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Displaying 1076 - 1100 of 1721

High-Frequency Dielectric Relaxation in Trehalose-Glycerol Mixtures

February 1, 2004
Author(s)
O Anopchenko, Jan Obrzut, Bert W. Rust
Broadband dielectric measurements were performed on a series of trehalose-glycerol mixtures in a wide concentration range of glycerol and temperature swept from 220 K to 350 K. Relaxation spectra were obtained directly from the measured dielectric spectra

Investigations of Electrospray Sample Deposition for Polymer MALDI Mass Spectrometry

February 1, 2004
Author(s)
S D. Hanton, I Z. Hyder, J R. Stets, K G. Owens, William R. Blair, Charles M. Guttman, Anthony A. Giuseppetti
In the interest of more thoroughly understanding the relationship between sample preparation technique and spectra quality produced in Matrix-Assisted Laser Desorption/Ionization (MALDI) mass spectrometry, we have investigated details of the Electrospray

Quantitative Response Measurement of Cell Substrate Interactions via RT-PCR

February 1, 2004
Author(s)
Matthew Becker, L A. Bailey, Karen L. Wooley, J Kohn, Eric J. Amis, N Washburn
High-throughput metrologies for the rapid and systematic evaluation of synthetic materials, which would elucidate a candidate s potential biocompatibility, are needed. New synthetic methodologies have enabled a remarkable advance in the rational design of

Significant Parameters in the Optimization of MALDI-TOF-MS

February 1, 2004
Author(s)
S Wetzel, Kathleen M. Flynn, James J. Filliben
One of the most significant issues in any analytical technique is optimization. Optimization and calibration are key factors in quantitation. In matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), one of the

Soft X-Ray Absorption Spectroscopic Study of a LiNi 0.5 Mn 0.5 O 2 Cathode During Charge

February 1, 2004
Author(s)
W S. Yoon, Mahalingam Balasubramanian, Xiao-Qing Yang, Ziwen Fu, Daniel A. Fischer, James McBreen
Soft X-ray (200 eV to 1000 eV) absorption spectroscopy (XAS) at the O K-edge and the metal L II, III-edges, in both the fluorescence yield (FY) and the partial electron yield (PEY) mode, has been used to probe the electronic structure of electrochemically

Strength of Silicon Containing Nanoscale Flaws

February 1, 2004
Author(s)
Antonia Pajares, Michael Chumakov, Brian R. Lawn
A study was made of the strength of highly polished silicon surfaces after nanoindentation with a Berkovich diamond. Strengths of the indented surfaces were measured as a function of flaw size, quantified by indenter penetration. Analogous data from etched

Bayesian Analysis of Ceria Nanoparticles From Line Profile Data

January 12, 2004
Author(s)
N G. Armstrong, A Dowd, James Cline, W Kalceff
A Bayesian/Maximum entropy (MaxEnt) method is applied to quantify the broadening of X-ray line profiles in terms of the nanocrystallite size effects in ceria. The analysis is in general agreement with transmission electron microscopy results, while

Combined NMR and XAS Study on Local Environments and Electronic Structures of the Electrochemically Li-Ion Deintercalated Li1-xCo1/3Ni1/3Mn1/302 Electrode System

January 1, 2004
Author(s)
W S. Yoon, C P. Grey, Mahalingam Balasubramanian, Xiao-Qing Yang, Daniel A. Fischer, James McBreen
Combined 6Li MAS NMR, in-situ metal K-edge (hard) XAS, and O K-edge (soft) XAS have been carried out during the first charging process for the layered Li1-xCo1/3Ni1/3Mn1/3O2 cathode material. The 6Li MAS NMR results showed the prescence of Li in the Ni2+

Flux Loss Measurements of Ag- Sheathed Bi-2223 Tapes

January 1, 2004
Author(s)
Mi-Hye Jang, Winnie K. Wong-Ng, Robert D. Shull, Lawrence P. Cook, DeaSik Suh
Alternating current (AC) losses of two Bi-2223 ([Bi, Pb] : Sr : Ca : Cu :O = 2:2:2:3) tapes [one untwisted (Tape I, twist-pitch of mm) and the other with a twist-pitch of 8mm (Tape II)] were measured and compared. These samples, produced by the powder-in

In-Vitro Contact Wear of Dental Composites

January 1, 2004
Author(s)
V S. Nagarajan, S Jahanmir, V P. Thompson
Three commercial dental composites with filler loading of 75-76 wt% were evaluated. The wear results were compared with those reported in an earlier study on a highly filled composite containing predominately alumino-silicate glass fillers and alumina at a

International Interlaboratory Comparison of Mixtures of Polystyrenes With Different End Groups Obtained by Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS): Preliminary Results

January 1, 2004
Author(s)
Charles M. Guttman, S Wetzel, Kathleen M. Flynn, B M. Fanconi, William E. Wallace, David L. VanderHart
NIST has sponsored a MALDI-TOF-MS interlaboratory comparison of mixtures of polymers of the same repeat unit with closely matching molecular masses but with different end groups. This interlaboratory comparison was designed to see how well a group of labs
Displaying 1076 - 1100 of 1721