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Speciation Of Heteroatoms In Coal By Sulfur- And Nitrogen-Selective Techniquestrogen-Selective Techniques, Stephen R. Palmer, Michael A. Kruge, Edwin J. Hippo, John C. Crelling

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The peroxyacetic acid oxidation products from a series of coals of organic sulfur content 0.5-9.8 wt% were examined. The distributions of organic S and N compounds were determined by gas chromatography with sulfur-selective flame photometric and nitrogen-selective thermionic specific detection respectively. A selected sample was also examined in greater detail using low-voltage high-resolution mass spectrometry. The distribution of organic sulfur compounds in the oxidation products was remarkably similar for all the coals. The number of sulfur compounds detected was small compared with that of organic nitrogen compounds detected. This suggests that the sulfur chemistry of coal is considerably simpler than …

Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Organic matter separated from calcareous sandstone from the upper portion of a deep-water tsunami deposit at Arroyo el Mimbral, Taumalipas (Mexico), which marks the biostratigraphically-defined Cretaceous-Tertiary boundary, consists primarily of fossil charcoal, including semifusinite and pyrofusinite. Analytical pyrolysis-gas chromatography-mass spectrometry revealed the highly aromatic and polyaromatic character of the organic matter assemblage, typical of the products of partial combustion. The organic matter probably originated as terrestrial vegetation that was caught in a firestorm and subsequently transported far offshore in the backwash of a megawave. These data are consistent with the hypothesis of combustion of large masses of vegetation triggered by …

Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Chemical analyses restricted to a single coal maceral permit a focus on rank effects without concern for variations in organic matter type. Vitrinite concentrates of high purity were isolated from coal samples of the Lower Kittanning seam by multi-step density gradient centrifugation, with reflectances ranging from 0.66 to 1.39% Rmax. In addition to the previously recognized losses of phenolic compounds, the vitrinite pyrolyzates exhibit marked increases in relative concentrations of tri- and tetraaromatic hydrocarbons (especially benzo[a]fluorene, methyl-phenanthrenes, methylfluorenes and methylchrysenes) above 0.9% Rmax, i.e., beyond the "second coalification jump" of Teichmüller. Thus, petrographically-recognizable physical transformations are shown …

Synthesis Of Malathion, Malaoxon, And Isomalathion Enantiomers And Examination Of Their Interactions With Acetylcholinesterase, Clifford E. Berkman

Dissertations

No abstract provided.

A Theoretical Investigation Of The Stability Of Hpc, Hannah S. Hong, Robert J. Cave

All HMC Faculty Publications and Research

Several ab initio methods are applied to the study of two linear isomers of methylidyne phosphine, HCP, and HPC. Single-reference correlation methods ranging from second-order Møller-Plesset theory to coupled cluster singles and doubles theory with noninterative inclusion of connected triple excitations were applied in a variety of basis sets of increasing size. In addition, complete active space self-consistent field wave functions, multireference singles and doubles configuration interaction, and averaged coupled pair functional theory were also applied to HPC. For HPC comparison of the single-reference based results is made with experimental data and previous theory to assess the accuracy …

Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan

Journal of the Arkansas Academy of Science

No abstract provided.

Analysis Of Ammunition By X-Ray Fluorescence, Michael W. Rapp, Teddy L. Townsend

Journal of the Arkansas Academy of Science

Nondestructive analysis of lead shotgun pellets by X-ray fluorescence (XRF) shows considerable promise in assignment of the identity of the ammunition source. X-ray fluorescence spectra of various shotgun pellets and of standard alloys were obtained using an energy-dispersive instrument and an Am-241 source. The correlation obtained between the precent antimony in the standard alloys and the intensity of the Ka fluorescence peak from antimony was excellent. Peak areas from antimony in shotgun pellets were measured and compared to calibration plots from the standard alloys. The method was capable of distinguishing among lead-based alloys, such as ammunition, with antimony content as …

Investigations Of Iron Cycling In Aquatic Systems, Heather A. Lounsbury

Honors Theses

A fully automated luminal-based chemiluminescence flow injection analysis system has been developed for rapid detection of Fe(IT) at natural levels in natural water systems. Similar detection limits are achieved for H202 by fluorometry using an enzyme mediated oxidation of the reagent p-hydroxyphenylacetic acid. Using these analytical systems, the rates of Fe(IT) oxidation by dissolved oxygen in 0.7 M NaO have been measured for nanomolar concentrations of Fe(II) over the pH range 7.0 to 8.3. When the production and decomposition of H202 in the system were considered, measured rates were in excellent agreement with a model based on previously reported rate …

Studies Of Silica As A Polymer Support For Regioselective Reactions On Sucrose, Lei Cheng

Masters Theses

Sucrose is a material that has potential for replacing oil as an industrial feedstock, at least in some instances. A major difficulty in utilizing sucrose is the lack of regioselectivity in its reactions due to the many reactive sites on the sucrose molecule.

This research is part of an attempt to study the technique of molecular recognition in an effort to increase reaction regioselectivity. Molecular recognition by template imprinting should be a way to create a material that would "recognize" and bind to sucrose in such a way as to block certain of the hydroxyl groups on the sucrose. The …

Studies Directed Toward The Synthesis Of Germacranolides Via [2+2] Cycloaddition Followed By Ring Expansion/Elimination Of Β-Lactones, Bryan E. Yates

Masters Theses

Exposure of α-trimethylsilyl β-lactones to magnesium bromide or boron trifluoride etherate in diethyl ether solvent resulted in the smooth generation of β,γ-unsaturated acid derivatives in good yield and isomeric purity. It is believed that this reaction occurs via the formation of a stable tertiary carbocation at the γ-carbon resulting from cleavage of the carbon-oxygen sigma bond due to the complexation of the Lewis acid with the ring oxygen atom. Rapid loss of an adjacent electrofuge then furnishes the unsaturated acids. The β-lactone precursors were prepared by a [2+2] cycloaddition of an aldehyde and an alkyl trimethylsilyl ketene. This method was …

The Synthesis And Characterization Of Ruii(Bpy){(Bpyrm)Ruii(Nh3)4}2](Pf6)6 And [Ruii(Bpy)2(Bpyrm)Ruii(Nh3)4](Pf6)4, Rick Anthony Pavinato

Masters Theses

This thesis describes the synthesis of a trimetallic Ru^II complex [Ru^II(bpy){(bpyrm)Ru^II(NH₃)₄}₂](PF₆)₆ and its bimetallic analog [Ru^II(bpy)₂(bpyrm)Ru^II(NH₃)₄](PF₆)₄. The trimetallic species was designed to be the first in a series of complexes where the reduction potential of the "bridging" complex could be varied (relative to the "terminal" sites) through systematic variation in the metal (M) and/or ligand (LL) … Generation of the [Ru^II-M^II-Ru^III] "mixed-valence" complex would then allow …

Carbonyl Homologation Via Α-Trimethylsilyl Β-Lactone Rearrangement: A Nonbasic Wittig Alternative, Yong Zhang

Masters Theses

Our research group has been interested in β-lactones as useful synthetic intermediates. Transformations of β-lactones, generally ring expansion/opening processes initiated by Lewis acids via ionization/cation-rearrangement or elimination mechanisms, provide efficient protocols for the syntheses of biologically important butyrolactones, β,γ-unsaturated carboxylic acids, or butenolides.

α-Trimethylsilyl β-lactones, synthesized via the BF₃- catalyzed [2+2] cycloaddition of trimethylsilylketene to carbonyl compounds, spontaneously undergo ionization and trimethylsilyl group migration to form α,β-unsaturated trimethylsilyl esters. The trimethylsilyl moiety facilitates the ionization process because of its β-cation stabilizing ability. The two-carbon homologated α,β-unsaturated acids are formed in yields from moderate to high (41-99%) upon aqueous …

Cyclic Voltammetry Of Polypyrroledodecylbenzenesulfonate Layers, T. Mccormac, W. Breen, A. Mcgee, John Cassidy, M. E.G. Lyons

Articles

Polypyrrole was deposited from solutions of NaCIO. and NaDBS, where DBS is dodecylbenzenesulfonate in aqueous solu\ion and characterizcd by voltammetry. It is found that the absence of the so-called 'double laver charging current' during cyclic voltammetry of the layers formed from solutions with surfactant is not because of' the" order in morphology of the layer, but irreversible incorporation of' the surfactant anion.

Initiation And Study Of Localized Corrosion By Scanning Electrochemical Microscopy, David O. Wipf

CAS Publications

This paper describes methods to study the initiation and formation of localized corrosion pits on stainless–steel and aluminum samples. These methods are based on the use of a scanned probe microscope, the scanning electrochemical microscope (SECM). The SECM is specifically designed for operation in electrolyte solution and so is uniquely suited for examination of corrosion processes. SECM imaging of a corrosion pit on stainless steel is presented. In addition, the initiation of single pits on aluminum and stainless steel by using the SECM tip to electrogenerate a local source of Cl^– is described.

Structural Characterization Of Recombinant Polypeptides Of &-Spectrin, Yirong Xu

Dissertations

No abstract provided.

Molecular Modeling Studies Of Hemoglobin Crosslinking Reactions, Patricia A. Pavlik

Master's Theses

No abstract provided.

The Chemistry Of Allergies, Henry Daley

Bridgewater Review

No abstract provided.

Oxidation Of Cyclohexene With Aqueous Potassium Peroxymonosulfate At Ph < 1.7, Wen-Qing Sun

Theses

Glycols are often used as starting materials for pharmaceuticals. They are currently manufactured by reacting alkenes with organic peroxy acids in organic solutions that contain chlorinated solvents. The aim of this research is to find ways to avoid the use of hazardous organic solvents in the manufacture of pharmaceuticals in order to prevent pollution. Our approach is to find alternative synthetic methods using water as solvent.

Based on literature information, it was decided to determine if the aqueous potassium peroxymonosulfate oxidation of water-immiscible cyclohexene at room temperature can be scaled up to become a new method to manufacture glycols. Acidic …

Comparing Normal And Sickle Hemoglobin Oxidation And Heme Transfer In The Presence Of Phosphatidylserine Vesicles, Qinghai Pan

Master's Theses

No abstract provided.

Ab Initio Study Of He(1s)+Cl2(X 1Σg,3Πu) Potential Energy Surfaces, G. Chalasinski, M. Gutowski, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The potential energy surface of the ground state He+Cl₂(¹Σ_g) is calculated by using the perturbation theory of intermolecular forces and supermolecular Møller–Plesset perturbation theory approach. The potential energy surface of the first excited triplet He+Cl₂(³Π_u) was evaluated using the supermolecular unrestricted Møller–Plesset perturbation theory approach. In the ground state two stable isomers are found which correspond to the linear He–Cl–Cl structure (a primary minimum, D_e=45.1 cm⁻¹, R_e=4.25 Å) and to the T‐shaped structure with He perpendicular to the molecular axis (a secondary …

Theoretical Study Of Hydrogen Bonding And Proton Transfer In The Ground And Lowest Excited Singlet States Of Tropolone, M. V. Vener, Steve Scheiner, N. D. Sokolov

Chemistry and Biochemistry Faculty Publications

Theoretical models of hydrogen bonding and proton transfer in the ground (S₀) and lowest excited ππ∗ singlet (S₁) states of tropolone are developed in terms of the localized OH...O fragment model and ab initio three‐dimensional potential energy surfaces (PESs). The PESs for proton transfer in the S₀ and S₁ states are calculated using ab initio SCF and CIS methods, respectively, with a 6–31G basis set which includes polarization functions on the atoms involved in the internal H bond. The Schrödinger equation for nuclear vibrations is solved numerically using adiabatic separation of the …

Reaction Of Titanocene Dichloride With Acetylenedicarboxylate, Tanya L. Hagler, Mark Draganjac, Paul M. Nave, J. Ed Bennett, Farooq Kahn, Robert Engelken, Gerard Williams, Chris Poole, Kwok Fai Yu

Journal of the Arkansas Academy of Science

The reaction of Cp2TiCl2 with either the mono- or dipotassium salt of acetylenedicarboxylic acid (ADC) gives high yields of an insoluble orange product. The insoluble compound shows potential semiconductor behavior, as evidenced by an apparent bandgap in the orange region of the visible spectrum. Under N2 ,the compound decomposes at 238° C, eventually losing approximately 46% total mass up to 1350° C. The exothermic decomposition in air, beginning at 235° C, results in the formation of titanium oxides.

Boron Phosphate And Aluminum Phosphate Aerogels, David A. Lindquist, Steven M. Poindexter, Sterling S. Rooke, D. Ritchie Stockdale, Kirk B. Babb, Alison L. Smoot, William E. Young

Journal of the Arkansas Academy of Science

Anhydrous sol-gel condensation of triethyl phosphate [(CH3CH2O)3PO] with boron trichloride (BCL3 ) or triethyl aluminum [(CH3CH2 ) 3A1] in organic solvents, led to formation of metallophosphate gels. The pore fluid of the gels was removed under supercritical conditions in a pressurized vessel to form aerogels. The aerogels were then calcined at progressively higher temperatures to produce high surface area phosphates. Since the initial gel reagent mixtures contained several NMR active nuclei, the condensation chemistry prior to the gel point was monitored by solution nB NMR. The surface areas, distribution of pore sizes, and total pore volumes of the aerogel products …

Hammett Correlations Of Half-Wave Reduction Potentials In A Series Of N-(Aryl Substituted)-Dichloronicotinamides, Cecil C. Persons, Ali U. Shaikh, Julie Shiflett, Frank L. Setliff

Journal of the Arkansas Academy of Science

Excellent correlations of Hammett substituent constants (sigmaR) of a series of N-(R-substituted aryl) -2,6-, 2,5-, and 5,6- dichloronicotinamides with polarographic half-wave potentials were observed. Although the correlations demonstrate that all three series of amides experience comparable sensitivity to the R groups at the carbonyl reduction site, the relative ease of reduction varies according to the chlorine substitution pattern on the pyridine ring. These differences are suggested to be due to combinations of mesomeric, inductive, and field effects which operate differently in the three systems. Correlation analysis also revealed that Hammett heteroatomic replacement constants previously determined by NMR studies are valid …

Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac

Journal of the Arkansas Academy of Science

Initial studies involved the thermal decomposition profile of five polysulfide complexes in air up to 550 °C. Since our first report to the Academy in 1990, we have obtained the capability to run samples up to 1500°C under various gases. Thermal Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA)of a series of transition metal polysulfide complexes are presented. Compounds analyzed included Cp2TiS5 ,MoS9 2",MoOS8 2", Zn(S x ) 2", Cd(S x ) 2-, Fe2S122 - and NiS82.

Ultrasound Assisted Oxidative Cleavage Of Alpha-Keto, Alpha-Hydroxy And Alpha-Halo Ketones By Superoxide, Yi Hong Cao, A. Toland, Dominic T.C. Yang

Journal of the Arkansas Academy of Science

No abstract provided.

Gender And Aphasia In The Stroke Data Bank, Daniel B. Hier, William B. Yoon, J. P. Mohr, Thomas R. Price, Philip A. Wolf

Chemistry Faculty Research & Creative Works

Aphasia Was Present in 19.4% of the Men and 22.5% of the Women in the Stroke Data Bank. There Were No Gender Differences in Aphasia Incidence among the Intracerebral Hemorrhages. Aphasia Was More Frequent among Women with Infarcts (37.0%) Than Men (28.3%). When Stroke Mechanism Was Controlled For, There Was an Excess of Aphasia among the Women with Stroke Due to Cardiac Embolism. When Stroke Site Was Controlled For, There Were No Gender Differences in Aphasia Frequency. Wernicke′s, Global, and Anomic Aphasias Were More Common in Women Than Men; Broca′s Aphasia Was Somewhat More Common in Men. Although There Were …

A Prospective Community-Based Study Of Stroke In Warsaw, Poland, Anna Czlonkowska, Danuta Ryglewicz, Thomas Weissbein, Maria Baranska-Gieruszczak, Daniel B. Hier

Chemistry Faculty Research & Creative Works

Background and Purpose Poland is a Country with High Morbidity and Mortality Rates from Cardiovascular Diseases. No Recent Studies Have Evaluated the Contribution of Cerebrovascular Diseases to This Morbidity and Mortality. Our Aim Was to Accurately Determine Stroke Incidence Rates in Warsaw, Poland. Methods a 2-Year Prospective and Population-Based Stroke Registry Was Maintained for Health Care Units 2 and 3 in Warsaw, Poland (Population, 182 285). Case Subjects Were Ascertained by Surveying Hospital Admissions, Outpatient Visits, and Death Certificates. Results during the 2 Years of the Study (1991 to 1992), 633 Cases of First-Event Strokes Were Registered, 462 of Which …

Distribution Of Sedimentary Phosphorus In Gulf Of Mexico Estuaries, Weng Huanxin, Bob J. Presley, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Sediment samples were collected from all the major bays and estuaries along the US Gulf of Mexico Coastline in 1986-1988 by the NOAA NS & T Program (NOAA (1989), The National Status and Trends Program for marine environmental quality; NOAA/OMA, Rockville, MD, USA). These have been analyzed for total phosphorus as well as leachable Al-P, Ca-P and Fe-P. Total phosphorus concentration ranges from 1·8 to 45·9 μmol/g and averages 11·3 μmol/g. Higher values were found in Louisiana estuaries than in those in Texas but the highest values occur in the phosphate rock mining region of southern Florida. Ca-P is the …

Chiral Isoparathion Methyl As A Stereospecific Probe Of Phosphorothiolate Mechanism Of Action; Novel Synthetic Approaches Toward Isoquinolone Alkaloids: Pancratistatin Study, Seungmin Ryu

Dissertations

No abstract provided.