IOH or I₂, which rapidly forms I₃ ^-. The kinetic data has been modeled as a first order process. First order rate constants have been obtained for the formation of iodine in the presence of MnO₂. The increase in iodide …

Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

The objective was to use electrochemical techniques to develop a thermodynamic understanding of actinide and lanthanide species in RTIL solutions, and use this data to effectively separate species with very similar chemical properties.

In consultation with a DOE collaborator, electrochemical methods and materials were evaluated and used to exploit the thermodynamic differences between similar chemical species enhancing the ability to selectively target and sequester individual species from mixtures. This project, in its third year, successfully completed phases 1, 2. Phase 3 was partially completed. The project expanded to include phase 4.

The following were specific goals for 2007-2008:

• To …

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System, Kenneth Czerwinski

Separations Campaign (TRP)

The research objective is to experimentally evaluate the fundamental speciation of Pu and U in the TBP-dodecane-nitric acid- AHA system and the effect of pertechnetate, specifically:

• To determine the influence of nitrate on the speciation of U and Pu in the TBP-dodecane-nitric acid system. The aqueous and organic speciation of U and Pu are examined as a function of the nitric acid concentration, nitrate concentration, actinide ion concentration, temperature, and time.

• To determine the speciation of U and Pu with AHA in the presence and absence of TBP-dodecane organic phase. The aqueous and organic speciation of U and …

Criticality Studies For Urex Processes, Denis Beller

Separations Campaign (TRP)

The completion of criticality experiments for mixtures of transuranic actinides (TRU; includes neptunium, plutonium, americium, and curium) that will be created during the separation of used nuclear fuel may be a requirement in order to construct prototype plants for the Global Nuclear Energy Partnership (GNEP). In this program and the Advanced Fuel Cycle Research and Development (AFC R&D) program that supports it, economic and environmental methods are being developed to reduce the impact of waste from commercial nuclear fuel cycles.

Recycling of used fuel by chemically separating it into U, fission products, and TRU would be the first step in …

F-Element Electrochemistry In Rtil Solutions: Electrochemical Separation Of Lanthanides And Actinides, David W. Hatchett

Separations Campaign (TRP)

Electrochemical methods can be used to effectively separate actinide and lanthanide species from complex mixtures. This is based on the unique electrochemical properties of each specific target species. In studies it has been found that, with the exception of Ce, aqueous solutions provide unsuitable electrochemical windows to effectively evaluate the thermodynamic properties that are useful for chemical separations. Therefore, a more novel approach was examined which eliminated the aqueous solution with a room temperature ionic liquid (RTIL) solution. RTIL solutions do not suffer from the side reactions that are prominent in aqueous environments. In addition, the potential window is much …

Evaluation Of Fundamental Radionuclide Extraction Data For Urex, Kenneth Czerwinski

Separations Campaign (TRP)

The speciation of technetium and actinides in advanced solvent extraction systems is the basis for their manipulation in separations. The ability to understand and predict radionuclide speciation is paramount to successful modeling of proposed separation systems. This project will examine the speciation of radionuclides in different stages of the uranium extraction (UREX) separation scheme, providing data useful to modeling. The areas to be examined include the speciation of uranium and plutonium with tributylphosphate and the kinetics and thermodynamics of lanthanides and actinides in the TALSPEAK (Trivalent actinide lanthanide separation by phosphorous reagent extraction from aqueous complexes) system. The complexation constants …

Improved High-Temperature Stability And Sun-Light-Driven Photocatalytic Activity Of Sulfur-Doped Anatase Tio2, Suresh Pillai, Declan Mccormack, Pradeepan Periyat, John Colreavy, Steve Hinder

Articles

No abstract provided.

Development Of Fullerene Based Sturctures For Photovoltaic And Electronic Applications, Amit Palkar

All Dissertations

Solar energy can be envisioned as a long term alternative to rapidly depleting fossil fuels. The energy from the sun can be harnessed by constructing donor-acceptor (D-A) type devices where the incident photon induces the transfer of an electron from the donor to the acceptor. If recombination is prevented, this electron can then be channeled through an external circuit, thus leading to the generation of photocurrent. Porphyrins, which are the naturally occurring pigments in photosynthesis, have been widely established as donors while fullerenes, such as C₆₀ and C₇₀ , due to their unique electron accepting properties, have been …

Lithium-Conducting Ionic Melt Electrolytes From Oligomeric Ethylene Glycols: Synthesis And Characterization, Boutros Hallac

All Dissertations

Commercial lithium ion cells consist of electrolytes that undergo salt concentration polarization which is acute upon high discharge currents. This type of polarization occurs as a result of the mobility of more than one ionic species in the presence of an electric field. One way to overcome it is by employing a material that would allow the mobility of one ionic species. This thesis will describe the synthesis and characterization of several fluorosulfonimide and fluorosulfonate based ionic liquids/melts as electrolytes having lithium as the only mobile ion. These materials were prepared by the nucleophilic addition reaction of a deprotonated polyether …

Thermodynaimic Study Of Nucleic Acids Recognition By Aminoglycosides , Hongjuan Xi

All Dissertations

ABSTRACT


Since the origin of first aminoglycosides antibiotics, streptomycin, isolated by Selman Waksman about 60 years ago, a number of aminoglycosides antibiotics were discovered to treat different infections. Neomycin class aminoglycosides were found to originally target the A site 16S rRNA in the 30S subunit of the ribosome within the Gram-negative bacteria. In addition to its antibacterial effect, aminoglycosides were also found to binding to various other viral RNA structures such as TAR and RRE of HIV, Group I introns and hammerhead ribozyme, implying its potential to be used as antiviral reagent.

Furthermore, previous studies in our laboratory discovered a …

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 …

Microcantilever Surface Modification For Chem-/Bio-Sensing, Hongwei Du

Doctoral Dissertations

One focus of the microcantilever (MCL) sensing area is to develop a novel surface modification approach to increase the microcantilever bending amplitudes and thus further improve sensitivities. In this dissertation, enzyme incorporated using the Layer by-Layer (LbL) process, LbL deposition of micro-, nano-hydrogel particles and electrophoretic deposition (EPD) of micro-, nano-hydrogel particles were applied to prepare a multilayer or thin hydrogel films on the surface of microcantilevers. Prior to applying to the microcantilevers, LbL and electrophoretic deposition techniques were also applied to gold coated silicon wafer surfaces to investigate the feasibility and deposition behavior using these techniques. The multilayers prepared …

Organic Geochemical Investigation Of A Highly Contaminated Urban Waterway: The Gowanus Canal, Brooklyn, New York, Usa, Michael A. Kruge, Kevin K. Olsen, Eric A. Stern

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Gowanus Canal is an industrial waterway constructed in the mid-19^th century by widening and deepening a natural tidal channel. It is ca. 3 km in length and empties into Gowanus Bay, an arm of New York Harbor. Its banks, reinforced by bulkheads and piers, became the site of intensive industrial activity, including oil refining, coal gasification, soap making and tanning. Even though much of the industrial activity along the canal has ceased, its sediments remain highly enriched in organic and inorganic contaminants, with combined sewer outfalls continuing to transport pollutants into the canal. The canal area remains densely …

A Novel Empirical Free Energy Function That Explains And Predicts Protein–Protein Binding Affinities, Joseph Audie, Suzanne Scarlata

Chemistry & Physics Faculty Publications

A free energy function can be defined as a mathematical expression that relates macroscopic free energy changes to microscopic or molecular properties. Free energy functions can be used to explain and predict the affinity of a ligand for a protein and to score and discriminate between native and non-native binding modes. However, there is a natural tension between developing a function fast enough to solve the scoring problem but rigorous enough to explain and predict binding affinities. Here, we present a novel, physics-based free energy function that is computationally inexpensive, yet explanatory and predictive. The function results from a derivation …

A Computational Chemistry Study Of Spin Traps., Jacob Fosso-Tande

Electronic Theses and Dissertations

Many defects in physiological processes are due to free radical damage: reactive oxygen species, nitric oxide, and hydroxyl radicals have been implicated in the parthenogenesis of cancer, diabetes mellitus, and rheumatoid arthritis. We herein characterize the phenyl-N-ter-butyl nitrone (PBN) type spin traps in conjunction with the most studied dimethyl-1-pyrroline-N-oxide (DMPO) type spin traps using the hydroxyl radical. In this study, theoretical calculations are carried out on the two main types of spin traps (DMPO and PBN) at the density functional theory level (DFT). The energies of the optimized structures, hyperfine calculations in gaseous and aqueous phases of the spin traps …

A Series Of Vertically Integrated Nanotechnology Experiments For The Undergraduate Curriculum, Kevin W. Kittredge, Lesley E. Russell, Michael C. Leopold

Chemistry Faculty Publications

We have designed three nanotechnology experiments that are vertically integrated for an undergraduate chemistry curriculum. They are an evolving set of experiments for sequential courses in an undergraduate chemistry program. These experiments are designed to match the student's level of understanding for each particular course. The participating student is involved in a "research" project that progresses in both theory and experimental technique. Students benefit from these vertically integrated experiments by being involved in multiple facets of a simulated research project. This mimics a traditional research project under an advisor's supervision without the undesired drawback of an unknown outcome.

Study On Fenbufen Electrochemical Behavior By The Linear Scanning Polarographic Method, Tian-Yang Xie, Hong-Gui Tuo, Ma-Tai Ding

Journal of Electrochemistry

The electrochemical behavior of fenbufen had been studied by linear scanning polarographic method.In 0.2mol L^-1 phosphate buffer solution(pH6.86),a sensitive reductive wave of fenbufen appeared at-1.38 V(vs.SCE).The linear relationship between the peak current and the fenbufen concentration in the range of 1.6～200.0 mg·L^-1(r=0.9958,n=10)were observed,the detection limit of this method was 0.8 mg·L^-1.RSD is 0.73%,found from the data of 6 independent determinations at the concentration level of 80.0 mg·L^-1.recovery ratio is 97.7%～109.2%.This fenbufen's electrochemical characteristic property may be used to determining the contents of tablets.

Determination Of Tetracyclines Based On The Flow-Through Electrochemical Detection Cell With Nickel Electrode, Dan-Mei Pan, Rong-Zong Hu, Dong-Ping Wei, Hao-Dong Ding

Journal of Electrochemistry

The electrochemical responses to tetracycline at the nickel electrode in alkaline solution were compared with that of gold and glassy carbon electrode by voltammetry.The electrocatalytic oxidation characteristics of tetracycline at nickel electrode were discussed.Subsequently a flow-through amperometric detection cell with nickel as the working electrode was designed to detect tetracycline,oxytetracycline,and doxycycline.Standard calibration graphs for the tetracyclines yielded linear ranges of 0.1~15 mg/L.Detection limits(S/N=3)of 35,45 and 43 μg/L were obtained for tetracycline,oxytetracycline and doxycycline,respectively.The system was applied for the determination of the three antibiotics in single-component drug formulations.

The Glow Discharge - A Multifaceted Optical Emission Source: From Solids Analysis To Metalloproteins, Timothy Brewer

All Dissertations

Glow discharges (GD) are well known for their application to direct solids elemental analysis of metals and alloys by optical emission spectroscopy (GD-OES). The most successful application of GD-OES has been the analysis of solid materials since the GD provides rapid, direct bulk and depth profiling analysis of solids, metals, powders, polymers, glasses and ceramics. However, solids analysis has typically suffered from the lack of true analytical blanks and the inability to study particulate solids in their native state. An approach for the analysis of solid powdered material entrapped in a sol-gel matrix by radio frequency glow discharge optical emission …

Analysis Of Nutraceuticals For Toxic Metals: Development And Validation Of Sample Preparation Method, Julia Cooper

All Theses

With increasing numbers of health-conscious consumers purchasing nutraceutical supplements, total sales in the nutrition industry have soared to over $200 billion in 2006. It is important to assess the safety of these nutraceutical products, with specific regards to toxic metals, including arsenic, cadmium, lead, and mercury. Because species of these metals may be more toxic than others, they can have hazardous health effects if ingested in excess quantities. The work described in this thesis focuses on the development of a sample preparation method for nutraceutical products, specifically ethanolic tinctures and glycerin-based matrices, and analysis of these products by inductively coupled …

Electrochemical Performance Of 1-Ethyl-3-Methylimidazolium Trifluoroacetic To The Electrolyte Of Electrochemical Double Layer Capacitor, Guo-Hua Sun, Kai-Xi Li, Qiang Li, Hui Fan, Jian-Yu Gu

Journal of Electrochemistry

The electrochemical performance of an Electrochemical Double Layer Capacitor consisted of higher specific surface area activated carbon and ionic liquid \CF₃COO was investigated by constant current charge/discharge and cyclic voltammegrams(CV) methods.The results indicated that the \CF₃COO had High specific capacitance,excellent cyclic characteristics and high charge/discharge efficiency.Specific capacitance of the EDLC increased with electrochemical window increase at the range of steady electrochemical window.Energy density increased with current and voltage increase,power density deduced with current increase but increased with electrochemical window increase.These conclusions revealed that the \CF₃COO was very suitable for the electrolyte of EDLC.

Rank-Ordering Protein-Ligand Binding Affinity By A Quantum Mechanics/ Molecular Mechanics/Poisson-Boltzmann-Surface Area Model, Mingliang Wang, Chung Wong

Chemistry & Biochemistry Faculty Works

The authors describe a quantum mechanics/molecular mechanics/Poisson-Boltzmann-surface area model for rank-ordering protein-ligand binding affinity in aqueous solution. Unlike many classical continuum electrostatics calculations in which the protein and ligand are treated as a uniform dielectric, this model uses quantum mechanics to explicitly describe the electronic polarization of the ligand by its environment. In solving the Poisson-Boltzmann equation, the authors use the quantum mechanical charge density directly rather than the common point-charge approximation. The authors show that useful results can be obtained by using experimental structure, by choosing a protein dielectric constant that is smaller than that typically used in classical …

An Experiment Using A Simple Photoassisted Fuel Cell Designed To Remediate Simulated Wastewater, John Cassidy, Faisa Touati, Kevin Mcguigan

Articles

Work in photochemistry work peaked in the 1980’s where there was the prospect of using sunlight shining on suspensions of titanium dioxide in order to catalytically cleave water into hydrogen and oxygen [1-5]. In this way a clean and efficient method of producing hydrogen as a fuel was envisaged. However, there was a requirement to use a rather high energy light to achieve the splitting and it was not as efficient with visible light[5]. Doped TiO2 layers have been used in a three electrode system for formic acid degradation[6]. In this work, the system uses an electrode coated with TiO2 …

Fast-Scan Cyclic Voltammetry - Scanning Electrochemical Microscopy, Luis Díaz-Ballote, Mario A. Apuche-Avlles, David O. Wipf

CAS Publications

The use of fast scan cyclic voltammetry (FSCV) to generate images in scanning electrochemical microscopy is demonstrated. In the FSCV-SECM method a cyclic voltammogram is acquired at each grid point of the scanned area. Thus, each point in the SECM image is a data array rather than a single value. This provides a significant increase in the amount of data collected per scan and provides the ability to make images of multiple analytes per scan. In addition, the use of cyclic voltammetry allows images based on adsorptive as well as diffusional processes. In this paper, we describe the FSCV-SECM experiment …

The Biophysical Analysis Of The Human Telomeric Repeat (Ttaggg)4 And Characterization Of Porphyrin Binding In Potassium Solutions, Cosimo Antonacci

Seton Hall University Dissertations and Theses (ETDs)

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