Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2002

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1231 - 1260 of 3435

Full-Text Articles in Physical Sciences and Mathematics

Exchange-Controlled Magnetic Anisotropy, Ralph Skomski May 2002

Exchange-Controlled Magnetic Anisotropy, Ralph Skomski

Ralph Skomski Publications

The magnetocrystalline anisotropy of 5f transition-metal atoms (actinides) is investigated. A simple model Hamiltonian reproduces the observed huge low-temperature anisotropy of cubic actinide compounds such as US and predicts the temperature dependence of the anisotropy. The dominance of the spin–orbit and crystal–field interactions means that the magnitude of the anisotropy is limited only by interatomic exchange. One consequence is that cubic and uniaxial 4f magnets have similar magnitudes of the anisotropy and similar temperatures dependencies.

Go to article

Magnetic Force Microscopy Observations Of The Magnetic Behavior In Co–C Nanodot Arrays, L. Gao, Sy_Hwang Liou, M. Zheng, Ralph Skomski, M. L. Yan, David J. Sellmyer, N.I. Polushkin May 2002

Magnetic Force Microscopy Observations Of The Magnetic Behavior In Co–C Nanodot Arrays, L. Gao, Sy_Hwang Liou, M. Zheng, Ralph Skomski, M. L. Yan, David J. Sellmyer, N.I. Polushkin

Sy-Hwang Liou Publications

The nanomagnetic behavior of Co–C nanodot arrays was investigated by magnetic force microscopy (MFM) and an alternative gradient force magnetometer. The direction of the easy axis can be observed directly with MFM by comparing the saturated magnetization state and the remanent magnetization state. Interaction of the domain wall with local defects was observed by field dependent MFM measurements. Some types of defects that can pin domain wall movement were identified.

Go to article

Magnetic Intergranular Interaction In Nanocomposite CoΧPt100-Χ:C Thin Films, Nathan D. Powers, M.L. Yan, L. Gao, Sy_Hwang Liou, David J. Sellmyer May 2002

Magnetic Intergranular Interaction In Nanocomposite CoΧPt100-Χ:C Thin Films, Nathan D. Powers, M.L. Yan, L. Gao, Sy_Hwang Liou, David J. Sellmyer

Sy-Hwang Liou Publications

Magnetization reversal and intergranular interactions have been studied in composite CoχPt100-χ:C thin films using several magnetic characterization techniques. The intergranular interactions, as determined by ΔM curves, were strongly dependent on the ratio of Co and Pt concentration. For films with high Co content, the intergranular exchange coupling was predominant, while dipolar interactions were exhibited in the film with the equiatomic concentration of Co and Pt. Magnetic intergranular interaction was directly observed using magnetic force microscopy. There is a strong correlation between the value of the ΔM and magnetic correlation length obtained from the magnetic …

Go to article

Magnetoresistance Study In Thin Zig Zag Nife Wires, J. L. Tsai, S.F. Lee, Y.D. Yao, C. Yu, Sy_Hwang Liou May 2002

Magnetoresistance Study In Thin Zig Zag Nife Wires, J. L. Tsai, S.F. Lee, Y.D. Yao, C. Yu, Sy_Hwang Liou

Sy-Hwang Liou Publications

Thickness dependence on the domain wall resistivity of zig zag thin permalloy wires was studied from 10 to 300 K. The maximum domain wall resistivity was obtained in wire with 100-nm-film thickness. The multidomain state resistivity was 14.29 µΩ cm, while single-domain state resistivity was 14.36 µΩ cm at 10 K. The ratio of domain wall magnetoresistance was measured to be 0.034%, 0.112%, and 0.258%, and the magnetic field where the domain wall started to switch was measured as –70, –40, and +80 Oe for wires with thicknesses of 20, 40, and 100 nm, respectively, at 250 K. Domain wall …

Go to article

Structure And Superconductivity Of Dy (Ba2-Y Lay) Cu3 Oz (0 ≤ Y ≤ 0.5) System, Amish G. Joshi, S. K. Malik, William B. Yelon May 2002

Structure And Superconductivity Of Dy (Ba2-Y Lay) Cu3 Oz (0 ≤ Y ≤ 0.5) System, Amish G. Joshi, S. K. Malik, William B. Yelon

Physics Faculty Research & Creative Works

Structural and superconducting properties of single-phase La-substituted compounds of the formula Dy(Ba 2-yLay)Cu3Oz (0.0≤y≤0.5) have been investigated by neutron diffraction, electrical resistivity, and magnetization measurements. The compound DyBa 2Cu3O7-δ (orthorhombic, space group Pmmm) exhibits superconductivity with transition temperature, T c, of about 90 K. Rietveld analysis of the neutron diffraction data on La containing compounds reveals that the orthorhombicity decreases with increasing La concentration and the compounds become tetragonal for higher La content. The overall oxygen content increases as divalent Ba is replaced by trivalent La and approximately compensates for …

Go to article

Neutron Diffraction Analysis Of Melt Spun 2:14:1 Type (Ndpr)-Fe-B Compounds With Ti And Zr Additions, Z. Chu, William B. Yelon, B. M. Ma, Z. Chen, D. N. Brown May 2002

Neutron Diffraction Analysis Of Melt Spun 2:14:1 Type (Ndpr)-Fe-B Compounds With Ti And Zr Additions, Z. Chu, William B. Yelon, B. M. Ma, Z. Chen, D. N. Brown

Physics Faculty Research & Creative Works

There has been continued technological and research interest in Nd 2Fe 14B-based compounds due to their excellent intrinsic magnetic properties [(BH) max*∼64MGOe,Ha∼73kOe]. It is found that Ti and Zr substitution in Nd 2Fe 14B leaves its magnetic properties largely unaffected. We have carried out neutron diffraction studies on Zr and Ti substituted 2:14:1 compounds. Three specimens of melt spun alloys of compositions (Nd 0.75Pr 0.25) 12Fe 80B 8, (Nd 0.75Pr 0.25) 8.4Fe 79.7Ti 4.7B 7.2 and (Nd 0.75Pr 0.25) 9.2Fe 79.2Ti 2 …

Go to article

Calculations On The Size Effects Of Raman Intensities Of Silicon Quantum Dots, Wei Cheng, Shang-Fen Ren May 2002

Calculations On The Size Effects Of Raman Intensities Of Silicon Quantum Dots, Wei Cheng, Shang-Fen Ren

Faculty publications – Physics

Raman intensities of Si quantum dots (QD's) with up to 11489 atoms (about 7.6 nm in diameter) for different scattering configurations are calculated. First, phonon modes in these QD's, including all vibration frequencies and vibration amplitudes, are calculated directly from the lattice-dynamic matrix by using a microscopic valence force field model combined with the group theory. Then the Raman intensities of these quantum dots are calculated by using a bond-polarizability approximation. The size effects of the Raman intensity in these QD's are discussed in detail based on these calculations. The calculations are compared with the available experimental observations. We are …

Go to article

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/02- 5/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper May 2002

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/02- 5/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to …

Go to article

Mechanically Milled Nanostructured (Sm,Pr) 12.5Co85.5Zr2 Magnets With Tbcu7 Structure, Hong Tang, Jian Zhou, David J. Sellmyer May 2002

Mechanically Milled Nanostructured (Sm,Pr) 12.5Co85.5Zr2 Magnets With Tbcu7 Structure, Hong Tang, Jian Zhou, David J. Sellmyer

David Sellmyer Publications

Nanostructured (Sm,Pr)(Co,Zr) magnets with the TbCu7-type structure have been synthesized by mechanically milling (Sm1-xPrx)12.5Co85.5Zr2 alloys (0≤x≤0.8) followed by appropriate annealing. Magnetic properties, structure, and microstructure have been investigated. It is found that single-phase (Sm,Pr)(Co,Zr) 7 magnets with the TbCu7 structure and with nanoscale grain size (14–19 nm) form in the whole composition range. Intrinsic coercivity Hci decreases from 20.7 to 5.6 kOe with increasing Pr content from 0 to 0.8, while energy products (BH)max shows an optimum value of 12.6 MGOe (Hciof 17.9 kOe) at …

Go to article

Fabrication And Characterization Of Co1−Xfex Alloy Nanowires, Petru S. Fodor, Georgy M. Tsoi, Lowell E. Wenger May 2002

Fabrication And Characterization Of Co1−Xfex Alloy Nanowires, Petru S. Fodor, Georgy M. Tsoi, Lowell E. Wenger

Physics Faculty Publications

Co1−xFex alloy nanowires with 40 nm diam and x=0–1.0 were fabricated by electrodeposition in nanopores of alumina templates. The crystalline structure of the nanowires is concentration dependent and shows a transition from the cobalt hexagonal-closed-packed structure (hcp) to a face-centered-cubic structure (fcc) in the concentration range 0

Go to article

Investigation Of The Magnetic Properties In Strontium–Borate Vanadate Glasses, Manford Chinkhota, Petru S. Fodor, G. D. Khattak, Lowell E. Wenger May 2002

Investigation Of The Magnetic Properties In Strontium–Borate Vanadate Glasses, Manford Chinkhota, Petru S. Fodor, G. D. Khattak, Lowell E. Wenger

Physics Faculty Publications

To further elucidate the nature of the valence state of V ions in vanadate glasses,magnetic susceptibility measurements in the temperature range of 5 to 300 K have been performed on a series of vanadium–strontium–borate (V2O5+SrO+B2O3) oxide glasses with V2O5 concentrations greater than 50 mol %. The magnetic susceptibility for these oxide glasses is found to consist of a temperature-independentparamagnetic contribution arising from V2O5 and a Curie–Weiss temperature-dependent contribution associated with magnetic V4+ ions being present in concentrations between 2% and 10% of the total V concentration. The negative Curie–Weiss temperatures in the range of 0 to −2.8 K indicate a …

Go to article

Magnetic And Mössbauer Studies On Oxygen Deficient Perovskite, La₀.₆Sr₀.₄Feo3-Δ, Jinbo Yang, William B. Yelon, William Joseph James, X.-D. Zhou, Yixiang Xie, Harlan U. Anderson, Zili Chu May 2002

Magnetic And Mössbauer Studies On Oxygen Deficient Perovskite, La₀.₆Sr₀.₄Feo3-Δ, Jinbo Yang, William B. Yelon, William Joseph James, X.-D. Zhou, Yixiang Xie, Harlan U. Anderson, Zili Chu

Physics Faculty Research & Creative Works

Samples of La0.6Sr0.4Fe3-δ with varying oxygen vacancy contents were prepared by heating them in different gas flows. Magnetization measurement showed that samples with low oxygen vacancies have a magnetic ordering temperature in the range of 300-325 K while those with 9%-12% oxygen vacancies have a magnetic ordering temperature of 800 K and higher. Mössbauer spectra at 300 K exhibit paramagnetic or weak magnetic characteristics for the N2, O2, and air-quenched samples, whereas an average hyperfine field of 52 T is found for the CO/CO2 reduced samples. The heat treatment in …

Go to article

Structure And Magnetic Properties Of The Mnbi Low Temperature Phase, Jinbo Yang, William B. Yelon, William Joseph James, Qingsheng Cai, Samit Roy, Naushad Ali May 2002

Structure And Magnetic Properties Of The Mnbi Low Temperature Phase, Jinbo Yang, William B. Yelon, William Joseph James, Qingsheng Cai, Samit Roy, Naushad Ali

Physics Faculty Research & Creative Works

High purity MnBi low temperature phase has been prepared and analyzed using magnetic measurements and neutron diffraction. The low-temperature phase of the MnBi alloy has a coercivity μ0iHc of 2.0 T at 400 K, and exhibits a positive temperature coefficient from 0 to at least 400 K. The neutron data refinement indicated that the Mn atom changes its spin direction from c axis above room temperature to nearly perpendicular to the c axis at 50 K. A canted magnetic structure has been observed below 200 K. The anisotropy field increases with increasing temperature which gives rise to …

Go to article

Magnetic Properties Of Iron-Rich Mixed Rare-Earth Sm₂-ₓtbₓfe17-YSiY Compounds, Kishore Kamaraju, Jinbo Yang, William B. Yelon, Oran Allan Pringle, William Joseph James, Ph. I'Héritier May 2002

Magnetic Properties Of Iron-Rich Mixed Rare-Earth Sm₂-ₓtbₓfe17-YSiY Compounds, Kishore Kamaraju, Jinbo Yang, William B. Yelon, Oran Allan Pringle, William Joseph James, Ph. I'Héritier

Physics Faculty Research & Creative Works

A series of Sm2-xTbxFe17-ySiy solid solutions with x = 0, 1, and 1.5 and y = 1, 2, and 3 were prepared by induction melting stoichiometric amounts of high purity elements. The x-ray diffraction data confirm that the postannealed samples are 2:17 intermetallics of the R3 space group. The lattice parameters and the unit cell volumes were calculated using a modified Rietveld program. The fitted intensities showed behavior related to a disordered rhombohedral structure as inferred from neutron data. It was observed that for a particular y, the unit cell volume decreased almost …

Go to article

Geochemistry Of Atmospheric Aerosols Generated From Lava-Seawater Interactions, Francis J. Sansone, Claudia R. Benitez-Nelson, Joseph A. Resing, Eric H. Decarlo, Sue M. Vink, Jacqueline A. Heath, Barry J. Huebert May 2002

Geochemistry Of Atmospheric Aerosols Generated From Lava-Seawater Interactions, Francis J. Sansone, Claudia R. Benitez-Nelson, Joseph A. Resing, Eric H. Decarlo, Sue M. Vink, Jacqueline A. Heath, Barry J. Huebert

Faculty Publications

[1] Trace elements were measured in the aerosol plume produced by lava‐seawater interactions along the shoreline of Kilauea volcano, Hawaii. Plume concentrations were normalized relative to Hawaiian basalt composition and showed a linear log‐log co‐variation with their emanation coefficient (an indicator of element volatility). Normalized aerosol concentrations also consistently covaried with corresponding normalized concentrations in dilute fumarolic gas from Kilauea volcano and fumarolic gas condensates from Kudryavy and Merapi volcanoes, despite different mechanisms of element volatilization. Conservatively estimated regional ocean deposition rates of Cu, Cd, Ni, Pb, Mn, Zn, Fe and P were >50 times background rates. Thus, upper ocean …

Go to article

Predictions And Observations In Theories With Varying Couplings, Christian Armendariz-Picon May 2002

Predictions And Observations In Theories With Varying Couplings, Christian Armendariz-Picon

Physics - All Scholarship

We consider a toy universe containing conventional matter and an additional real scalar field, and discuss how the requirements of gauge and diffeomorphism invariance essentially single out a particular set of theories which might describe such a world at low energies. In these theories, fermion masses and g-factors, as well as the electromagnetic coupling turn to be scalar field dependent; fermion charges and the gravitational coupling might be assumed to be constant. We then proceed to study the impact of a time variation of the scalar field on measurements of atomic spectra at high redshifts. Light propagation is not affected …

Go to article

High-Resolution Ir Spectrum Measurement Of The Line Parameters Of Hydrogen Fluoride In Gas Phase, Akhtam Khalilovich Amonov May 2002

High-Resolution Ir Spectrum Measurement Of The Line Parameters Of Hydrogen Fluoride In Gas Phase, Akhtam Khalilovich Amonov

Scientific Journal of Samarkand University

In this paper we present an unique high resolution FTIR rotation-vibration spectrum of H19F molecule and derived most necessary line by line parameters of the title complex. The formation mechanisms of the vibration-rotation infrared spectrum of the hydrogen fluoride have been explained. Optimal geometry and total electron density surface 3D have been mapped with electrostatic potential determined for (HF)3 cluster with mp2=full/6-311++g(3df,3pd) levels of theory.

Go to article

Frame Bounds For Biorthogonal Cosine-Modulated Filter Banks, Alfred Mertins May 2002

Frame Bounds For Biorthogonal Cosine-Modulated Filter Banks, Alfred Mertins

Faculty of Informatics - Papers (Archive)

We derive explicit expressions for the eigenvalues of the frame operator for cosine-modulated filter banks. The filter banks may be critically sampled or oversampled by an integer factor. The analysis of low-delay, biorthogonal filter banks shows that prototypes solely designed to minimize the stopband energy may lead to wide open frames and thus to an undesirable numerical behavior. Because the computational cost of determining the frame bounds with the proposed method is very low, we can directly use the bounds during prototype optimization and obtain prototypes with minimum stopband energy under the condition of fixed frame bounds.

Go to article

A Class Of Boron-Rich Solid-State Neutron Detectors, B. W. Robertson, Shireen Adenwalla, A. Harken, P. Welsch, Jennifer I. Brand, Peter A. Dowben, J.P. Claassen May 2002

A Class Of Boron-Rich Solid-State Neutron Detectors, B. W. Robertson, Shireen Adenwalla, A. Harken, P. Welsch, Jennifer I. Brand, Peter A. Dowben, J.P. Claassen

Peter Dowben Publications

Real-time solid-state neutron detectors have been fabricated from semiconducting boron–carbon alloys, deposited by plasma-enhanced chemical vapor deposition. Single neutrons were detected and signals induced by gamma rays were determined to be insignificant. The source gas closo-1,2-dicarbadodecaborane (ortho-carborane) was used to fabricate the boron–carbon alloys with only the natural isotopic abundance of 10B. Devices made of thicker boron–carbon alloy layers enriched in 10B could lead to increased detection efficiency and active diodes could use the inherent micron scale spatial resolution, increasing the range of possible applications. © 2002 American Institute of Physics. [DOI: 10.1063/1.1477942]

Go to article

Search For Leptoquark Pairs Decaying Into Νν + Jets In Pp̅ Collisions At √S = 1.8 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration May 2002

Search For Leptoquark Pairs Decaying Into Νν + Jets In Pp̅ Collisions At √S = 1.8 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We present the results of a search for leptoquark (LQ) pairs in (85.2 ± 3.7) pb-1 of pp̅ collider data collected by the D0 experiment at the Fermilab Tevatron. We observe no evidence for leptoquark production and set a limit on σ(pp̅→ LQ L̅Q̅→ νν + jets) as a function of the mass of the leptoquark (mLQ). Assuming the decay LQ → νq, we exclude scalar leptoquarks for mLQ< 98 GeV/c2, and vector leptoquarks for mLQ < 200 GeV/c2 and coupling which produces the minimum cross section, at a 95% confidence …

Go to article

Threshold-Related Enhancement Of The High-Energy Plateau In Above-Threshold Detachment, Bogdan Borca, M.V. Frolov, N.L. Manakov, Anthony F. Starace May 2002

Threshold-Related Enhancement Of The High-Energy Plateau In Above-Threshold Detachment, Bogdan Borca, M.V. Frolov, N.L. Manakov, Anthony F. Starace

Anthony F. Starace Publications

We present nonperturbative theoretical results showing a resonant-like enhancement of above-threshold detachment spectra in the region of the high-energy plateau as the laser intensity sweeps across channel thresholds. This enhancement has a pure quantum origin stemming from well-known threshold phenomena in multichannel problems whose features are clearly demonstrated in our numerical results. Similar well-known anomalies at neutral atom thresholds are expected to explain experimentally observed resonant-like enhancements of above-threshold ionization spectra.

Go to article

Footprinting, Circular Dichroism And Uv Melting Studies On Neomycin B Binding To The Packaging Region Of Human Immunodeficiency Virus Type-1 Rna, Mark P. Mcpike, Julie M. Sullivan, Jerry Goodisman, James C. Dabrowiak May 2002

Footprinting, Circular Dichroism And Uv Melting Studies On Neomycin B Binding To The Packaging Region Of Human Immunodeficiency Virus Type-1 Rna, Mark P. Mcpike, Julie M. Sullivan, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

We have studied the binding of neomycin to a 171mer RNA (Ψ-RNA) from the packaging region of the LAI strain of human immunodeficiency virus type-1, HIV-1 (LAI). The RNase I footprinting studies reveal that the primary binding site for the drug is in stem-loop 1, which contains the dimer initiation site of HIV-1. Loading this site with neomycin causes a structural change in the RNA, allowing nucleotides in the neighboring stem-loop 2 to participate in the drug site. Drug binding to secondary sites induces structural changes in other stem-loops of the RNA. Footprinting plots, showing cutting at a site as …

Go to article

Threshold-Related Effects In High-Order Harmonic Generation, Bogdan Borca, Anthony F. Starace, A. V. Flegel, M. V. Frolov, N. L. Manakov May 2002

Threshold-Related Effects In High-Order Harmonic Generation, Bogdan Borca, Anthony F. Starace, A. V. Flegel, M. V. Frolov, N. L. Manakov

Department of Physics and Astronomy: Faculty Publications

We present exact ab initio quantum results for harmonic generation (HG) by a weakly bound electron interacting with a strong monochromatic laser field. The analytic structure of the HG amplitude resulting from the multiphoton detachment thresholds is demonstrated. Our numerical results show that the HG spectrum is sensitive primarily to the distance in energy from the thresholds, thereby opening new possibilities for control of HG.

Go to article

Higher-Order Evaluation Of The Critical Temperature For Interacting Homogeneous Dilute Bose Gases, Frederico F. F. De Souza Cruz, Marcus Pinto, Rudnei O. Ramos, Paulo Sena May 2002

Higher-Order Evaluation Of The Critical Temperature For Interacting Homogeneous Dilute Bose Gases, Frederico F. F. De Souza Cruz, Marcus Pinto, Rudnei O. Ramos, Paulo Sena

Dartmouth Scholarship

We use the nonperturbative linear δ expansion method to evaluate analytically the coefficients c1 and c''2 that appear in the expansion for the transition temperature for a dilute, homogeneous, three-dimensional Bose gas given by Tc=T0(1+c1an1/3+[c′2ln(an1/3)+c''2]a2n2/3+O(a3n)), where T0 is the result for an ideal gas, a is the s-wave scattering length, and n is the number density. In a previous work the same method has been used to evaluate c1 to order δ2 with the result c1=3.06. Here, we push the calculation to the next two orders obtaining c1=2.45 at order δ3 and c1=1.48 at order δ4. Analyzing the topology …

Go to article

Statistical Properties Of Composite Distortions In Hfc Systems And Their Effects On Digital Channels, Ron D. Katznelson May 2002

Statistical Properties Of Composite Distortions In Hfc Systems And Their Effects On Digital Channels, Ron D. Katznelson

Ron D. Katznelson

The statistical properties of Composite Triple Beat (CTB) and Composite Second Order (CSO) distortion terms associated with the analog channels carried on Hybrid Fiber Coax (HFC) are presented. Both simulation and measurement results show that such distortion components falling on individual channels have amplitude Probability Density Function that is nearly Rayleigh distributed (having a Standard Deviation of 5.7 dB). It is shown that both CTB and CSO components have peak envelope power fluctuations that exceed their average (measured) power levels by more than 15 dB. The temporal statistical properties of these distortion components demonstrate peak envelope power fluctuations with characteristic …

Go to article

Towards Peer-To-Peer Semantic Web: A Distributed Environment For Sharing Semantic Knowledge On The Web, Madhan Arumugam, Amit P. Sheth, I. Budak Arpinar May 2002

Towards Peer-To-Peer Semantic Web: A Distributed Environment For Sharing Semantic Knowledge On The Web, Madhan Arumugam, Amit P. Sheth, I. Budak Arpinar

Kno.e.sis Publications

The real value of Semantic Web vision can be demonstrated if people and applications can create and discover new and interesting knowledge and share this knowledge in a transparent manner similar to the way data is exchanged today. Therefore, we believe that Semantic Web will consist of a distributed environment of shared and interoperable ontologies, which have emerged as common formalisms for knowledge representation. The users will need to discover new ontologies, which are not known to them before and use them to either annotate the content or to formulate their information requests. This requires an environment that supports creating, …

Go to article

Nonorthogonal Polyhedra Built From Rectangles, Melody Donoso, Joseph O'Rourke May 2002

Nonorthogonal Polyhedra Built From Rectangles, Melody Donoso, Joseph O'Rourke

Computer Science: Faculty Publications

We prove that any polyhedron of genus zero or genus one built out of rectangular faces must be an orthogonal polyhedron, but that there are nonorthogonal polyhedra of genus seven all of whose faces are rectangles. This leads to a resolution of a question posed by Biedl, Lubiw, and Sun [BLS99].

Go to article

Humidity And Temperature Boundaries For Biofilm Formation In Yucca Mountain, Terry Ann Else, Penny S. Amy, James Jay, Amy J. Smiecinski May 2002

Humidity And Temperature Boundaries For Biofilm Formation In Yucca Mountain, Terry Ann Else, Penny S. Amy, James Jay, Amy J. Smiecinski

Publications (YM)

To determine the long-term success of the recommended Yucca Mountain high-level nuclear waste repository, studies of bacterial colonization and biofilm development are needed. Bacteria involved in microbially-influenced corrosion and degradation are known to form biofilms with the potential to impact the integrity of repository packaging and structural materials. Temperature and humidity are environmental factors that can greatly affect biofilm formation. Therefore, it is necessary to determine the temperature and humidity conditions that affect biofilm formation. Microcosms, which simulated the repository environment of Yucca Mountain, were placed at temperatures ranging from 30° C to 70° C and in relative humidities ranging …

Go to article

Local Rings Of Countable Cohen-Macaulay Type, Craig Huneke, Graham J. Leuschke May 2002

Local Rings Of Countable Cohen-Macaulay Type, Craig Huneke, Graham J. Leuschke

Mathematics - All Scholarship

We prove (the excellent case of) Schreyer's conjecture that a local ring with countable Cohen-Macaulay type has at most a one-dimensional singular locus. Furthermore we prove that the localization of a Cohen-Macaulay local ring of countable CM type is again of countable CM type.

Go to article

Ecotones: The Heartbeat Of Huxley, 2002, Spring, Issue 04, Tennyson Ketcham, Laurel Eddy, Huxley College Of The Environment, Western Washington University May 2002

Ecotones: The Heartbeat Of Huxley, 2002, Spring, Issue 04, Tennyson Ketcham, Laurel Eddy, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.

Go to article

First Prev Next Last