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Displaying 30126 - 30150 of 73929

Precise Wavelengths for Fe, Ge and Pt in the Region Near 1935

October 16, 2008
Author(s)
Gillian Nave, Craig J. Sansonetti
Wavelengths of seven spectral lines of Fe I, Ge I and Pt I between 1932 and 1938 have been measured with uncertainties of less than 1x10 -4 (5 parts in 10 8) using Fourier transform spectroscopy. These lines provide accurate standards for wavelength

Precision Measurement of the 29 Si, 33 S, and 36 Cl Binding Energies

October 16, 2008
Author(s)
Maynard S. Dewey, Ernest G. Kessler Jr., R Deslattes, H G. Borner, M Jentschel, C Doll, P Mutti
The binding energies of 29Si, 33S, and 36Cl have been measured with a relative uncertainty 0.65 x 10 -6 using a flat-crystal spectrometer. The unique features of these measurements are 1) nearly perfect crystals whose lattice spacing is known in meters, 2

Predicting the Location of Low-Angle Boundaries in Single-Crystal Castings

October 16, 2008
Author(s)
R E. Napolitano, Robert J. Schaefer
A set of nickel-based superalloy single-crystal investment castings was produced and evaluated for crystal perfection. Defect structures near the seed emergence point and other geometric features were examined using x-ray topography. Topographic images

Prediction of Uniaxial Extension, Pure Shear and Equibiaxial Responses in Constant Deformation Rate Experiments from Single Step Stress Relaxation Experiments in Uniaxial Extension

October 16, 2008
Author(s)
J M. Niemiec, G B. McKenna, J Sweeney, I M. Ward
In working with non-linear constitutive descriptions for polymer melts, it is often forgotten how difficult it is to obtain the experimental data that are essential to their implementation in other than laboratory level tests. Here we adopt methods that

Preface to Dislocatrions 2000 Proceedings

October 16, 2008
Author(s)
Lyle E. Levine, L -. Kubin, R -. Becker
During the 1950's and 1960's, a widespread international effort was underway to lay the foundations for a fundamental, dislocations-based understanding of plastic deformation and strain hardening. This effort lagged, however, as the existing theoretical

Primary Radioactive Gas Standards (Excluding Radon)

October 16, 2008
Author(s)
Michael P. Unterweger
This paper presents an overview of the primary calibration of radioactive gas standards using length-compensated internal gas counters. The principal of length compensation and the effects of high voltage, detector material, and gas pressure are discussed

Processing Phase Diagram of Melt-Dispersed Carbon-Nanotubes

October 16, 2008
Author(s)
Erik K. Hobbie, Jan Obrzut, H Wang, E A. Grulke, D J. Fry
We measure the processing 'phase diagram' of a model carbon-nanotube polymer melt composite in the parameter space of concentration, shear stress, and confinement. With decreasing strain rate, we observe a hierarchy of flow-induced structure, from flow

Progress on low-frequency active vibration isolation

October 16, 2008
Author(s)
S J. Richman
The gravity group at JILA is constructing a three-stage active isolation system to demonstrate useful reduction of low-frequency seismic noise for a gravitational wave interferometer. The control loops on the first two stages are now fully functional in

Properties of Calcium Phosphate Carbonate Cements

October 16, 2008
Author(s)
Milenko Markovic, Shozo Takagi, Laurence C. Chow
The physicochemical and mechanical properties of two calcium phosphate carbonate cements (CPCC-1 and CPCC-2) formed in solution reaction of (1) [alpha]-tricalcium phosphate ([alpha]-TCP),[alpha]-Ca 3(PO 4)d2^, with calcium carbonate, CaCO 3, and (2)

Prospects for a Truly Portable Absolute Gravimeter

October 16, 2008
Author(s)
J E. Faller, A L. Vitouchkine
Absolute gravity measurements offer teh possibility of measuring vertical height changes (the subject of this meeting) at the centimeter level. Today's absolute instruments, though capable of achieving the requisite level of accuracy (1-2 gals), are still
Displaying 30126 - 30150 of 73929
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