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NIST, in collaboration with the National Institutes of Health Office of Dietary Supplements (NIH-ODS) and the Food and Drug Administration (FDA) is producing Standard Reference Materials (SRMs) for dietary supplements. This paper describes the how these
Hormones are chemical messengers that regulate many life functions. Deviations from normal hormone levels can have serious health consequences. Accurate measurement of hormone levels in serum can be beneficial in diagnosing, monitoring, and treating a
Hormones are chemical messengers that regulate many life functions. Deviations from normal hormone levels can have serious health consequences. Accurate measurement of hormone levels in serum can be beneficial in diagnosing, monitoring, and treating a
Eduard Rocas, Juan C. Collado Gomez, Nathan D. Orloff, James C. Booth
We present measurements and modeling of a self-heating mechanism responsible for third order intermodulation distortion in coplanar waveguide transmission lines. Temperature fluctuations, at the envelope frequency of the input signal, induce dynamic
Jennifer M. Lynch, John R. Kucklick, Steven O'Connell
Perfluorinated compounds (PFCs) are globally distributed persistent environmental contaminants. This study provides temporal trends as well as large-scale spatial trends of PFC concentrations in threatened juvenile loggerhead sea turtles from Florida (FL)
James E. Maslar, Ramon Cusco, Esther Alarcon-Llado, Luis Artus, Wilbur S. Hurst
We present a detailed investigation of the phonons and LO-phononplasmon coupled modes in the Ga1−x InxAsy Sb1−y alloy by means of Raman scattering. A generalization of the dielectric Raman lineshape model to quaternary alloys is described and used to
The two-channel reaction of collision-induced dissociation (CID) of the n-butylbenzene cation under the conditions of multipole collision cells of tandem mass spectrometers was studied computationally. The results were compared with the experimental data
Bret Windom, Tara Lovestead, Jennifer Riggs, Chris Nickell, Thomas J. Bruno
RP-1 is a long-established hydrocarbon fuel that continues to be widely used as the kerosene component in rocket propulsion systems. The desire in recent years to use rocket motors many times, rather than a single time, has led to reformulations of RP-1
The thermal decomposition of RP-2 and mixtures of RP-2 with four different additives has been investigated. The mixtures with RP-2 contained one of the following: 5 % /trans/-decahydronaphthalene (decalin); 5 % 1,2,3,4-tetrahydronaphthalene (tetralin); 5 %
Jessica L. Reiner, Shoji F. Nakayma, Mark J. Strynar, Amy D. Delinsky, Andrew B. Lindstrom
Despite efforts to develop robust analytical methods for the determination of perfluorinated compounds (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in surface water, little has been published on the importance of sample
Fabrizio R. Giorgetta, Ian R. Coddington, William C. Swann, Esther Baumann, Nathan R. Newbury
Dual, coherent frequency combs are used to measure the spectrum of an incoherent, quasi-thermal source through Fourier spectroscopy. The source spectrum is acquired over 1THz bandwidth with an absolute frequency accuracy set by the combs.
Christina A. Hacker, Mariona Coll Bau, Curt A. Richter
Scaling of conventional electronics has continued unabated to dimensions approaching fundamental physical limits. As technology continues to evolve there are increasing demands to identify alternate routes of performing electrical functions. One potential
Okan Esenturk, Joseph S. Melinger, Paul A. Lane, Edwin J. Heilweil
Intrinsic properties of organic semiconductors are investigated by Time-Resolved Terahertz Spectroscopy (TRTS) to assess their relative mobilities and efficiencies. Our results are well correlated with device measurements, and show the effectiveness and
Jocelyn L. Prendergast, Lorna T. Sniegoski, Michael J. Welch, Karen W. Phinney
NIST has been providing a Standard Reference Material (SRM) for glucose in human serum for many years to support accuracy in health care measurements. The definitive method (DM), now known as the reference measurement procedure (RMP), for the analysis of
Katherine E. Sharpless, Catherine A. Rimmer, Karen W. Phinney, Bryant C. Nelson, David L. Duewer, Stephen A. Wise
Key Comparison CCQM-K62 was designed to enable demonstration of the equivalence in capabilities for measurement of vitamins in a food matrix. A milk-based fortified human infant/adult formula was selected as the matrix based upon material availability and
Katherine E. Sharpless, Catherine A. Rimmer, Karen W. Phinney, Bryant C. Nelson, David L. Duewer, Stephen A. Wise
Key Comparison CCQM-K62 was designed to enable demonstration of the equivalence in capabilities for measurement of vitamins in a food matrix. A milk-based fortified human infant/adult formula was selected as the matrix based upon material availability and
NO3 has been stabilized in a neon matrix at 4.3 K in sufficient yield for detection of the absorptions between 7000 and 10000 cm-1 which arise from vibronically allowed transitions from its ground state to levels of the A 2E" state. The results confirm and
Jason Hattrick-Simpers, Chun Chiu, James E. Maslar, Leonid A. Bendersky, Michael E. Niemann, Sesha S. Srinivasan, Elias K. Stefanakos
In situ Raman spectroscopy was used to monitor the dehydrogenation of ball-milled mixtures of LiNH2 LiBH4 MgH2 nanoparticles. The as-milled powders were found to contain a mixture of Li4BN3H10 and Mg(NH2)2, with no evidence of residual LiNH2 or LiBH4. It
The primary fuel used within the general aviation industry is a petroleum based gasoline blended with small amounts of tetraethyl lead (a lead-based additive used to increase the octane number of gasoline without affecting its performance) called 100 LL
Stephen R. Decker, Robert N. Goldberg, Brian Lang, William Michener
Microcalorimetry, high-performance liquid chromatography (HPLC), and liquid chromatography-mass spectrometry (LC-MS) have been used to conduct a thermodynamic investigation of the hydrolysis reactions: 1-naphthyl acetate(aq) + H2O(l) = 1 naphthol(aq) +
Thomas J. Bruno, Evgenii Baibourine, Tara M. Lovestead
In recent years, civilian and military users of aviation kerosene have been interested in expanding the scope of fuel feed stocks to include non-petroleum sources. There are many reasons for this, the most important of which are the potential minimization
Stacy S. Vander-Pol, John R. Kucklick, Stefan D. Leigh, Barbara J. Porter, Michele M. Schantz
Toxaphene is a complex technical mixture that has been found ubiquitously in the environment but has caused issues for analysis, especially of individual congeners. This paper reports the elution order of 25 major toxaphene congeners on three gas