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An Equation of State for Fluid Ethylene

Description: Abstract: A thermodynamic property formulation for ethylene, developed as a part of a joint industry-government project, is presented. The formulation includes an equation of state, vapor pressure equation, and equation for the ideal gas heat capacity. The coefficients were determined by a least squares fit of selected experimental data. Comparisons of property values calculated using the equation of state with measured values are given. The equation of state is not valid in the critical region… more
Date: July 1981
Creator: McCarty, Robert D. & Jacobsen, Richard T.
Partner: UNT Libraries Government Documents Department
open access

Measurement of Optical Fiber Bandwidth in the Frequency Domain

Description: Abstract: The design, evaluation, and performance of a system for determining the magnitude of the transfer function (hence, the bandwidth) of a multimode optical fiber are presented. The system operates to about 1450 MHz using a tracking generator/spectrum analyzer combination for narrowband detection. It is constructed, almost entirely, from commercially available components. The system is less complex and easier to use than an equivalent time domain system and the measurement precision is co… more
Date: September 1981
Creator: Day, G. W.
Partner: UNT Libraries Government Documents Department
open access

Shielded Balanced and Coaxial Transmission Lines: Parametric Measurements and Instrumentation Relevant to Signal Waveform Transmission in Digital Service

Description: Abstract: A method is presented for determining the impulse and step responses of a shielded cable using time domain terminal measurements and a physically based mathematical model for the transmission line properties of the cable. The method requires a computer controlled time domain measurement system and was implemented using the NBS Automatic Pulse Measurement System (APMS). Data are also developed for the frequency domain complex propagation function (attenuation and its related minimum-ph… more
Date: June 1981
Creator: Gans, William L. & Nahman, N. S.
Partner: UNT Libraries Government Documents Department
open access

The Characterization of Optical Fiber Waveguides: A Bibliography with Abstracts, 1970-1980

Description: Abstract: This bibliography contains approximately 450 citations of papers concerning the characterization of optical fiber waveguides. Papers from scientific journals, trade journals and conferences are included along with book chapters. The citations of organized by parameter measured and measurement method. Where published abstracts are available they are included.
Date: June 1981
Creator: Day, G. W.
Partner: UNT Libraries Government Documents Department
open access

WR 10 Millimeter Wave Microcalorimeter

Description: Abstract: A microcalorimeter has been built in WR 10 waveguide, 75-110 GHz, to serve as a power standard at the National Bureau of Standards (NBS). Included here is an evaluation of the errors in using the microcalorimeter for the measurement of effective efficiency of bolometer mounts. The error analysis shows a systematic uncertainty of +/- .83 percent and a random uncertainty of .37 percent.
Date: June 1981
Creator: Weidman, Manly P. & Hudson, Paul A.
Partner: UNT Libraries Government Documents Department
open access

Excitation of a TEM Cell by a Vertical Electric Hertzian Dipole

Description: From abstract: The excitation of a transverse electromagnetic (TEM) cell by a vertical electric Hertzian dipole is analyzed where the gap between the septum and side wall is assumed to be small. Approximate expressions for the field distribution and characteristic impedance are derived. These expressions are numerically evaluated for some typical geometries, and good agreement with previously published results is shown. The formation also allows a vertical offset for the septum position, thus o… more
Date: March 1981
Creator: Wilson, Perry F.; Chang, David C. & Ma, Mark T.
Partner: UNT Libraries Government Documents Department
open access

Cryogenic Fluids Density Reference System: Provisional Accuracy Statement (1980)

Description: Abstract: The improved Density Reference System, the reference densimeter, and the method of determining sample density are described. The uncertainty of the density reference system is + 0.055%. The contribution from the estimated systema -ic error in density was + 0.022%. The estimated uncertainty caused by random error is three times the standard deviation of 0.011% and is based on sixty-three measurements of the densities of saturated liquid methane. The total density uncertainty is taken t… more
Date: April 1981
Creator: Siegwarth, J. D. & LaBrecque, J. F.
Partner: UNT Libraries Government Documents Department
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