Chemistry Commons^™

Chemical Imaging Comes Of Age, John F. Turner Ii

Chemistry Faculty Publications

Sophisticated analysis techniques allow researchers to extract meaningful results from spectral imaging data.

Effect Of Kraft Pulping On Oxygen Delignification, Haixuan Zou

Electronic Theses and Dissertations

The objective of the study reported here was to investigate experimentally the effect of the major Kraft pulping variables on the response of brownstock pulps to medium consistency oxygen delignification. Kraft pulping was performed on mixed Northeastern hardwood chips in a laboratory rocking digester. Kraft pulps of kappa number 16 and 20 mL KMnO₄ were produced by pulping under a variety of conditions. The effective alkali (EA) charged to the digester was varied over the range of 12 to 21% while the sodium sulfide content of the pulping liquor was varied between 0 to 30% sulfidity. Cooking temperatures of …

Dna Polymerase Iii Holoenzyme From Thermus Thermophilus Identification Expression Purification Of Components And Use To Reconstitute A Processive Replicase, James M. Bullard, Jennifer C. Williams, Wendy K. Acker, Carsten Jacobi, Nebojsa Janjic, Charles S. Mchenry

Chemistry Faculty Publications and Presentations

DNA replication in bacteria is performed by a specialized multicomponent replicase, the DNA polymerase III holoenzyme, that consist of three essential components: a polymerase, the β sliding clamp processivity factor, and the DnaX complex clamp-loader. We report here the assembly of the minimal functional holoenzyme from Thermus thermophilus (Tth), an extreme thermophile. The minimal holoenzyme consists of α (pol III catalytic subunit), β (sliding clamp processivity factor), and the essential DnaX (τ/γ), δ and δ′ components of the DnaX complex. We show with purified recombinant proteins that these five components are required for rapid and processive DNA synthesis …

Molecular Dynamics Simulation Of Sodium Dodecyl Sulfate Micelle In Water: Micellar Structural Characteristics And Counterion Distribution, Chrystal Bruce, Max Berkowitz, Lalith Perera, Malcolm Forbes

Chrystal D. Bruce

An all-atom 5 nanosecond molecular dynamics simulation of a water-solvated micelle containing 60 sodium dodecyl sulfate monomers was performed. Structural properties such as the radius of gyration, eccentricity, micellar size, accessible surface area, dihedral angle distribution, carbon atom distribution, and the orientation of the monomers toward the micelle center of mass were evaluated. The results indicate a stable micellar system over the duration of the simulation. Evaluation of the structure and motion of the sodium counterions show (1) a long equilibration time (1 nanosecond) is required to achieve a stable distribution of counterions and (2) approximately 25% of the sodium …

Chiral Discrimination In Cyclodextrin Complexes Of Amino Acid Derivatives: Β-Cyclodextrin/N-Acetyl-L-Phenylalanine And N-Acetyl-D Phenylalanine Complexes, Jennifer M. Alexander, Joanna L. Clark, Tom J. Brett, John J. Stezowski

John J. Stezowski Publications

In a systematic study of molecular recognition of amino acid derivatives in solid-state β-cyclodextrin (β-CD) complexes, we have determined crystal structures for complexes of β-cyclodextrin/N -acetyl-L-phenylalanine at 298 and 20 K and for N-acetyl-D-phenylalanine at 298 K. The crystal structures for the N-acetyl-L-phenylalanine complex present disordered inclusion complexes for which the distribution of guest molecules at room temperature is not resolvable; however, they can be located with considerable confidence at low temperature. In contrast, the complex with N-acetyl-D-phenylalanine is well ordered at room temperature. The latter complex presents an example of a complex in this series …

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quarterly Report, William Culbreth, Pang Tao

Separations Campaign (TRP)

During the first two quarters of the work, the tasks included training students in the use of Monte Carlo codes used in radiation transport studies and the assessment of neutron multiplication factors for specific problems outlined by ANL-East through Drs. Laidler and Vandegrift.

The proposal also included objectives for the first year of work on this project, as listed below. The work conducted in the second quarter of the project was in partial completion of these objectives.

• Train UNLV students in the use of SCALE and/or MCNP for the assessment of nuclear criticality.

• Assess neutron multiplication factor, k …

Footprinting And Circular Dichroism Studies On Paromomycin Binding To The Packaging Region Of Human Immunodeficiency Virus Type-1, Mark P. Mcpike, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

We have studied the interaction of the aminoglycoside drug, paromomycin, with a 171-mer from the packaging region of HIV-1 (ψ-RNA), using quantitative footprinting and circular dichroism spectroscopy. The footprinting autoradiographic data were obtained by cutting end-labeled RNA with RNase I or RNase T1 in the presence of varying paromomycin concentrations. Scanning the autoradiograms produced footprinting plots showing cleavage intensities for specific sites on the ψ-RNA as functions of drug concentration. Footprinting plots showing binding were analyzed using a two-state model to give apparent binding constants for specific sites of the ψ-RNA. These plots show that the highest-affinity paromomycin binding site …

A Three-Domain Structure For The Delta Subunit Of The Dna Polymerase Iii Holoenzyme Delta Domain Iii Binds Delta' And Assembles Into The Dnax Complex, James M. Bullard, Arthur E. Pritchard, Min Sun Song, Bradley P. Glover, Anna Wieczorek, Joe Chen, Nebojsa Janjic, Charles S. Mchenry

Chemistry Faculty Publications and Presentations

Using ψ-BLAST, we have developed a method for identifying the poorly conserved δ subunit of the DNA polymerase III holoenzyme from all sequenced bacteria. This approach, starting withEscherichia coli δ, leads not only to the identification of δ but also to the DnaX and δ′ subunits of the DnaX complex and other AAA⁺-class ATPases. This suggests that, although not an ATPase, δ is related structurally to the other subunits of the DnaX complex that loads the β sliding clamp processivity factor onto DNA. To test this prediction, we aligned δ sequences with those of δ′ and, using …

Method Of Solubilizing Unshortened Carbon Nanotubes In Organic Solutions, Robert C. Haddon, Jian Chen, Mark A. Hamon

Chemistry Faculty Patents

Naked carbon nanotubes are dissolved in organic solutions by terminating the nanotubes with carboxylic acid groups and attaching an aliphatic carbon chain so as to render the carbon nanotubes soluble.

Applications Of Nmr To Structure-Based Drug Design In Structural Genomics, Robert Powers

Robert Powers Publications

Structural genomics is poised to have a tremendous impact on traditional structure-based drug design programs. As a result, there is a growing need to obtain rapid structural information in a reliable form that is amenable to rational drug design. In this manner, NMR has been expanding and evolving its role in aiding the design process. A variety of NMR methodologies that cover a range of inherent resolution are described in the context of structure-based drug design in the era of structural genomics.

Kink-Based Path Integral Calculations Of Atoms He-Ne, Randall W. Hall

Collected Faculty and Staff Scholarship

An adaptive, kink-based path integral formalism is used to calculate the ground state energies of the atoms He–Ne. The method uses an adaptive scheme to virtually eliminate the sign difficulties. This is done by using a Monte Carlo scheme to identify states that contribute significantly to the canonical partition function and then include them in the wavefunctions to calculate the canonical averages. The calculations use the 6-31G basis set and obtain both precision and accuracy.

The Southern African Regional Science Initiative (Safari 2000): Overview Of The Dry Season Field Campaign, R. J. Swap, H. J. Annegarn, J. T. Suttles, J. Haywood, M. C. Helmlinger, C. Hely, Peter V. Hobbs, B. N. Holben, J. Ji, M. D. King, T. Landmann, W. Maenhaut, L. Otter, B. Pak, S. J. Piketh, S. Platnick, J. Privette, D. Roy, A. M. Thompson, Darold E. Ward, Robert J. Yokelson

Chemistry and Biochemistry Faculty Publications

The Southern African Regional Science Initiative (SAFARI 2000) is an international science project investigating the earth-atmosphere-human system in southern Africa. The programme was conducted over a two-year period from March 1999 to March 2001. The dry season field campaign (August-September 2000) was the most intensive activity and involved over 200 scientists from eighteen countries. The main objectives were to characterize and quantify biogenic, pyrogenic and anthropogenic aerosol and trace gas emissions and their transport and transformations in the atmosphere, and to validate NASA's Earth Observing System's satellite Terra within a scientific context. Five aircraft - two South African Weather Service …

A New Layered Iron Fluorophosphates, Amitava Choudhury

Chemistry Faculty Research & Creative Works

A new iron fluorophosphate of the composition, [C₆N₄H₂₁] [Fe₂F₂(HPO₄)₃][H₂PO₄]·2H₂O, I. has been prepared by the hydrothermal route. This compound contains iron fluorophosphate layers and the H₂PO₄^- anions are present in the interlayer space along with the protonated amine and water molecules. The compound crystallizes in the monoclinic space group P2₁/c. (a = 13.4422(10) Å, b = 9.7320(10) Å, c = 18.3123(3) Å, ? = 92.1480°, V = 2393.92(5) ų, Z = 4, …

Separation Of Enantiomers With Chiral Dendrimer, Jie Zhuang

Masters Theses

Chiral dendrimers with .unique ordered structures are especially attractive for the recognition of chiral molecules based on the three point contact model. We have successfully synthesized first generation chiral dendrimers containing L- and D- tryptophan methyl ester moieties and characterized them by NMR, IR, UV-Visible, MS, and optical activity. L-tryptophan methyl ester dendrimer was converted to its acid form in order to attach it to aminopropyl silica for the HPLC separation of enantiomers. The aminopropyl silica containing 1.52mmols/g of NH₂ groups binds about 0.3mmols of dendrimer per gram and has about 0.4mmols of free NH₂ groups per gram. …

Production Of A Monoclonal Antibody Against Benzo[Α]Pyrene Diol Epoxide Dna Adducts, Brian Peden Austin

Chemistry & Biochemistry Theses & Dissertations

Benzo[α]pyrene is a ubiquitous pollutant produced from the incomplete combustion of organic material such as fossil fuels. It is found in the workplace, urban air, drinking water, and the food supply. Recently, it has been proposed that benzo[α]pyrene may be the causative agent in the formation of lung adenocarcinomas among some Taiwanese women exposed to cooking oil fumes without adequate ventilation. In this study, calf thymus DNA was modified in vitro with benzo[α]pyrene-diol epoxide (BPDE) to a level consistent with that found in biological samples. This DNA of low modification was used as an immunogen in the production of a …

Styrene Monomer Solubility In Artificial And Natural Seawaters Of The Lower Chesapeake Bay, Eric Joseph Miller

Chemistry & Biochemistry Theses & Dissertations

Used for making a variety of plastic products, styrene monomer is an aromatic hydrocarbon frequently shipped in bulk quantities through the Port of Hampton Roads, Virginia. Despite its common use around the world and its high aquatic toxicity, little research has been conducted on the chemical's aqueous solubility and reactions during a major spill. In this study, the solubility of styrene monomer was measured in artificial seawater and natural waters collected from four sites on the lower Chesapeake Bay and Elizabeth River. The samples represented a range of different water chemistries in terms of salinity (13.8 — 29.0%) and the …

Scitech News Volume 70, No. 3 (2016)

Sci-Tech News

Table of Contents:

Columns and Reports

From the Editor 3

Division News

Science-Technology Division 4

Chemistry Division 6

Conference Reflections (SPARKS Award Recipient) 12

Engineering Division 14

Engineering Division Awards Report 23

Aerospace Section of the Engineering Division 25

Reviews

Sci-Tech Book News Reviews 26

Adverstisements

IEEE 24

WeBuyBooks.net 28

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report Fourth Quarter (December 2001 To February 2002), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) Director to the U.S. Department of Energy (DOE) as described in the UNLV AAA proposal and Statement of Work for the Fourth Quarter.

The UNLV AAA UPP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies (HRC) to ensure that work conducted under the UNLV AAA UPP meets program objectives. The UNLV AAA program consists of three components: Program Support, Research Infrastructure Augmentation, and Student Research.

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (December 1, 2001 – February 28, 2002) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including HT- 9, EP 823 and 422. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these alloys will be evaluated in environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. The extent and morphology of cracking of these alloys will further be evaluated …

Two-Phase Decay Of Aerobic Sludge Shown By Online Fluorescence And Modeled With Interaction Of Heterotrophs And Nitrifiers, Xu Li, Lu-Kwang Ju

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Both heterotrophs and autotrophic nitrifiers are present in aerobic sludge digestion systems. The endogenous heterotrophic metabolism releases ammonium that, via oxidation to nitrite and nitrate, serves as the energy substrate for growth and survival of nitrifiers. The population interaction was used to explain the two-phase decay behavior observed in this study for the biosolids collected from rotating biological contactors (RBC) as well as the mixed primary and secondary sludge. Separated by an intermediate transition, the two phases followed different first-order decay kinetics, with the first phase being much faster. The two-phase phenomenon was supported by the on-line fluorescence profile monitored …

Third Quarter Report, Covering January Through March 2002, John Farley

Transmutation Sciences Materials (TRP)

Progress from June 2001-November 2001 was presented at the winter meeting of the American Nuclear Society in Reno (November 12-15, 2001), and incorporated into a refereed conference proceeding. A copy of the refereed conference proceeding has been provided to Tony Hechanova. In brief, the paper described the new program to examine the corrosive effects of lead-bismuth eutectic (LBE) on steels. We employed various types of surface studies (Scanning Electron Microscope [SEM], and X-ray Photoelectron Spectrometry [XPS]) to examine steel samples that had been exposed to LBE for various lengths of time at various temperatures. The goal is to understand the …

Inside Unlv, Diane Russell, Betty Blodgett, Kevin Force, Jennifer Vaughan, Cate Weeks, Jonathan Paver

Inside UNLV

No abstract provided.

The Effect Of Reactor Geometry On Frontal Polymerization Spin Modes, John A. Pojman, Jonathan Masere, Enrico Petretto, Mauro Rustici, Do-Sung Huh, Min Suk Kim, Vladimir Volpert

Faculty Publications

Using reactors of different sizes and geometries the dynamics of the frontal polymerization of 1,6-hexanediol diacrylate (HDDA) and pentaerythritol tetraacrylate (PETAC), with ammonium persulfate as the initiator were studied. For this system, the frontal polymerization exhibits complex behavior that depends on the ratio of the monomers. For a particular range of monomers concentration, the polymerization front becomes nonplanar, and spin modes appear. By varying the reactor diameter, we experimentally confirmed the expected shift of the system to a greater number of "hot spots" for larger diameters. For square test tubes a "zig-zag" mode was observed for the first time in …

Polymorphous Transformations In Alkaline-Earth Silicates, Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy

Physics Faculty Publications

Structural phase transitions in Ca₂SiO₄ and Sr₂SiO₄ are investigated by molecular dynamics simulations. The simulations are based on the potentials calculated from the Gordon–Kim modified electron gas formalism extended to molecular ions. We successfully reproduced the transition γ -α’_H and β-α’_L - α’_H - α in Ca₂SiO₄, and the transition β-α’ in Sr₂SiO₄. We find that the α’_L phase of Ca₂SiO₄ is an ax3b x c superstructure of the α’_H phase, while the α’_H phase …

Molecular Dynamics Simulations Of Phase Transition In Agno3, Jianjun Liu, Chun-Gang Duan, M. M. Ossowski, Wai-Ning Mei, Robert W. Smith, J. R. Hardy

Chemistry Faculty Publications

Structural phase transition in AgNO₃ at high temperature is simulated by molecular dynamics. The simulations are based on the potentials calculated from the Gordon–Kim modified electron-gas formalism extended to molecular ionic crystals. AgNO₃ transforms into rhombohedral structure at high temperature and the phase transition is associated with the rotations of the NO₃ ions and displacements of the NO₃ and Ag ions.

An Anion Characterization Of A Constructed Wetland Used For Chlorinated Ethene Remediation, Bradley M. Bugg

Theses and Dissertations

Chlorinated ethenes physical properties as well as its ubiquitous state at DOD installations makes it a priority for innovative remediation efforts. Current techniques are expensive and time consuming to maintain. Constructed wetlands suggest an inexpensive and operational alternative to conventional technologies. Sub-surface flow wetlands provide the anaerobic zones necessary to reduce the recalcitrant chlorinated solvents prior to anaerobic or aerobic mineralization of its daughter products. A vertical flow cell to include sequential sedimentary layers of two hydric soil lifts and a mix of hydric soil and woody compost was the subject of this investigation. This study focused on the statistical …

Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Perchlorate Contaminated Groundwater, Jeffrey C. Parr

Theses and Dissertations

Groundwater contamination by perchlorate has recently been recognized as a significant environmental problem across the United States, and especially at Department of Defense facilities. In this study, a model is used to evaluate the potential of a innovative in situ bioremediation technology using Horizontal Flow Treatment Wells (HFTWs) to manage perchlorate-contaminated groundwater. The technology uses HFTWs to mix an electron donor into perchlorate-contaminated groundwater in order to promote reduction of the perchlorate by indigenous microorganisms in bioactive zones within the aquifer, as well as recirculate the contaminated water between treatment well pairs to achieve multiple passes of contaminated water through …

Determination Of Copper In The Waste Water Of Plating By Chronocoulometry For Flowing Solution, Xin-Hua Lin, Wei Chen

Journal of Electrochemistry

The chronocoulometry for flowing solution was devoloped and applied to the detemination of copper(Ⅱ) in the waste water of plating.The linear range of copper(Ⅱ) was 2～16mg/L,and the relative standard deviation was less than 0.1% ( n =8).The recovery was 98%～103% for copper(Ⅱ) in the waste water.Chronocoulometry for flowing solution overcomed noise disturbance resulting from capacity current and variety of property of electrode surface.This method was sensitive,accurate and well reproducible.

Study On The Viscosity Of Lbg/Acetone Solution Mixed With Different Silica, Sheng-Liang Zhao, Guang-Ming Zhu, Cui-Ying Wang, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

LBG is a copolymer of vinylidene fluoride (VF2) and hexafluorpropylene (HFP), factors that influence the viscosity of the LBG solution such as the shear rate, plasticizer, the content of the fumed silica with different surface treatment are discussed in detail.

Photoelectrochemistry Of La~(3+) Doped Semiconductor Porous Films Sensitized By Ru(Bpy)_2(Ncs)_2 Dye, Li Zhang, Yan-Jie Ren, Sheng-Min Cai

Journal of Electrochemistry

The La 3+ _doped TiO 2 nanoparticles were prepared with hydrothermal method.The photoelectrochemical properties of La 3+ _doped TiO 2 nanoporous_film electrode sensitized by Ru(bpy) 2(NCS) 2 were studied.The conversion efficiency of light to electricity and the energy conversion efficiencies were ineased with the depth of La 3+ _doped TiO 2 nanoporous_film electrode.