Physical Sciences and Mathematics Commons^™

Studies On The Electrochemical Properties Of Phosphate Derivatives Of C_(60), Ying Liu, Li Ding, Lou-Zhen Fan, Fu-Yong Cheng, Zhong-Da Wu

Journal of Electrochemistry

The phosphorus chemistry of fullerene was investigated for the first time. We have synthesised three novel phosphate derivatives of C 60 .Their electrochemical properties were detected by cyclic voltammetry (CV).The influence of different substituents on the electron_accepting ability of methanofullerenes was also observed by the comparative study on the electrochemical properties of different C 60 derivertives.

Codeposition And Corrosion Resistance Of Nickel-Cerium-Phosphorus Amorphous Alloys, Jiang Liu, Xiong Jiang, Lin-Cai Jiang, Ze-Shan Zhu

Journal of Electrochemistry

The possibility of electrodeposition of rare earth alloys from aqueous bath was investigated using varous techniques such as linear potential sweeping, cyclic voltammetry, electrodepositon at constant potential etc. The Ni Ce P alloys with different cerium content were electrodeposited from a weakly acidic solution containing CeCl 3, NaH 2PO 2 and so on the crystal structure and component were characterized by XPS, AES, XRD and SEM observation. The codeposits were found to be more highly corrosion resistent than that of Ni P amorphous alloys by measuring polarization resistance and corrosion potential. The effects of codeposition conditions on the corrosion resistance …

Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin

Journal of Electrochemistry

The periodic,aperiodic,chaotic and mixed_mode oscillations can occur in the process of the anodic electrodissolution of carbon steel in the solution of dilute phosphoric acid. More plentiful dynamic behaviors can be found in this system compared with the system of Fe/H 3PO 4/Pt.

Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode With Electrochemical Impedance Spectroscopy, Xian Xia Yuan, Nai Xin Xu

Journal of Electrochemistry

Electrochemical impedance spectroscopy was employed to determine the hydrogen diffusion coefficient in MlNi 3.75 Co 0.65 Mn 0.4 Al 0.2 metal hydride electrode with various states of charge(SOC) at room temperature and with 50% SOC at various temperatures. It was found that hydrogen diffusion coefficient in this electrode decreases with the increase in SOC at ambient temperature, and for the electrode with 50%SOC, hydrogen diffusion coefficient increases with the increase of temperature and the activation energy for hydrogen diffusion in it is 35 kJ/mol.

Electrochemical Impedance Spectroscopy Study On A3 Steel In Anti-Corrosive Pigment Extract Solution, Zhi-Jun Gu, Yong-Gui Liao, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su, Wen-Yun Hu, Yan-Zhen Chen

Journal of Electrochemistry

The corrosion behaviors of A3 steel in different pH, 3.5%NaCl, modified zinc phosphate and aluminum triphosphate extract solutions have been studied by EIS. Results show:(a) The resistance increases with the increase of pH value under the same circumstances, but the capacity is the reverse.(b) Zinc phosphate, because of its low solubility, shows no inhibitive performance for A3 steel in 3.5% NaCl extract solutions. (c) Aluminum triphosphate has good inhibitive performance for A3 steel in 3.5% NaCl extract solutions at a pH of 6, probably because the triphosphate ion can complex with the corrosion_product, such as ferric and ferrous ions, and …

Formation Of Ordered Ice Nanotubes Inside Carbon Nanotubes, Kenichiro Koga, G. T. Gao, Hideki Tanaka, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Following their discovery, carbon nanotubes have attracted interest not only for their unusual electrical and me-chanical properties, but also because their hollow interior can serve as a nanometre-sized capillary, mould, or template in material fabrication. The ability to en¬capsulate a material in a nanotube also offers new possibili¬ties for investigating dimensionally confined phase transi¬tions . Particularly intriguing is the conjecture that matter within the narrow confines of a carbon nanotube might ex¬hibit a solid–liquid critical point beyond which the distinc¬tion between solid and liquid phases disappears. This unusual feature, which cannot occur in bulk material, would allow for the direct …

Crystal Growth, Structure Determination And Magnetism Of A New Hexagonal Rhodate: Ba9rh8o24, Katharine E. Stitzer, M. D. Smith, J. Darriet, Hans Conrad Zur Loye

Faculty Publications

Single crystals of Ba9Rh8O24, grown from a molten potassium carbonate flux, crystallize in the spacegroup R¯3c with lattice parameters of a = 10.0899(4) and c = 41.462(2) Å. Magnetic measurements on oriented single crystals reveal the existence of magnetic anisotropy

Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

The goal is to achieve a basic understanding of the corrosion of stainless steel by Lead Bismuth Eutectic (LBE), which has been proposed for use in the transmuter as both a coolant and as a sputtering target.

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth, Pang Tao

Separations Campaign (TRP)

To mitigate the waste created by conventional fission reactors, spent nuclear fuel must be mechanically separated from its cladding. For the development of fuel processing technology to support the Advanced Accelerator Applications (AAA) Program, aqueous and pyrochemical processes will be used to further separate technetium and iodine, uranium and the higher actinides (see Figure 1 for an example of the process layout)1. The higher actinides, including plutonium, americium, curium, and neptunium will be separated from the waste to facilitate their fabrication into new fuel for placement in a transmuter. High-energy neutrons generated by spallation in the transmuter break down these …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Randy Clarksean

Separations Campaign (TRP)

Two activities are proposed: the development of a Systems Engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model will be the start of an integrated approach to the analysis of the materials separations associated with the national AAA program. A second portion of the project will streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to the systems engineering …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes of two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. …

Reversible Melting And Crystallization Of Short And Long Flexible Chain Molecules By Temperature-Modulated Calorimetry, Jeongihm Pak

Doctoral Dissertations

Melting and crystallization of linear, flexible molecules of different lengths was studied by temperature-modulated differential scanning calorimetry, TMDSC. Various techniques for TMDSC with single and multifrequency modulations have been analyzed to optimize the conditions for the present study. The finally chosen method involved a quasi-isothermal mode with a temperature amplitude of 0.5 K and a period of 60 s (frequency = 0.167 Hz). The interpretation of the reversible and irreversible melting was developed by comparison of a variety of different modes of analysis (sinusoidal, sawtooth, and complex sawtooth). The analyzed molecules ranged from n-paraffins, oligomeric fractions of polyethylene and poly(oxyethylene) …

Nuclear Magnetic Resonance And Humanistic Mathematics: A Farewell, Linley Erin Hall

Humanistic Mathematics Network Journal

No abstract provided.

Theoretical Study On The Mechanism Of Removing Nitrogen Oxides Using Isocyanic Acid., Taraneh Nowroozi-Isfahani

Electronic Theses and Dissertations

The mechanism of RAPRENO_x reactions - RAPid REduction of Nitrogen Oxides using Isocyanic acid - proposed by Robert A. Perry¹ in an attempt to help control the emission of nitrogen oxides pollutant into the atmosphere, has been re-investigated theoretically. The study of reaction mechanisms was carried out using Chemist software². All mathematically possible elementary steps have been evaluated and the chemically reasonable ones have been considered to propose new sets of reaction mechanisms. Density Functional Theory (B3LYP/6-31 G**) calculations using Gaussian 98³ were made in order to study the relative energies of all species and …

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Brendan O'Toole, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the effect of hydrogen on cracking of candidate target materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The test materials will undergo appropriate thermal treatments prior to being hydrogen-charged by potentiostatic cathodic polarization technique in a simulated aqueous environment at different temperatures of interest. The specimens, upon completion of testing, will be metallographically examined. Further, the scanning electron microscopy (SEM) will be used to determine the extent and nature of cracking in the specimens tested. The thrust of the proposed …

A Qualitative Investigation Of The Polymerization Process In The Ihss Humic Substances Extraction Procedure Using Model Phenolic Compounds, Roger J. Germay

Masters Theses

Achard (1786) extracted peat with alkali and reported obtaining dark compounds now called humic substances. These are complex, high molecular weight, polyphenolic compounds naturally occurring in soil, in fresh-water and in marine environments. They are biodegradation products of plant materials.

The International Humic Substances Society (IHSS) adapted Achard's method to separate humic substances into three fractions: (1) humic acids (HA), soluble only at high pH; (2) fulvic acids (FA), water-soluble at any pH; and (3) humin, insoluble at any pH. The IHSS method involves contact of soil with 0.1N.NaOH solution, followed by acidification with HCl.

In this study, 0.01 N. …

Magnetic And Conversion Electron Mössbauer Spectral Study Of Amorphous Thin Films Of Dyₓfe₁₀₀₋ₓ And Dy₂₀Fe80-YCoY, Karl Fleury-Frenette, Jacques P. Delwiche, Fernande Grandjean, Denis Vandormael, Gary J. Long

Chemistry Faculty Research & Creative Works

Amorphous thin films of Dy_xFe_100-x and Dy₂₀Fe_80-yCo_y, with various x and y values and of ~40 nm thickness, have been prepared by sputtering on polyimide films. Their magnetization curves and the Mössbauer spectra indicate that at 295 K the iron moments are preferentially oriented parallel to the film in Dy₂Fe₉₈ and that Dy₆Fe₉₄ is paramagnetic. The Dy_xFe_100-x thin films, where x is 17, 20, 24, 29, 32, 35, and 37, show perpendicular magnetic anisotropies and moderate coercive fields of at most 150 …

Synthesis And Use Of Chiral Surfactants., Xiaoye Yang

Electronic Theses and Dissertations

It has been previously shown that micelles formed from surfactants with chiral head groups serve to induce a chiral reaction medium, leading to enhanced enantioselectivities in the reaction products. This utilization of chiral surfactants will offer an economical alternative to traditional chial solvents while simultaneously reducing organic waste. We have successfully dimethlated S-leucinol in an 85% yield, and have synthesized a hydrocarbon-based surfactant with this molecule as a head group. We have also formed polymeric surfactants that have polydimethylsiloxane as the hydrophobic portion with the (S)-dimethylleucinol as a head group. Tests of the solubility of these surfactants have been conducted. …

Alkyl Nitrates In Dickson During The Sos 1999 Field Campaign, Mei Ma

Masters Theses

Measurements of alkyl nitrates were performed during the Southern Oxidants Study (SOS) 1999 Summer Field Campaign in Dickson, TN from June 10 to July 15, 1999. The developed GC-ECD method was tested and used successfully. Nine alkyl nitrates were measured and six alkyl nitrates were quantified. The measured alkyl nitrates expect methyl nitrate showed higher mixing ratios under northeasterly and southeasterly wind, which brought anthropogenic sources to the measurement site, and lower mixing ratios when wind came from northwest and southwest, which brought NOx and clean air, respectively. The contribution of the measured alkyl nitrates to the total oxidized nitrogen …

Synthesis Of Nano-Structured Monoclinic W03 Particles, Zhixiang Lu

Electronic Theses and Dissertations

The goal of this research is: 1) to develop synthetic methods for generating nanosized particles of monoclinic W0₃ (m-W0₃) and 2) to use the high surface area of the nano-sized material in infrared spectroscopic studies of the reactions of gaseous molecules with the particulate surface. Two methods of making nano-structured monoclinic tungsten trioxide (m-W0₃) particles are investigated. In one method, the sol formation occurs in the presence of a solution containing chelating agents and in a second approach, the sol formation occurs in a water-in oil emulsion. Commercial m-W0₃ particles are approximately 1 micron …

Managing Birds And Controlling Aircraft In The Kennedy Airport–Jamaica Bay Wildlife Refuge Complex: The Need For Hard Data And Soft Opinions, Kevin Brown, R. Michael Erwin, Milo E. Richmond, P A. Buckley, John Tanacredi Ph.D., Dave Avrin

Faculty Works: CERCOM (1977-2016)

During the 1980s, the exponential growth of laughing gull (Larus atricilla) colonies, from 15 to about 7600 nests in 1990, in the Jamaica Bay Wildlife Refuge and a correlated increase in the bird-strike rate at nearby John F. Kennedy International Airport (New York City) led to a controversy between wildlife and airport managers over the elimination of the colonies. In this paper, we review data to evaluate if: (1) the colonies have increased the level of risk to the flying public; (2) on-colony population control would reduce the presence of gulls, and subsequently bird strikes, at the airport; …

Metalation Of The Di- And Tri-Methoxybenzenes, Phillip Shelton

Masters Theses & Specialist Projects

Hydrocarbon solvents are known to be unreactive towards organolithium reagents and also to afford little support for ortho-metalation reactions. In contrast, both m- and odimethoxybenzene afford 80% "ion-multiple specific" monometalation in hydrocarbon solvent (n-hexane, cyclohexane, toluene) without the addition of any catalyst (ether or amine). These observations are, in part, attributed to the 1,2- and 1,3- formation of the n-BuLi dimer, the most reactive form of n-BuLi. In other words these substrates are acting in a "substrate-catalyzed" manner. Extensions of these concepts to 1,2,3-, 1,2,4- and 1,3,5-trimethoxybenzenes have led to further unusual observations. In particular, the 1,2,3-system affords an interesting …

43rd Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 43rd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 29 - August 2, 2001.

Structural And Functional Imaging With Carbon Nanotube Afm Probes, J. H. Hafner, Chin Li Cheung, A. T. Woolley, C. M. Lieber

Barry Chin Li Cheung Publications

Atomic force microscopy (AFM) has great potential as a tool for structural biology, a field in which there is increasing demand to characterize larger and more complex biomolecular systems. However, the poorly characterized silicon and silicon nitride probe tips currently employed in AFM limit its biological applications. Carbon nanotubes represent ideal AFM tip materials due to their small diameter, high aspect ratio, large Young’s modulus, mechanical robustness, well-defined structure, and unique chemical properties. Nanotube probes were first fabricated by manual assembly, but more recent methods based on chemical vapor deposition provide higher resolution probes and are geared towards mass production, …

Cyp83b1 Is The Oxime-Metabolizing Enzyme In The Glucosinolate Pathway In Arabidopsis, Carsten Horslev Hansen, Liangcheng Du, Peter Naur, Carl Erik Olsen, Kristian B. Axelsen, Alastair J. Hick, John A. Pickett, Barbara Ann Halkier

Liangcheng Du Publications

CYP83B1 from Arabidopsis thaliana has been identified as the oxime-metabolizing enzyme in the biosynthetic pathway of glucosinolates. Biosynthetically active microsomes isolated from Sinapis alba converted p-hydroxyphenylacetaldoxime and cysteine into S-alkylated p-hydroxyphenylacetothiohydroximate, S-(p-hydroxyphenylacetohydroximoyl)-L-cysteine, the next proposed intermediate in the glucosinolate pathway. The production was shown to be dependent on a cytochrome P450 monooxygenase. We searched the genome of A. thaliana for homologues of CYP71E1 (P450ox), the only known oxime-metabolizing enzyme in the biosynthetic pathway of the evolutionarily related cyanogenic glucosides. By a combined use of bioinformatics, published expression data, and knock-out phenotypes, we identified the …

Nature Of Oxygen At Rocksalt And Spinel Oxide Surfaces, Marjorie Langell, J.G. Kim, D. L. Pugmire, W. Mccarroll

Marjorie A. Langell Publications

The chemical environment of oxygen in cobalt-containing metal oxides with compositions M _xM′_{( x – 1)} O and M _xM′_{(3x – 1)} O₄ (M,M′ = Mn,Ni,Co) has been studied by Auger, x-ray and ultraviolet photoelectron, and high resolution electron energy loss spectroscopies. While there is a single type of lattice oxygen in the bulk structure of simple rocksalt and spinel oxides, the nature of oxygen at the surface of the spinel oxides is considerably more complex. Photoemission from core oxygen states in these materials often shows multiple peaks and satellite structure which have been …

Relativistic Effects On Interchannel Coupling In Atomic Photoionization: The Photoelectron Angular Distribution Of Xe, Oliver Hemmers, S. T. Manson, M. M. Sant'anna, P. Focke, H. Wang, I. A. Sellin, Dennis W. Lindle

Environmental Studies Faculty Publications

Measurements of the photoelectron angular-distribution asymmetry parameter β for Xe 5s photoionization have been performed in the 80–200 eV photon-energy region. The results show a substantial deviation from the nonrelativistic value of β=2 and provide a clear signature of significant relativistic effects in interchannel coupling.

Intrasteric Inhibition Of Atp Binding Is Not Required To Prevent Unregulated Autophosphorylation Or Signaling By The Insulin Receptor, Mark Frankel, Ararat J. Ablooglu, Joseph W. Leone, Elena Rusinova, J. B. A. Ross, Robert L. Heinrikson, Ronald A. Kohanski

Chemistry and Biochemistry Faculty Publications

Receptor tyrosine kinases may use intrasteric inhibition to suppress autophosphorylation prior to growth factor stimulation. To test this hypothesis we made an Asp1161Ala mutant in the activation loop that relieved intrasteric inhibition of the unphosphorylated insulin receptor (IR) and its recombinant cytoplasmic kinase domain (IRKD) without affecting the activated state. Solution studies with the unphosphorylated mutant IRKD demonstrated conformational changes and greater catalytic efficiency from a 10-fold increase in kcat and a 15-fold-lower K_{m ATP} although K_{m peptide} was unchanged. Kinetic parameters of the autophosphorylated mutant and wild-type kinase domains were virtually identical. The Asp1161Ala mutation increased the …

Quorum Sensing In The Dimorphic Fungus Candida Albicans Is Mediated By Farnesol, Jacob M. Hornby, Ellen C. Jensen, Amber C. Lisec, Joseph J. Tasto, Brandon Jahnke, Richard Shoemaker, Patrick Dussault, Kenneth W. Nickerson

Patrick Dussault Publications

The inoculum size effect in the dimorphic fungus Candida albicans results from production of an extracellular quorum-sensing molecule (QSM). This molecule prevents mycelial development in both a growth morphology assay and a differentiation assay using three chemically distinct triggers for germ tube formation (GTF): L-proline, N-acetylglucosamine, and serum (either pig or fetal bovine). In all cases, the presence of QSM prevents the yeast-to-mycelium conversion, resulting in actively budding yeasts without influencing cellular growth rates. QSM exhibits general cross-reactivity within C. albicans in that supernatants from strain A72 are active on five other strains of C. albicans and vice versa. …

Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations With Weak Carbon Nucleophiles, M. Azad Hossain, Myung-Jong Jin, William Donaldson

Chemistry Faculty Research and Publications

The reaction of acyclic tricarbonyl(pentadienyl)iron(1+) cations with allyl trimethylsilane or with excess furan leads to (E,E-diene)iron complexes. Attack of these weak nucleophiles on the transoid form of the pentadienyl cation is presumably faster than attack on the more stable cisoid form.