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2014

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Articles 541 - 570 of 1401

Full-Text Articles in Chemistry

Avd Tablet Labs: Virtual Chemistry Laboratories, Honors Chemistry, Grade:10, Caleb A. Arrington, Tina Kanipe, Deep Sangani Apr 2014

Avd Tablet Labs: Virtual Chemistry Laboratories, Honors Chemistry, Grade:10, Caleb A. Arrington, Tina Kanipe, Deep Sangani

Arthur Vining Davis High Impact Fellows Projects

With the increased prevalence of student computers in secondary schools, we created six virtual chemistry laboratories using the virtual lab environment created by Carnegie-Mellon University. Students, using their laptop or tablet computer, can manipulate typical laboratory instrumentation found in an introductory chemistry lab. While not designed to replace traditional wet laboratories, the virtual laboratory environment allows students to examine the nuances of experimental techniques in a low stakes, easily repeatable, environment. The six virtual laboratories developed for this project cover the introductory chemistry subjects of: 1.) density measurements and significant figures, 2.) reaction stoichiometry, 3.) measurements of grams and moles, …

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Interfacial Rheology Of Bacterial Biofilms At Air/Water And Oil/Water Interfaces, Patrick Rühs, R. Inglis, Peter Fischer Apr 2014

Interfacial Rheology Of Bacterial Biofilms At Air/Water And Oil/Water Interfaces, Patrick Rühs, R. Inglis, Peter Fischer

Biology Department Faculty Works

No abstract provided.

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In Situ Detection On Electrochemical Chloride Removal Of Reinforcement In Concrete By Combined Ph/Cl- Probes, Jing-Jing Wang, Shi-Gang Dong, Xiao-Juan Zhang, Hong-Wei Lv, Yun-Chang Wu, Rong-Gui Du, Chang-Jian Lin Apr 2014

In Situ Detection On Electrochemical Chloride Removal Of Reinforcement In Concrete By Combined Ph/Cl- Probes, Jing-Jing Wang, Shi-Gang Dong, Xiao-Juan Zhang, Hong-Wei Lv, Yun-Chang Wu, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

In this work, the concrete samples polluted by chloride ion were electrochemically treated using galvanostatic technique, and the distributions of chloride ion concentration and pH value in the polluted concretes were in-situ monitored by embedding a combined pH/Cl- probe during the electrochemical chloride removal. The corrosion behaviors of reinforcing steel in the concrete were simultaneously studied by using linear polarization and electrochemical impedance spectroscopy techniques (EIS). The micro environment of the concrete and corrosion rate of steel were explored during the electrochemical chloride removal. It was indicated that the Cl- concentration in the concrete pore solution decreased with …

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Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong Apr 2014

Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The CoFe2O4/GNS was synthesized by a simple one-pot solvothermal method. The results obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the CoFe2O4 particles with sizes of 15 nm dispersed on the surface of graphene uniformly. Electrochemical tests indicated that the CoFe2O4/GNS nanocomposite exhibited excellent cyclic stability with almost 95.8% capacity retention after 100 cycles at the current density of 500 mA·g-1 and delivered a high reversible capacity of 482 mAh·g-1 at the current density of 2 A·g-1.

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Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu Apr 2014

Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu

Journal of Electrochemistry

Three kinds of conductive carbon films were prepared with Super-P (SP), KB and MWCNTs, and then the as-prepared carbon films were applied as an interlayer between a sulfur electrode and a separator for constructing a coin-type lithium-sulfur (Li-S) cell, respectively. The assessment results show that all the cells delivered the reversible capacities higher than 800 mAh·g-1 after 40 cycles when the sulfur loading was up to 80% (by mass) in the sulfur electrode. Due to significant differences of physical properties among the carbon materials, the cell with a KB interlayer exhibited higher electrochemical polarization; the cycling performance of the …

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Electrodeposition Of Copper From A Choline Chloride Based Ionic Liquid, Rostom Ali M., Ziaur Rahman Md., Sankarsaha S. Apr 2014

Electrodeposition Of Copper From A Choline Chloride Based Ionic Liquid, Rostom Ali M., Ziaur Rahman Md., Sankarsaha S.

Journal of Electrochemistry

The electrodeposition of copper from a solution containing copper chloride in either an ethylene glycol (EG)-choline chloride based or a urea-choline chloride based ionic liquid has been carried out onto a steel cathode by constant current and constant potential methods at room temperature. The influences of various experimental conditions on electrodeposition and the morphology of the deposited layers have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is shown that very smooth, shiny and dense with good adherence and bright metallic coloured copper coatings can be obtained from both EG and urea based ionic liquids at …

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Electrocatalytic Oxidation Of Glycerol At The Platinum Electrode Modified With An Nd-Fe-Moo42- Cyano-Bridged Mixed Coordination Polymer, Yong-Jun Ma, Yu-Xiu Tian, Jing Liu, Min Zhou, Jing Ding, Zhi-Mei Jin, Xiang-Mei Wang Apr 2014

Electrocatalytic Oxidation Of Glycerol At The Platinum Electrode Modified With An Nd-Fe-Moo42- Cyano-Bridged Mixed Coordination Polymer, Yong-Jun Ma, Yu-Xiu Tian, Jing Liu, Min Zhou, Jing Ding, Zhi-Mei Jin, Xiang-Mei Wang

Journal of Electrochemistry

A platinum electrode decorated with the ordered Nd-Fe-MoO42- cyano-bridged mixed coordination polymer was successfully prepared by electrodeposition in virtue of the lyotropic liquid crystal soft template methods, and electrocatalytic oxidation behavior of glycerol was investigated on the chemically modified electrode by cyclic voltammetry. The influences of experimental factors such as the concentrations of H+ and SO42- in electrolytes, glycerol concentration and scan rate on the electrocatalytic activity of glycerol at the modified electrode were also studied. It indicated that the proper amount of SO42- in weakly acidic electrolyte could help to improve the …

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Detection Of Glucosamine Hydrochloride By Ion Chromatography With Integrated Pulsed Amperometric Detector, Yan-Qun Fan, Qing-Yang Chen, Jin-Mei Xia, Jian-Zhong Xu, Xun Xu, Chen Xu Apr 2014

Detection Of Glucosamine Hydrochloride By Ion Chromatography With Integrated Pulsed Amperometric Detector, Yan-Qun Fan, Qing-Yang Chen, Jin-Mei Xia, Jian-Zhong Xu, Xun Xu, Chen Xu

Journal of Electrochemistry

Factors (integral potential, concentration of NaOH and flow rate) affecting detection of Glucosamine hydrochloride by ion chromatography with integrated pulsed amperometric detector were studied. As the integral potential increased, the detection signal first increased and then decreased, while the detection background and noise increased directly. The suitable integral potential should be 0.1 V. With the concentration of NaOH increased, the retention time descended sharply, while the integral area increased quickly before they are coming back into balance. The number of theoretical plates increased firstly and then decreased. The optimum concentration of NaOH was 50 mmol·L-1. As the flow …

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Synthesis Of Platinum Nanocrystallites And Possible Electrocatalytic Properties For Methanol, Lei-Lei Lu, Bao-Zhong Du, Sha Sun, Jin-Fen Niu, Jie Zhao Apr 2014

Synthesis Of Platinum Nanocrystallites And Possible Electrocatalytic Properties For Methanol, Lei-Lei Lu, Bao-Zhong Du, Sha Sun, Jin-Fen Niu, Jie Zhao

Journal of Electrochemistry

Platinum nanocrystallites were synthesized by the colloidal method using oxamide as the stabilizer. The morphologies and electrocatalytic performances for methanol of platinum nanocrystallites prepared at different pH values and with different reactant ratios of precursor and stabilizer were investigated. It was found that the platinum nanocrystallites synthesized at pH=5 and with the reactant ratio of 1:20 showed the best electrocatalytic activity for methanol. The peak current density reached up to 1709 μA·cm-2. Furthermore, the electrocatalytic activity of platinum nanocrystallites for methanol reduced significantly although the cyclic voltammograms in the blank solution were not obviously changed after exposing in …

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Preparation Of A New Laccase Biosensor Based On Bimetallic Pt/Au Particles And Chitosan/Silica Sol-Gel Hybrid Films For Determination Of Catechol, Tong-Fang Lou, Jian-Ying Qu, Huan-Huan Xing, Xue-Ping Du, Ying Dong Apr 2014

Preparation Of A New Laccase Biosensor Based On Bimetallic Pt/Au Particles And Chitosan/Silica Sol-Gel Hybrid Films For Determination Of Catechol, Tong-Fang Lou, Jian-Ying Qu, Huan-Huan Xing, Xue-Ping Du, Ying Dong

Journal of Electrochemistry

A novel laccase (Lac) biosensor was fabricated successfully by means of entrapping Lac into bimetallic Pt/Au particles and chitosan/silica (CS-SiO2) sol-gel hybrid films, and then applied to determine catechol (CC) concentration. The experiment results showed that the biosensor can electrocatalyze the reduction of CC, and the peak current increased linearly with the concentration of CC in the range of 8×10-7 ~ 1×10-4 mol·L-1 (r = 0.9993) with a detection limit of 7.9×10-8 mol·L-1 by cyclic voltammetric response. The biosensor exhibited good sensitivity, stability and reproducibility, with a broad linear range for potential applications.

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Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie Apr 2014

Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie

Journal of Electrochemistry

Based on the experiments about the output characteristics of a home-made temperature-controlled PEMFC system with atmospheric pressure and no external humidifying condition in different loading voltages and operating temperatures, the optimum operating temperature at different loading voltages can be obtained by tracking the output characteristics of PEMFC operating over a range of temperatures. By analyzing the fitted data the kinetic parameters are evaluated and the effect of different operating temperatures on the PEMFC performance is discussed from a view of electrode kinetics.

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Fabrication And Electrochemical Properties Of Graphene-Zno Nanocomposite, Chuan-Ling Men, Wan Wang, Jun Cao Apr 2014

Fabrication And Electrochemical Properties Of Graphene-Zno Nanocomposite, Chuan-Ling Men, Wan Wang, Jun Cao

Journal of Electrochemistry

In this work, the graphene-ZnO nanocomposite was successfully synthesized through a one-step solvothermal approach, using ethylene glycol as the solvent and reducing agent. The ZnO particles could be attached to the surfaces and edges of graphene sheet. The electrochemical performance of the nanocomposite was investigated by performing cyclic voltammetry, A.C. impedance and chronopotentiometry tests in 6 mol·L-1 KOH. The results showed that the graphene-ZnO nanocomposite exhibited a nice electrochemical specific capacitance of 115 F·g-1 determined in cyclic voltammetry test, or 71 F·g-1 evaluated in chronopotentiometry test and good reversible charge/discharge behavior.

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Electrochemical Deposition Of Gasb Thin Films For Phase Change Memory In Aqueous Solutions, Yu-Lin Xiong, Yuan-Chun Pan, Bai-Sheng Sa, Jian Zhou, Zhi-Mei Sun Apr 2014

Electrochemical Deposition Of Gasb Thin Films For Phase Change Memory In Aqueous Solutions, Yu-Lin Xiong, Yuan-Chun Pan, Bai-Sheng Sa, Jian Zhou, Zhi-Mei Sun

Journal of Electrochemistry

The synthesis of GaSb thin films has been successfully performed by a method involving one-step potentiostatic electrodeposition and thermal annealing. The effect of ethylene glycol as a solvent in aqueous electrolyte solution on the crystallinity and morphology of the prepared thin films was discussed. The electrodeposition mechanisms of GaSb were studied by cyclic voltammetry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to analyze structure, morphology and composition of the thin films. The results show that SbO+ is first reduced to Sb, and Ga3+ is deposited via the induced co-deposition mechanism. The …

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Implementation And Application Of The Mmff94 Force Field, Hongbo Zhu Apr 2014

Implementation And Application Of The Mmff94 Force Field, Hongbo Zhu

Department of Chemistry: Dissertations, Theses, and Student Research

MMFF94 is implemented for molecular mechanics calculation in the quantum chemistry polarizable force field program (QuanPol). As a general force field for organic molecules, the availability of MMFF94 expends the capability of the QuanPol program. The MMFF94 force field atom type determination and parameter matching methods are established and corresponding program routines are written in the FORTRAN language. In this implementation, the MMFF94 atom types can be determined automatically from the connectivity of the input atoms with no or minimum information of formal charges. This implementation of MMFF94 is validated using the 761 standard tests, thus is a complete implementation. …

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Preparation Of Pt/H-Tio2 Catalyst With Improved Catalytic Performance For Methanol Electrooxidation, Jin Han, Zhi-You Zhou, Qiang Wang, Miao-Qiang Lv, Chi Chen, Shi-Gang Sun Apr 2014

Preparation Of Pt/H-Tio2 Catalyst With Improved Catalytic Performance For Methanol Electrooxidation, Jin Han, Zhi-You Zhou, Qiang Wang, Miao-Qiang Lv, Chi Chen, Shi-Gang Sun

Journal of Electrochemistry

White TiO2 nanorods were synthesized by hydrothermal method with TiCl4 as a precursor. As-synthesized TiO2 nanorods were further subjected to high-temperature (550 oC) heat treatment for 2 h under H2 atmosphere to prepare gray black hydrogen-treated TiO2 (H-TiO2) nanorods with oxygen vacancies and Ti3+ interstitial atoms. The Pt nanoparticles of 1.9 nm were supported on these two types of TiO2 nanorods to form Pt/TiO2 and Pt/H-TiO2 catalysts. XRD data indicates that the crystal structure of TiO2 was still reserved as rutile after hydrogen treatment, but the surface …

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Electrochemical Behavior Of Ionic Liquid Confined Into Nanopores Of Silica Gel Matrix, Zuo-Peng Li, Ya-Qiong Wen, Mei-Xia Wu, Yong Guo Apr 2014

Electrochemical Behavior Of Ionic Liquid Confined Into Nanopores Of Silica Gel Matrix, Zuo-Peng Li, Ya-Qiong Wen, Mei-Xia Wu, Yong Guo

Journal of Electrochemistry

Imidazolium Ionic liquids (ILs) nano aggregates confined into nanopores of silica gel matrices (ILs-sg) modified electrodes were prepared by sol-gel process and characterized by cyclic voltammetry. Furthermore, the amounts of 15% ~ 28% ILs-sg and nano aggregates coated with ILs silica gel (ILs/sg) were prepared and their conductivities were evaluated by performing electrochemical AC impedance measurements from 20 oC to 80 oC. The abnormal results showed that, 1) comparing with the bulk IL, the confined IL had a positive shift effect of Fc/Fc+ redox potential; 2) when IL confined into a nanospace, the electrochemical stability became poor; 3) …

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Electro-Catalytic Oxidation Of Hydrogen Peroxide On Au/ L-Methionine /Gc Electrode, Jian-Feng Fan, Xue-Mei Luo, Jing Li, Lou-Zhen Fan Apr 2014

Electro-Catalytic Oxidation Of Hydrogen Peroxide On Au/ L-Methionine /Gc Electrode, Jian-Feng Fan, Xue-Mei Luo, Jing Li, Lou-Zhen Fan

Journal of Electrochemistry

The modified electrodes have been fabricated by generation of Au nanoparticle chains, which was produced by reaction between HAuCl4 and sodium citrate without any additional capping agents or surfactants. The self-assembled Au nanoparticles were attached to the surface of glassy carbon electrode (GCE) layer by layer, using L-methionine (L-Met), thiourea (TU), allyl thiourea (ATU) and polyvinylpyrrolidone (PVP) as a crosslinking agent, respectively. The experimental results showed that the electrochemical performance of the different modified electrodes varied in [Fe(CN)6]3-/4- solution. The Au/L-Met/GCE exhibited an excellent electrochemical property, which is superior to other modified electrodes. In addition, the catalysis …

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An Equivalent Circuit Model For Redox Flow Battery Stack, Dong-Jiang You, Hua-Min Zhang Apr 2014

An Equivalent Circuit Model For Redox Flow Battery Stack, Dong-Jiang You, Hua-Min Zhang

Journal of Electrochemistry

This paper introduces an equivalent circuit model for a redox flow battery stack. The model combines the electrochemical reaction of the battery cell and the shunt current of the battery stack. An all-vanadium redox flow battery stack of 1kW rated output power is tested through transient response and self-discharge experiments. All the parameters used for the modeling are obtained. Calculated shunt current and distribution of calculated battery voltage are shown in the results. It is concluded that the impedance of the battery stack can be obtained by the experimental results of the transient response and self-discharge measurements. The capacity lose …

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Interpretation Of Chemical Environments By Rna And The Implications To The Origins Of Life, Brian Larson Apr 2014

Interpretation Of Chemical Environments By Rna And The Implications To The Origins Of Life, Brian Larson

Dissertations and Theses

We describe the initial realization of behavior in the biosphere, which we term behavioral chemistry. If molecules are complex enough to attain a stochastic element to their structural conformation in such a way as to radically affect their function in a biological (evolvable) setting, then they have the capacity to behave. This circumstance is described here as behavioral chemistry, unique in its definition from the colloquial chemical behavior. This transition between chemical behavior and behavioral chemistry need be explicit when discussing the root cause of behavior, which itself lies squarely at the origins of life and is the foundation of …

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Application Of Ionic Liquid Pp14Tfsi In Electrolyte Systems For Rechargeable Mg Batteries, Jin-Jie Zhu, Fei-Fei Wang, Yong-Sheng Guo, Jun Yang, Yan-Na Nuli, Jiu-Lin Wang Apr 2014

Application Of Ionic Liquid Pp14Tfsi In Electrolyte Systems For Rechargeable Mg Batteries, Jin-Jie Zhu, Fei-Fei Wang, Yong-Sheng Guo, Jun Yang, Yan-Na Nuli, Jiu-Lin Wang

Journal of Electrochemistry

A phenolated-based Mg salt was prepared. The mixture of THF and N-methyl-N-butyl-piperidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI) serves as the mixed solvent instead of pure THF for rechargeable Mg batteries systems. This new type of electrolyte system not only has optimal reversibility of Mg, but also owns a wide electrochemical window (2.7 V vs. Mg) and high ionic conductivity (7.77 mS·cm-1). More importantly, the addition of Ionic Liquid suppresses the volatility of THF and improves the safety of rechargeable Mg batteries. The result shows that the mixture of THF and piperidyl-based Ionic Liquid could be regarded as a good solvent candidate …

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Effect Of Al-Doping In Li-Rich Material Li1.2Mn0.543Co0.078Ni0.155Al0.030O2 For Lithium-Ion Batteries, Xiao-Xi Jin, Yi-Xiao Li, Yong Yang, Zhou-Cheng Wang Apr 2014

Effect Of Al-Doping In Li-Rich Material Li1.2Mn0.543Co0.078Ni0.155Al0.030O2 For Lithium-Ion Batteries, Xiao-Xi Jin, Yi-Xiao Li, Yong Yang, Zhou-Cheng Wang

Journal of Electrochemistry

The Al-doped 0.5Li2MnO3·0.5Li(Mn0.4Co0.2Ni0.4)O2 compounds were successfully synthesized as cathode materials for lithium-ion batteries. The pristine and Al-doped materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and laser Raman spectroscopy. The results indicated that all the prepared materials were indexed as a hexagonal structure with R-3m space group, and Al element had been introduced into lattice. When cycled at 180 mA·g-1 (1 C-rate), the capacity retention of 4% (by mole) Al-doped 0.5Li2MnO3·0.5Li(Mn0.4Co0.2Ni …

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Combustion Products Of Ethyl Tert-Butyl Ether Using Synchrotron Photoionization, Rong Yao, Martin Ng, David Osborn, Craig Taatjes, Giovanni Meloni Apr 2014

Combustion Products Of Ethyl Tert-Butyl Ether Using Synchrotron Photoionization, Rong Yao, Martin Ng, David Osborn, Craig Taatjes, Giovanni Meloni

Creative Activity and Research Day - CARD

The photolytically Cl initiated oxidation reaction of ETBE was investigated at the Advanced Light Source located in the Lawrence Berkeley National Laboratory. Using the multiplex photoionization mass spectrometer data were collected at the low pressure (4-8 Torr) and temperature (298 – 700 K) regimes. Data analysis was performed via characterization of the reaction species photoionization spectra and kinetic traces. A reaction schematic including branching fractions determination is presented and discussed.

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Investigation Of Oxidation Reaction Products Of 2-Phenylethanol Using Synchrotron Photoionization, Magaly Wooten, Anthony Medrano, David Osborn, Craig Taatjes, Giovanni J. Meloni Apr 2014

Investigation Of Oxidation Reaction Products Of 2-Phenylethanol Using Synchrotron Photoionization, Magaly Wooten, Anthony Medrano, David Osborn, Craig Taatjes, Giovanni J. Meloni

Creative Activity and Research Day - CARD

Photolytically Cl-initiated oxidation reaction of 2-phenylethanol (2-PE) was carried out at the Advanced Light Source (ALS) in the Lawrence Berkeley National Laboratory. Using the multiplex photoionization mass spectrometer, coupled with the tunable vacuum ultraviolet radiation of the ALS, data were collected at low pressure (4 – 6 Torr) and temperature (298 – 550 K) regimes. Data analysis was performed via characterization of the reaction species photoionization spectra and kinetic traces.

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Effect Of Microwave Heating On The Migration Of Additives From Ps, Pp And Pet Container Into Food Simulants, Ruoyin Cai, Kereilemang Khana Mokwena Nthoiwa, Changfeng Ge Apr 2014

Effect Of Microwave Heating On The Migration Of Additives From Ps, Pp And Pet Container Into Food Simulants, Ruoyin Cai, Kereilemang Khana Mokwena Nthoiwa, Changfeng Ge

Journal of Applied Packaging Research

The main objective of this thesis is to test three different microwaving packaging materials that are the most common material in the market, viz. polystyrene (PS), polypropylene (PP), and polyethylene terephthalate (PET), migrated into four food simulant solutions. Four different simulant solutions were used based on the food type and FDA recommendations and regulations. These food simulants include vegetable pure oil, 3% (v/v) aqueous acetic acid, 15% (v/v) ethanol, and olive oil in the temperature of 100°C.Headspace gas chromatography with mass spectrometric detection (GC/MS) was used to determine the relative migration values from packaging materials into food by putting the …

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Polyethylene Glycol Containing Rompolymers For The Modification Of Neuro-Protective Hemoglobin, Andrea L. Mccollum Apr 2014

Polyethylene Glycol Containing Rompolymers For The Modification Of Neuro-Protective Hemoglobin, Andrea L. Mccollum

Honors College Theses

Polyethylene glycol (PEG) has shown the ability to improve compatibility when used in combination with cell-free hemoglobin in the treatment of traumatic brain injuries. It has been demonstrated that the covalently bonded PEG increases the hydrodynamic radius of the hemoglobin and hence generates a physical barrier while slowing down the oxygen delivery of the strongly oxidative hemoglobin. In this context, I have been working on the development of synthetic pathways to incorporate PEG into monomers and polymers through both direct modification of (7-oxa)norbornene derivatives and post polymerization modification. Starting from the (7-oxa)norbornene anhydride derivatives, we have developed pathways to cationic …

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Antimicrobial And Antiinsectan Phenolic Metabolites Of Dalea Searlsiae, Gil Belofsky, Mario Aronica, Eric Foss, Jane Diamond, Felipe Santana, Jacob Darley, Patrick F. Dowd, Christina M. Coleman, Daneel Ferreira Apr 2014

Antimicrobial And Antiinsectan Phenolic Metabolites Of Dalea Searlsiae, Gil Belofsky, Mario Aronica, Eric Foss, Jane Diamond, Felipe Santana, Jacob Darley, Patrick F. Dowd, Christina M. Coleman, Daneel Ferreira

All Faculty Scholarship for the College of the Sciences

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A–D (1–4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1–5, 7 …

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Effect Of Sulfuric Acid Exposure On Common Mineral Dust Particles, Miguel D. Mendoza Apr 2014

Effect Of Sulfuric Acid Exposure On Common Mineral Dust Particles, Miguel D. Mendoza

Celebrating Scholarship & Creativity Day (2011-2017)

Mineral dust has a large effect on cloud formation and ultimately the climate. Several studies have shown the addition of acid to these mineral dust particles decreases their ability to nucleate ice. This study explores what chemistry occurs between common components of mineral dust particles and sulfuric acid. Hematite (Fe2O3), calcite (CaCO3), and quartz (SiO2) were exposed to sulfuric acid, and then analyzed using a combination of Attenuated Total Reflectance-FTIR, Diffuse Reflectance-FTIR Spectroscopy, X-Ray Diffraction, and Inductively Coupled Plasma Atomic Emission Spectroscopy to identify functional groups, mineral species, and aqueous phase elements. …

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Kir2.1 Effects On Craniofacial And Limb Development In Knockout Mice, Joy Williams, Dr. Emily Bates Apr 2014

Kir2.1 Effects On Craniofacial And Limb Development In Knockout Mice, Joy Williams, Dr. Emily Bates

Journal of Undergraduate Research

Birth defects arise because of both genetic and environmental factors. Children with genetic alteration of the inwardly-rectifying potassium ion channel Kir2.1 channel have heart arrhythmias, impaired cognitive function, and facial and limb abnormalities. Children that suffer from Fetal Alcohol Syndrome have cognitive and social development problems, heart defects, and facial abnormalities—including small eyes, small head, small upper jaw, and a small upper lip1. Kir2.1 is bound and blocked by alcohol2 and thus we predicted that it is the molecular target of Fetal Alcohol Syndrome. We designed experiments to determine how Kir2.1 is required during development and found that within 14 …

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The Use Of Alpha-1-Antitrypsin (Aat) In The Downregulation Of Nuclear Factor Kappa-Light-Chain-Enhancer Of Activated B Cells (Nf-Κb) As A Treatment For Acquired Immunodeficiency Syndrome (Aids), Aaron Mcbride, Dr. Gregory F. Burton Apr 2014

The Use Of Alpha-1-Antitrypsin (Aat) In The Downregulation Of Nuclear Factor Kappa-Light-Chain-Enhancer Of Activated B Cells (Nf-Κb) As A Treatment For Acquired Immunodeficiency Syndrome (Aids), Aaron Mcbride, Dr. Gregory F. Burton

Journal of Undergraduate Research

Current Human Immunodeficiency Virus (HIV) treatment is greatly hindered due to viral reservoirs throughout the body prolonging and perpetuating infection.i Large stores of HIV exist in the follicular dendritic cell (FDC) microenvironment, located primarily in the lymph nodes and spleen. Free-floating virus has a half-life of less than two hours; however, FDC-trapped virus has a half-life of over eight weeks and can be rescued in its infectious state longer than nine months after the initial infection,ii showing the role of FDCs as an HIV reservoir.iii Studies in the Gregory Burton laboratory focus on the interactions between HIV, FDCs, and CD4+ …

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Structure Of The Phlp1-Gβ-Cct Complex Reveals A Molecular Mechanism For Gprotein Β Subunit Folding And Βγ Dimer Assembly, Devon Blake, Dr. Barry Willardson Apr 2014

Structure Of The Phlp1-Gβ-Cct Complex Reveals A Molecular Mechanism For Gprotein Β Subunit Folding And Βγ Dimer Assembly, Devon Blake, Dr. Barry Willardson

Journal of Undergraduate Research

Cells detect and respond to a myriad of extracellular signals via seven-transmembrane G protein-coupled receptors and their associated G protein signaling pathways. The pathway is initiated by the binding of a signaling molecule, such as a hormone or neurotransmitter, to its binding site on the extracellular side of the receptor. This interaction activates the G protein heterotrimer, composed of Gβ, Gβ, and Gβ subunits, which functions by propagating the signal throughout the cell. First, however, the G protein heterotrimer must be assembled from its nascent polypeptides. The initial step in this process is the formation of the Gβγ dimer. Gβγ …

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