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Displaying 601 - 625 of 807

Search for a T-odd, P-even Triple Correlation in Neutron Decay

September 14, 2012
Author(s)
Jeffrey S. Nico, T E. Chupp, K P. Coulter, R L. Cooper, S. J. Freeman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Hans P. Mumm, Alan K. Thompson, C A. Trull, F. E. Wiefeldt, J. F. Wilkerson
Time-reversal-invariance (T) violation, or equivalently, assuming charge-conjugation-parity-time-reversal (CPT) invariance, CP violation may explain the observed cosmological baryon asymmetry as well as signal physics beyond the Standard Model. In the

A New Limit on Time-Reversal Violation in Beta Decay

September 2, 2012
Author(s)
Hans P. Mumm, T E. Chupp, K P. Coulter, R L. Cooper, S J. Freedman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Jeffrey S. Nico, Alan K. Thompson, C A. Trull, J. F. Wilkerson, F. E. Wiefeldt
We report the results of an improved determination of the triple correlation DP • (p_e × p_v) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is

Vertically Segregated Structure and Properties of small molecule-polymer blend semiconductors for organic thin film transistors

August 27, 2012
Author(s)
Nayool Shin, Dean DeLongchamp, Jihoon Kang, Regis J. Kline, Lee J. Richter, Vivek Prabhu, Balaji Purushothamanc, John E. Anthony, Do Y. Yoon
The phase-segregated structure and the electrical properties of thin film blends of the small-molecule semiconductor fluorinated 5,11-bis(triethylsilylethynyl) anthradithiophene with insulating binder polymers were studied for organic thin film transistor

High-resolution neutron radiography of through-plane liquid water distribution in polymer electrolyte membrane and gas diffusion layer

August 14, 2012
Author(s)
Daniel S. Hussey, David L. Jacobson, Richard Fu, Ugur Pasaogullari, Takeshi Shiomi, Yuichiro Tabuchi
We re-investigate our previously studied water transport phenomena under nonisothermal conditions by measuring the through-plane liquid water distribution across PEFC components with the state-of-the-art high-resolution neutron radiography. A corrective

Solution-phase and Magnetic Approach Towards Understanding Iron Gall Inks

August 13, 2012
Author(s)
Harshita Kumari, Steven R. Kline, Cindi L. Dennis, Andrew V. Mossine, Rick L. Paul, Carol A. Deakyne, Jerry L. Atwood
Crystallization of compounds of iron with polyphenols, such as iron gall inks, has been an ongoing challenge. As with iron-gall inks, iron complexes of 1,2,3-trihydroxphenol-containing marocycles have also proved difficult to crystallize. Despite this

A gamma and X-ray dector for cryogenic, high magnetic field applications

July 13, 2012
Author(s)
Thomas R. Gentile, R L. Cooper, R. Alarcon, M J. Bales, E J. Beise, H Breuer, J. Byrne, T E. Chupp, Kevin J. Coakley, Maynard S. Dewey, Changbo Fu, Hans P. Mumm, Jeffrey S. Nico, B. O'Neill, K. Pulliam, Alan Keith Thompson, F E. Wietfeldt
As part of an experiment to measure the spectrum of photons emitted in beta-decay of the free neu- tron, we developed and operated a detector consisting of 12 bismuth germanate (BGO) crystals coupled to avalanche photodiodes (APDs). The detector was

In-situ Polarized 3He system for the Magnetism Reflectometer at the Spallation Neutron Source

July 2, 2012
Author(s)
Thomas R. Gentile, X Tong, C Y. Jiang, V Lauter, H. Ambaye, D. Brown, L Crow, R J. Goyette, W-T Lee, A. Parizzi
We report on the in-situ polarized 3He neutron polarization analyzer developed for the time-of-flight Magnetism Reflectometer (MAGICS) at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). Using the spin exchange optical pumping

Pronounced micro-segregation in a sorbitol water mixture observed through variable temperature neutron scattering

May 16, 2012
Author(s)
Shin G. Chou, Sheila Khodadadi, Joseph E. Curtis, Susan Krueger, Evgenyi Shalaev, Alan Soper, Andy Fitch, T Narayanan, Michael Szutucki, Marcus T. Cicerone
In this study, we use small and wide angle X-ray and neutron scattering measurements, to study the structure of concentrated sorbitol solutions and glasses at different temperatures. The analysis of the data suggests the water forms clusters with a

Neutron reflectivity characterization of the photoacid reaction-diffusion latent and developed images of molecular resists for extreme-ultraviolet lithography

May 11, 2012
Author(s)
Vivek M. Prabhu, Shuhui Kang, Wen-Li Wu, Sushil K. Satija, Christopher K. Ober, Jing Sha, Peter V. Bonnesen
Lithographic feature size requirements have approached a few radius of gyration of chemically-amplified photoresist polymers used in thin film patterning. Further, the feature dimensions are commensurate with the photoacid diffusion length that defines the

Inelastic Neutron Scattering on Polymer Electrolytes for Lithium-Ion Batteries

May 7, 2012
Author(s)
Huagen H. Peng, Madhu Sudan Tyagi, Kirt A. Page, Christopher Soles
The relationship between ion transport and polymer dynamics is central to the pursuit of solid polymer electrolytes for lithium batteries. This understanding is critical to achieve solid polymer electrolyte systems of sufficiently high ion conductivities

Response of large area avalanche photodiodes to low energy X-rays

April 30, 2012
Author(s)
Thomas R. Gentile, Uwe Arp, M J. Bales, R Farrell
For an experiment to study neutron radiative beta-decay, we operated large area avalanche photodiodes (APDs) at liquid nitrogen temperature to detect X-rays with energies between 0.2 keV and 15 keV. Whereas there are numerous reports of X-ray spectrometry

Frequency-stabilized cavity ring-down spectroscopy

March 21, 2012
Author(s)
David A. Long, A. Cygan, Roger D. van Zee, Mitchio Okumura, C. E. Miller, D Lisak, Joseph T. Hodges
This Frontiers article describes frequency-stabilized cavity ring-down spectroscopy (FS-CRDS), an ultraprecise refinement of conventional cw-CRDS. We review the technique and highlight some recent studies which have utilized FS-CRDS to perform precision

Double-Focusing Thermal Triple-Axis Spectrometer at the NCNR

February 2, 2012
Author(s)
Y. Chen, Sung Chang, Yang Zhao, Songxue Chi, William D. Ratcliff, B. G. Ueland, Ross Erwin
The new thermal triple-axis spectrometer at the NIST Center for Neutron Research (NCNR) is located at the BT-7 beam port. The 165 mm diameter reactor beam is equipped with a selection of Söller collimators, beam-limiters, and pyrolytic graphite (PG) filter

Quantum Hall effect on centimeter scale chemical vapor deposited graphene films

December 7, 2011
Author(s)
Tian T. Shen, Wei Wu, Qingkai Yu, Curt A. Richter, Randolph E. Elmquist, David B. Newell, Yong P. Chen
We report observations of well developed half integer quantum Hall effect on mono layer graphene films of 7 mm × 7 mm in size. The graphene films are grown by chemical vapor deposition on copper, then transferred to SiO2/Si substrates, with typical carrier

Determination of Moisture Content of Single-Wall Carbon Nanotubes

October 17, 2011
Author(s)
Rolf L. Zeisler, Rabia Oflaz, Ralph E. Sturgeon, Rick L. Paul, Brian E. Lang, Jeffrey A. Fagan, Joseph W. Lam, Anthony Windust, P Grinberg, Benoit Simard, Christopher T. Kingston
Several techniques were evaluated for the establishment of reliable water/moisture content of single-wall carbon nanotubes. Karl Fischer titration (KF) provides for a direct measure of the water content and was used for benchmarking against results
Displaying 601 - 625 of 807