Physical Sciences and Mathematics Commons^™

Theoretical Considerations Concerning The Separation Of Enantiomeric Solutes By Liquid Chromatography, Richard E. Boehm, Daniel E. Martire, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

A statistical thermodynamic theory of chiral solute retention and separation using chiral stationary phase high-performance liquid chromatography (CSP-HPLC) is formulated and applied in the limit of infinite dilution of solute to models of chemically bonded CSPs consisting of either chiral tetrahedral moieties or chiral molecular cavities intended to simulate a cyclodextrin CSP. Explicit expressions are derived for the corresponding separation factors and the likelihood of enantiomeric separation is investigated as a function of the multitude of possible interactions and retention modes for the enantiomers and CSPs considered. The separation factor reduces to a simple Boltzmann factor whenever a dominant retention …

Rate Enhancements In The Dnase I Footprinting Experiment, Brian Ward, Robert Rehfuss, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

Footprinting experiments for DNase I digests of a 139-base-pair segment of pBR-322 DNA in the presence of either netropsin or actinomycin D were carried out. Plots of oligonucleotide concentration as a function of drug concentration were analyzed to study the enhancement in cleavage rates at approximately 30 sites, accompanying drug binding at other sites. The pattern of enhancements is not consistent with drug-induced DNA structural changes, but agrees with a redistribution mechanism involving DNase I. Since the total number of enzyme molecules per fragment remains unchanged, drug binding at some sites increases the enzyme concentration at other sites, giving rise …

Chalcogen Elements In Snow: Relation To Emission Source, Kuen Y. Chlou, Oliver Manuel

Chemistry Faculty Research & Creative Works

We have measured the concentrations of S, Se, and Te in samples of 1986 snow and compared our results with those of earlier measurements. We were unable to find any earlier reports on Te in snow, but values of the Se/S concentration ratio in 1986 are about a factor of 6 lower than that in snow and glacial ice of 800 B.C. Measurements on intermediate samples demonstrate that most of the decline in the Se/S ratio occurred during the past 200 years, i.e., since the start of the Industrial Revolution. This temporal change in values of the Se/S ratio probably …

Oxidation Of N,N-Dimethylformamide And N,N-Dimethylacetamide In A Photoreactor, Su-Jen Syu

Theses

Oxidation of N,N-dimethylformamide(DMF) and N,N-dimethylacetamide(DMA) was investigated in a 30 liter semi-batch reactor. Five reaction processes were studied by using UV alone, O₃ alone, O₂/UV, O₂/O₃/UV and H2 O₂/UV respectively. Mathematical models have been developed to interpret the reaction kinetics. Reaction rate constants and mass transfer coefficients were determined by using Rosenbrock Hillclimb optimization algorithm. The experimental data and the predicted results from the models were compared. The kinetic parameters obtained from the previous semi-batch modes were applied to the continuous stirred tank reactor (CSTR) system. Results of this work show …

Regioselectivity In The Cyclization Of Delta, Epsilon-Epoxy Esters, William F. Prout

Dissertations

No abstract provided.

Erratum: Determination Of Dissociation Energies And Thermal Functions Of Hydrogen Bond Formation Using High Resolution Ftir Spectroscopy [J. Chem. Phys. 8 7, 5674 (1987)], B. A. Wofford, M. E. Eliades, Shannon Lieb, J. W. Bevan

Scholarship and Professional Work - LAS

Erratum

The Spectroscopy And Molecular Dynamics Of The High Frequency Ν1 6 Intermolecular Vibrations In Hcn‐‐‐Hf And Dcn‐‐‐Df, B. A. Wofford, M. W. Jackson, Shannon Lieb, J. W. Bevan

Scholarship and Professional Work - LAS

Gas phase rovibrational analysis of the high frequency intermolecular hydrogen bonded bending overtone 2ν⁰ ₆ [ν₀=1132.4783(2) cm^{− 1}] in HCN‐‐‐HF and its corresponding perdeuterated fundamental ν¹ ₆ [ν₀=409.1660(2) cm^{− 1}] are reported. Evaluated rovibrational parameters provide the basis for quantitative modeling of the molecular dynamics associated with this vibration. A quantum mechanical calculation permits determination of the quadratic and quartic force constants K _{6 6}=537(17) and K _{6 6 6 6}=4.98(12) cm^{− 1} which in turn are used to estimate the pertinent cubic band stretching interaction constants …

Going Beyond Single Figure Fertilizer Recommendations, S J. Burgess

Journal of the Department of Agriculture, Western Australia, Series 4

Single-figure fertilizer recommendations are useful guidelines but they do not tell a farmer anything about the consequences of applying fertilizer at rates other than those recommended.

The Treatment Of Exchange In Path Integral Simulations Via An Approximate Pseudopotential, Randall W. Hall

Collected Faculty and Staff Scholarship

An approximate form that includes the effects of exchange is suggested for the short time propagator used in path integral simulations. The form is inspired physically by the approximation made in Hartree–Fock treatments of atoms and molecules. The approximate propagator is used with q u a n t i t a t i v e accuracy in two systems: an ideal gas of fermions localized in a three‐dimensional harmonic well and the triplet state of the sodium dimer.

Substituted Silabenzenes, Kim K. Baldridge, Mark S. Gordon

Mark S. Gordon

Ab initio calculations have been carried out on a group of substituted monosilabenzenes. Twelve different substituents are considered (Cl, F, SH, OH, PH2, NH2, CH3, SiH3, N02, CN, OCH3, COOH), each placed in the four unique positions on the ring. The relative energies and stabilities, aromaticities (as measured by bond separation reactions), electron density distributions, and dipole moments of these compounds are considered and discussed with the aid of density difference plots.

Structure And Bonding In Cycloalkanes And Monosilacycloalkanes, Jerry A. Boatz, Mark S. Gordon, Richard L. Hilderbrandt

Mark S. Gordon

The structural parameters and vibrational frequencies are predicted for the cycloalkanes C.H2• and silacycloalkanes SiC,_1H2n, n = 3-6, using the 3-21G* basis set and SCF wave functions. Bent bond lengths are predicted by tracing the paths of maximum electron density connecting atomic centers. Strain energies and heats of formation are predicted for these compounds and some smaller acyclic alkylsilanes by using MP2/6-31G(d) energies at the 3-21G* geometries and the appropriate homodesmic reactions.

Theoretical Study Of The Lowest Triplet Potential Energy Surface Of Silasilene, Shiro Koseki, Mark S. Gordon

Mark S. Gordon

Bent silasilene, SiSiH2 (C,, 3A"), which has been reported as a global minimum on the lowest triplet potential energy surface of Si2H2, is found to be higher in energy than planar silasilene (C2v, 3A2) by about 2 kcaljmol at the MP4SDTQ/6-31 ++G(d,p) level, suggesting that triplet silasilene (still the global minimum) must have a planar geometry. Trans-bent HSiSiH (C2h, 3Au) should be the most stable triplet disilyne, instead of the twisted structure reported earlier, while the cis-bent structure (C., 3 A") might be observable.

River Discharge Study, Laughlin, Nevada: Colorado River Model And Diffusion Study, B. Dennis Hugh, David L. Stringfield, Jill C. Bicknell, Robert A. Ryder, Clark County Sanitation District, Nevada

Publications (WR)

A water quality modeling study of the Mohave Reach of the Lower Colorado River (from Davis Dam to the Nevada/California Stateline) was conducted to evaluate potential water quality impacts resulting from a proposed Laughlin, Nevada wastewater effluent discharge. The study included four major components: (1) review of the current regulatory framework; (2) a field data collection program to document existing water quality conditions in winter, summer, and fall; (3) development and verification of far-field and near-field (mixing zone) water quality models; and (4) application of the models to project future river quality conditions for several treatment-discharge alternatives as well as …

Incorporation Of A Product Of Mevalonic Acid Metabolism Into Proteins Of Chinese Hamster Ovary Nuclei, Michael Sinensky, L. A. Beck, T. Hosick

Faculty Publications, Biological Sciences

We have examined the nuclear localization of isoprenylated proteins in CHO-K1 cells labeled with [14C]mevalonate. Nuclear proteins of 68, 70, and 74 kD, posttranslationally modified by an isoprenoid, are also components of a nuclear matrix-intermediate filament preparation from CHO cells. Furthermore, the 68-, 70-, and 74-kD isoprenylated polypeptides are immunoprecipitated from cell extracts with two different anti-lamin antisera. Based on exact two-dimensional comigration with lamin B, both from rat liver lamin and CHO nuclear matrix-intermediate filament preparations, and its immunoprecipitation with anti-lamin antisera, we conclude that the 68-kD isoprenylated protein found in nuclei from [14C]mevalonate-labeled CHO cells is lamin B. …

Borate Rods As An On-Site Remedial Treatment For Control Of Decay In Wood Decks, Mark G. Dietz, Elmer L. Schmidt

Journal of the Minnesota Academy of Science

A conventional wood recreational deck constructed with spruce-pine-fir lumber was sampled for active growth of wood decay fungi before and 10 months after remedial preservation treatment with fused disodium octaborate rods (IMPEL®) at boric acid levels from 1.5-10 kg/m3. Extent of boron distribution was observed with a color indicator dye (curcumin) after 10 months exposure. Remedial treatment with the boron rods. was nearly 100% effective. Active decay cultures from treated material were found only in samples obtained from boards treated at the inhibition dosage level (1.5kg/m3) of boric acid. Suggested lethal dosages (>3kg/m3) were effective in all cases as …

Roles Of A 67-Kda Polypeptide In Reversal Of Protein Synthesis Inhibition In Heme-Deficient Reticulocyte Lysate, Bansidhar Datta, Debopam Chakrabarti, Ananda L. Roy, Naba K. Gupta

Chemistry Department: Faculty Publications

During heme deficiency in reticulocyte lysates, the heme-regulated protein synthesis inhibitor, HRI, phosphorylates the a subunit of eukaryotic initiation factor 2 (eIF-2) and thus inhibits protein synthesis. Two factors, eIF-2 and a reticulocyte-lysate supernatant factor that we term RF, reverse this inhibition. We now report the following. (i) An active eIF-2 preparation contained, in addition to the three subunits (α,β, and γ), a 67-kDa polypeptide. Pretreatment of eIF-2 with polyclonal antibodies against either isolated a subunit or 67-kDa polypeptide almost completely inhibited the reversal activity. Upon further fractionation, three-subunit eIF-2 and the 67-kDa polypeptide were resolved. Neither the …

Incorporation Of A Product Of Mevalonic Acid Metabolism Into Proteins Of Chinese Hamster Ovary Nuclei, Michael Sinensky, L. A. Beck, T. Hosick

Michael Sinensky

We have examined the nuclear localization of isoprenylated proteins in CHO-K1 cells labeled with [14C]mevalonate. Nuclear proteins of 68, 70, and 74 kD, posttranslationally modified by an isoprenoid, are also components of a nuclear matrix-intermediate filament preparation from CHO cells. Furthermore, the 68-, 70-, and 74-kD isoprenylated polypeptides are immunoprecipitated from cell extracts with two different anti-lamin antisera. Based on exact two-dimensional comigration with lamin B, both from rat liver lamin and CHO nuclear matrix-intermediate filament preparations, and its immunoprecipitation with anti-lamin antisera, we conclude that the 68-kD isoprenylated protein found in nuclei from [14C]mevalonate-labeled CHO cells is lamin B. …

Projectile-Charge Dependence Of Ejected-Electron Spectra, V. D. Irby, Timothy James Gay, Jimmie Garwin Edwards, Edward Boyd Hale, M. L. Mckenzie, Ronald E. Olson

Physics Faculty Research & Creative Works

We have studied H⁺+He and He⁺+3+He ionizing collisions at intermediate energies (60 to 120 keV/amu) and have observed a significant shift in the velocity position of the maxima in forward-ejected electron spectra when changing projectiles from protons to particles. In ionizing collisions, a large portion of the ejected electrons are stranded near the transitory equiforce, or saddle point, position between the target ion and receding projectile. The shift in the electron spectra maxima to smaller velocities, due to changing projectiles from protons to particles, is consistent with the shift in the saddle-point velocity when the projectile …

New Synthetic Transformations Of 1-Benzyl, 3,5-Dibromo, 1h-1,2,4-Triazole /C, Adam Michael Fivush

Retrospective Theses and Dissertations

This report details the study of the nucleophilic substitution of 1-benzyl-3,5-dibromo-lH-1,2,4-triazole. A variety of nucleophiles have been studied to date. The nucleophiles studied primarily fall into the categories of Phosphorous, Oxygen and Sul fur species. Some of the initially formed substitution products are thermally unstable and undergo unique rearrangements. The report describes the physical properties, 1H NMR, 13c NMR, IR and Mass spectra for all of the synthesized compounds. Possible mechanistic pathways are presented for the formation of the prepared compounds. Recommendations are made in order to suggest future research opportunities in this area.

Determination Of Tributyltin In The Marine-Environment, Rg Huggett, Michael A. Unger, Fa Espourteille, Cd Rice

VIMS Articles

Tributyltin (TBT) is a biocide used in antifouling paints to protect hulls from nuisance organisms such as barnacles, worms and algae. The use of TBT paints has increased over the past decade due to its effectiveness as an antifoulant which is related to its toxicity. Water concentrations of less than 100 ng L- have been shown to harm some aquatic species in laboratory tests and observations in the natural environment indicate that levels below 10 ng L- may be harmful. Tributyltin is bioconcentrated by many species to levels of one thousand, or more, times ambient water concentrations. Sediment-water partitioning coefficients …

Fuel Efficiency Automobile Testing (F.E.A.T.), Donald H. Stedman, Gary A. Bishop, James A. Armstrong, Jackie Maddox

Fuel Efficiency Automobile Test Publications

No abstract provided.

An Ab Initio Investigation Of The Stabilization Of Selected Β-Substituted Ethyl Cations And Α-Substituted Methyl Cations, Julia C. White, Robert J. Cave, Ernest R. Davidson

All HMC Faculty Publications and Research

In this study, we calculate the stabilization of β-substituted ethyl cations (R = H, Li, BeH, BH_2, CH_3, NH_2, OH, F, Na, MgH, AlH_2, SiH_3, PH_2, SH, Cl) and α-substituted methyl cations (R = H, Li, CH_3, NH_2, OH, F, Na, SiH_3, PH_2, SH, Cl) in order to obtain a relationship between the nature of the substituent and the degree of stabilization of the cation. Results show that the stabilization energy is related to the electronegativity of the β substituents, but not the α substituents. The rotational barrier of the β-substituted ethyl cation is linearly related to the Mulliken population …

Ab Initio Investigation Of Several Low-Lying States Of All-Trans Octatetraene, Robert J. Cave, Ernest R. Davidson

All HMC Faculty Publications and Research

The results of ab initio calculations that examine vertical and nonvertical transitions to several low-lying states of all-trans-octatetraene are presented. It is found that the lowest vertical excitation is to a valence π → π* ¹B_u state, and the nominally doubly excited 2¹A_g state occurs approximately 0.4 eV higher at the geometry of the ground state. Using estimated excited-state equilibrium geometries, we find that the 2¹A_g state is indeed the lowest singlet excited state, having a 0-0 tarnsition energy of 4.15 eV. The 0-0 transition energy for the 1¹B_u state is calculated to be 4.56 eV. The present results …

A Theoretical Investigation Of Several Low-Lying States Of Trans, Trans-1,3,5-Hexatriene, Robert J. Cave, Ernest R. Davidson

All HMC Faculty Publications and Research

Results from ab initio calculations concerning several low-lying electronic states of trans,trans-1,3,5-hexatriene are presented and compared with experimental and previous theoretical results. The lowest excited singlet state is predicted to be the ¹B_u state, having essentially valencelike π → π* character. The nominally doubly excited 2¹A_g state is found to lie approximately 0.6-0.9 eV above the 1¹B_u state. Results are also presented for several Rydberg states. The implications of the present results for current parametrizations of semiempirical π molecular orbital schemes are discussed.

Evaluation Of Dye-Micelle Binding Constants Using Diffusion Sensitive Band Broadening Effects, Daniel W. Armstrong, R. A. Menges, S. M. Han

Chemistry Faculty Research & Creative Works

The diffusion coefficients of small solutes can be significantly altered by the presence of association colloids such as micelles. A relationship is utilized that relates the diffusion coefficient of a solute to its partitioning or binding behavior to a micellar pseudo phase. The Taylor-Aris dispersion method was used to evaluate the diffusion coefficient of several dyes in the presence and absence of sodium dodecyl sulfate micelles. With this approach, all binding constants can be determined easily and reproducibly. The theory, experimental approach, and advantages of this technique are discussed. © 1988.

The Stroke Data Bank: Design, Methods, And Baseline Characteristics, Mary A. Foulkes, Philip A. Wolf, Thomas R. Price, J. P. Mohr, Daniel B. Hier

Chemistry Faculty Research & Creative Works

The National Institute of Neurological and Communicative Disorders and Stroke Initiated the Stroke Data Bank, which is a Multicenter Project to Prospectively Collect Data on the Clinical Course and Sequelae of Stroke. Additional Objectives Were to Provide Information that Would Enable a Standard Diagnostic Clinical Evaluation, to Identify Prognostic Factors, and to Provide Planning Data for Future Studies. a Brief Description of the Structure and Methods Precede the Baseline Characterization of 1,805 Patients Enrolled in the Stroke Data Bank between July 1983 and June 1986. Two Thirds of These Patients Were Admitted within 24 Hours after Stroke Onset. Medical History, …

A Study Of Surface Dynamics Of Polymers. Ii. Investigation By Plasma Surface Implantation Of Fluorine–Containing Moieties, T. Yasuda, T. Okuno, K. Yoshida, H. Yasuda

Chemistry Faculty Research & Creative Works

Macromolecules at the surface of a polymeric solid have considerable mobility, and the specific arrangement of functional groups of macromolecules at the surface is dictated by the environmental conditions in which the surface is placed. Consequently, the change of environmental conditions, such as immersion in water or placement in a biological surrounding, could cause a considerable degree of change in the surface characteristics of a polymer from those evaluated in the laboratory against ambient air. The mobile nature of a polymer surface can be investigated by surface‐implanting fluorine‐containing moieties, mainly—CF3, by the plasma implantation technique and following the disappearance and …

A Study Of Surface Dynamics Of Polymers. Iii. Surface Dynamic Stabilization By Plasma Polymerization, T. Yasuda, K. Yoshida, T. Okuno, H. Yasuda

Chemistry Faculty Research & Creative Works

As demonstrated in Part II of this series of studies, the hydrophobic character of CF4 plasma‐treated Nylon 6 and poly (ethylene terephthalate) (PET) decay with time of water immersion, and the rate of decay can be used as a measure for the surface mobility of (substrate) polymers. The same method of using fluorine‐containing moieties introduced by CF4 plasma treatment as surface labeling is applied to investigate the influence of a thin layer of plasma polymer of methane applied onto the surface of those polymers. An ultrathin layer of plasma polymer provides a barrier to the rotational and diffusional migration of …

Dryland Pasture Legume Programme, C. K. Revell, G. Croker, J. Simmons, L. Heinrich

Experimental Summaries - Plant Research

1. Medic variety evaluation

a. Row Evaluation - 88ME122 - Merredin.
This method of assessment was used to test a range of new medic material originating from the South Australian Department of Agriculture.

b. Evaluation of burr medics on Morrel soils. - 88ME84 - Nokaning.

c. Evaluation of burr medics on Whitegum soils. 88ME85 - North Kellerberrin.

d. Evaluation of Santiago in low rainfall areas - 88ME86 - Mukinbudin.

e. Selection of early maturing M. murex. 88SC30 - Merredin.

f. Medic species evaluation - large plots. 88NO88 - Tammin.

g. Medic species evaluation - large plots. 85M43 - Merredin Research …

I. Evaluation Of Iron Whiskers And Stainless Steel Microwaves As Catalysts For Ammonia Synthesis Ii. Hydrodechlorination Of Chloralkanes On Iron Whisker Catalysts, Diane Kaefer-Northcott

Retrospective Theses and Dissertations

This report consists of two parts. Part I concerns the evaluation of stainless steel microwires and iron whiskers, as catalysts for ammonia synthesis. Several comparison catalysts were also evaluated for their catalytic ability for ammonia synthesis. The effect of potassium promotion on filament and comparison catalysts was determined.

Part II concerns the evaluation of iron whisker catalysts with regard to their catalytic ability for their hydroechlorination fo chloroalkanes. The chloroalkanes that were used in the hydroechlorination reactions were carbon tetrachlorida, chloroform, methylene chloride, and 1, 1, 1-trichloroethane. The hydroechlorination reactions were conducted in the gas phase, either in the prsence …