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Journals

A Matrix-Free Algorithm for the Large-Scale Constrained Trust-Region Subproblem

April 28, 2006

Author(s)

Anthony J. Kearsley

A new matrix-free algorithm for the solution of linear inequality constrained, large-scale trust-region sub-problems is presented. The matrix-free nature of the...

Methyltriacetylene (Ch₃C₆H) Toward TMC-1: Presently, the Largest Detected Symmetric Top

April 28, 2006

Author(s)

A Remijan, J M. Hollis, Lewis E. Snyder, P R. Jewell, Francis J. Lovas

We report the detection of a new interstellar methylpolyyne, CH3C6H (methyltriacetylene) with the 100-m Green Bank Telescope (GBT). Ten spectral lines of this...

Inertance Tube Optimization for Pulse Tube Refrigerators

April 27, 2006

Author(s)

Ray Radebaugh, Michael A. Lewis, Ercang Lou, John M. Pfotenhauer, G. F. Nellis, L. F. Schunk

The efficiency of regenerative refrigerators is generally maximized when the pressure and flow are in phase near the midpoint of the regenerator. Such a phase...

Regenerator Operation at Very High Frequencies for Microcryocoolers

April 27, 2006

Author(s)

Ray Radebaugh, Agnes A. O'Gallagher

The size of Stirling and Stirling-type pulse tube cryocoolers is dominated by the size of the pressure oscillator. Such cryocoolers typically operate at...

Amorphous FeCoCrZrB Ferromagnets for Use as High-Temperature Magnetic Refrigerants

April 27, 2006

Author(s)

Freemon Johnson, Robert D. Shull

Magnetic metallic glasses, having large magnetic moments and high Curie Temperatures (TC), have not been widely studied as magnetic refrigerants. In this study...

The Effects of Small Metal Additions (Co, Cu, Ga, Mn, Al, Bi, Sn) on the Magnetocaloric Properties of the Gd₅Ge₂Si₂ Alloy

April 26, 2006

Author(s)

Robert D. Shull, Virgil Provenzano, Alexander J. Shapiro, A Fu, M W. Lufaso, E Karapetrova, G Kletetschka, V Mikula

It was shown that adding one atomic percent Fe to Gd5Ge2Si2 greatly reduced its large hysteresis losses, broadened the magnetic entropy change, ?Sm, versus...

Effect of Surfactants on Physicochemical Properties of Amorphous Calcium Phosphate Filled Composites

April 26, 2006

Author(s)

Joseph M. Antonucci, Drago Skrtic

Our recent research on amorphous calcium phosphate (ACP) dental materials has resulted in biocompatible composites with high remineralizing ability and moderate...

Structure/Property Relationships in Urethane Dimethacrylate-Based ACP Composites

April 26, 2006

Author(s)

William Regnault, Tonya Icenogle, Joseph M. Antonucci, Da-Wei Liu, Drago Skrtic

In this study, the effects of two comonomers (the low molecular mass, hydrophilic 2-hydroxyethyl methacrylate (HEMA) vs. the high molecular mass, less...

Strong Calcium Phosphate Cement-Chitosan-Mesh Construct Containing Cell-Encapsulating Hydrogel Beads for Bone Tissue Engineering

April 25, 2006

Author(s)

Michael Weir, Hockin D. Xu, Carl G. Simon Jr.

Calcium phosphate cement (CPC) can conform to complex cavity shapes and set in situ to form bioresorbable hydroxyapatite. The aim of this study was to introduce...

Quantum depletion of a soliton condensate

April 25, 2006

Author(s)

Lu Deng, Guoxiang Huang

We present rigorous results on the diagonalization of Bogoliubov Hamiltonian for a soliton condensate. Using the complete and orthonormalized set of...

Multiparameter Equations of State for Selected Siloxanes

April 25, 2006

Author(s)

P. Colonna, R. Nannan, A. Guardone, Eric Lemmon

The development of technical equations of state using the 12-parameter Span-Wagner functional form for four siloxanes is presented in two parts. The fluids...

The Effect of Stress Induced Anisotropy in Patterned FeCo Thin Film Structures

April 24, 2006

Author(s)

W Yu, J A. Bain, Willard C. Uhlig, John Unguris

In this work, 1 υm thick FeCeo films with -320 MPa compressive stress and FeCo/NiFe films with 600 MPa tensile stress were patterened into 5υm x 20 υm elements...

Improved Liquid Chromatography Methods for the Separation and Quantification of Biotin in Multivitamin/Multielement Tablets

April 24, 2006

Author(s)

B C. Nelson, Katherine E. Sharpless, Lane C. Sander

Two independently developed liquid chromatography (LC) methods for the quantitative determination of biotin in multivitamin/multielement tablets (NIST Standard...

High Speed Quantum Key Distribution System Supports One-Time Pad Encryption of Real-Time Video

April 21, 2006

Author(s)

Alan Mink, Xiao Tang, Lijun Ma, Anastase Nakassis, Barry J. Hershman, Joshua C. Bienfang, David H. Su, Ronald F. Boisvert, Charles W. Clark, Carl J. Williams

NIST has developed a high-speed quantum key distribution (QKD) test bed incorporating both free-space and fiber systems. These systems demonstrate a major...

Unusual Magnetization Reversal in [Co/Pt]4 Multilayers With Perpendicular Anisotropy

April 21, 2006

Author(s)

X M. Cheng, Valerian I. Nikitenko, Alexander J. Shapiro, Robert D. Shull, C L. Chien

Unusual magnetization reversal of [Co(4 )/Pt(10 )]4 multilayers with perpendicular magnetic anisotropy has been revealed macroscopically by magnetometry...

Characterization of Magnetic Properties at Edges by Edge Mode Dynamics

April 21, 2006

Author(s)

Brian B. Maranville, Robert McMichael, Sudook A. Kim, Ward L. Johnson, C A. Ross, J Cheng

We have used trapped spinwave or edge modes of magnetic precession to probe the magnetic environment near magnetic film edges magnetized perpendicular to the...

Near-Field Imaging of High Frequency Magnetic Fields with Calorimetric Cantilevers Probes

April 21, 2006

Author(s)

Simone Lee, Y. C. Lee, Thomas Mitchell (Mitch) Wallis, John M. Moreland, Pavel Kabos

Calorimetric probes for near-field imaging of high-frequency (1-20 GHz) magnetic fields were fabricated by depositing patterned metal structures on...

Structure and Magnetocaloric Properties of the Fe-Doped HoTiGe Alloy

April 20, 2006

Author(s)

Virgil Provenzano, B Baumgold, Robert D. Shull, Alexander J. Shapiro, Keiichi Koyama, Kazuo Watanabe, N K. Singh, K G. Suresh, A K. Nigam, S K. Malik

The structure and magnetocaloric properties of the Fe-doped HoTiGe compound were investigated by means of scanning electron microscopy (SEM), energy dispersive...

Hot-wire chemical vapor synthesis for a variety of nano-materials with novel aplications

April 20, 2006

Author(s)

Anne Dillon, A. H. Mahan, Rohit Deshpande, J. L. Alleman, Jeffrey Blackburn, P. A. Parillia, M. J. Heben, Chaiwat Engtrakul, K.E.H. Gilbert, Kevin M. Jones, Bobby To, S Lee, John H. Lehman

Hot-wire chemical vapor deposition (HWCVD) has been demonstrated as a simple economically scalable technique for the synthesis of a variety of nano-materials in...

Particle Size Distribution by LASER Diffraction Spectrometry: Application to Cementitious Powders

April 19, 2006

Author(s)

Chiara F. Ferraris, Jeffrey W. Bullard, Vincent A. Hackley

Particle size distribution (PSD) measurements are now routinely employed to characterize cement powders. A variety of techniques is available for this purpose...

Interface Characterization of Molecular-Monolayer/SiO2 Based Molecular Junctions

April 19, 2006

Author(s)

Curt A. Richter, Christina Hacker, Lee J. Richter, Oleg A. Kirillov, John S. Suehle, Eric M. Vogel

We present a correlation of the results of dc-current-voltage (IV) and ac-capacitance-voltage (CV) measurements with vibrational spectroscopy of Au/monolayer...

Magnetic Fluids' Phase Transition Between Micelle and Mono-Dispersed Phases

April 18, 2006

Author(s)

S Taketomi, R V. Drew, Robert D. Shull

A very stably dispersed magnetic fluid (Mother MF) and its 1000-times diluted solution were independently zero-field-cooled from room temperature to 5 K...

Controlling Polar Molecules in Optical Lattices

April 17, 2006

Author(s)

Svetlana A. Kotochigova, Eite Tiesinga

We determine conditions for effective quantum control over internal and external degrees of freedom of polar alkali-metal molecules in optical lattices. We show...

Electronic Effects in Length Distribution of Atom Chains

April 17, 2006

Author(s)

Jason Crain, Mark D. Stiles, Joseph A. Stroscio, Daniel T. Pierce

Gold deposited on Si(553) leads to self assembly of atomic chains, which are broken into finite segments by atomic defects. Scanning tunneling microscopy is...

Suppression of Orange-Peel Coupling in Magnetic Tunnel Junctions by Preoxidation

April 17, 2006

Author(s)

William F. Egelhoff Jr., Robert McMichael, Cindi L. Dennis, Mark D. Stiles, Alexander J. Shapiro, Brian B. Maranville, Cedric J. Powell

We have found that preoxidation of the bottom Co electrode in magnetic tunnel junctions (MTJs) very effectively suppresses orange-peel coupling. The result is a...

Erbium-doped Gold Sensor Films for Magnetic Microcalorimeter X-ray Detectors*

April 17, 2006

Author(s)

Barry L. Zink, Kent D. Irwin, Gene C. Hilton, Joel Ullom, David P. Pappas

We briefly review the principles of a magnetic microcalorimeter x-ray detector and the requirements for fabricating an array of these sensors, which include a...

Size Dependent Transition from Shape to Exchange Dominated Magnetic Nanostructures in Patterned Zigzags

April 17, 2006

Author(s)

Willard C. Uhlig, John Unguris

In order to quantitatively investigate the interplay between shape anisotropy (magnetostatics) and exchange, patterned zigzag structures were prepared with...

Optimization of Transition-Edge Calorimeter Performance

April 15, 2006

Author(s)

Joel N. Ullom, James A. Beall, William B. Doriese, William Duncan, S. L. Ferreira, Gene C. Hilton, Kent D. Irwin, Galen C. O'Neil, Carl D. Reintsema, Leila R. Vale, Barry L. Zink

Calorimeters that exploit the superconducting-to-normal transition are used to detect individual photons from near-infrared to γ-ray wavelengths. Across this...

Normal Metal-insulator-superconductor Junction Technology for Bolometers

April 15, 2006

Author(s)

Dan Schmidt, William Duncan, Kent D. Irwin, Konrad Lehnert, Nathan A. Tomlin, Joel Ullom

Normal metal-insulator-superconductor tunnel junctions are candidates for large-format arrays of ultra-low noise equivalent power bolometers. Using a wafer...

Laser Cooling Without Repumping: A Magneto-Optical Trap for Erbium Atoms

April 14, 2006

Author(s)

Jabez J. McClelland, James L. Hanssen

We report on a novel mechanism that allows for laser cooling of atoms that do not have a closed cycling transition. This mechanism is observed in a magneto...

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