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Articles 2461 - 2490 of 4155

Full-Text Articles in Chemistry

Electrochemical Fabrication Of The Ordered Polyaniline Nanowires Array, Yan-Xin Gao, Li-Chao Sun, Su-Yuan Xie, Kang Shi Feb 2012

Electrochemical Fabrication Of The Ordered Polyaniline Nanowires Array, Yan-Xin Gao, Li-Chao Sun, Su-Yuan Xie, Kang Shi

Journal of Electrochemistry

The effects of electrochemical fabrication methods in different aniline concentrations on the morphologies of polyaniline, which was polymerized on the aligned-multi-walled carbon nanotubes electrode in H2SO4 or HClO4 electrolyte solution, were investigated. It was demonstrated that the polyaniline nanowires would not be prepared by cyclic voltammotry, whereas the nanowires could be obtained by the potentiostatic method without forming the ordered array. Only when the aniline concentration in HClO4 solution was high enough, the ordered polyaniline nanowires array could be fabricated by the constant current method.


Preparation And Hydrogen Evolution Properties Of Ni/Ag2O/Ruo2-Pt Cathodes, Shu Huang, Xue-Ming Li, Wu-Lin Li, Wen Wang Feb 2012

Preparation And Hydrogen Evolution Properties Of Ni/Ag2O/Ruo2-Pt Cathodes, Shu Huang, Xue-Ming Li, Wu-Lin Li, Wen Wang

Journal of Electrochemistry

The Ni/Ag2O/RuO2-Pt composite cathode was prepared by sol-gel method using RuCl3 and H2PtCl6 as raw materials. The effects of heat treatment conditions and AgNO3 concentrations on hydrogen evolution properties were investigated. The morphology and composition of Ni/Ag2O/RuO2-Pt composite cathode have been characterized by XRD, XPS and SEM-EDS. It is demonstrated that the surface structure of Ni/Ag2O/RuO2-Pt composite cathode is more compact, with fewer cracks and larger surface roughness than pure nickel. At the conditions of 0.3 A·cm-2, 90 oC, and …


Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhe Zhang, Ming-Zi Jia, Le Ruan Feb 2012

Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhe Zhang, Ming-Zi Jia, Le Ruan

Journal of Electrochemistry

The Ag nanoparticles were prepared in aqueous solutions through a chemical reduction method and transferred from water phase to toluene phase with the protection of 1-dodecanethiol (DDT). The polished iron electrode was immersed in the DDT-protected metal nanoparticles toluene solutions to form DDT/Ag nanoparticles self-assembled mixed films. Electrochemical methods such as electrochemical impedance spectroscopy and polarization curve measurement were used to study the inhibition properties of the self-assembled films in the 0.5 mol·L-1 H2SO4 solution. The appearance of elements such as S and Ag from the XPS data identified the presences of DDT and Ag nanoparticles.


One-Pot Synthesis In Polyamines For Preparation Of Water-Soluble Magnetite Nanoparticles With Amine Surface Reactivity, Haiou Qu, Hui Ma, Aurélien Riviere, Weilie Zhou, Charles J. O'Connor Jan 2012

One-Pot Synthesis In Polyamines For Preparation Of Water-Soluble Magnetite Nanoparticles With Amine Surface Reactivity, Haiou Qu, Hui Ma, Aurélien Riviere, Weilie Zhou, Charles J. O'Connor

Chemistry Faculty Publications

Magnetite nanoparticles with hydrophilic surface coating are prepared in polyamine solvents. The resulting products are highly stable in polar solvent. The surface amine groups are available for secondary reactions.


Analysis Of The Penney-Ante Game Using Difference Equations: Development Of An Optimal And A Mixed-Strategies Protocol, Carl Barratt, Pauline Schwartz Jan 2012

Analysis Of The Penney-Ante Game Using Difference Equations: Development Of An Optimal And A Mixed-Strategies Protocol, Carl Barratt, Pauline Schwartz

Chemistry and Chemical Engineering Faculty Publications

Penney-Ante is a well known two-player (Player I and Player II) game based on an information paradox. We present a new approach, using difference-equations, to analyzing the outcome for each player. One strategy yields a winning outcome of 75% for Player II, the player playing second. The approach also permits investigation of non-optimal strategies, and demonstrates how mixing of such strategies can be used to tune the winning edge of either player. We generalize the analysis to accommodate the possibility of a biased coin.


Kinetic Models Of The Prebiotic Replication Of Dsrna Under Thermal Cycling Conditions, Pauline Schwartz, Dante M. Lepore, Carl Barratt Jan 2012

Kinetic Models Of The Prebiotic Replication Of Dsrna Under Thermal Cycling Conditions, Pauline Schwartz, Dante M. Lepore, Carl Barratt

Chemistry and Chemical Engineering Faculty Publications

We present computational models for the replication of double stranded RNA (dsRNA) or related macromolecules under thermal cycling conditions that would reflect prebiotic (i.e. non-enzymatic) environments. Two models of the replication of dsRNA are represented as multi-step chemical systems. The objective of this investigation was to better understand the kinetic features of such chemical systems. It is shown that thermal cycling in a chemical system is advantageous (relative to a fixed temperature) if there are two competing reactions, one favored at high temperature and one favored at low temperature. For the prebiotic replication of dsRNA, a high temperature favors formation …


Metal Chalcogenide Nanoparticle Gel Networks: Their Formation Mechanism And Application For Novel Material Generation And Heavy Metal Remediation Via Cation Exchange Reactions, Irina Ramona Pala Jan 2012

Metal Chalcogenide Nanoparticle Gel Networks: Their Formation Mechanism And Application For Novel Material Generation And Heavy Metal Remediation Via Cation Exchange Reactions, Irina Ramona Pala

Wayne State University Dissertations

METAL CHALCOGENIDE NANOPARTICLE GEL NETWORKS: THEIR FROMATION MECHANISM AND APPLICATION FOR NOVEL MATERIAL GENERATION AND HEAVY METAL REMEDIATION VIA CATION EXCHANGE REACTIONS

by

IRINA R. PALA

February 2012

Advisor: Dr. Stephanie L. Brock

Major: Chemistry

Degree: Doctor of Philosophy

The dissertation research is focused on (1) uncovering the mechanism of metal chalcogenide nanoparticle gel formation; (2) extending the cation exchange reaction protocol to zinc sulfide gel networks, with the goal of accessing new aerogel chemistries and understanding the factors that drive the process; and (3) conducting a quantitative analysis of the ability of ZnS aerogels to remove heavy metal ions …


New Precursors And Chemistry For The Growth Of Transition Metal Films By Atomic Layer Deposition, Thomas Joseph Knisley Jan 2012

New Precursors And Chemistry For The Growth Of Transition Metal Films By Atomic Layer Deposition, Thomas Joseph Knisley

Wayne State University Dissertations

The advancing complexity of advanced microelectronic devices is placing rigorous demands on currently used PVD and CVD deposition techniques. The ALD deposition method is proposed to meet the film thickness and conformality constraints needed by the semiconductor industry in future manufacturing processes. Unfortunately, there is a limited number of chemical precursors available that have high thermal stability, reactivity, and vapor pressure suitable for ALD film growth to occur. These properties collectively contribute to the lack of suitable transition metal precursors available for use in ALD. In this thesis, we report the discovery of a series of novel transition metal diazadienate …


Understanding Fracture, Allison Marsh Jan 2012

Understanding Fracture, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.


Catalytic Effects Of Period Iv Transition Metal In The Oxidation Of Biodiesel, Bradley Clark Jan 2012

Catalytic Effects Of Period Iv Transition Metal In The Oxidation Of Biodiesel, Bradley Clark

Wayne State University Theses

CATALYTIC EFFECTS OF PERIOD IV TRANSITION METALS IN THE OXIDATION OF BIODIESEL

BRADLEY R CLARK

December 2011

Advisors: Dr. Steve Salley, Dr. Simon Ng, Dr. Naiem Henien

Major: Alternative Energy Technology

Degree: Masters of Science

Transition metals have the ability to catalyze free radical autoxidation of unsaturated fatty acid methyl esters (i.e., biodiesel). The catalytic effects of the eight period IV transition metals: V, Cr, Mn, Fe, Co Ni, Cu and Zn in soybean oil and cottonseed oil-based biodiesel are investigated. All metals produced a reduction of the induction period of biodiesel, although there are considerable differences in their catalytic …


A Novel Fabrication Technique For Three-Dimensional Nanostructures, Ravi Kiran Bonam Jan 2012

A Novel Fabrication Technique For Three-Dimensional Nanostructures, Ravi Kiran Bonam

Legacy Theses & Dissertations (2009 - 2024)

Three dimensional micro- and nano-structures are commonly used in the field of Photonics, Optoelectronics, Sensors and Biological applications. Although numerous physical models are developed, a major challenge has been in their fabrication which is commonly limited to conventional layer-by-layer techniques. In this dissertation, a novel method for fabricating three dimensional structures using Electron Beam Lithography (EBL) will be presented.


Organic Photovoltaics: A Charge Transfer Perspective In The Study Of Donor-Acceptor Pairs, Marco Olguin Jan 2012

Organic Photovoltaics: A Charge Transfer Perspective In The Study Of Donor-Acceptor Pairs, Marco Olguin

Open Access Theses & Dissertations

The present research involves the study of donor-acceptor (D/A) dyad complexes from a charge transfer energy perspective. The aim is to provide insight and predictive understanding into the charge transfer processes of the molecular-level components in donor-acceptor based organic solar cells using computational methods to describe photochemical processes at the quantum mechanical level within the Density Functional Theory (DFT) approximation. Predictive understanding is anchored in reproducing experimental results, wherein the present work a perturbative excited-state DFT method is described in detail and shown to give CT energies in excellent agreement with benchmark experimental data. With an accurate excited state method …


Why Do We Collect?, Allison Marsh Jan 2012

Why Do We Collect?, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.


Spotlight On Usc: A.C. Moore Herbarium, Allison Marsh Jan 2012

Spotlight On Usc: A.C. Moore Herbarium, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.


Imaging And Aesthetics, Allison Marsh Jan 2012

Imaging And Aesthetics, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.


Observing The Minuscule, Allison Marsh Jan 2012

Observing The Minuscule, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.


Listen, Allison Marsh Jan 2012

Listen, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.


Spotlight On Usc: Mechanical Engineering, Allison Marsh Jan 2012

Spotlight On Usc: Mechanical Engineering, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.


Photographic Evidence, Allison Marsh Jan 2012

Photographic Evidence, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.


Influencing Art, Allison Marsh Jan 2012

Influencing Art, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.


Capturing Motion, Allison Marsh Jan 2012

Capturing Motion, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.


Applications Of Density Functional Theory In Materials Science And Engineering, Manuel Alvarado Jan 2012

Applications Of Density Functional Theory In Materials Science And Engineering, Manuel Alvarado

Open Access Theses & Dissertations

Density Functional Theory (DFT) is a powerful tool that can be used to model various systems in materials science. Our research applies DFT to two problems of interest. First, an organic/inorganic complex dye system known as a Mayan pigment is modeled to determine chemical binding sites, verifying each model with physical data such as UV/Vis spectra. Preliminary studies on palygorskite-based mayan pigments (mayacrom blue, mayacrom purple) show excellent agreement with experimental studies when using a dimer dye geometry binding with tetrahedrally-coordinated aluminum impurity sites in palygorksite. This approach is applied to a sepiolite-based organic/inorganic dye system using thioindigo attached to …


Electrical Characterization Of Microcrystalline Lifepo4 For Application In Lithium Ion Batteries, Sukhdeep Amarjeet Labana Jan 2012

Electrical Characterization Of Microcrystalline Lifepo4 For Application In Lithium Ion Batteries, Sukhdeep Amarjeet Labana

Open Access Theses & Dissertations

Electrical Characterization of Microcrystalline LiFePO4 for application in lithium ion batteries. Mainly, to study about the electrical properties of Lithium Iron Phosphate as a cathode material to increase its Electrical consumption.


Techniques For Sensor-Integrated Robotic Systems: Raman Spectra Analysis, Image Guidance, And Kinematic Calibration, Luke Anthony Reisner Jan 2012

Techniques For Sensor-Integrated Robotic Systems: Raman Spectra Analysis, Image Guidance, And Kinematic Calibration, Luke Anthony Reisner

Wayne State University Dissertations

Robotics and sensor technology have made impressive advancements over the years. There are now robotic systems that help perform surgeries or explore the surface of Mars, and there are sensors that detect trace amounts of explosives or identify diseased human tissue. The most powerful systems integrate robots and sensors, which are natural complements to each other. Sensors can provide information that might otherwise be unavailable due to indirect robotic manipulation (e.g., images of the target environment), and robots can provide suitably precise positioning of an analytical sensor.

To have an effective sensor-integrated robotic system, multiple capabilities are needed in the …


Microscopic And Spectroscopic Analysis Of Wo3 And Ti-Doped Wo3 Thin Films, Young Taek Yun Jan 2012

Microscopic And Spectroscopic Analysis Of Wo3 And Ti-Doped Wo3 Thin Films, Young Taek Yun

Open Access Theses & Dissertations

Tungsten oxide (WO3) has been a subject of high interest for its unique properties, and recently for its importance in different types of industrial applications which ranges from non-emissive displays, optical, microelectronic, catalytic/photocatalytic, humidity, temperature, gas, and biosensor devices. In this study, WO3 and Ti doped thin films were prepared using radio frequency magnetron reactive sputtering at different substrate temperatures ranging from room temperature to 500 ºC in increments of 100 ºC. After forming a hypothesis based on knowledge of established WO3 properties, we attempt in this work to investigate how the doping influences the roughness and the mean grain …


Tunable Gold Nanostructures With Nanocapsules As Template Reaction Vessels, Balasubramanian Ramjee, Srujana Prayakarao, Sangbum Han, Wei Cao Jan 2012

Tunable Gold Nanostructures With Nanocapsules As Template Reaction Vessels, Balasubramanian Ramjee, Srujana Prayakarao, Sangbum Han, Wei Cao

Chemistry & Biochemistry Faculty Publications

Hollow, polymeric, thiol-ene resorcinarene nanocapsules can act as template reaction vessels for the synthesis of gold nanoshells or spherical aggregates of gold nanoparticles depending on the reaction conditions. The spherical nanoparticle aggregates were evaluated as catalysts in the biphasic reduction of 4-nitrophenol.


Development Of Tailor-Designed Gold-Platinum Nanoparticles Binary Catalysts For Efficient Formic Acid Electrooxidation, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof Jan 2012

Development Of Tailor-Designed Gold-Platinum Nanoparticles Binary Catalysts For Efficient Formic Acid Electrooxidation, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

The modification of a glassy carbon (GC) electrode with platinum (PtNPs) and gold (AuNPs) nanoparticles is targeted to fabricate efficient anodes for the electrooxidation of formic acid (FA). A proper adjustment of the deposition sequence of PtNPs and AuNPs could eventually enhance the electrocatalytic activity of the electrode in such a way that suppresses the CO poisoning effect during FA oxidation. The highest catalytic activity is obtained at the Au/Pt/GC electrode (with PtNPs firstly deposited on the GC electrode followed by AuNPs). This superb enhancement is quantified by comparing the relative ratio of the direct vs. the indirect oxidation peaks …


Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith Jan 2012

Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

The probability that freshly nucleated nanoparticles can survive to become cloud condensation nuclei is highly sensitive to particle growth rates. Much of the growth of newly formed ambient nanoparticles can be attributed to oxidized organic vapors originating from biogenic precursor gases. In this study we investigated the chemical composition of size-selected biogenic nanoparticles in the size range from 10 to 40 nm. Particles were formed in a flow tube reactor by ozonolysis ofα-pinene and analyzed with a Thermal Desorption Chemical Ionization Mass Spectrometer. While we found similar composition in 10 and 20 nm particles, the relative amounts of …


Overview Of The 2010 Carbonaceous Aerosols And Radiative Effects Study (Cares), Rahul A. Zaveri, William J. Shaw, Daniel J. Cziczo, Beat Schmid, Richard Ferrare, M. Lizabeth Alexander, Raul Alvarez, W. Patrick Arnott, Dean B. Atkinson, Sunil Baidar, Robert M. Banta, James Barnard, Josef Beranek, Larry K. Berg, Fred Brechtel, W. Alan Brewer, John F. Cahill, Brian Cairns, Christopher D. Cappa, D. Chand, S. China, Jennifer M. Comstock, Manvendra K. Dubey, Robert C. Easter, M. H. Erickson, Jerome Fast, Cody Floerchinger, B. Flowers, Edward C. Fortner, Jeffrey S. Gaffney, Mary K. Gilles, Kyle Gorkowski, William Gustafson, Madhu Gyawali, J. Hair, R. M. Hardesty, Joseph Harworth, Scott C. Herndon, Naruki Hiranuma, Chris Hostetler, John M. Hubbe, John T. Jayne, H. Jeong, B. Tom Jobson, Evgueni Kassianov, Lawrence I. Kleinman, C. Kluzek, W. Berk Knighton, Katheryn R. Kolesar, Chongai Kuang, Alena Kubátová, Andrew O. Langford, Alexander Laskin, N. Laulainen, Richard D. Marchbanks, Claudio Mazzoleni, Fan Mei, Ryan C. Moffet, Dan Nelson, Michael Obland, Hilke Oetjen, Timothy B. Onasch, I. Ortega, Matteo Ottaviani, Mikhail Pekour, Kimberly A. Prather, James Gregory Radney, Raymond R. Rogers, Scott P. Sandberg, Arthur J. Sedlacek, Christoph J. Senff, Gunnar I. Senum, Ari Setyan, John E. Shilling, Manishkumar Shrivastava, C. Song, Stephen R. Springston, R. Subramanian, Kaitlyn Suski, Jason Tomlinson, Rainer M. Volkamer, H. W. Wallace, Jian Wang, A. M. Weickmann, Douglas R. Worsnop, Xiao-Ying Yu, Alla Zelenyuk, Qi Zhang Jan 2012

Overview Of The 2010 Carbonaceous Aerosols And Radiative Effects Study (Cares), Rahul A. Zaveri, William J. Shaw, Daniel J. Cziczo, Beat Schmid, Richard Ferrare, M. Lizabeth Alexander, Raul Alvarez, W. Patrick Arnott, Dean B. Atkinson, Sunil Baidar, Robert M. Banta, James Barnard, Josef Beranek, Larry K. Berg, Fred Brechtel, W. Alan Brewer, John F. Cahill, Brian Cairns, Christopher D. Cappa, D. Chand, S. China, Jennifer M. Comstock, Manvendra K. Dubey, Robert C. Easter, M. H. Erickson, Jerome Fast, Cody Floerchinger, B. Flowers, Edward C. Fortner, Jeffrey S. Gaffney, Mary K. Gilles, Kyle Gorkowski, William Gustafson, Madhu Gyawali, J. Hair, R. M. Hardesty, Joseph Harworth, Scott C. Herndon, Naruki Hiranuma, Chris Hostetler, John M. Hubbe, John T. Jayne, H. Jeong, B. Tom Jobson, Evgueni Kassianov, Lawrence I. Kleinman, C. Kluzek, W. Berk Knighton, Katheryn R. Kolesar, Chongai Kuang, Alena Kubátová, Andrew O. Langford, Alexander Laskin, N. Laulainen, Richard D. Marchbanks, Claudio Mazzoleni, Fan Mei, Ryan C. Moffet, Dan Nelson, Michael Obland, Hilke Oetjen, Timothy B. Onasch, I. Ortega, Matteo Ottaviani, Mikhail Pekour, Kimberly A. Prather, James Gregory Radney, Raymond R. Rogers, Scott P. Sandberg, Arthur J. Sedlacek, Christoph J. Senff, Gunnar I. Senum, Ari Setyan, John E. Shilling, Manishkumar Shrivastava, C. Song, Stephen R. Springston, R. Subramanian, Kaitlyn Suski, Jason Tomlinson, Rainer M. Volkamer, H. W. Wallace, Jian Wang, A. M. Weickmann, Douglas R. Worsnop, Xiao-Ying Yu, Alla Zelenyuk, Qi Zhang

Chemistry Faculty Publications and Presentations

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program’s Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was …


Bifunctional Bisphosphonates For Delivering Biomolecules To Bone, Jivan N. Yewle Jan 2012

Bifunctional Bisphosphonates For Delivering Biomolecules To Bone, Jivan N. Yewle

Theses and Dissertations--Chemistry

Active targeting with controlled delivery of therapeutic agents to bone is an ideal approach for treatment of several bone diseases. Since bisphosphonates (BPs) are known to have high affinity to bone mineral and are being widely used in treatment of osteoporosis, they are well-suited for drug targeting to bone. For this purpose, bifunctional hydrazine-bisphosphonates (HBPs) with spacers of various lengths and lipophilicity were synthesized and studied. Crystal growth inhibition assays demonstrated that the HBPs with shorter spacers bound more strongly to bone mineral, hydroxyapatite (HA), than did alendronate. HBPs were also demonstrated to be non-toxic to MC3T3-E1 pre-osteoblasts. The targeted …