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

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

Amorphous calcium phosphate-based bioactive polymeric composites for mineralized tissue regeneration.
May 1, 2003... Amorphous calcium phosphate (ACP), a postulated precursor in the formation of biological hydroxyapatite, has been evaluated as a filler phase in bioactive polymeric composites that utilize dental monomers to form the matrix phase on...

An experimental method for measuring mechanical properties of rat pulmonary arteries verified with latex.
May 1, 2003... This paper describes a test method for measuring the mechanical properties of small, nonlinear membranes samples from a rat model for pulmonary hypertension. The size and nonlinearity of the pulmonary artery samples poses a challenge for...

Dependence of electron density on Fermi energy in n-type gallium antimonide.
May 1, 2003... The majority electron density as a function of the Fermi energy is calculated in zinc blende, n-type GaSb for donor densities between [10.sup.16] [cm.sup.-3] and [10.sup.19] [cm.sup.-3]. These calculations solve the charge neutrality equation...

Radiometric measurement comparison on the integrating sphere source used to calibrate the moderate resolution imaging spectroradiometer (MODIS) and the landsat 7 Enhanced Thematic Mapper Plus (ETM+).
May 1, 2003... As part if a continuing effort to validate the radiometric scales assigned to integrating sphere sources used in the calibration of Earth Observing System (EOS) instruments, a radiometric measurements comparison was held in May 1998 at...

Relating fresh concrete viscosity measurements from different rheometers.
May 1, 2003... Concrete rheological properties need to be properly measured and predicted in order to characterize the workability of fresh concrete, including special concretes such as self-consolidating concrete (SCC). It was shown by a round-robin test...

Repeatability and reproducibility standard deviations in the measurement of trace moisture generated using permeation tubes.
May 1, 2003... Permeation-tube moisture generators are used in industry as calibrated sources of water vapor and carrier gas mixtures. Measurements were made using three permeation-tube moisture generators of the type used in the semiconductor industry. This...

NIST researchers develop improved high-resistance standards.(General Developments)
May 1, 2003... Researchers at NIST have developed a new generation of high-resistance standards and delivered the standards to the Primary Standards Laboratories of the Army and Air Force. The new standards, with nominal resistances of 1 G[ohm] and 10 G[ohm],...

Elastic moduli data for polycrystalline oxide ceramics added to webbook.(General Developments)(Brief Article)
May 1, 2003... A major compilation of elastic moduli data (Young's modulus, shear modulus, bulk modulus, and Poisson's ratio) for oxide ceramics has been completed and added to the online NIST Ceramics WebBook. The variation of material properties with...

NIST releases split-cylinder resonator measurement software.(General Developments)(Brief Article)
May 1, 2003... NIST has released SplitC, an automated software program for measuring the high-frequency electrical properties of dielectric substrates using a split-cylinder resonator. With this software, developed by a NIST scientist, manufacturers of...

Fundamental noise limitations on supercontinua generated in microstructure fiber determined by NIST.(General Developments)
May 1, 2003... NIST recently completed a thorough study of the amplitude noise on supercontinua generated by injecting femtosecond laser pulses into microstructure fiber. Supercontinuum generation in microstructure fiber has the potential of providing an...

NIST demonstrates single photon source.(General Developments)(Brief Article)
May 1, 2003... A NIST scientist has demonstrated the emission of individual photons on demand, a major accomplishment in the development of "single photonics," which utilizes the photon as the fundamental particle of optical metrology. A low density of InGaAs...

NIST uses high-frequency noise to characterize commercial recording heads.(General Developments)
May 1, 2003... A NIST researcher has completed a study of high-frequency magnetic noise in commercial magneto-resistive recording heads. The study was done in collaboration with two private U.S. companies involved in the manufacture of disk drives and...

Broadly tunable microwave reference oscillator developed.(General Developments)(Brief Article)
May 1, 2003... The measurement of phase-modulation (PM) noise and amplitude-modulation (AM) noise of clocks and oscillators presumes the availability of stable, low-noise reference oscillators at the desired measurement frequencies. However, it is too...

Reproducibility of optical frequency studied.(General Developments)(Brief Article)
May 1, 2003... The mercury-ion optical-frequency standard has the potential for an accuracy surpassing that of the cesium-fountain standard by two or more orders of magnitude. With a Q factor greater than [10.sup.14] and a transition that is relatively...

Geometrical-phase quantum-logic gate demonstrated.(General Developments)(Brief Article)
May 1, 2003... The recent demonstration of a novel, two-qubit, geometrical-phase quantum-logic gate significantly advances prospects for quantum computation. This new gate appears to have features that overcome a number of difficulties identified earlier. ...

Pathway provided to scalable quantum architectures with non-local quantum gates.(General Developments)(Brief Article)
May 1, 2003... One of the basic requirements for building a scalable quantum computer is the need to interact arbitrary pairs of qubits (quantum bits) within the computer. However, most quantum interactions have only a short range, limiting interactions...

NIST researches EUV radiation source for electronics manufacturing.(General Developments)(Brief Article)
May 1, 2003... Integrated-circuit manufacturers require increasingly shorter wavelength radiation in order to print increasingly smaller features on semiconductor wafers. Near-term development is focused on systems employing excimer-laser radiation at 193 nm...

NIST releases updated software reference data set for use by computer forensics community.(General Developments)(Brief Article)
May 1, 2003... NIST recently released Version 2.1 of the National Software Reference Library (NSRL) Reference Data Set (RDS) to the computer forensics community. The RDS is a resource for law enforcement, corporate, and other organizations investigating...

[M.sup.3] writes line patterns.(General Developments)(Brief Article)
May 1, 2003... Using the NIST-developed Molecular Measuring Machine ([M.sup.3]), nanoscale lines have been accurately drawn on a silicon substrate. The writing method is based on scanning probe oxidation lithography, previously developed at NIST. The...

CD-SEM shape-sensitive linewidth measurement final report submitted.(General Developments)(Brief Article)
May 1, 2003... The final report for a one-year project to apply a model-based library (MBL) method to measurements performed with critical dimension scanning electron microscopes (CD-SEMs) has been submitted to International SEMATECH. CD-SEM images of...

Standard bullets project featured in Science News.(General Developments)
May 1, 2003... The Jan. 11, 2003, edition of Science News featured an article entitled "A Shot in the Light," about the Standard Bullets Project led by a NIST researcher. The article discussed the automated image analysis systems and databases for linking...

NIST researchers study imaging at the interface of materials science with biology.(General Developments)(Brief Article)
May 1, 2003... NIST scientists have designed and built a multimodal optical coherence microscope (OCM) that they have dedicated to in vitro tissue engineering metrology. This OCM with a collinear confocal fluorescence microscope (OCM/CFM) was constructed to...

Paper on measurement of the nanomechanical properties of thin films using AFAM receives recognition.(General Developments)(Brief Article)
May 1, 2003... NIST researchers are developing atomic force acoustic microscopy (AFAM) methods to quantitatively determine the elastic properties of thin films. The AFAM technique measures the frequencies of an atomic force microscope (AFM) cantilever's first...

Microwave measurement technique developed by NIST researcher adopted by commercial instrument manufacturer.(General Developments)
May 1, 2003... A measurement method developed by a NIST researcher is now being widely used in the microwave industry. The method for measuring equivalent source match, published in the October 1997 issue of Microwave Journal, enables more accurate power...

Proposed NIST Distributed Testbed for First Responders.(General Developments)
May 1, 2003... Over the past several months, NIST has been working on novel communications and networking technologies for first responders at disaster sites. The goal of the NIST Distributed Testbed for First Responders is to save lives during natural or...