Digital Commons Network^™

Artificial Neural Networks Used To Predict Electrical Properties Of Polymers, Sanjay K. Mitra, Qing Luo, Jerry A. Darsey

Journal of the Arkansas Academy of Science

The ability to predict properties of molecules prior to their synthesis can be of great importance in optimizing their design. Substantial savings in time as well as cost can be achieved if some desired properties can be predicted prior to the synthesis of the molecule. The outer orbitals of a molecule are primarily responsible for many different properties of the molecules. These outer orbital parameters can be utilized by an intelligent computing system like an Artificial Neural Network to extract necessary knowledge about the properties of the molecule. An Artificial Neural Network was trained to extract electrical parameters of several …

New Studies Of Polyfuran And Polymers Of 3-Substituted Furan Rings, Rose M. Mcconnell, Walter E. Godwin, Bradley Phillips

Journal of the Arkansas Academy of Science

No abstract provided.

Reductive Dechlorinatin Of A 2-Chloronicotinic Acid Under Finkelstein Conditions, Frank L. Setliff, Leslie B. Coop

Journal of the Arkansas Academy of Science

No abstract provided.

Suprachiasmatic Nucleus Neurons Are Glucose Sensitive, Adam C. Hall, Roselle M. Hoffmaster, Edra L. Stern, Mary E. Harrington, David Bickar

Chemistry: Faculty Publications

The suprachiasmatic nucleus (SCN) in the hypothalamus serves as the pacemaker for mammalian circadian rhythms. In a hamster brain slice preparation, the authors were able to record spontaneous activity from SCN cells for up to 4 days in vitro and verify a self-sustained rhythm in firing. The phase of this rhythm was altered by the concentration of glucose in the bathing medium, with time of peak firing advanced for a 20 mM glucose condition and slightly delayed for a 5 mM glucose condition, relative to 10 mM. The advancing effect of 20 mM glucose and the delaying effect of 5 …

Crystal Structure Of (Μ-Tranis-4,4'-Dinitro-2,2'-Biimidazolato-N,N: N'',N''') Bis[Bis(Triphenylphosphine Copper(I))] N,N-Dimethylformamide, [C42h37cun4o3p2]2, R. G. Baughman, C. A. Hester, Harvest L. Collier

Chemistry Faculty Research & Creative Works

No abstract provided.

Varietal Differences In The Total And Enantiomeric Composition Of Theanine In Tea, K. Helen Ekborg-Ott, Andre Taylor, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Theanine is the main amino acid component in tea. It usually constitutes between 1 and 2% of the dry weight of the tea leaves. It is as prevalent in tea as all other free amino acids combined. Both enantiomers of theanine were found to have a similar sweet taste, with little or no aftertaste. It was found that black and half-green teas (except for Formosa Oolong) contained as much, or more, theanine as green teas. No correlation was found between the absolute concentration of theanine in tea and its enantiomeric composition. An inverse correlation was found between certain grades of …

Immunologic And Hematopoietic Effects Of Cd40 Stimulation After Syngeneic Bone Marrow Transplantation In Mice, Satoshi Funakoshi, Dennis D. Taub, Miriam R. Anver, Arati Raziuddin, Osamu Asai, Prakash Reddy, Helen C. Rager, William C. Fanslow, Dan L. Longo, William J. Murphy

Chemistry Faculty Research & Creative Works

CD40 is a molecule present on multiple cell types including B lymphocyte lineage cells. CD40 has been shown to play an important role in B cell differentiation and activation in vitro, although little is known concerning the effects of CD40 stimulation in vivo. We therefore examined the effects of CD40 stimulation in mice using a syngeneic bone marrow transplantation (BMT) model in an effort to augment B cell recovery after high dose therapy with hematopoietic reconstitution. After the BMT, mice were treated with or without 2-6 μg of a soluble recombinant murine CD40 ligand (srmCD40L) given intraperitoneally twice a week. …

Calcium Metabolismn In Volvox Carteri, Bridget Anne Neville

Honors Theses

Calcium metabolism is involved in many ways in the cellular activities of the colonial green alga, Volvox carteri. Various drugs that are known in other systems to cause specific changes in calcium metabolism, gave rise to various visible metabolic effects in this study. These effects provide evidence for calcium's role in Volvox growth and development and in its cytoskeleton. Another way that calcium exerts its effect on Volvox is by acting as a second messenger in a G-protein/inositol phosphate signal transduction pathway.

This study also supports the fact that cytoskeletal components are important for development in Volvox. Both microtubules and …

Computational Studies Of Hydroboration: Remote Functional Groups And Ring Size Effects, Sarah Liberty Olbrich

Honors Theses

This study is a preliminary computational study of the energies of complex molecules. We are looking at the roles of remote heteroatoms in the hydroboration of propellane systems and ring size effects in the solvolysis of cyclic alkyl halides was examined using computational methods. Geometry and transition state optimizations were done using semi empirical (MNDO. AMI) and ab initio (STO-3G, 3-2IG, and 6-31G*) methods. Attempts to correlate computational results with previously reported data will be presented.

Suspended Particulate Matter And Sediment Of Penobscot Estuary, Craig M. Pochini

Honors Theses

An automated scanning electron microscope with an energy dispersive spectrometer was used to gather morphological and chemical information on individual particles from the suspended particulate matter of the Penobscot Estuary and the sediment of Goose Cove/Pond. The goals of the Penobscot Estuary study were to investigate the transport of particles into and through an estuary, the speciation of elements, the abundance of heavy metals, and the background levels of heavy metals. The majority of particles were aluminosilicates originating from a riverine source. Heavy metals were not abundant in the Penobscot Estuary. The objectives of the Goose Cove/Pond study were to …

A Chemical Extraction Study Of Lead Contaminated Soil From Granite City, Il, Yan Zhang

Masters Theses

Granite City, IL, surface soil ( 0-10 cm ) contaminated with lead was studied by both single- and a four-step sequential chemical extraction procedures designed to establish the partitioning, mobility and availability of lead in soil. The five fractions corresponding to the selected extractants were exchangeable, carbonates-bound, Fe-Mn oxides bound, organic matter and residual. Lead contamination of the soil was determined as a function of particle size and soil depth.

The contaminated sample had the highest lead content of 573.1 mg/kg at the 4 cm soil depth level, and on average was about 8.8 times that of background soil. Most …

Azo Dyes Based On 1,10-Phenanthroline, Minchong Mao

Masters Theses

A series of new phenanthroline based azo-dye ligands, produced by diazotizing 5-amino-1,10-phenanthroline (5-NH₂-phen) and then coupling this intermediate to a variety of coupling components, has been synthesized and characterized. The coupling components used were β-naphthol, phenol, and 2,6-dimethylphenol, and the three dye ligands were named phen-azo-β-naphthol, phen-azo-p-phenol, and phen-azo-2,6-dimethylphenol, respectively. ¹H-NMR and IR spectra showed that the dyes exist primarily in the azo form in DMSO solution and as solids. UV-Vis spectra (in MeOH) showed intense (ε ≅ 10⁴ M^-1cm^-1) absorptions ranging from 380 nm to 500 nm for these ligands.

The …

Surface Morphology Of Gan Films Determined From Quantitative X-Ray Reflectivity, D Lederman, Zhonghai Yu, T H. Myers, Michelle Richards-Babb

Faculty & Staff Scholarship

The surface of two GaN films grown under Ga-rich conditions by molecular beam epitaxywas characterized using x-ray reflectivity, assuming a self-affine/fractal surface morphology. The surface height fluctuations were similar for both samples at the largest lateral length scales at which the fractal description is valid, although this lateral length was significantly greater and the “jaggedness” significantly smaller for the sample grown under higher Ga flux. Previous atomic force microscopy images revealed a higher density of large features on the surface for the sample grown under lower Ga flux. The lateral size of the features are dominated by a convolution of …

Multinuclear Magnetic Resonance Studies Of Anion Binding To Copper, Zinc-Superoxide Dismutase, And Of Lithium Transport And Binding In Cultured Neuroblastoma Cells, Cherian Zachariah

Dissertations

No abstract provided.

Development Of Crosslinking Reagents, And Intra- And Intermolecular Multi-Linking Hemoglobin Molecules As Potential Blood Substitutes, Yaguo Zheng

Dissertations

No abstract provided.

A Multinuclear Magnetic Resonance Study Of Cesium And Chloride Distribution In Human Erythrocyte Suspensions, Wanrong Lin

Dissertations

No abstract provided.

Asymmetric Synthesis By Palladium (Ii) Catalysis: Chirality Transfer And New A Symmetric Catalytic System, Othman Hamed

Dissertations

No abstract provided.

Oxidative Reactions In Normal And Sickle Hemoglobin-Lipid Mixtures Under Various Conditions, Merita Nirmali Dias

Dissertations

No abstract provided.

Ph And Osmolality Effects On Lipid-Enhanced Sickle And Normahemoglobin Oxidation, Sharron Kay Jenkins

Dissertations

No abstract provided.

Molecular Dynamics Of Crosslinked And Normal Hemoglobins, Liang Zhao

Master's Theses

No abstract provided.

The Application Of Matrix Assisted Laser Desorption Ionization Time Of-Flight Mass Spectrometry (Maldi Tof Ms) For Dna Adducts And Cross-Linked Hemoglobin Analysis, Xiaomei Gu

Master's Theses

No abstract provided.

Effects Of Perinatal Exposure To Cocaine On Sexually Differentiated Gonadotropin Regulation In Rats, Jihun M. Lee

Master's Theses

No abstract provided.

A Comparison Of The Kinetics Of Fatty-Acid Metabolism In Smokers And Nonsmokers, Patricia A. Valusek

Honors Theses, 1963-2015

For many years, the United States government has required labels on all cigarette packages warning against the many ill effects associated with smoking. One of the major factors contributing to the unhealthy aspects of smoking is its profound impact on nutrient levels within the body. Free radicals found in both the gas and tar phases of cigarette smoke may pose a significant threat to the fatty-acid levels in the body. One method of assessing this threat is to examine the fatty-acid synthesis rates of smokers and nonsmokers. An assumption was made that a destruction of fatty-acids will be displayed as …

Preparation And Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations: Applications To Organic Synthesis, William A. Donaldson

Chemistry Faculty Research and Publications

No abstract provided.

Hexakis(Dimethylformamide)Bis(Hexaphenylcyclohexasiloxanehexaolato)Hexacopper(Ii) Dimethylformamide Solvate, Sergey V. Lindeman, Olga I. Shchegolikhina, Yulia A. Molodtsova, Alexandr A. Zhdanov

Chemistry Faculty Research and Publications

The sandwich-like title complex, hexakis(dimethylformamide)-1O,2O,3O,4O,5O,6O-bis[2,4,6,8,10,12-hexaphenylsiloxane-2,4,6,8,10,12-hexaolato(6-)-1:2²O¹,2:3²O²,3:4²O³,- 4:5²O⁴,5:6²O⁵,1:6²O⁶]hexacopper(II) tetrakis(dimethylformamide) solvate, [Cu₆(C₃H₇NO)₆{(C₆H₅)₆O₁₂Si₆}₂].4C₃H₇NO, is comprised of two regular crown-shaped macrocyclic hexadentate organosiloxanolate ligands chelating a flat Cu₆ hexagon, as in the ethanol-solvated analogue investigated previously. The title complex has a more distorted shape …

N-Methylbenzothiazole-2(3H)-Selone, C8H7Nsse, Steinar Husebye, Sergey V. Lindeman, Martin D. Rudd

Chemistry Faculty Research and Publications

The crystal structure of N-methyl1,3-benzothiazole-2(3H)-selone, (mbts) has been studied to estimate the changes in the molecular geometry of the mbts ligand upon coordination. Hypervalent complexes of mbts with Te^II and I^I have been studied by us previously. A significant elongation of the Se=C bond [from 1.817 (7) in mbts to 1.85-1.88 Å in the complexes] was found, but there were no significant changes in the other geometric parameters of the ligand. The only other bond-length decrease of note was for SeC-NMe [from 1.35 (1) in mbts to 1.32-1.34 Å in the complexes]. Thus, only the …

Solvent Impregnated Resins For The Recovery Of Gold From Gold(I)Thiourea Solutions, Fiona Fitzpatrick

Masters

Solvent Impregnated Resins (SIRs) are high surface area, macroporous, polymeric resins which have been physically impregnated with an organic solvent. In this research, three resins have been impregnated with Di-2-ethylhexyl phosphoric acid, a solvent which has shown selectivity to gold. The ability of the resins to recover gold (1) thiourea perchlorate from solution has been investigated. The resins have been studied both bare and when impregnated with the solvent and their efficiency was seen to increase upon impregnation. The overall efficiency of the resins was found to be pH dependent. It is also related to the level of impregnation of …

Features Of Graft Copolymer Formation Through Reaction Of Functionalized Polyolefins With Poly-\Epsilon-Caprolactam, Elisa Passaglia, Francesco Picchioni, Mauro Aglietto, Giocomo Ruggeri, Francesco Ciardelli

Turkish Journal of Chemistry

The reaction in the melt of polyolefins containing 2-diethylsuccinate groups (DES) with poly-\epsilon-caprolactam (PA6) to give a graft copolymer was investigated under different conditions. Even using a large excess of DES groups over the PA6 terminal amino groups the graft copolymer yield resulted only partial thus suggesting a kinetic control of the reaction. The effect of various catalysts was then examined taking into account results obtained in a model reaction between a low molecular weight amine and diethylsuccinate. The results are discussed in terms of side reactions and miscibility of the pristine polymers.

Determination Of Asphaltenes In Petroleum Crude Oils By Fourier Transform Infrared Spectroscopy, Brian K. Wilt

Theses, Dissertations and Capstones

An analytical method was developed to quantitatively determine the asphaltene content in petroleum crude oils by Fourier transform infrared spectroscopy (FT-IR). Asphaltenes are a solubility class of compounds found in crude oils. They are black to dark brown solids defined by their insolubility in n-alkane solvents. The structure of asphaltene molecules is polynuclear aromatic rings with alkyl side chains and heteroatoms, such as nitrogen, oxygen, and sulfur attached. Asphaltenes are known to cause oil well plugging and irreversible catalyst deactivation in refineries. The asphaltene content of 50 crude oils from a wide array of geochemical conditions was determined by the …

Observation Of Upper Tropospheric Sulfur Dioxide- And Acetone-Pollution: Potential Implications For Hydroxyl Radical And Aerosol Formation, F. Arnold, J. Schneider, K. Gollinger, H. Schlager, P. Schulte, Donald E. Hagen, Philip D. Whitefield, Peter F. J. Van Velthoven

Physics Faculty Research & Creative Works

Aircraft-based measurements of sulfur dioxide, acetone, carbon dioxide, and condensation nuclei (CN) were made over the north-eastern Atlantic at upper tropospheric altitudes, around 9000 m. On October 14, 1993, strong SO ₂- and acetone-pollution (both up to 3 ppbv) were observed, which were accompanied by a CO ₂-enhancement of up to 6 ppmv, and large CN-concentrations of up to about 1500 cm ^-3 (for radii ≥ 6 nm). CN, excess CO ₂, and to a lesser degree also acetone, were positively correlated with SO ₂. Air mass trajectory analyses indicate, that most of the air masses …