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Selected Works

2009

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Articles 1 - 19 of 19

Full-Text Articles in Chemistry

Optimizing Harvest Of Corn Stover Fractions Based On Overall Sugar Yields Following Ammonia Fiber Expansion Pretreatment And Enzymatic Hydrolysis, Rebecca G. Ong, Shishir Ps Chundawat, Venkatesh Balan, Bruce E. Dale Nov 2009

Optimizing Harvest Of Corn Stover Fractions Based On Overall Sugar Yields Following Ammonia Fiber Expansion Pretreatment And Enzymatic Hydrolysis, Rebecca G. Ong, Shishir Ps Chundawat, Venkatesh Balan, Bruce E. Dale

Rebecca Ong

Background: Corn stover composition changes considerably throughout the growing season and also  varies  between  the  various  fractions  of  the  plant.  These  differences  can  impact  optimal pretreatment  conditions,  enzymatic  digestibility  and  maximum  achievable  sugar  yields  in  the process of converting lignocellulosics to ethanol. The goal of this project was to determine which combination of corn stover fractions provides the most benefit to the biorefinery in terms of sugaryields and to determine the preferential order in which fractions should be harvested. Ammoniafiber expansion (AFEX) pretreatment, followed by enzymatic hydrolysis, was performed on early and late harvest corn stover fractions (stem, leaf, husk …

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Experimental And Theoretical Study Of The Structures And Enthalpies Of Formation Of The Synthetic Reagents 1,3-Thiazolidine-2-Thione And 1,3-Oxazolidine-2-Thione., María Victoria Roux, Manuel Temprado, Pilar Jiménez, Concepción Foces-Foces, Rafael Notario, Archana R. Parameswar, Alexei V. Demchenko, James S. Chickos, Carol A. Deakyne, Alicia K. Ludden, Joel F. Liebman Oct 2009

Experimental And Theoretical Study Of The Structures And Enthalpies Of Formation Of The Synthetic Reagents 1,3-Thiazolidine-2-Thione And 1,3-Oxazolidine-2-Thione., María Victoria Roux, Manuel Temprado, Pilar Jiménez, Concepción Foces-Foces, Rafael Notario, Archana R. Parameswar, Alexei V. Demchenko, James S. Chickos, Carol A. Deakyne, Alicia K. Ludden, Joel F. Liebman

James Chickos

No abstract provided.

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Absolute Nitrogen Atom Density Measurements By Two-Photon Laser-Induced Fluorescence Spectroscopy In Atmospheric Pressure Dielectric Barrier Discharges Of Pure Nitrogen, Et-Touhami Es-Sebbar, Christian Sarra-Bournet, Nicolas Naudé, Françoise Massines, Nicolas Gherardi Oct 2009

Absolute Nitrogen Atom Density Measurements By Two-Photon Laser-Induced Fluorescence Spectroscopy In Atmospheric Pressure Dielectric Barrier Discharges Of Pure Nitrogen, Et-Touhami Es-Sebbar, Christian Sarra-Bournet, Nicolas Naudé, Françoise Massines, Nicolas Gherardi

Dr. Et-touhami Es-sebbar

In this paper, two-photon absorption laser induced fluorescence spectroscopy is used to follow the nitrogen atom density in flowing dielectric barrier discharges fed with pure nitrogen and operating at atmospheric pressure. Two different dielectric barrier discharge regimes are investigated: the Townsend regime, which is homogeneous although operating at atmospheric pressure, and the more common filamentary regime. In both regimes, densities as high as 3x1014 /cm3 are detected. However, the N atoms kinetic formation depends on the discharge regime. The saturation level is reached more rapidly with a filamentary discharge. For a given discharge regime, the N atom density depends strongly …

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Contributions To The Development Of The S.E.T.U.P. (Experimental And Theoretical Simulations Useful For Planetology) Project, E. Arzoumanian, C. Romanzin, M-C. Gazeau, Et. Es-Sebbar, A. Jolly, S. Perrier, Y. Benilan Oct 2009

Contributions To The Development Of The S.E.T.U.P. (Experimental And Theoretical Simulations Useful For Planetology) Project, E. Arzoumanian, C. Romanzin, M-C. Gazeau, Et. Es-Sebbar, A. Jolly, S. Perrier, Y. Benilan

Dr. Et-touhami Es-sebbar

No abstract provided.

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Multiwavelength Studies For Titan's Atmospheric Composition Analysis, Y. Benilan, Et. Es-Sebbar, N. Fray, M-C. Gazeau, A. Jolly, M. Schwell, J. Guillemin Oct 2009

Multiwavelength Studies For Titan's Atmospheric Composition Analysis, Y. Benilan, Et. Es-Sebbar, N. Fray, M-C. Gazeau, A. Jolly, M. Schwell, J. Guillemin

Dr. Et-touhami Es-sebbar

Titan's atmosphere mainly made of nitrogen and methane is rich in organic molecules. Hydrocarbons are formed from the photolytic dissociation of CH4 and nitriles are created by dissociation of N2 followed by reactions with hydrocarbons. In order to understand the physicochemical mechanisms responsible for the evolution of Titan's atmosphere, photochemical models are built. The latter need constrains for vertical profiles of organic compounds from the high thermosphere down to the low stratosphere as well as photodissociation rates. Those profiles over the entire atmosphere can be retrieved from Cassini observations, in particular by limb sounding, coupling infrared and ultraviolet spectroscopy. However, …

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Vuv Photostability Of Prebiotic Species, M. Schwell, Y. Bénilan, M.-C. Gazeau, N. Fray, A. Jolly, Et. Es-Sebbar, N. Champion, S. Leach, H. W Jochims, H. Baumgärtel, E. Rühl Sep 2009

Vuv Photostability Of Prebiotic Species, M. Schwell, Y. Bénilan, M.-C. Gazeau, N. Fray, A. Jolly, Et. Es-Sebbar, N. Champion, S. Leach, H. W Jochims, H. Baumgärtel, E. Rühl

Dr. Et-touhami Es-sebbar

No abstract provided.

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S.E.T.U.P. Experimental And Theoretical Simulations Useful For Planetology- Related Studies In The Frame Of A Program Of Titan’S Atmosphere Laboratory Simulations, M.-C. Gazeau, Et. Es-Sebbar, E. Arzoumanian, C. Romanzin, A. Jolly, S. Perrier, Y. Bénilan Sep 2009

S.E.T.U.P. Experimental And Theoretical Simulations Useful For Planetology- Related Studies In The Frame Of A Program Of Titan’S Atmosphere Laboratory Simulations, M.-C. Gazeau, Et. Es-Sebbar, E. Arzoumanian, C. Romanzin, A. Jolly, S. Perrier, Y. Bénilan

Dr. Et-touhami Es-sebbar

No abstract provided.

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Characterization Of An N2 Flowing Microwave Post-Discharge By Oes Spectroscopy And Determination Of Absolute Ground-State Nitrogen Atom Densities By Talif, Et. Es-Sebbar, Y. Benilan, A. Jolly, M-C. Gazeau Jun 2009

Characterization Of An N2 Flowing Microwave Post-Discharge By Oes Spectroscopy And Determination Of Absolute Ground-State Nitrogen Atom Densities By Talif, Et. Es-Sebbar, Y. Benilan, A. Jolly, M-C. Gazeau

Dr. Et-touhami Es-sebbar

A flowing microwave post-discharge source sustained at 2.45 GHz in pure nitrogen has been investigated by optical emission spectroscopy (OES) and two-photon absorption laser-induced fluorescence (TALIF) spectroscopy. Variations of the optical emission along the post-discharge (near, pink and late afterglow) have been studied and the gas temperature has been determined. TALIF spectroscopy has been used in the late afterglow to determine the absolute ground-state nitrogen atomic densities using krypton as a reference gas. Measurements show that the microwave flowing post-discharge is an efficient source of N (4S) atoms in late afterglow. In our experimental conditions, the maximum N (4S) density …

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Simultaneous Quantitation Of Multiple Classes Of Organohalogen Compounds In Fish Oils With Direct Sample Introduction Comprehensive Two-Dimensional Gas Chromatography And Time-Of-Flight Mass Spectrometry, Eunha Hoh, Steven J. Lehotay, Kristin C. Pangallo, Katerina Mastovska, Helen L. Ngo, Christopher M. Reddy, Walter Vetter Apr 2009

Simultaneous Quantitation Of Multiple Classes Of Organohalogen Compounds In Fish Oils With Direct Sample Introduction Comprehensive Two-Dimensional Gas Chromatography And Time-Of-Flight Mass Spectrometry, Eunha Hoh, Steven J. Lehotay, Kristin C. Pangallo, Katerina Mastovska, Helen L. Ngo, Christopher M. Reddy, Walter Vetter

Kristin Pangallo

We successfully optimized an analytical method using gel permeation chromatography followed by direct sample introduction comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry to quantify multiple groups of targeted persistent organic pollutants and halogenated natural products (HNPs) simultaneously in fish oil samples. This new method has a wider analytical scope than the traditional approach to use multiple methods to cover each class of compounds. Our analysis revealed that the relatively more volatile and lighter organic compounds, such as polychlorinated biphenyls (PCBs), organochlorine pesticides, and other smaller organohalogen compounds, were still present in two brands of “PCB-free” cod liver oils, albeit …

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Capabilities Of Direct Sample Introduction-Comprehensive Two-Dimensional Gas Chromatography-Time-Of-Flight Mass Spectrometry To Analyze Organic Chemicals Of Interest In Fish Oils., Eunha Hoh, Steven J. Lehotay, Katerina Mastovska, Helen L. Ngo, Walter Vetter, Kristin C. Pangallo, Christopher M. Reddy Apr 2009

Capabilities Of Direct Sample Introduction-Comprehensive Two-Dimensional Gas Chromatography-Time-Of-Flight Mass Spectrometry To Analyze Organic Chemicals Of Interest In Fish Oils., Eunha Hoh, Steven J. Lehotay, Katerina Mastovska, Helen L. Ngo, Walter Vetter, Kristin C. Pangallo, Christopher M. Reddy

Kristin Pangallo

Most analytical methods for persistent organic pollutants (POPs) focus on individual groups of targeted analytes. Therefore, analysis of multiple classes of POPs typically entails several sample preparations, fractionations, and injections, whereas other chemicals of possible interest are neglected or lost. To analyze a wider scope of organic contaminants in fish oil, we developed an approach to combine the analysis of targeted and untargeted chemicals using an automated direct sample introduction (DSI) and comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC/ToF-MS). DSI-GC×GC/ToF-MS is a powerful tool that attains high quality separations to achieve high selectivity while still providing a wide …

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Catena-Poly[[(Pyridine-Κn)Copper(Ii)]-Μ3-Pyridine-2,6-Dicarboxylato-Κ3o2:O2′,N,O6:O6′], Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath Mar 2009

Catena-Poly[[(Pyridine-Κn)Copper(Ii)]-Μ3-Pyridine-2,6-Dicarboxylato-Κ3o2:O2′,N,O6:O6′], Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath

Nigam Rath

In the title compound, [Cu(C7H3NO4)(C5H5N)]n, the CuII atom is in a slightly distorted octa­hedral coordination environment. Each CuII atom is bound to two N atoms and one O atom of the pyridine­dicarboxyl­ate (PDA) ligand in a tridentate manner, one N atom of the pyridine mol­ecule and two bridging carboxyl­ate O atoms of adjacent PDA ligands, leading to a linear one-dimensional chain running along the c axis. These chains are further assembled via weak C-H...O and [pi]-[pi] inter­actions into a three-dimensional supra­molecular network structure. The centroid-centroid distance between the [pi]-[pi] inter­acting pyridine rings is 3.9104 (13) Å. The two N atoms …

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Researches On Copper. History & Metallurgy, Fathi Habashi Feb 2009

Researches On Copper. History & Metallurgy, Fathi Habashi

Fathi Habashi

The present volume is a collection of selected papers dealing with the extractive metallurgy of copper published by the author and his coworkers. They are reproduced here in a facsimile edition in 240 pages. In addition ten new chapters were specially written in 150 pages. The book is fully illustrated by many colored pictures, flowsheets, and diagrams. It is hoped that it will be useful for students, engineers, chemists, geologists, and for research workers.

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Gold. History, Metallurgy, Culture, Fathi Habashi Feb 2009

Gold. History, Metallurgy, Culture, Fathi Habashi

Fathi Habashi

Gold, the first metal used by man, has a special place among metals. It plays an important role in society and in world economics. It caused unprecedented mass migrations on three continents, and at least one war. It was responsible for creating many large cities, is highly prized, has been the inspiration of numerous myths, was the ultimate goal of alchemists, stored in the vaults of banks, widely on display in oriental bazaars, and is generously used in decorating churches and temples. The present volume is composed of two parts: a collection of selected papers published by the author on …

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Alamethicin In Lipid Bilayers: Combined Use Of X-Ray Scattering And Md Simulations, Jianjun Pan, D. Peter Tieleman, John F. Nagle, Norbert Kučerka, Prof. Stephanie Tristram-Nagle Ph.D. Dec 2008

Alamethicin In Lipid Bilayers: Combined Use Of X-Ray Scattering And Md Simulations, Jianjun Pan, D. Peter Tieleman, John F. Nagle, Norbert Kučerka, Prof. Stephanie Tristram-Nagle Ph.D.

Prof. Stephanie Tristram-Nagle Ph.D.

We study fully hydrated bilayers of two di-monounsaturated phospholipids diC18:1PC (DOPC) and diC22:1PC with varying amounts of alamethicin (Alm). We combine the use of X-ray diffuse scattering and molecular dynamics simulations to determine the orientation of alamethicin in model lipids. Comparison of the experimental and simulated form factors shows that Alm helices are inserted transmembrane at high humidity and high concentrations, in agreement with earlier results. The X-ray scattering data and the MD simulations agree that membrane thickness changes very little up to 1/10 Alm/ DOPC. In contrast, the X-ray data indicate that the thicker diC22:1PC membrane thins with added …

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Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth(Iii) Bromide Catalyzed Synthesis Of Substituted Tetrahydroquinoline Derivatives, Ram S. Mohan, Jamie L. Rogers, Justin J. Ernat, Herbie Yung Dec 2008

Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth(Iii) Bromide Catalyzed Synthesis Of Substituted Tetrahydroquinoline Derivatives, Ram S. Mohan, Jamie L. Rogers, Justin J. Ernat, Herbie Yung

Ram S. Mohan

The bismuth bromide catalyzed synthesis of a range of substituted tetrahydroquinoline derivatives via a three component coupling reaction between substituted anilines and enol ethers is reported. Bismuth compounds are attractive for use as catalysts because of their remarkably low toxicity. Bismuth bromide is relatively inexpensive and easy to handle, and hence preferable to other corrosive catalysts previously used for synthesis of tetrahydroquinoline derivatives.

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Synthesis Of Facial Amphiphile 3,7-Diamino-5Α-Cholestane Derivatives As A Molecular Receptor, Md Wasi Ahmad, Young Mee Jung, Sharaf Nawaz Khan, Hong Seok Kim Dec 2008

Synthesis Of Facial Amphiphile 3,7-Diamino-5Α-Cholestane Derivatives As A Molecular Receptor, Md Wasi Ahmad, Young Mee Jung, Sharaf Nawaz Khan, Hong Seok Kim

Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)

A series of facial amphiphiles 3,7-diaminocholestane were synthesized from 3,7-diketocholestane via 2 sequential reductive aminations and anion recognition was evaluated with acetate, chloride, bromide, fluoride and phosphate anions. The stereo-selective reductive amination protocol was utilized to synthesized facial amphiphiles afforded receptors in high yields. The molecular receptor 2 showed the highest binding constant with acetate in a 1:1 ratio.

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Towards Self-Configurable Overlay Networks, Philadelphia University Dec 2008

Towards Self-Configurable Overlay Networks, Philadelphia University

Philadelphia University, Jordan

No abstract provided.

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Synthesis, Characterization And Application Of Al,Fe-Pillared Clays, Zeljko D. Cupic Dec 2008

Synthesis, Characterization And Application Of Al,Fe-Pillared Clays, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.

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Suitability Assessment Of Water Quality Of Shinta River And Its Impacts On The Users: A Case Study From Gondar, Ethiopia, Mohammad Mansoob Khan Dr, H. R. Sharma Dr Dec 2008

Suitability Assessment Of Water Quality Of Shinta River And Its Impacts On The Users: A Case Study From Gondar, Ethiopia, Mohammad Mansoob Khan Dr, H. R. Sharma Dr

Dr. Mohammad Mansoob Khan

No abstract provided.

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