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Displaying 3526 - 3550 of 74061

Optical Frequency Synthesis Based on Modelocked Lasers

October 12, 2021
Author(s)
S T. Cundiff, Jun Ye, John L. Hall
The synthesis of optical frequencies from the primary cesium microwave standard has traditionally been a difficult problem due to the large difference in frequencies. Recently a dramatic advance in this field has occurred due to the introduction of the use

Optical Probes for Monitoring Intercalation and Exfoliation in Melt Processed Polymer Nanocomposites

October 12, 2021
Author(s)
P H. Maupin, Jeffrey W. Gilman, Richard H. Harris Jr., S Bellayer, Anthony J. Bur, S C. Roth, A B. Morgan, J R. Harris, M Murariu
Laser induced fluorescence spectroscopy of the optical probe Nile Blue A in polymer clay nanocomposites is described. Concentration quenching of fluorescence dominates probe behavior until the clay platelets are physically separated by polymer

Optical Pulse Synthesis From Two Separate Femtosecond Lasers

October 12, 2021
Author(s)
R K. Shelton, L -. Ma, H C. Kapteyn, M M. Murnane, J L. Hall, Jun Ye
Two independent mode-locked femtosecond lasers are tightly synchronized and phase locked. The rms timing jitter between the lasers is 4.3 fs within a 160 Hz bandwidth. The rms noise of the beat frequency between the two optical combs is 140 mHz at 1s

Optimizing Available Tools for Obtaining Result Standardization: A Joint Committee on Traceability in Laboratory Medicine (JCTLM) Project

October 12, 2021
Author(s)
Mauro Panteghini, Federica Braga, Johanna Camara, Vincent Delatour, Katleen Van Uytfanghe, Hubert Vesper, Tianjiao Zhang
BACKGROUND: The JCTLM created a Task Force on Reference Measurement System Implementation (TFRMSI) to provide guidance on metrological traceability implementation for the in vitro diagnostics (IVD) community. CONTENT: TF-RMSI investigated the reference

Optimum Press and Sinter Processing for Aluminum/SiC Composites

October 12, 2021
Author(s)
G T. Campbell, R Raman, Richard J. Fields
Previous research by the present authors has revealed the importance of relative particle size [d(SiC)/d(Al)] in the development of strength in Al/SiC composites. The earlier work focused on just two size ratios. Here, the effect of numerous size ratios

Ordered Water Monolayer on Ultra-Smooth Hydroxylated Amorphous SiO^d2

October 12, 2021
Author(s)
I M. Aarts, A C. Pipino, J P. Hoefnagels, W M. Kessels, M C. van de Sanden
Polarized near-IR evanescent wave absorption spectra reveal the structure of awater monolayer bound to an ultra-smooth hydroxylated amorphous SiO2 surfaceunder equilibrium conditions. Employing a variant of cavity ring-downspectroscopy, combination spectra

Orientation and Magnetic Properties of FePt and CoPt Films Grown on MgO(110) Single-Crystal Substrate by Electron-Beam Coevaporation

October 12, 2021
Author(s)
M-H Yu, Hiroyuki Ohguchi, Antonio Zambano, Ichiro Takeuchi, J P. Liu, Daniel Josell, Leonid A. Bendersky
We have studied the orientation and magnetic properties of FePt and CoPt films deposited by electron-beam co-evaporation on MgO(110) single-crystal substrates at different substrate temperatures between 500 and 700 degrees C. We observed that the long

Particulate and Bioaerosols in Dental Facilities

October 12, 2021
Author(s)
Hanu Batchu, Steve Gruninger, Gary E. Schumacher, F Eichmiller, P L. Fan
Particulates and bioaerosols were generated during simulated dental procedures in a dental operatory with 5.5 and 11 air changes per hour. Air sampling of particulates was performed using cassette filters and a laser particle counter. Bioaerosols were

Pb electrodeposition on (111)-textured Cu in the Presence and Absence of C1superscript -}: a Combined Oblique Incidence Reflectivity Difference and In-situ AFM Study

October 12, 2021
Author(s)
G Y. Wu, S E. Bae, A A. Gewirth, J Gray, X D. Zhu, Thomas P. Moffat, W Schwarzacher
Oblique incidence reflectivity difference measurements reveal differences in the earliest stages of growth between Pb electrodeposition on (111)-textured Cu in the presence and absence of C1superscript -}. At moderate over potentials, when only 100 mM

Percolation Theory Prediction of Green Strength in Composites

October 12, 2021
Author(s)
Y Shim, Lyle E. Levine, Richard J. Fields
We have measured the mechanical strength of composites made by pressing mixed powders of deformable aluminum (Al) and non-deformable silicon carbide (SiC) as a function of the volume fraction of SiC and porosity. The experimental results show a peak in

Perpendicular Anisotropy in Co/Pd Multilayers

October 12, 2021
Author(s)
J I. Hong, S Sankar, A. E. Berkowitz, William F. Egelhoff Jr.
The two principal mechanisms for explaining the perpendicular anisotropy in Co-Pd multilayers were investigated. These mechanisms are the broken symmetry at sharp Co surfaces, and the magnetostriction of interfacial Co-Pd alloys under stress due to epitaxy

Phase Control of Wave Packet Dynamics Using Shape Femtosecond Pulses

October 12, 2021
Author(s)
R Uberna, Z Amitay, R A. Loomis, S R. Leone
Coherent vibrational and rotational dynamics of the Li 2 molecule is controlled by varying the relative phases, φ n, of the rovibrational wave packet components, /n>e i(ωnt+φn). The coherent superposition is created by excitation of a set of ten rovibronic

Photon Echoes in Disordered Semiconductor Quantum Wells

October 12, 2021
Author(s)
D G. Steel, Steven T. Cundiff
Photon echo spectroscopy provides an important tool for studying excitonic relaxation in disordered quantum wells. Localization of excitons due to interface fluctuations results in inhoniogeneous broadening of the spectrum and relaxation due to migration

Picosecond Pulse Amplification With an External Passive Optical Cavity

October 12, 2021
Author(s)
E Potma, Christopher J. Evans, X. Xie, R. J. Jones, Jun Ye
We experimentally demonstrate the amplification of picosecond pulses at high repetition rates through coherent addition of successive pulses of a mode-locked pulse train in a high finesse optical cavity equipped with cavity dumping. Amplification greater

Pinhole Coupling Strength in Giant Magnetoresistance Spin Valves: A Statistical Approach

October 12, 2021
Author(s)
D X. Yang, E J. Repetski, H D. Chopra, B J. Spencer, D Parks, P J. Chen, William F. Egelhoff Jr.
The nature of pinhole coupling and its strength in 'giant' magnetoresistance (GMR) spin valves is far from understood. In the present study, a statistical model has been developed that correctly predicts the coupling strength due to pinholes, using the
Displaying 3526 - 3550 of 74061