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A link-level simulator of the cdma2000 reverse-link physical layer
No full textThe cdma2000 system is an evolutionary enhancement of the IS-95 standards which support 3G services defined by the International Telecommunications Union (ITU). cdma2000 comes in two phases: 1XRTT and 3XRTT (1X and 3X indicates the number of 1.25 MHz wide radio carrier channels used and RTT stands for Radio Transmission Technology). The cdma2000 1XRTT, which operates within a 1.25 MHz bandwidth, can be utilized in existing IS-95 CDMA channels as it uses the same bandwidth, while 3XRTT requires the commitment of 5 MHz bandwidth to support higher data rates. This paper describes a software model implementation of the cdma2000 reverse link and its application for evaluating the effect of rake receiver design parameters on the system performance under various multipath fading conditions. The cdma2000 models were developed at the National Institute of Standards and Technology (NIST), using SPW ( Signal Processing Worksystem) commercial software tools. The model has been developed in a generic manner that includes all the reverse link six radio configurations and their corresponding data rates, according to cdma2000 specifications. After briefly reviewing the traffic channel characteristics of the cdma2000 reverse link ( subscriber to base station), the paper discusses the rake receiver implementation including an ideal rake receiver. It then evaluates the performance of each receiver for a Spreading Rate 3 (3XRTT) operation, which is considered as a true ""3G"" cdma2000 technology. These evaluations are based on the vehicular IMT-2000 ( International Mobile Telecommunication 2000) channel model using the link budget defined in cdma2000 specifications for the reverse link
Interlaboratory comparison of magnetic thin film measurements
No full textA potential low magnetic moment standard reference material (SRM) was studied in an interlaboratory comparison. The mean and the standard deviation of the saturation moment m(s), the remanent moment m(r), and the intrinsic coercivity H-c of nine samples were extracted from hysteresis-loop measurements. Samples were measured by thirteen laboratories using inductive-field loopers, vibrating-sample magnetometers, alternating-gradient force magnetometers, and superconducting quantum-interference-device magnetometers. NiFe films on Si substrates had saturation moment measurements reproduced within 5% variation among the laboratories. The results show that a good candidate for an SRM must have a highly square hysteresis loop (m(r)/m(s) > 90%), H-c approximate to 400 A.m(-1) (5 Oe), and m(s) approximate to 2 x 10(-7) A.m(2) (2 x 10(-4) emu)
Thermal conductivity measurement of an electron-beam physical-vapor-deposition coating
No full textAn industrial ceramic thermal-barrier coating designated PWA 266, processed by electron-beam physical-vapor deposition, was measured using a steady-state thermal conductivity technique. The thermal conductivity of the mass fraction 7% yttria-stabilized zirconia coating was measured from 100 degreesC to 900 degreesC. Measurements on three thicknesses of coatings, 170 micrometers, 350 micrometers, and 510 micrometers resulted in thermal conductivity in the range from 1.5 W/(m.K) to 1.7 W/(m.K) with a combined relative standard uncertainty of 20%. The thermal conductivity is not significantly dependent on temperature
An experimental method for measuring mechanical properties of rat pulmonary arteries verified with latex
No full textThis paper describes a test method for measuring the mechanical properties of small, nonlinear membrane samples from a rat model for pulmonary hypertension. The size and nonlinearity of the pulmonary artery samples poses a challenge for developing a test method that will generate quality, reproducible data in the pressure range experienced by the hypertensive pulmonary artery. The experimental method described here has sufficient precision to yield a combined relative standard uncertainty of 4 %. The method is calibrated against 75 micrometers thick latex and the data agree well with the neo-Hookian model
(Audio Part 2 of 2) Oral history interview of Bourdon F. Scribner, February 24, 2003 / by Lisa Greenhouse, Bill Martin, and David Lide
No full textBourdon Scribner, former Chief of the Spectrochemistry division, discusses his career at NBS, including working with Dr. William Meggers, his testimony before Congress on the AD-X2 battery additive, and his visits to the Bureau when his father, Bourdon W. Scribner, worked at NB
(Audio Part 1 of 3) Oral history interview of George Porter, March 3, 2003 / by Norm Belecki, Reeves Tilley, and Lisa Greenhouse
No full textGeorge Porter, former head of the Personnel Division of NBS, discusses his nearly 24 years working at the Bureau. Porter came to NBS in 1950 and was Chief of the Personnel Division from 1951-1974. Porter discusses the attitudes of scientists at the Bureau towards the civil service system in the 1950s and 1960s, management and staff relations, and notable events including the AD-X2 controversy. Also mentioned are the NBS Graduate School Program, the relocation of the Bureau from Washington, D.C. to Gaithersburg, and the role of women in the Bureau
Dana K. Bailey
No full textDANA K. BAILEY
NBS: 1947 - 1955, 1959 - 1965
B: November 22, 1916
D: August 27, 1999
EDUCATION:
University of Arizona: BA (Astronomy), 1937
Rhodes Scholar, Queens College, Oxford University, BA, 1940; MA, 1940; ScD, 1967
POSITIONS HELD AT NBS (BOULDER):
Physicist, CRPL
Radiophysicist, CRPL
HONORS:
Department of Commerce: Silver Medal, 1952; Gold Medal, 1956
Arthur S. Fleming Government Award, 1951
MEMBERSHIPS:
Cosmos Club
American Association for the Advancement of Science (Fellow)
American Physical Society (Fellow)
American Geographical Society (Fellow)
Royal Astronomical Society (Fellow)
Royal Geographical Society (Fellow)
Sigma Xi
American Geophysical Union
American Astronomical Society
Explorers Club
PUBLICATIONS:
Bailey, D.K., R. Bateman, L.V. Berkner, H.G. Booker, G.F. Montgomery, E.M. Purcell, W.W Salisbury and J.B. Weisner, “A new kind of radio propagation at very high frequencies observable over long distances,” Phys. Rev. 86 (2) (1952) 141-145
Bailey, D.K., R. Bateman and R.C. Kirby, “Radio transmission at VHF by scattering and other processes in the lower atmosphere,” Proc. IRE, 43 (10) (1955) 1181-1230
Bailey, D.K., “Disturbances in the lower ionosphere observed at VHF following the solar flare of 23 February 1956, with particular reference to auroral zone absorption,” J. Geophys. Res., 62 (3) (1957) 431-463
Bailey, D.K., “Abnormal ionization in the lower ionosphere associated with cosmic ray flux enhancements,” Proc. IRE, 47 (2) (1959) 255-26
Joseph Hilsenrath
No full textJOSEPH HILSENRATH
Inducted: 2003
Citation:
For his leadership in the creation of the NBS Postdoctoral Fellowship program, and the creation of OMNITAB, a computer program for statistical and numerical analysis.
Tenure: 1948 - 1974
Birth: 1912, Tarnapol, Poland
Death: 2004
Education:
State Teachers College of New Jersey, BA (Mathematics), 1937; MA (Mathematics), 1940
Renssaelar Polytechnic Institute, BS (Physics), 1946
Positions held:
Director of Employee Training
Chief, Equation of State Section, Heat Division
Leader, Data Systems Development Group, Standard Reference Data Program
Honors:
Department of Commerce: Silver Medal, 1963; Gold Medal, 1970
Memberships:
American Association for Computing Machinery
American Association of University Professors
American Documentation Institute (President)
American Mathematical Society
American Physical Society
American Society for Engineering Education
National Council of Teachers of Mathematics
Washington Academy of Sciences (Fellow)
Publications:
Tables of Thermal Properties of Gases: Comprising Tables of Thermodynamic and Transport Properties of Air, Argon, Carbon Dioxide, Carbon Monoxide, Hydrogen, Nitrogen, Oxygen, and Steam (with coauthors), NBS Circular 564 (1955)
Tables of Thermodynamic and Transport Properties of Air, Argon, Carbon Dioxide, Carbon Monoxide, Hydrogen, Nitrogen, Oxygen, and Steam (with coauthors), Pergamon Press, New York (1960)
Tables of Einstein Functions: Vibrational Contributions to the Thermodynamic Functions (with Guy G. Ziegler), NBS Monograph 49 (1962)
OMNITAB, a Computer Program for Statistical and Numerical Analysis (with coauthors), NBS Handbook 101 (1968)
OMNIDATA, an Interactive System for Data Retrieval, Statistical and Graphical Analysis, and Database Management (with Bettijoyce Breen), NBS Handbook 125 (1978