Physical Sciences and Mathematics Commons^™

Computer Simulation Of The Melting Process In Linear Macromolecules, Donald W. Noid, George A. Pfeffer, Stephen Z.D. Cheng, Bernhard Wunderlich

Chemistry Faculty Publications

Polymer crystal melting kinetics is simulated by using molecular dynamics. A simplified molecular model of polyethylene crystal melting consisting of one extended chain on a polyethylene-like crystal surface is presented. The simulation data indicate that the end-to-end distance (eed) of radius of gyration (rg) has a simple exponential dependence on time. The rate constants for eed and rg are found to be temperature and molecular length dependent. A more detailed analysis of polymer crystal melting will be described.

Unexpected Products From The Reactions Of 1-(Bromodifluoromethyl)-2-(Bromoalkanes With Potassium Hydroxide,Characterization Of Some Gen-Difluorodienes And Attempted Syntheses Of Gem-Difluorocyclopropanes, Mariana Michael

Retrospective Theses and Dissertations

This research report discusses the reactions of CF2Br2 with various alkenes. Attempts to synthesize some gemdifluorocyclopropanes from alkenes and CF2x2 (X=Br, I) by modified Simmons-Smith procedures were Dehydrohalogenation reactions of some not successful. 1,3-dibromo-1,1- difluoroalkanes were conducted with potassium hydroxide or tributylamine. Heating cis or trans 1-(bromodifluoromethyl)- 2-bromocyclohexane with potassium hydroxide does not produce the expected gem-difluorodienes but instead gives the corresponding a,$ -unsaturated carboxylic acid. The mechanism for the productions of the various reaction intermediates from the reaction of the cyclic dibromide with potassium hydoxide is proposed. Experimental evidence supporting the proposed mechanism is presented. Gemdifluorodienes are isolated when …

Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1987. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.

Vibrational Frequencies And Intensities Of H‐Bonded And Li‐Bonded Complexes. H3n⋅⋅Hcl And H3n⋅⋅Licl, M. M. Szczesniak, I. J. Kurnig, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The geometries, energetics, and vibrational spectra are calculated for the two complexes at the SCF and correlated MP2 levels using the 6‐31G∗∗ basis set, augmented by a second set of d functions on Cl. While correlation represents an important factor in the binding of H₃ N⋅⋅HCl, it contributes little to the stronger Li bond. Unlike the HCl stretch ν_s which decreases substantially in frequency and is greatly intensified in H₃ N⋅⋅HCl, the frequency of the LiCl stretch undergoes an increase and little change is noted in its intensity, conforming to prior spectral measurements. The intensities of the …

Ni(Ii) (Dioxo[16]Anen5)-Induced Methane Formation From Methyl Coenzyme M, Charles Michael Drain, Barry B. Cordon, David B. Sable

Publications and Research

The nickel tetrapyrrole containing factor, F430, is implicated in the final methane evolution step in methanogenic ba~terial-~ and has attracted considerable a t t e n t i ~ n . ~T- ~he essential role of F430 in methane formation was demonstrated by Ankel-Fuchs and Thauer, who reported the in vitro catalysis of H3CSCH2CH2S03-, methyl coenzyme M (methyl-CoM), to methane and CoM by purified methyl-CoM reductase under reducing condit i o n ~ .S~in ce F,,o exists in both the Ni(1) (or Ni(II1)) and the Ni(I1) states in Methanobacterium thermoautotrophicum,loi,t ll is of interest to examine the role of the …

Vibrational Frequencies And Intensities Of H‐Bonded And Li‐Bonded Complexes. H3n⋅⋅Hcl And H3n⋅⋅Licl, M. M. Szczesniak, I. J. Kurnig, Steve Scheiner

Steve Scheiner

The geometries, energetics, and vibrational spectra are calculated for the two complexes at the SCF and correlated MP2 levels using the 6‐31G∗∗ basis set, augmented by a second set of d functions on Cl. While correlation represents an important factor in the binding of H₃ N⋅⋅HCl, it contributes little to the stronger Li bond. Unlike the HCl stretch ν_s which decreases substantially in frequency and is greatly intensified in H₃ N⋅⋅HCl, the frequency of the LiCl stretch undergoes an increase and little change is noted in its intensity, conforming to prior spectral measurements. The intensities of the …

Optimized Spectroscopic Signal Estimates Using Integration And Matched Filters, Stephen E. Bialkowski

Stephen E. Bialkowski

This paper examines theories of signal processing as applied to peak magnitude estimation in absorption and emission spectroscopy. Signals obtained from Fourier transform, fixed wavelength, and scanning dispersive instruments are modeled in terms of the time required to obtain a spectrum. The differences between these techniques and the signal processing procedures that should be used for each technique are characterized for a Lorentzian spectral feature. Including the time required to scan over a range of optical frequencies results in optimal signal processing procedures that are different from those previously supposed. In particular, it is found that the optimal matched filter …

The Synthesis Of Quinone-Capped Cyclodextrins, Michael Vernie Cossette

Dissertations, Theses, and Masters Projects

No abstract provided.

Highly Selective Protein Separations With Reversed Micellar Liquid Membranes, Daniel W. Armstrong, Weiyong Li

Chemistry Faculty Research & Creative Works

No abstract provided.

Development Of Solid Substrate Luminescence And Chromatographic Techniques For Chemical Analysis, William J. Long

Theses and Dissertations

Room Temperature Phosphorimetry (RTP) is a sensitive and selective technique which is well suited to the analysis of compounds of environmental and pharmaceutical interests. Absolute sensitivity is generally in the low to subnanograrn range. Selectivity of this technique is due to the fact that only several hundred compounds phosphoresce at room temperature. In these studies attempts are made to gain a greater understanding of the phenomenon of solid substrate room temperature phosphorimetry and to extend the application range of the technique.

This goal is approached through several directions, all leading to a greater understanding of solid substrate luminescence in general, …

Electrochemical And Surface Enhanced Resonance Raman Study Of Heme Proteins At Bare Metal Electrodes, David Edward Reed

Theses and Dissertations

Direct heterogeneous electron transfer reactions between horse heart cytochrome g_and silver electrodes were investigated by electrochemical and spectroelectrochemical methods. The kinetics of these reactions were established as being quasi-reversible, with a formal heterogeneous rate constant (k°'s,h) ranging between 0.18 - 1.5 x 10^-3 cm/s, for both polished and electrochemically roughened silver surfaces. Such reactions were stable and reproducible for over ten hours at room temperature. These results clearly demonstrate that neither electrode surface modification nor the inclusion of mediators is necessary to study electron transfer reactions of heme proteins at metal electrodes.

A crucial factor in obtaining the quasi-reversible …

Medium Resolution Atmospheric Pressure Ionization Mass Spectrometer, Andrew H. Grange, Robert J. O'Brien, Douglas F. Barofsky

Chemistry Faculty Publications and Presentations

An atmospheric pressure ionization (API) source for a VG 7070E‐HF mass spectrometer has been built and successfully operated at an accelerating potential of 6 kV. Hydrated protons and hydrated organic ions formed in the API source can be either partially or completely disaggregated by collisionally induced dissociation before entering the mass analyzer. The protonated molecular ions of pinacolone and 2,4‐pentanedione can be fully separated (R=2800, m/z 101,

Analytical Chemistry Applications Of Synchrotron Radiation, Juana Acrivos

Faculty Publications, Chemistry

Lecture given at the University of California at Berkeley as NSF Woman Chemistry Professor.

Power Absorption Of Y1ba2cu307-G From 2 To 8 Mhz Near Zero Fields, Juana Acrivos

Faculty Publications, Chemistry

We have prepared compounds with the nominal composition Y1Ba2Cu307-s (6->0, usually identified by the Y,Ba,cu stoichiometry: (1,2,3) and have characterized the materials (in addition to the usual X-ray diffraction and fluorescence) by EMF measurements in the electrochemical cell: Cu/CuBr2 (0.05 Min methanol)/(1,2,3)/Cu or Pt versus temperature from 298 to 150 K. The superconducting transition temperatures were determined using the Meissner effect: in static magnetic fields by weight changes and, in radio frequency fields from 2 to 8 MHz by the power absorption near magnetic fields H = o. The observation of structure in the rf signals near H = …

Theoretical Vibrational Study Of The Fx⋅⋅⋅O(Ch3)2 Hydrogen‐Bonded Complex, Y. Bouteiller, C. Mijoule, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

This paper presents the first ab initio attempt to reconstruct the observed band profile of the stretching fundamental v_FX (X=H,D) in the FX⋅⋅⋅O(CH₃)₂ hydrogen‐bonded system. The two‐dimensional potential energy surface V(r_FH,R_F⋅⋅⋅O) is evaluated by means of large basis set SCF calculations. The related force constants up to the fourth order are obtained via the analytical fit to a polynomial expansion. The vibrational problem is solved by means of a variational treatment which includes the effects of mechanical anharmonicity. The side bands of the …

Linked Beta-Cyclodextrins, Richard Desider Nemeth

Dissertations, Theses, and Masters Projects

No abstract provided.

Cyclic Ether Synthesis Via Lewis Acid Promoted Carbon-Carbon Bond Forming Cyclization Reactions Of Unsaturated And Saturated Symmetric Acetals, Elizabeth Gonda

Dissertations, Theses, and Masters Projects

No abstract provided.

The Development And Application Of A Helium Discharge Detector For Gas Chromatography, Margaret Laverne Ware

Dissertations, Theses, and Masters Projects

No abstract provided.

Coal Desulfurization Using Pyrite Conversion Through Dielectric Heating, Daniel C. Cleaveland

Masters Theses

The Illinois State Geological Survey is currently developing a three step coal desulfurization process which depends upon the in-situ generation of catalytic troilite (FeS) by reduction of the pyrite (FeS₂) present in the mineral fraction of coal. After catalyst generation, ethanol is added to the system and is dehydrogenated to acetaldehyde and hydrogen which removes organic sulfur as hydrogen sulfide. The research reported in this thesis shows that the process can be improved by the use of dielectric heating in place of thermal heating for catalyst generation and perhaps organic sulfur removal. It is found that pyrite reduction …

Characterization Of The Lipopolysaccharides From Rhizobium Phaseoli Symbiotic Mutants, Francisca Garcia

Masters Theses

The lipopolysaccharides (LPSs) of the Rhizobium phaseoli CE3 and its mutants CE109, CE309 and the transconjugate Rhizobium leguminosarum LB2/109.11 were isolated and analyzed by gas chromatography (GC) and ¹H nuclear magnetic resonance (NMR) spectroscopy. CE3 is the wild type strain which is nodulation-proficient (Nod⁺). Strain CE109 and CE309 have a transposon, Tn5, inserted into Region I and Region III of their respetive chromosomes. Mutants CE109 and CE309 are defective in nodule development (Ndv^-). Transconjugate R. leg. LB2/109.11 has the DNA of the R. leg. LB2 wild type and also Region I portion of the CE109 …

Thermal, Mechanical And Interfacial Characterization Of A Fiberglass Reinforced Plastic Composite, Theodore J. Williams

Masters Theses

The effects of a glass fiber reinforcer on the properties of poly(methyl methacrylate) were evaluated. A silane coupling agent (M8550 Petrarch Systems, Inc.) was employed to promote adhesion between the materials. FTIR analysis, ESCA/Auger and SEM techniques were used to characterize the silane coating.

The mechanical properties, such as bending strength, improved with an increase in the volume percent of fiber. The addition of the M8550 silane directly into the monomer solution showed the most improvement, 23 percent increase, when compared to the uncoated glass fiber. The glass transition temperature as measured by DSC and the heat distortion temperature (HDT) …

Ion-Association Complexes Of Thallium And Mercury With Rhodamine 6g In Aqueous Solution, Nasrein El-Masri

University of the Pacific Theses and Dissertations

The present study involves the determination of traces of thallium and mercury in aqueous solution by forming ion-association complexes of these metals with rhodamine 6G (R6G) in the presence of iodide. Thallium(lll) and mercury(Il) are able to quench the fluorescence of R6G in the presence of iodide by forming ion—association complexes, and the degree of quenching correlates with the thallium(III) or mercury(II) concentrations . By using this method, the minimum amount of thallium- (III) that can be determined in aqueous solutions is approximately 4.00 X 10-6m, while the minimum amount of mercury(II) is approximately 3.00 X 10-6m. Thallium(I) cannot be …

Studies On The Effect Of Palmitylcarnitine Chloride On The Solubility Of Etoposide, Lola Kashyap

University of the Pacific Theses and Dissertations

The effect of an endoqenous surfactant, palmitylcarnitine chloride (PCC), on the solubility of etoposide was investigated. Preliminary studies were conducted to establish optimum experimental conditions for subsequent equilibrium solubility determinations. Infrared spectroscopy and thin layer chromatography techniques were used to establish the purity and identity of PCC. PCC was found to undergo rapid hydrolysis in aqueous solutions at 37.0° ± 0.5° C and the degradation was independent of concentration. The effect of pH on the stability of PCC was investigated. These studies revealed that PCC was most stable in the range pH 3.0 - 4.0. Etoposide was found to be …

Influence Of Dna On The Rate Of Porphyrin Metallation, Robert F. Pasternack, E. J. Gibbs, R. Santucci, Stephanie A. Schaertel , '86, Panayiotis A. Ellinas , '87, Stanley C. Mah , '87

Chemistry & Biochemistry Faculty Works

Poly(dG–dC)₂ and poly(dA–dT)₂ have marked influences on the rate of insertion of copper(II) into cationic porphyrins reflecting the interaction mode of the porphyrin with the nucleic acid.

Comment On ‘‘Relations Between Microscopic And Macroscopic Lowest-Order Optical Nonlinearities Of Molecular Crystals With One- Or Two-Dimensional Units’’, K.M. White, Craig J. Eckhardt

Craig J. Eckhardt Publications

An algebraic error in an earlier paper [J. Zyss and J. L. Oudar, Phys. Rev. A 26, 2028 (1982)] led to an interpretation regarding the desirable polarizability characteristics of a molecule for second-harmonic generation in crystals which is opposite to that actually desired. Optimum response is obtained from crystals comprised of molecules with significant in-plane polarizabilities.

“Macromolecules 86": An International Conference On Functional Polymers And Biopolymers, Otto Vogl, Geoffrey C. Eastmond

Otto Vogl

No abstract provided.

University Of Missouri-Rolla Cloud Simulation Facility: Proto Ii Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, Alfred R. Hopkins, Max B. Trueblood, Max W. Alcorn, William L. Walker

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Graduate Center for Cloud Physics Research at UMR Has Developed a Cloud Simulation Facility to Study Phenomena Occurring in Terrestrial Clouds and Fogs. the Facility Consists of a Pair of Precision Cooled-Wall Expansion Chambers Along with Extensive Supporting Equipment. the Smaller of These Chambers, Described in This Article, is Fully Operational, and is Capable of Simulating a Broad Range of In-Cloud Thermodynamic Conditions. It is Currently Being Used to Study Water Drop Growth and Evaporation for Drops Nucleated (Activated) on Well-Characterized Aerosol Particles. Measurements Have Been Made Not Only for Continuous Expansions (Simulated Updraft) But Also for Cyclic Conditions, …

Kinetics Of The Metal-Exchange Reaction Between N-(2-Pyridylmethyl)Iminodiacetatonickel(N) And Copper(Ii), Kassahun W. Beyene

Masters Theses

The reaction between N-(2-pyridylmethyl)iminodiacetatonickel(II) and copper(II) was studied spectrophotometrically between pH 2.30 and 3.30 over a 10-fold variation in copper concentration at an ionic strength of 1.25M, and a temperature of 25.0+0.1^oC. The reaction is first order in both NiPyIDA and copper(II). Terms involving proton attack and a copper dependent dissociation of the nickel complex were resolved from the data. Evidence is given for a stepwise unwrapping mechanism PyIDA from the nickel complex, followed by copper attack to give a dinuclear intermediate. A general mechanism is presented which is consistent with the kinetic data.

Comparisons to analogous nickel-aliphatic …

River Discharge Study, Laughlin, Nevada: Field Survey Data, 1987, B. Dennis Hugh, David L. Stringfield, Jill C. Bicknell, Robert A. Ryder, Clark County Sanitation District, Nevada

Publications (WR)

A report of the first field data collection effort for the Laughlin River Discharge Study, conducted by Kennedy/Jenks/ChiIton in February, 1987, on the Mohave Reach of the Colorado River. This report also serves to transmit the laboratory analysis reports for all of the analyses performed and summary tables of the results.

This report is organized as follows:

1. Field Conditions and Methodology

2. Summary of Sampling and Analysis Results

3. Deviations from the Proposed Sampling Program

4. Recommendations for Future Sampling

5. Attachments:

A. Climatological Data

B. Davis Dam Average Hourly Releases

C. Laboratory Analysis Reports

Investigation Of The Synthesis And Polymerization Behavior Of Vinyl Benzoate, Selim Mehmet Erhan

Dissertations

The goal of this study is to present a method that gives higher conversions and molecular weights for the polymerization of vinyl benzoate than obtained in previous investigations.

Polyvinyl benzoate has benzene rings attached to the backbone chain, therefore is hard and rigid. This is a characteristic which has a large application area. However previous studies in polymerizing vinyl benzoate with bulk and solution polymerizations reported low yields and troublesome crosslinking, which has limited its application. Emulsion polymerization method has the advantage of giving high polymerization rates together with high molecular weights, and therefore was chosen as the method for …