Physical Sciences and Mathematics Commons^™

The Advanced Glycation End Product, NE-(Carboxymethyl)Lysine, Is A Product Of Both Lipid Peroxidation And Glycoxidation Reactions, Min-Xin Fu, Jesus R. Requena, Alicia J. Jenkins, Timothy J. Lyons, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Nepsilon-(Carboxymethyl)lysine (CML) is an advanced glycation end product formed on protein by combined nonenzymatic glycation and oxidation (glycoxidation) reactions. We now report that CML is also formed during metal-catalyzed oxidation of polyunsaturated fatty acids in the presence of protein. During copper-catalyzed oxidation in vitro, the CML content of low density lipoprotein increased in concert with conjugated dienes but was independent of the presence of the Amadori compound, fructoselysine, on the protein. CML was also formed in a time-dependent manner in RNase incubated under aerobic conditions in phosphate buffer containing arachidonate or linoleate; only trace amounts of CML were formed from …

Program Abstracts, 108th Session, Iowa Academy Of Science, April 26-27, 1996, Iowa Academy Of Science

Iowa Academy of Science Documents

Presentation abstracts from the annual meeting of the Iowa Academy of Science

The Annual Meeting Of The Iowa Academy Of Science April 26-27, 1996 [Program, 108th Meeting], Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Program Summary --- 4
General Session Speakers --- 7
Awards --- 10
Symposia Programs --- 11
Poster Session --- 13
Map --- Centerfold
Section Programs/Special Sessions --- 15
Agricultural Sciences --- 15
Anthropology --- 16
Botany --- 18
Biology: Cellular, Molecular, & Micro --- 19
Chemistry: Inorganic --- 20
Chemistry: Organic --- 21
Conservation --- 22
Engineering --- 23
Geology --- 24
Linguistics/Psychology --- 25
Physics --- 26
Physiology --- 27
Zoology --- 29
Science Teaching --- 30
Local Arrangements Committee --- 31
Annual Meeting Committee --- 31
IAS Officers & Directors --- 32
Future Meetings --- 32

Pursuit Of A Chiral Amino Aldehyde Intermediate In The Synthesis Of (+)-Obafluorin, A B-Lactone Antibiotic, Jim Cwik '96

Honors Projects

This research is focused on synthesizing a chiral amino aldehyde from L-Serine. The proposed synthesis of the amino aldehyde would yield a stereochemically pure product working through an L-Serine beta-lactone intermediate. The amino aldehyde is a proposed intermediate in the synthesis of (+)-obafluorin, a beta-lactone antibiotic of interest. The proposed synthesis might provide a simpler, more versatile way to synthesize obafluorin.

Fabrication Of Large Arrays Of Micron-Scale Magnetic Features By Selective Area Organometallic Chemical Vapor Deposition, D. Welipitiya, Y.L. He, Jiandi Zhang, P.I. Oden, T. Thundat, R.J. Warmack, Ismail Gobulukoglu, Z.S. Shan, David J. Sellmyer, Peter A. Dowben

Peter Dowben Publications

We demonstrate that it is possible to deposit a wide range of magnetic features, using photoassisted selective area organometallic chemical vapor deposition. Large arrays of identical micron-scale Ni features were deposited on a Si(111) wafer by this method. Their magnetic properties were studied by alternating gradient force magnetometry as well as magnetic force microscopy. Our morphological and magnetic measurements show that the structures are spatially well defined, and the magnetic properties are related to the structural shapes of the features. This method can be adapted to the fabrication of smaller-scale magnetic and electronic devices. ©1996 American Institute of Physics.

Evaluation Of Propane Exploders As White-Tailed Deer Deterrents, J. L. Belant, T. W. Seamans, C.P. Dwyer

United States Department of Agriculture Wildlife Services: Staff Publications

In response to increased white-tailed deer (Odocoileus virginianus) depredation of agricultural crops and encroachment on airports, we evaluated the effectiveness of systematic and motion-activated propane exploders as deer frightening devices. We conducted three experiments in a 2200 ha fenced facility in northern Ohio with high (91/km²) deer densities during 1994-1995. Systematic exploders were calibrated to detonate once at 8 to 10 min intervals, whereas motion-activated exploders detonated 8 times/deer intrusion. Systematic propane exploders were generally ineffective, deterring deer from corn for <2 days only, whereas motion-activated exploders repelled deer for O-6 weeks. Repellency of motion-activated exploders varied seasonally, possibly in response to variations in deer density, availability of alternate food, or reproductive and social behavior. We recommend motion-activated exploders over systematic exploders as deer frightening devices for crop damage mitigation and on airports; however, systematic exploders may have utility for short-term (a few days) use.

Toward An Efficient Method Of Detecting Cocaine Metabolite In Urine, C.J. Summers '96

Honors Projects

The primary metabolite of cocaine is benzoyl ecognine (BE). A desirable method for detecting cocaine use is the extraction of BE from urine into an organic phase solvent and subsequent analysis by High Performance Liquid Chromatography (HPLC). The attempt to develop such a method is hindered by the extreme water solubility of BE, making extraction into an organic phase extremely difficult. The present study attempts to use an ion-pairing agent to bind with BE and form a large, organically soluble ion-pair. The ion pairing agent used was Reinecke Salt in a I% solution. An aqueous solution of 50 ug/mL BE …

Modeling The Effects Of A Phase-Locked Higher Harmonic In Synchronous Sonoluminescence, Aaron Trickey

Honors Capstone Projects and Theses

No abstract provided.

Software Engineering And Hypermedia Application Design: The Classic Life Cycle Vs. Relationship Management Methodology, Stacy Lukins

Honors Capstone Projects and Theses

No abstract provided.

Powerfaids: Building A Road To Financial Aid Efficiency, Lauri Nichols '96

Honors Projects

To most students, the Financial Aid office is a small room in the basement of Holmes Hall where they are occasionally sent to sign over a paper or two. It has something to do with money, and every so often, these students get something in the mail that tells them just how much it's going to cost them to continue their education here at Illinois Wesleyan. They know that papers are filled out, usually by their parents, and then in a couple of months, a figure jumps out of nowhere and becomes "Your Financial Aid Package."

Very High Density Clumps And Outflowing Winds In Qso Broad-Line Regions, J. A. Baldwin, Gary J. Ferland, K. T. Korista, R. F. Carswell, F. Hamann, M. M. Phillips, D. A. Verner, Belinda J. Wilkes, R. E. Williams

Physics and Astronomy Faculty Publications

Intercomparison of the spectra of seven high-luminosity quasi-stellar objects (QSOs) shows that there is a gradation of properties in their broad emission-line regions (BELRs) that can be understood as differing mixtures of different gas components. Six of these seven objects have unusually narrow BELR profiles, which greatly facilitates the disentangling of blends and measuring of weak lines. In the QSO 0207 - 398, the BELR is made up of at least three kinematically distinct components; its spectrum is in fact a composite of the spectra of the more homogeneous BELRs in the QSOs at either end of our sequence of …

High Metal Enrichments In Luminous Quasars, Gary J. Ferland, Jack A. Baldwin, Kirk T. Korista, Fred Hamann, R. F. Carswell, Mark Phillips, Belinda J. Wilkes, Robert E. Williams

Physics and Astronomy Faculty Publications

We discuss observations of the broad emission line in luminous intermediate redshift quasars, with emphasis on Q0207 -398. This object has relatively sharp lines, allowing us to deconvolve the profiles into distinct components. In this paper we examine the high ionization region, which we show must be matter-bounded, partially transparent to ionizing radiation. We measure a large N V λ1240/He II λ1640 ratio in Q0207-398, but detailed calculations predict this ratio to be ~1 for standard cloud properties. We show that no choice of incident continuum, ionizing photon flux, density, or even the appeal to nonradiative energy sources, can reproduce …

The Chemical Enrichment Of Gas In Broad Absorption Line Qsos: Rapid Star Formation In The Early History Of Galaxies, Kirk Korista, Fred Hamann, Jason W. Ferguson, Gary J. Ferland

Physics and Astronomy Faculty Publications

Utilizing spectra from ground-based and Hubble Space Telescope observations, Korista et al. identified at least 12 broad absorption lines in the broad absorption line (BAL) QSO 0226-1024 (z_em = 2.256), many for the first time. In the present paper we use seven of their measured column densities to investigate the BAL gas ionization equilibrium and metallicity. We assume that the metal abundances follow the rapid star formation (RSF) models of Hamann & Ferland or are simply scaled from solar ratios to (1) limit the free parameters in constraining the overall metallicity and (2) test the applicability of such a …

Facile Liquid Chromatographic Enantioresolution Of Native Amino Acids And Peptides Using A Teicoplanin Chiral Stationary Phase, Alain Berthod, Youbang Liu, Christina Bagwill, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

The glycopeptide antibiotic teicoplanin is shown to be a highly effective stationary phase chiral selector for the resolution of underivatized amino-acid and imino-acid enantiomers. Fifty four of these compounds (including all chiral protein amino acids) as well as a number of dipeptides were resolved. Hydro-organic mobile phases are used and no buffers or added salts are needed in most cases. Hence the purified analytes are easily isolated in pure form, if needed, by evaporating of the solvent. The effect of pH, organic modifier type and amount are discussed. The enantioselective separation mechanism is examined using both molecular modeling and retention …

Potential Atmospheric Impact Of The Toba Mega‐Eruption ∼71,000 Years Ago, G. A. Zielinski, Paul Andrew Mayewski, L. D. Meeker, S. Whitlow, M. S. Twickler, K. Taylor

Earth Science Faculty Scholarship

An ∼6‐year long period of volcanic sulfate recorded in the GISP2 ice core about 71,100 ± 5000 years ago may provide detailed information on the atmospheric and climatic impact of the Toba mega‐eruption. Deposition of these aerosols occur at the beginning of an ∼1000‐year long stadial event, but not immediately before the longer glacial period beginning ∼67,500 years ago. Total stratospheric loading estimates over this ∼6‐year period range from 2200 to 4400 Mt of H₂SO₄ aerosols. The range in values is given to compensate for uncertainties in aerosol transport. Magnitude and longevity of the atmospheric loading may …

Magnetic Hardening Of Melt-Spun Nanocomposite Nd2Fe14B/Fe Magnets, I. Panagiotopoulos, L. Withanawasam, A.S. Murthy, George C. Hadjipanayis, E.W. Singleton, David J. Sellmyer

David Sellmyer Publications

Coercivity optimization studies were done on melt-spun nanocomposite Nd₄R₂Fe_87-xNbT_xB₆ (R=Nd,Y,Dy; T=Ag,Cu) isotropic ribbon samples. The maximum attainable coercivities, after adjusting the annealing time, were found to be very sensitive to the annealing temperatures. The optimum magnetic properties [H_c=3.9 kOe, (BH) _max=10 MGOe] were obtained by annealing at 750–775 °C for a few minutes. Optimization by flash annealing gave similar results. Microstructural studies show that the grain size is greater than the theoretically predicted grain size for optimum coupling between the hard and the soft phase. With the …

Electronic Origins Of Ordering In Multicomponent Metallic Alloys: Application To The Cu-Ni-Zn System, J. D. Althoff, Duane D. Johnson, F. J. Pinski, J. B. Staunton

Duane D. Johnson

We investigate the ordering tendencies of the fcc Cu-Ni-Zn system using a recently developed first-principles, density-functional-based theory of atomic short-range order (ASRO) in disordered substitutional alloys of an arbitrary number of components. We find for the binary alloys a variety of effects which should lead to competition in the ternaries: commensurate ordering (Ni-Zn), long-period ordering (Cu-rich Cu-Zn), and clustering (Cu-Ni), in agreement with experiment. We calculate the ASRO of various disordered ternary alloys (as described by the Warren-Cowley pair-correlation function) and discuss its relationship to the electronic structure of the binary and ternary disordered alloys. We find [100]-type ASRO over …

Magnetic Properties And Magnetization Reversal In Co/Au Multilayers (Abstract), Z. S. Shan, J. X. Shen, Roger D. Kirby, David J. Sellmyer

Roger Kirby Publications

We report studies of magnetic properties in CoX Å/Au60 Å multilayers (X = 5,6,7,8,12,20 Å), which were prepared by sputtering on Si(111) substrates, with emphasis on the magnetization reversal. Magnetization reversal was investigated by measurements of initial magnetization curves, minor loops, coercivity as a function of the maximum field of minor loops, temperature dependence of magnetic properties using Kronmüller’s model, time decay of Kerr rotation angle UK, and the field-sweep speed dependence of coercivity H_c(dH_a/dt) at room and/or low temperature. It is found that (1) the thermal activation volumes determined by H_{c …}

Magnetic And Magneto-Optical Properties Of MnXPt1–X–YZnY, Kurt W. Wierman, Roger D. Kirby

Roger Kirby Publications

In this work we have prepared thin films of the ternary alloy Mn_xPt_1–x–yZn_y by magnetron sputtering onto quartz substrates. We have found a wide range of compositions which are strongly ferromagnetic at room temperature. A transition from a cubic to tetragonal phase with decreasing Pt content is confirmed by x-ray diffraction. X-ray diffraction measurements also show a strong (001) reflection consistent with long range order along the c axis for the tetragonal phase. These films show large complex Kerr rotations (up to 0.7°) in the visible spectrum. This combined with their anisotropic structure suggests …

Spin Polarization Of The Conduction Bands And Secondary Electrons Of Gd(0001), Dongqi Li, J. Pearson, S.D. Bader, D.N. Mcilroy, C. Waldfried, Peter A. Dowben

Peter Dowben Publications

Angle- and spin-resolved photoemission was utilized to investigate the 5d bulk bands and the surface state of Gd(0001) in the temperature range of 130–350 K. The bulk bands at 1–2 eV below the Fermi energy E_F show Stoner-like behavior, while the temperature dependence of the surface state near E_F indicates spin-mixing behavior due to fluctuating local 5d moments. The secondary electron spectra of the Gd surfaces both before and after initial oxygen adsorption show a polarization dip at low kinetic energies due to the extra scattering channel for minority electrons via the unoccupied 4f level. The temperature dependencies …

Magnetic Viscosity And Switching Volumes Of Annealed Fe/Pt Multilayers, C.P. Luo, Z.S. Shan, David J. Sellmyer

David Sellmyer Publications

Magnetic viscosity and the phenomenon of the sweep-rate dependence of the coercivity are important for the characterization of magnetic recording media. The activation volume of magnetization reversal or switching volume is directly related to medium noise. The magnetic viscosity behavior of annealed Fe/Pt multilayers was studied and the switching volumes were obtained by both measurements of the sweep-rate dependence of coercivity and time dependence of magnetization. It is found that samples with larger coercivities have smaller switching volumes, and an estimate of the magnetic grain diameter is about 9 nm. The coercivity mechanisms are also discussed.

Mössbauer Study Of Permanent-Magnet R2Fe17-XMXCY Compounds, I. A. Al-Omari, E.W. Singleton, Y. Zheng, George C. Hadjipanayis, David J. Sellmyer

David Sellmyer Publications

We report Fe⁵⁷ Mössbauer spectroscopy studies of the effect of carbon doping on the magnetic properties of the Fe sites of R₂Fe_17-xM_xC_y, and of the presence of multiple phases in these systems. In this study two systems, Sm₂Fe₁₄Al₃C_y, where y=0, 1.0, 2.0, and 3.0, and Nd₂Fe_14.54Si_2.46C_y, where y=0, 0.432, and 2.544, were measured at room temperature and analyzed. The ternary compounds R₂Fe_17-xM_xC_y studied here have the …

Co-Sm (1̅100)[0001]//Cr (1̅21̅)[ 1̅01] Epitaxy And Its Effects On Magnetic Properties Of Co-Sm//Cr Films, Yi Liu, David J. Sellmyer, B. W. Robertson

David Sellmyer Publications

It is well known that the Cr underlayer plays a critical role in generating large in-plane coercivity in Co-based magnetic thin films. In this paper we report in detail the Co-Sm (1̅100)[0001]//Cr (1̅21̅)[ 1̅01] epitaxy revealed by high resolution electron microscopy. The lattice mismatch between Co-Sm (1̅100) and Cr (1̅21̅) is less than 2%, suggesting an energetically favorable configuration. The high anisotropy observed in Co-Sm films is discussed by this epitaxial relation.

Self-Stabilized Magnetic Colloids: Ultrafine Co Particles In Polymers, Diandra Leslie-Pelecky, X.Q. Zhang, Reuben D. Reike

Diandra Leslie-Pelecky Publications

Self-stabilized magnetic colloids consist of magnetic particles dispersed in an appropriate matrix. Fixing the particles in a stabilizing matrix has the advantage of preventing particle agglomeration, increasing resistance to oxidation, and allowing control over the interparticle spacing and particle size. We describe the chemical synthesis of cobalt nanoparticles in a polystyrene/triphenylphosphine polymer matrix. Depending on the synthesis parameters, magnetic properties of the as-synthesized nanocomposites range from superparamagnetic to ferromagnetic with coercivities on the order of 130 Oe. Solvent choice and polymer crosslinking significantly affect the magnetic properties. Annealing in vacuum produces coercivities of up to 600 Oe and remanence ratios …

Superparamagnetic Magnetic Force Microscopy Tips, P.F. Hopkins, John Moreland, S.S. Malhotra, Sy_Hwang Liou

Sy-Hwang Liou Publications

We report on magnetic force microscopy (MFM) images of a thin-film magnetic recording head taken using batch micromachined silicon tips coated with nanocomposite Fe₆₀ (SiO₂)₄₀ and Fe₇₀ (SiO₂)₃₀ films. The small Fe grain size (<10 nm) and dilute Fe volume fraction (0.29–0.4) of these granular films produce tip coatings of low remanence and essentially zero coercivity, reduced by the superparamagnetic properties of these films. We have used these tips to obtain MFM images of the write field of the head with high spatial and magnetic-field resolution. In comparison to images taken using commercial Co₈₅Cr₁₅-coated tips, these MFM images show reduced tip memory effects and clearly delineate the gap field from the pole pieces.

Magnetic Properties Of Nanometer-Size Copt Particles, Sy_Hwang Liou, Yi Liu, S.S. Malhotra, M. Yu, David J. Sellmyer

Sy-Hwang Liou Publications

We have prepared nanometer-size, isolated CoPt particles. The particles in the range of 100–300 nm in diameter were formed by annealing thin films in the temperature range of 550–800 °C. Films with magnetic coercivity as high as 30 kOe were achieved. The results indicate that the high magnetic coercivity was obtained because the crystallite size approaches that of noninteracting single-domain particles.

High Coercivity Rare Earth–Cobalt Films, S.S. Malhotra, Yi Liu, Z.S. Shan, Sy_Hwang Liou, D.C. Stafford, David J. Sellmyer

Sy-Hwang Liou Publications

Rare earth–cobalt (RCo, R=Sm, Pr) films with thicknesses from 30 to 700 nm have been prepared with and without a Cr underlayer by dc magnetron sputtering from a R₂Co₇ composite target. The as-deposited SmCo films with a Cr underlayer (SmCo║Cr) have magnetic coercivities of about 500–2800 Oe and the PrCo║Cr films have coercivities of about 100–300 Oe, but after annealing at 500 °C coercivities as high as 31 kOe for SmCo║Cr films and 10 kOe for PrCo║Cr films were observed. The as-deposited PrCo films are composed mostly of an amorphous phase with about 30 vol % of …

Site Affinity Of Substituents In Nd₂Fe₁₇₋ₓtₓ (T=Cu,Zr,Nb,Ti,V) Alloys, William B. Yelon, Z. Hu, William Joseph James, G. K. Marasinghe

Physics Faculty Research & Creative Works

In order to understand the magnetic properties of the substituted rare-earth-iron alloys, it is especially important to know the location of the substitutional atoms within the iron lattice. The site distributions of some nontransition-metal substituents in the substituted Nd₂Fe_17-xT_x alloys have previously been reported. Here we report the site distributions of some transition-metal substituents (Cu,Zr,Nb,Ti,V) in the Nd₂Fe_17-xT_x alloys and compare them with those of the nontransition-metal substituted compounds. Rietveld analysis of neutron powder diffraction data indicates that the nontransition-metal substituents show very similar site affinity at low substituent content. …

Neutron Diffraction And Magnetic Studies Of Rfe₁₂₋ₓtₓcY (R=Y,Er; T=V,Ti,Mo) Alloys, Z. Hu, William B. Yelon, X. D. Zhang, William Joseph James

Physics Faculty Research & Creative Works

RFe_12-xT_xC_y, (R=Y,Er; T=V,Ti,Mo) alloys were prepared by rf induction melting and analyzed using neutron powder diffraction and superconducting quantum interference device (SQUID) measurements. Rietveld analysis of the neutron diffraction data indicates that V, Ti, and Mo atoms all prefer the 8i sites. The refined amount of carbon atoms found in the interstitial sites from neutron diffraction data is significantly less than the nominal carbon content. All samples have the easy direction along the c axis. The Er sublattice couples to the Fe sublattice antiferromagnetically. The average Fe site moments range from 1.3 to 2.8 …

Neutron Diffraction Studies Of Ndₙfeₘ₋ₓ₋YVₓalY [(N,M)=(1,12), (2,17), (3,29)], Z. Hu, William B. Yelon, William Joseph James

Physics Faculty Research & Creative Works

Several Nd_nFe_m-x-yV_xAl_y [(n,m)=(1,12), (2,17), (3,29)] samples were prepared and analyzed using neutron powder diffraction. Rietveld analysis of the neutron diffraction data indicates that the V and Al substituents take those sites with similar environments in all three phases, as observed in our previous study of Ti-substituted compounds. It was confirmed that the diffraction data of the 3:29 compound can be better refined using the A2/m space group than using the P2₁/c space group. The SQUID measurements show that all samples have Curie temperatures well above room temperature. The neutron diffraction results …