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Displaying 22676 - 22700 of 74178

Nanomechanical properties of polyethylene glycol brushes on gold substrates

February 15, 2012
Author(s)
Gheorghe NMN Stan, Frank W. DelRio, Robert I. MacCuspie, Robert F. Cook
Brushes of polyethylene glycol (PEG) were directly anchored onto bare gold substrates in solution. The nucleation kinetics of PEG binding were investigated successively in solution and dry air using atomic force microscopy (AFM) imaging. In addition, force

Penning traps with unitary architecture for storage of highly charged ions

February 15, 2012
Author(s)
Joseph N. Tan, Samuel M. Brewer, Nicholas D. Guise
Penning traps are made extremely compact by embedding rare-earth permanent magnets in the electrode structure. Axially-oriented NdFeB magnets are used to produce 0.32 T for ion trapping in unitary architectures that functionally couple the electric and

Semiclassical fifth virial coefficients for improved ab initio helium--4 standards

February 15, 2012
Author(s)
Katherine Shaul, Andrew Schultz, David A. Kofke, Michael R. Moldover
For helium-4, we present ab initio, semi-classical calculations of virial coefficients Bn for for n = 2, 3, 4, and 5 from 50 K to 1000 K. Using our values of B4 and B5 and the more accurate literature values of B2 and B3, we argue that the ab initio virial

Spatial distribution of bottlenose dolphins (Tursiops truncatus) inferred from stable isotopes and priority organic pollutants

February 15, 2012
Author(s)
Rachel Wilson, John Kucklick, Brian C. Balmer, Randall Wells, Jeffery Chanton, Doug Nowacek
Differences in priority organic pollutants (POPs), analyzed by gas chromatography-mass spectrometry, and stable isotope ratios (δ¹³C, δ³⁴S, and δ¹⁵N; analyzed by isotope ratio-mass spectrometry), divide 77 bottle- nose dolphins (Tursiops truncatus) from

Temperature Dependence of Structure and Density for D 2 O Confined in MCM-41-S

February 15, 2012
Author(s)
William A. Kamitakahara, Antonio Faraone, Kao-Hsiang Liu, Chung-Yuan Mou
Using neutron diffraction, we have tracked the temperature dependence of structural properties for heavy water confined in the nanoporous silica matrix MCM-41-S. By observing the correlation peak corresponding to the pore-pore distance, which is determined

Quantum state preparation and control of single molecular ions

February 14, 2012
Author(s)
Dietrich G. Leibfried
Preparing molecules at rest and in a highly pure electronic, rotational and vibrational quantum state is a long standing dream in chemistry and physics, so far only achieved for a select set of molecules in experimental setups dedicated to that species

Anharmonic Phonons and Magnons in BiFeO 3

February 13, 2012
Author(s)
O. Delaire, M. B. Stone, J. Ma, A. Huq, D. Gout, Craig Brown, K. F. Wang, Z. F. Ren
The phonon density of states (DOS) and magnetic excitation spectrum of polycrystalline BiFeO 3 were measured for temperatures 200 less than or equal to}Τ less than or equal to} 750K, using inelastic neutron scattering (INS). Our results indicate that the

Demonstration of code-division multiplexing for x-ray microcalorimeters

February 13, 2012
Author(s)
Greg Stiehl, W.Bertrand (Randy) Doriese, Gene C. Hilton, Kent D. Irwin, Carl D. Reintsema, Dan Schmidt, Daniel Swetz, Joel Ullom, Leila R. Vale, Joseph Fowler
We demonstrate the code-division multiplexing (CDM) readout of eight transition-edge sensor microcalorimeters. The energy resolution is 3.0 eV (full width at half-maximum) or better at 5.9 keV, with a best resolution of 2.3 eV and a mean of 2.6 eV over the

Advanced Code-Division Multiplexers for Superconducting Detector Arrays

February 11, 2012
Author(s)
Kent D. Irwin, Hsiao-Mei Cho, William B. Doriese, Joseph W. Fowler, Gene C. Hilton, Michael D. Niemack, Carl D. Reintsema, Daniel R. Schmidt, Joel N. Ullom, Leila R. Vale
Multiplexers based on the modulation of superconducting quantum interference devices are now regularly used in multi-kilopixel arrays of superconducting detectors for astrophysics, cosmology, and materials analysis. Over the next decade, much larger arrays

Formation and structure of 360 and 540 degree domain walls in thin magnetic stripes

February 10, 2012
Author(s)
Youngman Jang, Samuel R. Bowden, Mark Mascaro, John Unguris, Caroline Ross
360˚, 540˚ and other complex transverse domain walls have been created in narrow Co wires connected to injection pads by cycling a magnetic field perpendicular to the wire length. The composite walls, formed by impingement of 180˚ transverse walls of

Experimental Study of the Three Dimensional Internal Structure of Underventilated Compartment Fires in an ISO 9705 Room.

February 8, 2012
Author(s)
Kelly M. Opert, Andrew J. Lock, Matthew F. Bundy, Erik L. Johnsson, Cheolhong Hwang, Anthony P. Hamins, Stephen P. Fuss, Ki-Yong Lee
This report documents a set of 9 full scale ISO 9705 room under-ventilated compartment fire experiments for the purpose of guiding the development of the National Institute of Standards and Technology (NIST) computer fire model - Fire Dynamics Simulator

Low Energy Spin Dynamics in the Spin Ice, Ho 2 Sn 2 O 7

February 8, 2012
Author(s)
G. Ehlers, A. Huq, S. O. Diallo, C. Adriano, K. C. Rule, A. L. Cornelius, P. Fouquet, P. G. Pagliuso, Jason S. Gardner
The magnetic properties of Ho 2Sn 2O 7 have been investigated and compared to other spin ice compounds. Although the lattice has expanded by 3% relative to the better studied Ho 2Ti 2O 7 spin ice, no significant changes were observed in the high

Using Truncated Data Sets in Spherical Scanning Antenna Measurements

February 8, 2012
Author(s)
Ronald C. Wittmann, Carl F. Stubenrauch, Michael H. Francis
We discuss the mitigation of truncation errors in spherical scanning measurements. The main emphasis is the spherical harmonic representation of probe transmitting and receiving functions; however, our method is applicable to near-field measurement of

A New Generation of Grain Moisture Meters

February 6, 2012
Author(s)
Gloria D. Lee
One of the current technologies used in the commercial determination of grain moisture is dielectric technology, a technology that has been used for over 60 years. Although this technology has some inherent limitations, meter moisture determination has
Displaying 22676 - 22700 of 74178