An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
We make a detailed study on the dynamics of gain-assisted superluminal optical solitons in a three-state active-Raman-gain medium at room temperature. Using a method of multiple-scales we derive a high-order nonlinear Schrödinger equation with correction
This document describes NIST's high pressure natural gas flow calibration service (NGFCS). Flow calibrations are conducted offsite at the Colorado Experimental Engineering Station Incorporated (CEESI) in Garner, Iowa. A parallel array of nine turbine meter
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications provide for (1) a composition explicit data channel for each distillate fraction (for both qualitative and
Lane C. Sander, K. Putzbach, Bryant C. Nelson, Catherine A. Rimmer, Mary Bedner, Jeanice M. Brown Thomas, Barbara J. Porter, Laura J. Wood, Michele M. Schantz, Karen E. Murphy, Katherine E. Sharpless, Stephen A. Wise, James H. Yen, P. H. Siitonen, R. I. Evans, A. NguyenPho, M. C. Roman, J. M. Betz
In this work we present a brief review of recent results for water line shapes obtained by means of the frequency stabilized cavity ring-down spectroscopy (FS-CRDS) technique. We demonstrate its ability to enable precise spectroscopic measurements of
Ian R. Coddington, William C. Swann, Nathan R. Newbury
The output of a femtosecond fiber laser can be both spectrally broadened and stabilized, thereby providing a broadband coherent source in the near infrared. In the frequency domain, the result is a frequency comb with frequency stabilities at the
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications provide for (1) temperature and volume measurements of low uncertainty, (2) temperature control based upon fluid
David Point, J. I. Garcia Alonso, William C. Davis, Steven J. Christopher, Aurore Guichard, O.F. X. Donard, Paul R. Becker, Gregory C. Turk, Stephen A. Wise
The origins and the processes driving the inadvertent transformations of inorganic mercury (iHg) and methylmercury (MeHg) in cryogenically stored and homogenized fresh-frozen versus freeze-dried biological Standard Reference Materials (SRM) were
Neutron depth profiling (NDP) is a surface analysis technique based on the illumination of samples with thermal or sub-thermal neutrons, and subsequent release of charged particles. Emitted particles rapidly lose kinetic energy primarily through
Ian R. Coddington, William C. Swann, Nathan R. Newbury
A stabilized frequency comb provides a broadband array of highly resolved comb lines. Using a multiheterodyne technique, we measure the amplitude and phase of every comb line, allowing for massively parallel, high-resolution spectroscopy.
Robert F. Berg, Michael R. Moldover, M Yao, G A. Zimmerli
We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids, near the critical point of xenon. The data span the range of reduced shear rates: 0.001 < γτ < 700, where γτ is the shear rate scaled by the relaxation time τ of
Yadu D. Tewari, David J. Vanderah, Michele M. Schantz, Robert N. Goldberg, J D. Rozzell, J F. Liebman, Raymond W. Hui, Yitzy Nissenbaum, Ahmad R. Parniani
The equilibrium constants K for the ketoreductase-catalyzed reduction reactions of 1-benzyl-3-pyrrolidinone, ethyl 2-oxo-4-phenylbutyrate, ethyl 4-chloroacetoacetate, 1-benzyl-4-piperidone, and 1-benzyl-3-piperidone were measured in n-hexane at T = 298.15
S M. Whitney, Robert Gregory Downing, S Biegalski, D S. O'Kelly
The University of Texas (UT) at Austin has collaborated with the National Institute of Standards and Technology for comparisons of concentration versus depth profiles of samples containing 10B. Technology sharing from NIST has allowed UT to avoid many
B C. Nelson, Christine M. Pfeiffer, Ming Zhang, David L. Duewer, Katherine E. Sharpless, Katrice Lippa
Background: The National Institute of Standards and Technology (NIST) and the Centers for Disease Control and Prevention (CDC) have recently developed Standard Reference Material (SRM) 1955 Homocysteine and Folate in Frozen Human Serum with certified
David J. Vanderah, Marlon L. Walker, Mark A. Rocco, Kenneth A. Rubinson
The self-assembled monolayers (SAMs) of the ?-methyl oligo(ethylene oxide) disulfide [S(CH2CH2O)6CH3]2, [S(EO)6]2 {OEO disulfide}, on Au from 95 % ethanol and from water are described. Spectroscopic ellipsometry and reflection-absorption infrared
Paul C. DeRose, Melody V. Smith, Klaus Mielenz, Douglas H. Blackburn, Gary W. Kramer
Standard Reference Material (SRM) 2941 is a cuvette-shaped, uranyl-ion-doped glass, recommended for use for relative spectral correction of emission and day-to-day performance validation of fluorescence spectrometers. Properties of this standard that
We show the possibility of generating gain-assisted superluminal optical solitons in a room- temperature three-state active Raman gain medium. We demonstrate both analytically and numerically that under appropriate conditions a signal field of very low
We report the first direct comparison of relative carrier mobilities in semiconducting organic polymer films measured using non-contact optical pump terahertz probe spectroscopy to those reported in electrical device studies. Relative transient signal
Room temperature p-type GaSb bulk coupled mode spectra were measured as a function hole concentration. These spectra were obtained using an optical system based on 752.55 nm excitation in order to obtain more sensitivity to bulk GaSb coupled mode
D J. Robichaud, Joseph T. Hodges, D Lisak, Charles E. Miller, Mitchio Okumura
We describe a high-precision method for measuring pressure shifting of absorption lines. The technique involves the acquisition of high-resolution spectra using a cavity ring-down spectrometer whose length is continuously locked to a frequency-stabilized
We present a new and simple approach to broadband coherent anti-Stokes Raman scattering (CARS) microscopy that yields background-free vibrational spectra. We present evidence for a mechanism where two different frequency components in a continuum pulse
Historically, contaminants in seabird tissues were monitored by considering physically visible effects; however, subtle, sub-lethal effects are also important. Several long-term monitoring and specimen banking programs are in place for seabirds, and the