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Displaying 3626 - 3650 of 74137

Proton-Pumping Capabilities of the M-Fast and M-Slow Photocycles of Bacteriorhodopsin

October 12, 2021
Author(s)
R W. Hendler, John Kakareka, P D. Smith, T J. Pohida, Curtis W. Meuse
The parallel model for the bacteriorhodopsin (BR) photocycle at neutral pH and a temperature near 20 contains an M-fast cycle with steps BR >K >L >Mf >N >O >BR and an M-slow cycle which contains steps BR >K >L >Ms >BR. With increasing actinic laser

Pulsed Laser Deposition and Characterization of Hf Based High-k Dielectric Thin Films

October 12, 2021
Author(s)
M A. Sahiner, Joseph Woicik, P Gao, P McKeown, Mark Croft, M Gartman, B Benapfl
The continuous downward scaling of the complementary metal oxide semiconductor (CMOS) devices has enabled the Si-based semiconductor industry to meet the technological requirements such as high performance and low power consumption. However, the

Quantitative EELS of Alloy Nanoparticles

October 12, 2021
Author(s)
J H. Scott, Dale Newbury
Quantitative electron energy-loss spectroscopy (EELS) is used to characterize the chemical composition of Fe-Co alloy nanoparticles. A 300-keV analytical microscope equipped with an imaging energy filter is used to acquire parallel EELS spectra from metal

Quantitative Evaluation of Perfluorinated Alkylthiol Molecular Order on Gold Surfaces

October 12, 2021
Author(s)
L Gamble, D Radford, Daniel A. Fischer, D W. Grainger, David G. Castner
Self-assembled monolayers (SAMs) of perfluoroalkylthiols [CF 3(CF 2) xCH 2CH 2SH (x=3, 5, 7, and 9)] on gold were examined by X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure (NEXAFS), and static time of flight secondary

Quantitative Studies of Bose-Einstein Condensation in a Dilute Atomic Vapor

October 12, 2021
Author(s)
D S. Jin, J R. Ensher, M R. Matthews, C E. Wieman, Eric A. Cornell
We observe Bose-Elinstein condensation (BEC) in a dilute atomic gas cooled below 170 nK. 87Rb atoms are optically trapped and precooled loaded into a magnetic trap, and them evaporatively cooled through the BEC phase transition. We present results of

Quantitative Surface Characterization of DNA Immobilized on Gold

October 12, 2021
Author(s)
D Y. Petrovykh, H Y. Kimura-Suda, L J. Whitman, Michael J. Tarlov
We describe the complementary use of x-ray photoelectron spectroscopy (XPS) and fourier transform infrared (FTIR) spectroscopy to quantitatively characterize the immobilization of thiolated poly(dT025 single-stranded DNA on gold. When electron attenuation

Quantum Logic via the Exchange Blockade in Ultracold Collisions

October 12, 2021
Author(s)
D Hayes, Paul S. Julienne, I H. Deutsch
A nuclear spin can act as a quantum switch that turns on or off ultracold collisions between atoms even when there is neither interaction between nuclear spins nor between the nuclear and electron spins. This exchange blockade is a new mechanism for

Quantum State Via Trap-Induced Shape Resonance in Ultracold Atomic Collisions

October 12, 2021
Author(s)
R Stock, I H. Deutsch, E L. Bolda
We investigate controlled collisions between trapped but separated ultracold atoms. The interaction between atoms is treated self consistently using an energy-dependent delta-function pseudopotential model, whose validity we establish. At a critical

Radio-Frequency Output Coupling of the Bose-Einstein Condensate in Atom Lasers

October 12, 2021
Author(s)
Y B. Band, Paul S. Julienne, M Trippenbach
Experiments have conclusively demonstrated coherence properties of Bose-Einstein condensates [BECs] [1] and the radio-frequency [rf] radiation output coupling of BE condensates [2]. Hence, the concept of an atom laser [3 9] based upon a BEC that is output

Reagentless Cleavage of the Peptide Backbone Using Light-Generated Radicals

October 12, 2021
Author(s)
Barbara J. Jones, Mathew J. Vergne, David M. Bunk, Laurie E. Locascio, M A. Hayes
A key step for protein identification and characterization is cleavage into distinct fragments. All current cleavage methods require the addition of reagents, either proteolytic enzymes or chemical agents, and often a second reagent to discontinue cleavage

Recent Experiments with Bose-Condensed Gases at JILA

October 12, 2021
Author(s)
D S. Hall, J R. Ensher, D S. Jin, M R. Matthews, C E. Wieman, Eric A. Cornell
We consider a binary mixture of two overlapping Bose-Einstein condensates in two different hyperfine states of 87Rb with nearly indentical magnetic moments. Such a system has been simply realized through application of radio frequency and microwave which

Recertification of the SRM 1483a, a Polyethylene

October 12, 2021
Author(s)
Kathleen M. Flynn, William R. Blair
The recertification of a narrow molecular weight distribution poly(ethylene) Standard Reference Material, SRM 1483a, is described. Studies by size exclusion chromatography to obtain the bottle-to-bottle homogeneity are described. The intrinsic viscosity at

Reciprocal Space Neutron Imaging

October 12, 2021
Author(s)
D A. Pushin, D G. Cory, Muhammad D. Arif, David L. Jacobson, M Huber
Here we introduce a Fourier based method for phase contrast neutron imag-ing, report its experimental implementation, show results for a 1-D test phan-tom, and outline the reconstruction methodology. This new approach makes useof neutron interferometry to

Recommendations for Improving Serum Creatinine Measurement: A Report From the Laboratory Working Group of the National Kidney Disease Education Program

October 12, 2021
Author(s)
Gary L. Myers, W. G. Miller, J Coresh, J Fleming, Neil Greenberg, T Greene, T Hostetter, A S. Levey, Mauro Panteghini, Michael J. Welch, John H. Eckfeldt
Background:The National Kidney Disease Education Program (NKDEP) has promulgated suggestions for diagnosing and treating chronic kidney disease (CKD). The National Kidney Foundation s Kidney Disease Outcomes Quality Initiative (K/DOQI) has issued clinical

Recommended Dose Calculation Formalisms and Consensus Dosimetry Parameters for Intravascular Brachytherapy Dosimetry: An Update of the 1999 AAPM Task Group 60 Report

October 12, 2021
Author(s)
Sou-Tung Chiu-Tsao, Dennis Schaart, Christopher G. Soares, Ravinder Nath
Since the publication of AAPM Task Group 60 report in 1999, a considerable amount of dosimetry data for the three coronary brachytherapy systems in use in the United States has been reported. A subgroup of the AAPM working group on Unconventional

Recovery of Forming Gas Damaged Pb(Nb,Zr,Ti)O 3 Capacitors

October 12, 2021
Author(s)
S Aggarwal, S R. Perusse, C J. Kerr, R Ramesh, D B. Romero, J T. Evans, L Boyer, J Velasquez
We report on the recovery of fully integrated Pb(Nb,Zr,Ti)O 3 ferroelectric capacitors damaged during forming gas (4% H 2, balance N 2) annealing. In such capacitors oxygen loss, lead loss and hydrogen incorporation are three degradation mechanisms that

Recrystallization Texture and Magnetic Properties of Electrodeposited FePt on Cu(001)

October 12, 2021
Author(s)
Erik B. Svedberg, J Mallett, S Sayan, Alexander J. Shapiro, William F. Egelhoff Jr., Thomas P. Moffat
A near equiatomic FePt fcc alloy has been grown by electrodeposition onto Cu(001). Annealing at 450 (degrees) C results in the onset of a Al fcc to L1(subscript o) fct phase transformation with a dominant FePt(001) (two vertical lines) Cu(002)
Displaying 3626 - 3650 of 74137