Journal of Research of the National Institute of Standards and Technology articles from January 2003

Journal of Research of the National Institute of Standards and Technology archives from January 2003

Mass absorption coefficient of tungsten and tantalum, 1450 eV to 2350 eV: experiment, theory and application.
January 1, 2003... The mass absorption coefficients of tungsten and tantalum were measured with soft x-ray photons from 1450 eV to 2350 eV using an undulator source. This region includes the [M.sub.3], [M.sub.4], and [M.sub.5] absorption edges. X-ray absorption...

A double-primary dead-weight tester for pressures (35-175) kPa in gage mode.
January 1, 2003... Primary pressure standards in the atmospheric pressure range are often established using mercury manometers. Less frequently, controlled-clearance deadweight testers in which one component (normally the piston) has been dimensionally measured...

Design and uncertainty analysis for a PVTt gas flow standard.
January 1, 2003... A new pressure, volume, temperature, and, time (PVTt) primary gas flow standard at the National Institute of Standards and Technology has an expanded uncertainty (k = 2) of between 0.02 % and 0.05 %. The standard spans the flow range of 1 L/min...

Potassium bromate assay by redox titrimetry using arsenic trioxide.
January 1, 2003... Bromate, a disinfectant, is one of the analytes of interest in wastewater analysis. Environmental laboratories have a regulatory need for their measurements to be traceable to NIST standards. Bromate is not currently certified as a NIST...

Optical diffraction in close proximity to plane apertures, part 2, comparison of half-plane diffraction theories.
January 1, 2003... The accuracy and physical significance of the classical Rayleigh-Sommerfeld and Kirchhoff diffraction integrals are assessed in the context of Sommerfeld's rigorous theory of half-plane diffraction and Maxwell's equations. It is shown that the...

Uncertainties in interpolated spectral data.
January 1, 2003... Interpolation is often used to improve the accuracy of integrals over spectral data convolved with various response functions or power distributions. Formulae are developed for propagation of uncertainties through the interpolation process,...

Quantitative synthetic polymer mass spectrometry workshop. (Conference Report).
January 1, 2003... Gaithersburg, MD November 7-8, 2002. 1. Introduction Mass spectrometry is a rapidly evolving measurement technique for synthetic polymers. It holds the promise of providing not only absolute molecular mass distributions but also...

New volumetric gas flow standard has reduced uncertainty. (General Developments).(Brief Article)
January 1, 2003... A new pressure, volume, temperature, and time (PVTt) primary gas flow standard for calibrating flowmeters has an expanded uncertainty (k = 2) of between 0.02 % and 0.05 %. This uncertainty is approximately five times better than the previously...

Simulation and measurement of a head-disk collision in magnetic data storage. (General Developments).(Brief Article)
January 1, 2003... Magnetic data storage technology has been following Moore's law, with data storage density doubling every 18 months. In the face of this, the National Storage Industry Consortium, now the Information Storage Industry Consortium, has set the...

Superconformal electrodeposition using derivitized substrates. (General Developments).(Brief Article)
January 1, 2003... State-of-the-art manufacturing of microelectronics involves the electroplating of copper for on-chip wiring. Electroplating in the presence of organic additives enables seam-free and void-free filling of trenches and vias to create the...

NIST updates Federal Information Processing Standard (FIPS) for secure hash standard to include additional algorithms. (General Development).(Brief Article)
January 1, 2003... On Aug. 1, 2002, the Secretary of Commerce approved FIPS 180-2, Secure Hash Standard (SHS). The standard replaces FIPS 180-1, which was issued in 1992. FIPS 180-1 specified an algorithm (SHA-l) for producing a 160 bit output called a message...

NIST publishes computer security guidelines. (General Development).(Brief Article)
January 1, 2003... NIST recently issued three new computer security documents, available at http://csrc.nist.gov/publicationsnistpubs/index.html. NIST Special Publication (SP) 800-40, Procedures for Handling Security Patches. Timely patching is critical to...

A new spin on condensed-matter physics using two-level atoms. (General Development).(Brief Article)
January 1, 2003... The incredibly long coherence times of atomic hyperfine states make them ideally suited for frequency standards and quantum information processing. Recent experiments on quantum gases have utilized this cherished trait of cold atoms for the...

Long-term carrier-envelope phase coherence achieved. (General Development).(Brief Article)
January 1, 2003... NIST researchers have reported a significant extension of the laser technology being developed for optical frequency metrology and optical atomic clocks. While frequency-domain stabilization had heretofore been the chief concern, there are...

Specimens collected from pilot whale stranding for nist specimen bank. (General Development).
January 1, 2003... On Monday, July 29, 2002, a mass stranding of 57 long-finned pilot whales (Globicephala melas) occurred in Dennis, MA, on Cape Cod. Strandings of marine mammals occur regularly at Cape Cod; however, a stranding of this magnitude creates...

NIST Chemistry WebBook receives award. (General Development).(Brief Article)
January 1, 2003... The NIST Chemistry WebBook was voted the winner in the Portals and Information Hubs category of the "Best Chemical Sites on the Web" contest, sponsored by two private companies and the Royal Society of Chemistry, United Kingdom. These awards...

NIST physical models for carrier mobilities transferred to industry. (General Development).(Brief Article)
January 1, 2003... Technology roadmaps from consensus-based planning efforts, such as the National Electronics Manufacturing Initiative (NEMI), stress the need for predictive physical models that describe carrier transport in compound semiconductors. As a...

Neutrons effective in probing magnetic cluster sizes in magnetic recording disks. (General Developments).
January 1, 2003... The equivalent of Moore's law for magnetic recording is that the areal density of magnetically written bits increases at 60% to 100% per year. To achieve this, the noise in the magnetic media must be reduced continuously, which is accomplished...

NIST'S Computer Forensics Tool Testing project helps to assure the accuracy of computer forensics investigations. (General Developments).(Brief Article)
January 1, 2003... The first test report based on the Computer Forensics Tool Testing (CFTT) program was published by the National Institute of Justice at http://www.ojp.usdoj.gov/nij/pubs-sum/196352.htm. The test report documents results of testing dd GNU...

Spectral responsivity bilateral comparison completed. (General Developments).(Brief Article)
January 1, 2003... NIST and the National Research Council of Canada (NRC) recently completed a bilateral comparison of routine spectral responsivity calibrations from 250 nm to 1800 nm, using silicon, germanium, and indium gallium arsenide photodiodes as transfer...

NIST hosts 12th biennial symposium on optical fiber measurements in Boulder. (General Developments).(Brief Article)
January 1, 2003... Since 1980, optical fiber metrologists from around the world have gathered every other year at NIST in Boulder for the Symposium on Optical Fiber Measurements (SOFM), which covers measurement issues associated with optical fibers, related...

NIST develops refreshable tactile graphic display technology. (General Developments).(Brief Article)
January 1, 2003... In cooperation with the National Federation of the Blind, NIST has developed a new refreshable tactile graphic technology that allows blind and visually impaired users to view images using the sense of touch. Unlike current devices that make a...

NIST-developed algorithms reveal fundamental flaws in coordinate measuring machine fitting software. (General Developments).(Brief Article)
January 1, 2003... NIST researchers recently presented new findings which indicate that serious problems can exist in some fitting algorithms used by commercial software packages. Coordinate measuring systems rely on embedded software algorithms to fit geometric...

Nano-optics for atomic-scale optical resolution. (General Developments).(Brief Article)
January 1, 2003... Theoretical simulations have been performed at NIST to explain the extreme, atomic-scale optical sensitivity obtained in recent nano-optics experiments that probe atomic steps on silver surfaces. Nano-optics is a rapidly emerging field of...

Researchers construct thermodynamic databases for multicomponent alloys. (General Developments).(Brief Article)
January 1, 2003... Thermodynamic modeling allows the prediction of the phases present in complex alloys composed of many elements. Such phase equilibria calculations can be used to show composition, crystal structure, and volume fraction of the various phases,...

Carbon nanotubes influence materials performance. (General Developments).(Brief Article)
January 1, 2003... Researchers from NIST, Purdue University, the University of Cincinnati, and the U.S. Air Force measured the arrangement of carbon nanotubes in suspensions in an effort to better understand their effect on the physical properties of the...

Molecular-electronics theorist proposes mechanism for molecular switches. (General Developments).(Brief Article)
January 1, 2003... A NIST researcher has proposed a mechanism for the negative-differential resistance (an electrical off-on switching behavior) that has been observed in devices made from conjugated organic compounds. The model is based on first-principles,...

NIST releases enhanced version of airflow and indoor air quality modeling software. (General Developments).(Brief Article)
January 1, 2003... NIST has released CONTAMW, a multi-zone airflow and contaminant transport simulation program. It can be used to assess the adequacy of ventilation rates in a building, to estimate the impact of building envelope tightening efforts on...

Nist researchers report special test of high-speed photoreceiver to 110 GHz. (General Developments).(Brief Article)
January 1, 2003... NIST researchers have provided the first special test of the modulation response magnitude and phase of a commercially available photoreceiver to 110 GHz. High-speed photoreceivers are commonly used in fiber optic test equipment and...

Cryogenic capability added to NIST's pulsed inductive microwave magnetometer. (General Developments).(Brief Article)
January 1, 2003... NIST's recently developed Pulsed Inductive Microwave Magnetometer (P1MM) has now been enhanced with variable temperature capability. The new instrument can measure the magnetodynamic response of magnetically soft, thin-film materials at...

International comparison of temperature completed. (General Developments).(Brief Article)
January 1, 2003... Key comparisons, organized by the consultative committees of the CIPM, have the purpose of quantitatively establishing the level of agreement between the national measurement standards of signatories to the Treaty of the Metre, forming the...

NIST performs first comparison of the gamut assessment standard with other NMIs. (General Developments).(Brief Article)
January 1, 2003... A NIST scientist conducted interlaboratory color measurement comparisons with the National Physical Laboratory (NPL) of the United Kingdom and the National Research Council (NRC) of Canada. These measurement intercomparisons among national...

NIST remembers the first computer. (General Developments).(Brief Article)
January 1, 2003... The early National Bureau of Standards (NB S) Electronic Automatic Computer (SEAC) was the first electronic computer in the United States to store programs internally. Designed, built in 1950, and operated at NBS by engineers, scientists, and...

NIST's Jin recognized by Discover Magazine. (General Developments).(Brief Article)
January 1, 2003... In its November issue, Discover Magazine has recognized Deborah Jin of NIST as one of "The 50 Most Important Women in Science." Jin was cited for her pioneering work in creating fermion quantum gases. Like Bose-Einstein Condensates (BECs),...

For state-of-the-art superconductors, NIST investigates the mechanical behavior of RABiTS. (General Developments).(rolling-aligned biaxially textured substrates)(Brief Article)
January 1, 2003... One of the major challenges facing the development of an economical, practical, high-temperature superconductor has been the extremely weak mechanical behavior of Y-Ba-Cu-O coated onto rolling-aligned biaxially textured substrates (RABiTS). The...

New developmental tool for high-efficiency lighting being used. (General Developments).(Brief Article)
January 1, 2003... There are an estimated 1 billion plasma light sources in service in the United States, consuming an estimated 600 billion kilowatt-hours (2 exajoules) of electrical energy annually. These sources principally include fluorescent lamps and...

Measuring local birefringence in photonic materials. (General Developments).(Brief Article)
January 1, 2003... Novel polymer materials with structure on the scale of the wavelength of light, such as high-molecular-weight block co-polymers (BCs), have been noted for their potential use in photonic devices. These materials selfassemble to form spatial...

Non-newtonian polymer solution for rheology now available. (Standard Reference Materials).(Brief Article)
January 1, 2003... A new Standard Reference Material, SRM 2491, is available for calibration of rheometers (instruments used to measure flow behavior of fluids). SRM 2491, a polydimethylsiloxane, is a companion standard to SRM 2490 for which NIST has certified...