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2003

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Articles 1411 - 1440 of 3876

Full-Text Articles in Physical Sciences and Mathematics

Copt Hard Magnetic Nanoparticle Films Synthesized By High Temperature Chemical Reduction, Yucheng Sui, Lanping Yue, Ralph Skomski, Xingzhong Li, J. Zhou, David J. Sellmyer May 2003

Copt Hard Magnetic Nanoparticle Films Synthesized By High Temperature Chemical Reduction, Yucheng Sui, Lanping Yue, Ralph Skomski, Xingzhong Li, J. Zhou, David J. Sellmyer

David Sellmyer Publications

The synthesis of hard-magnetic CoPt nanoparticle films by hydrogen reduction of Co nitride and Pt chloride mixture is reported. Thin porous alumina films are adopted as the carrier of the initial aqueous solution and of the final reducing products of CoPt nanoparticles. It is found that chemical ordering of L0–CoPt occurs above 400 °C. Partial phase transformation occurs in the alumina substrate when the treatment temperature is higher than 600 °C. The film coercivity increases with increasing annealing temperature and reaches a maximum value of 24.2 kOe when the reduction is carried out at 700 °C for 2 …

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Magnetic Hysteresis Of Mechanically Alloyed Sm–Co Nanocrystalline Powders, J. Zhou, Ralph Skomski, David J. Sellmyer May 2003

Magnetic Hysteresis Of Mechanically Alloyed Sm–Co Nanocrystalline Powders, J. Zhou, Ralph Skomski, David J. Sellmyer

David Sellmyer Publications

Mechanically alloyed Sm–Co powders and Sm12 (Co,Cu,Ti) 88 powders are investigated. X-ray diffraction patterns show that after annealing, structures of 2:7, 1:5, and 1:7 phases form. A room-temperature coercivity of 41 kOe was obtained in Sm2Co7 powders. Magnetic hysteresis was investigated by the method of δ m curves. Positive value δ m curves were obtained in Sm2Co7 and SmCo5, while negative values were found in SmCo7.3 and SmCo8 indicating different magnetization reversal mechanisms. Nanocrystalline powders of Sm12 (Co,Cu,Ti) 88 with a mixture of 1:5 and 2:17 phases form …

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Spin Structure At Nanojunctions And Constrictions, Ralph Skomski, David J. Sellmyer May 2003

Spin Structure At Nanojunctions And Constrictions, Ralph Skomski, David J. Sellmyer

David Sellmyer Publications

A micromagnetic Green-function approach is used to investigate the effect of nanojunctions, constraints, and other obstacles on spin-dependent conduction. Depending on geometry, the determination of the spin structure involves several types of Bessel functions. A common feature of the Green functions is the involvement of the domain-wall width of the main phase, which can be interpreted as the decay length of the magnetization perturbation away from the junction. This length is typically on the order of 10 nm and independent of the strength of the perturbation. Only the magnitude of the magnetization perturbation depends on the strength of the inhomogenity. …

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A Bootstrap Confidence Interval Procedure For The Treatment Effect Using Propensity Score Subclassification, Wanzhu Tu, Xiao-Hua Zhou May 2003

A Bootstrap Confidence Interval Procedure For The Treatment Effect Using Propensity Score Subclassification, Wanzhu Tu, Xiao-Hua Zhou

UW Biostatistics Working Paper Series

In the analysis of observational studies, propensity score subclassification has been shown to be a powerful method for adjusting unbalanced covariates for the purpose of causal inferences. One practical difficulty in carrying out such an analysis is to obtain a correct variance estimate for such inferences, while reducing bias in the estimate of the treatment effect due to an imbalance in the measured covariates. In this paper, we propose a bootstrap procedure for the inferences concerning the average treatment effect; our bootstrap method is based on an extension of Efron’s bias-corrected accelerated (BCa) bootstrap confidence interval to a two-sample problem. …

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Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper May 2003

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

Progress continues on the analysis of casting and solidification of the melt into molds. Modeling results for constant pressure casting, which is more realistic, have been obtained and produce physically realistic results for flow that starts, flows, and then eventually stops as it enters the mold. Potential mass transfer modeling features (Lammuir’s law for example) are being studied to enhance the capabilities of a mass transfer in a detailed system model. Different parameters are being varied as part of a parametric study to evaluate factors that impact the flow of the melt into the molds. The ability to include the …

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Poly(2-Alkylacrylic Acid) Polymers Deliver Molecules To The Cytosol By Ph-Sensitive Disruption Of Endosomal Vesicles, Rachel A. Jones, C. Y. Cheung, F. E. Black, J. K. Zia, P. S. Stayton, A. S. Hoffman, Mark R. Wilson May 2003

Poly(2-Alkylacrylic Acid) Polymers Deliver Molecules To The Cytosol By Ph-Sensitive Disruption Of Endosomal Vesicles, Rachel A. Jones, C. Y. Cheung, F. E. Black, J. K. Zia, P. S. Stayton, A. S. Hoffman, Mark R. Wilson

Faculty of Science - Papers (Archive)

The permeability barrier posed by cell membranes represents a challenge for the delivery of hydrophilic molecules into cells. We previously proposed that poly(2- alkylacrylic acid)s are endocytosed by cells into acidified vesicles and are there triggered by low pH to disrupt membranes and release the contents of endosomes/lysosomes to the cytosol. If this hypothesis is correct, these polymers could be valuable in drug delivery applications. This report provides functional comparisons of a family of three poly(2-alkylacrylic acid)s. Poly(2-propylacrylic acid) (PPAA), poly(2-ethylacrylic acid) (PEAA), and poly(2-methylacrylic acid) (PMAA) were compared in red blood cell haemolysis assays and in a lipoplex gene …

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Equivalence Of Sweep-Rate And Magnetic-Viscosity Dynamics, Ralph Skomski, Roger D. Kirby, David J. Sellmyer May 2003

Equivalence Of Sweep-Rate And Magnetic-Viscosity Dynamics, Ralph Skomski, Roger D. Kirby, David J. Sellmyer

Roger Kirby Publications

The irreversible response of magnetic materials to magnetic fields of arbitrary time dependence is investigated by a master-equation approach. The magnetization reversal is expressed in terms of renormalized magnetization modes, and the resulting set of two-level master equations is solved by direct integration. The theory applies not only to linear energy-barrier laws but also to the physically more reasonable case where the activation energy is a nonlinear function of the applied field. Particular emphasis is on the relation between sweep-rate and magnetic-viscosity dynamics. Other regimes, such as oscillating magnetic fields, can be mapped onto sweep-rate dynamics. Magnetic-viscosity and sweep-rate experiments …

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Giant Magnetoresistance Properties Of The La1-2xrxaxmno3 (R=Nd, A=Ca) Perovskites, Darshan C. Kundaliya, A. A. Tulapurkar, S. R. Shinde, R. Pinto, William B. Yelon, R. G. Kulkarni, S. K. Malik May 2003

Giant Magnetoresistance Properties Of The La1-2xrxaxmno3 (R=Nd, A=Ca) Perovskites, Darshan C. Kundaliya, A. A. Tulapurkar, S. R. Shinde, R. Pinto, William B. Yelon, R. G. Kulkarni, S. K. Malik

Physics Faculty Research & Creative Works

The giant magneto resistive behavior of an antiferromagnetic insulator, LaMnO3, was investigated by studying the effect of simultaneous substitution of Nd and Ca on the compound. the volume of unit cell decreased with increasing concentration of Nd/Ca. the changes in the temperature dependent resistivity, and ferromagnetic transition were observed with the increase in the compound series. the observing of metal-insulator transition at different temperatures, and magnetoresistance in the 2 T applied field were also recorded.

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Finite-Temperature Spin Polarization In Half-Metallic Ferromagnets, Peter A. Dowben, Ralph Skomski May 2003

Finite-Temperature Spin Polarization In Half-Metallic Ferromagnets, Peter A. Dowben, Ralph Skomski

Peter Dowben Publications

The temperature dependence of the spin polarization of half-metallic ferromagnets is investigated. A unitary spinor transformation shows that the corresponding spin mixing goes beyond finite-temperature smearing of the Fermi level, leading to a nonzero density of states in the gap of the insulating spin channel. As a consequence, the resistance ratio of the two spin channels changes from infinity to some finite value and, in a strict sense, half-metallic ferromagnetism is limited to zero temperature. Bloch-type spin waves and crystal imperfections contribute to the density of states in the gap but only partly explain the pronounced changes at about 0.2 …

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Magnetic Properties Of L10 Fept And Fept:Ag Nanocluster Films, Yinfan Xu, Zhiguang Sun, Y. Qiang, David J. Sellmyer May 2003

Magnetic Properties Of L10 Fept And Fept:Ag Nanocluster Films, Yinfan Xu, Zhiguang Sun, Y. Qiang, David J. Sellmyer

David Sellmyer Publications

A sputtering gas-aggregation technique has been used to prepare FePt and FePt:Ag nanocluster films. The cluster size was controlled in a range from 3 to 6 nm. FePt cluster films were directly deposited onto Si substrate; FePt:Ag cluster films were fabricated by depositing a FePt cluster layer between a Ag underlayer and overlayer. Nanostructure and magnetic properties of the samples were characterized by x-ray diffraction, transmission electron microscopy, and magnetometry. The high magnetic anisotropy L10 fct phase was realized in the films annealed at a temperature of 550 °C and above. The orientation of clusters is random. The …

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Effects Of Rapid Thermal Annealing On Nanostructure, Texture And Magnetic Properties Of Granular Fept:Ag Films For Perpendicular Recording (Invited), Y. Shao, M.L. Yan, David J. Sellmyer May 2003

Effects Of Rapid Thermal Annealing On Nanostructure, Texture And Magnetic Properties Of Granular Fept:Ag Films For Perpendicular Recording (Invited), Y. Shao, M.L. Yan, David J. Sellmyer

David Sellmyer Publications

We report effects of rapid thermal annealing on nanostructure, texture, and magnetic properties of granular FePt:Ag films. It was found that the orientations of FePt grains were dependent strongly on the as-deposited multilayer structure and the annealing processes. Through the control of the annealing processes, (001) textured L10 granular FePt:Ag films were obtained. Magnetic measurements revealed that saturation magnetization Ms, perpendicular coercivity Hc, and remanence ratio Mr/Ms, were also dependent on the annealing temperature, annealing time and Ag content. Perpendicular Hc values increased from 1.5 to 15 kOe …

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Spin-Wave Modes In Magnetic Nanowires, Ralph Skomski, M. Chipara, David J. Sellmyer May 2003

Spin-Wave Modes In Magnetic Nanowires, Ralph Skomski, M. Chipara, David J. Sellmyer

David Sellmyer Publications

Spin-wave modes in magnetic transition-metal nanowires having diameters of about 10 nm and lengths on the order of 1 µm are investigated by model calculations. There are quasicontinuous modes with k vectors parallel to the wires axis and discrete modes with k vectors perpendicular to the wire axis. Due to the small cross section of the wires, the perpendicular modes can be ignored in many cases and the low-temperature behavior of the wires is quasi one-dimensional. Using an analytic approach and exploiting the analogy between micromagnetism and quantum mechanics it is shown that all spin-wave modes with k vectors parallel …

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Resonant Tunneling In Magnetoresistive Ni/Nio/Co Nanowire Junctions, Andrei Sokolov, Ildar F. Sabiryanov, Evgeny Y. Tsymbal, Bernard Doudin, Xingzhong Li, Jody G. Redepenning May 2003

Resonant Tunneling In Magnetoresistive Ni/Nio/Co Nanowire Junctions, Andrei Sokolov, Ildar F. Sabiryanov, Evgeny Y. Tsymbal, Bernard Doudin, Xingzhong Li, Jody G. Redepenning

Chemistry Department: Faculty Publications

Magnetotransport studies performed on electrodeposited Ni/NiO/Co nanojunctions show a broad distribution of magnetoresistance values spanning from +40% to –25%, with an average of about 2%, corresponding to observations on large-area junctions. The dispersion in the results can be understood in terms of tunneling via localized states in the barrier. Calculations based on Landauer–Büttiker theory explain this behavior in terms of disorder-driven statistical variations in magnetoresistance with a finite probability of the inversion of tunnel magnetoresistance sign due to resonant tunneling.

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Recording Characteristics Of Perpendicular Magnetic Media With Cozrnb, Nifenb, And Exchange-Pinned Nifenb Soft Magnetic Underlayers, Min Zheng, Albert Chekanov, Geon Choe, Kenneth E. Johnson, Lan Gao, Sy_Hwang Liou May 2003

Recording Characteristics Of Perpendicular Magnetic Media With Cozrnb, Nifenb, And Exchange-Pinned Nifenb Soft Magnetic Underlayers, Min Zheng, Albert Chekanov, Geon Choe, Kenneth E. Johnson, Lan Gao, Sy_Hwang Liou

Sy-Hwang Liou Publications

The recording performance of perpendicular media with amorphous CoZrNb, nanocrystalline NiFeNb, and exchange-pinned FeMn/NiFeNb soft magnetic underlayers (SULs) has been studied. A method has been proposed to quantify the spike noises from the SUL. We found that media with higher permeability NiFeNb SULs showed 4 db higher signal-to-noise ratio than media with lower permeability CoZrNb SULs. The exchange-pinned NiFeNb SUL suppresses spike noise and offers good recording performance. Furthermore, the recording frequency dependence of dynamic coercivity (Hc) was strongly affected by the use of different SULs. The increase in dynamic Hc with linear density is negligibly …

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Magnetotransport Properties Of Cro2 Films Down To Single-Grain Sizes, Lu Yuan, Y. Ovchenkov, Andrei Sokolov, C.-S. Yang, Bernard Doudin, Sy_Hwang Liou May 2003

Magnetotransport Properties Of Cro2 Films Down To Single-Grain Sizes, Lu Yuan, Y. Ovchenkov, Andrei Sokolov, C.-S. Yang, Bernard Doudin, Sy_Hwang Liou

Sy-Hwang Liou Publications

The magnetotransport properties of CrO2 films down to single-grain sizes have been investigated. The magnetoresistance of highly grain oriented CrO2 (100) films, deposited onto TiO2 (100) substrates using a high pressure cell, has been measured in the temperature range of 1.5–300 K and in magnetic fields up to 6 T. The difference in the magnetoresistance at the low temperature of these samples is related to the value of the residual resistance ratio (RRR = R273 K/R4.2 K) of the samples. The negative magnetoresistance observed in some of these films is likely due …

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A Late Quaternary Diatom Record Of Tropical Climatic History From Lake Titicaca (Peru And Bolivia), Pedro M. Tapia, Sherilyn C. Fritz, Paul A. Baker, Geoffrey A. Seltzer, Robert B. Dunbar May 2003

A Late Quaternary Diatom Record Of Tropical Climatic History From Lake Titicaca (Peru And Bolivia), Pedro M. Tapia, Sherilyn C. Fritz, Paul A. Baker, Geoffrey A. Seltzer, Robert B. Dunbar

Department of Earth and Atmospheric Sciences: Faculty Publications

A composite high-resolution diatom stratigraphy from three piston cores and one box-core in the deep sub-basin of Lake Titicaca reveals large moisture variations during the past 30 kyr in the Altiplano region. Diatom sequences indicate orbital and millennial-scale variability in water level and salinity. The pelagic freshwater diatom species Cyclotella andina and Cyclotella stelligera dominate Glacial-age sediments, suggesting that the lake was above its present outlet. Generally, wet conditions continued until 11,000 cal yr BP, as indicated by high percentages of freshwater planktonic diatoms. Large pulses of benthic diatom species between about 11,000 and 10,000 cal yr BP suggest brief …

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A Vegetation And Fire History Of Lake Titicaca Since The Last Glacial Maximum, Gina M. Paduano, Mark B. Bush, Paul A. Baker, Sherilyn C. Fritz, Geoffrey O. Seltzer May 2003

A Vegetation And Fire History Of Lake Titicaca Since The Last Glacial Maximum, Gina M. Paduano, Mark B. Bush, Paul A. Baker, Sherilyn C. Fritz, Geoffrey O. Seltzer

Department of Earth and Atmospheric Sciences: Faculty Publications

Fine-resolution fossil pollen and charcoal analyses reconstruct a vegetation and fire history in the area surrounding Lake Titicaca (3810 m, Peru/Bolivia) since ca. 27,500 cal yr BP (hereafter BP). Time control was based on 26 accelerator mass spectrometer (AMS) radiocarbon dates. Seventeen AMS dates and 155 pollen and charcoal samples between ca. 17,500 BP and ca. 3,100 BP allow a centennial-scale reconstruction of deglacial and early- to mid-Holocene events. Local and regional fire signals were based on the separation of two charcoal size fractions, ≥180 μm and 179–65 μm. Charcoal abundance correlated closely with the proportion of woody taxa present …

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Development Of Dose Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton May 2003

Development Of Dose Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton

Transmutation Sciences Physics (TRP)

A research consortium comprised of representatives from several universities and national laboratories has been established as part of this on-going project to generate internal and external dose conversion coefficients for radionuclides produced in spallation neutron sources. Information obtained from this multi-year study will be used to support the siting and licensing of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and the Advanced Fuel Cycle Initiative (AFCI) Projects. Determination of these coefficients will also fill data gaps for several hundred radionuclides that exist in Federal Guide Report No. 11 and in …

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Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper May 2003

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of a 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 …

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Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix, Spencer M. Steinberg May 2003

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix, Spencer M. Steinberg

Separations Campaign (TRP)

The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of radioactive iodine. This proposal will develop and examine the use of Fullerene Containing Carbon (FCC) compounds as potential sorbents for iodine release from the reprocessing of nuclear fuel. This work will also include the development of bench-scale testing capabilities at UNLV to allow the testing of the FCC material in a simulated process off-gas environment. This experimental capability will also be used to test other potential sorbtion materials and processes, such as natural organic matter (NOM) and other promising alternatives. …

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Melting Processes And Fluid And Sediment Transport Rates Along The Alaska-Aleutian Arc From An Integrated U-Th-Ra-Be Isotope Study, Rhiannon George, Simon Turner, Chris Hawkesworth, Julie Morris, Chris Nye, Jeffrey G. Ryan, Shu-Hui Zheng May 2003

Melting Processes And Fluid And Sediment Transport Rates Along The Alaska-Aleutian Arc From An Integrated U-Th-Ra-Be Isotope Study, Rhiannon George, Simon Turner, Chris Hawkesworth, Julie Morris, Chris Nye, Jeffrey G. Ryan, Shu-Hui Zheng

Geology Faculty Publications

A comprehensive data set for young lavas erupted along the Alaska-Aleutian arc is used to examine how fluid and sediment transport rates and melting processes vary in response to systematic changes in subduction rate and dip along the arc and across the ocean-continent boundary. Positive correlations between convergence rate, volcano volume, and 238U excesses suggest that magmatic output is closely linked to the size of the fluid flux which occurred <10 kyr prior to eruption. Sediment-sensitive tracers like Th/Nb, Ce/Ce*, and 10Be/9Be also increase with convergence rate. However, the inferred 10Be/9Be ratio of this component is low relative to that in the incoming sediments, …

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Curie–Weiss Analysis Of Ferromagnetic And Glassy Transitions In Nanostructured Gdal2, D. Williams, P. M. Shand, C. Stark, T. Pekarek, R. Brown, Lanping Yue, Diandra Leslie-Pelecky May 2003

Curie–Weiss Analysis Of Ferromagnetic And Glassy Transitions In Nanostructured Gdal2, D. Williams, P. M. Shand, C. Stark, T. Pekarek, R. Brown, Lanping Yue, Diandra Leslie-Pelecky

Diandra Leslie-Pelecky Publications

Structural inhomogeneity on length scales comparable to magnetic interaction lengths can produce complex magnetic behavior. Crystalline GdAl2 is a ferromagnet with a Curie temperature of 170 K, while amorphous GdAl2 thin films exhibit classic spin-glass behavior with a freezing temperature of 16 K. Nanostructured GdAl2, made by mechanically milling initially crystalline GdAl2, exhibits ferromagnetic and spin-glass-like transitions; however, the spin-glass-like transition occurs at a higher temperature than the freezing temperature of amorphous GdAl2 thin films. Curie–Weiss analysis suggests that the paramagnetic-to-ferromagnetic transition is due to the ferromagnetic ordering of small GdAl2 clusters …

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Cation Intermixing And Ordering Phenomenon In M-O Layer Of Msr2ycu2oz(M-1212) Compounds With M=Fe, Co, Al, And Ga: A Neutron Powder Diffraction Study, V. P.S. Awana, E. Takayama-Muromachi, S. K. Malik, William B. Yelon, M. Karppinen, H. Yamauchi, V. V. Krishnamurthy May 2003

Cation Intermixing And Ordering Phenomenon In M-O Layer Of Msr2ycu2oz(M-1212) Compounds With M=Fe, Co, Al, And Ga: A Neutron Powder Diffraction Study, V. P.S. Awana, E. Takayama-Muromachi, S. K. Malik, William B. Yelon, M. Karppinen, H. Yamauchi, V. V. Krishnamurthy

Physics Faculty Research & Creative Works

M-1212 compounds with the composition MSr2YCu2Oz (with M = Fe, Co, Al and Ga) were studied. the phenomena of M-cation intermixing with Cu, and the ordering in the M-O layer of the M-1212 compounds when compared with the parent CuBa2YCu2O7-δ compound were investigated. Magnetization measurements and neutron powder diffraction results were presented.

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Regulation And Localization Of Endogenous Human Tristetraprolin, Anna-Marie Fairhurst, John E. Connolly, Katharine A Hintz, Nicolas J Goulding May 2003

Regulation And Localization Of Endogenous Human Tristetraprolin, Anna-Marie Fairhurst, John E. Connolly, Katharine A Hintz, Nicolas J Goulding

Dartmouth Scholarship

Tumor necrosis factor (TNF) has been implicated in the development and pathogenicity of infectious diseases and autoimmune disorders, such as septic shock and arthritis. The zinc-finger protein tristetraprolin (TTP) has been identified as a major regulator of TNF biosynthesis. To define its intracellular location and examine its regulation of TNF, a quantitive intracellular staining assay specific for TTP was developed. We establish for the first time that in peripheral blood leukocytes, express

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Linearized Stability Analysis Of Accelerated Planar And Spherical Fluid Interfaces With Slow Compression, John D. Ramshaw, Peter A. Amendt May 2003

Linearized Stability Analysis Of Accelerated Planar And Spherical Fluid Interfaces With Slow Compression, John D. Ramshaw, Peter A. Amendt

Physics Faculty Publications and Presentations

We present linearized stability analyses of the effect of slow anisotropic compression or expansion on the growth of perturbations at accelerated fluid interfaces in both planar and spherical geometries. The interface separates two fluids with different densities, compressibilities, and compression rates. We show that a perturbation of large mode number on a spherical interface grows at precisely the same rate as a similar perturbation on a planar interface subjected to the same normal and transverse compression rates.

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Leading Proton Production In E + P Collisions At Hera, S. Chekanov, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Anzivino, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari May 2003

Leading Proton Production In E + P Collisions At Hera, S. Chekanov, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Anzivino, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari

Faculty Publications

Events with a final-state proton carrying a large fraction of the proton beam momentum, x L >0.6, and the square of the transverse momentum p T2

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Ecomorphology Of Bats: Comparative And Experimental Approaches Relating Structural Design To Ecology, Sharon M. Swartz, Patricia W. Freeman, Elizabeth F. Stockwell May 2003

Ecomorphology Of Bats: Comparative And Experimental Approaches Relating Structural Design To Ecology, Sharon M. Swartz, Patricia W. Freeman, Elizabeth F. Stockwell

School of Natural Resources: Faculty Publications

The past several decades have seen the beginning of integration of discoveries in the ecology and morphology of bats into an ecomorphological whole that promises to be greater than the sum of its parts. However, achieving this integration is challenging. Each of the elements of this interdisciplinary field is, in itself, avast and complex subject. This book is a testament to the breadth and depth of ecological studies of bats. Morphological studies now extend be- yond descriptive anatomy in both outlook and method, and incorporate, for example, aspects of genetics, physiology, solid and fluid mechanics, and developmental biology. There is …

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Efficient Security For Bgp Route Announcements, David M. Nicol, Sean W. Smith, Meiyuan Zhao May 2003

Efficient Security For Bgp Route Announcements, David M. Nicol, Sean W. Smith, Meiyuan Zhao

Computer Science Technical Reports

The Border Gateway Protocol (BGP) determines how Internet traffic is routed throughout the entire world; malicious behavior by one or more BGP speakers could create serious security issues. Since the protocol depends on a speaker honestly reporting path information sent by previous speakers and involves a large number of independent speakers, the Secure BGP (S-BGP) approach uses public-key cryptography to ensure that a malicious speaker cannot fabricate this information. However, such public-key cryptography is expensive: S-BGP requires a digital signature operation on each announcement sent to each peer, and a linear (in the length of the path) number of verifications …

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Evidence For A Suprathermal Seed Population Of Heavy Ions Accelerated By Interplanetary Shocks Near 1 Au, Mihir I. Desai, Glenn M. Mason, Joseph R. Dwyer, Joseph E. Mazur, Robert E. Gold, Stamatios M. Krimigis, Charles W. Smith, Ruth M. Skoug May 2003

Evidence For A Suprathermal Seed Population Of Heavy Ions Accelerated By Interplanetary Shocks Near 1 Au, Mihir I. Desai, Glenn M. Mason, Joseph R. Dwyer, Joseph E. Mazur, Robert E. Gold, Stamatios M. Krimigis, Charles W. Smith, Ruth M. Skoug

Aerospace, Physics, and Space Science Faculty Publications

We have surveyed the 0.1-10 MeV nucleonˉ¹ elemental abundances at 72 interplanetary (IP) shocks observed by the Ultra-Low-Energy Isotope Spectrometer on board the Advanced Composition Explorer from 1997 October through 2002 September. We find the following: (1) The C/O ratios in IP shocks were substantially depleted (by more than ∼40%) relative to solar wind values. (2) The IP shock abundances were poorly correlated with those measured in the slow and fast solar wind. (3) Energetic ions above ∼0.1 MeV nucleonˉ¹ from impulsive and gradual solar energetic particle events (SEPs) were present upstream of all the IP shocks in our survey. …

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Travel Time Study At The Wetlands Park National Preserve, Brandon Bair May 2003

Travel Time Study At The Wetlands Park National Preserve, Brandon Bair

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis reports on a study of the residence time of water in the Wetlands Park Nature Preserve in Henderson, Nevada. Rhodamine WT was used in order to test for the travel time of the water from the Monson Channel inflow to the Nature Preserve outflow to the Las Vegas Wash. The initial hypothesis was that the water would stay in the system for approximately 8 days. Residence time was tested using an ISCO sampling machine along with a Sequoia-Turner model 450 fluorimeter to test for the fluoresce of the dye in the water. All samples collected were taken immediately …

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