An Equation of State for Fluid Ethylene (open access)

An Equation of State for Fluid Ethylene

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 (pc + 0.3 pc for temperatures of Tc + 0.05 Tc). Errors on the order of 20 percent for derived properties and 10 percent for density may be encountered near the critical point. Tables of the thermodynamic properties of ethylene for the liquid and vapor phases for temperatures from the freezing line to 450 K with pressures to 40 MPa are presented. The equation of state and its derivative and integral functions for calculating thermodynamic properties are included. Estimates of the accuracy of calculated properties are given. A guide for use of computer programs for the calculation of thermodynamic properties of ethylene with listings of subprograms and a sample program to illustrate the use and results of the program are included.
Date: July 1981
Creator: McCarty, Robert D. & Jacobsen, Richard T.
System: The UNT Digital Library
The Characterization of Optical Fiber Waveguides: A Bibliography with Abstracts, 1970-1980 (open access)

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

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.
System: The UNT Digital Library
Finline Diode Six-Port: Fundamentals and Design Information (open access)

Finline Diode Six-Port: Fundamentals and Design Information

Abstract: The preliminary design and testing of a planar circuit six-port with diode detectors is described. The planar circuit medium was chosen to be finline, and all preliminary work was done in WR-42 waveguide (18-26.5 GHz). The finline substrate was alumina, and initially commercial beam-lead diodes were bonded to the finline metalization. The goal is to design an integrated circuit which could be fabricated on one chip (with diode detectors) and used as part of a six port network analyzer in the waveguide bands above 18 GHz. Initial designs proved to b unsatisfactory because of high losses and reflections. Most of the problems have b en solved, and a usable integrated finline circuit is a good possibility for a millimeter wave six-port.
Date: December 1985
Creator: Weidman, Manly P.
System: The UNT Digital Library
Basic Tables for Chemical Analysis (open access)

Basic Tables for Chemical Analysis

Abstract: Tables of important data for use in the analytical chemistry laboratory are provided. These tables contain information for use in gas chromatography, liquid chromatography, infrared and ultraviolet spectrophotometry, mass spectrometry, and wet chemical techniques. Tables relating to safe practice in the analytical laboratory are also included.
Date: April 1986
Creator: Bruno, Thomas J. & Svoronos, Paris D. N.
System: The UNT Digital Library
Phase Equilibria: an Informal Symposium (open access)

Phase Equilibria: an Informal Symposium

From introduction: The accurate prediction of phase equilibria plays an important. role in the chemical process industries. A grief overview of final phase equilibria predictive techniques is presented with special emphasis on methods in current use in industry. Areas were better fundamental understanding will lead to improved models are discussed whenever possible.
Date: January 1983
Creator: Eaton, B. E.; Ely, James F.; Hanley, H. J. M.; McCarty, Robert D. & Rainwater, James C.
System: The UNT Digital Library
VOR Calibration Services (open access)

VOR Calibration Services

from Introduction: The National Bureau of Standards has designed, constructed, and evaluated a standard for the support of very-high-frequency omnidirectional range (VOR) air navigation aids. The standard consists of two instruments: (1) a digital waveform signal generator for the composite VOR audio waveform, and (2) a standard phasemeter based on time series analysis of this waveform. Experimental results, a statistical analysis of them, and the principal software listings are included.
Date: April 1985
Creator: Larsen, Neil T.; Vecchia, Dominic F. & Sugar, George R.
System: The UNT Digital Library
Electromagnetic Compatibility and Interference Metrology (open access)

Electromagnetic Compatibility and Interference Metrology

From abstract: The material included in this report is intended for a short course on electromagnetic compatibility/interference (EMC/EMI) metrology to be offered jointly by the staff of the Fields Characterization Group (723.03) and the Interference Characterization Group (723.04) of the Electromagnetic Fields Division (723). The purpose of this short course is to present a review of some of the radiated EMC/EMI measurement methods, to which the National Bureau of Standards (NBS) at Boulder, Colorado, has made significant contributions during the past two decades.
Date: July 1986
Creator: Ma, Mark T. & Kanda, M.
System: The UNT Digital Library
Thermophysical Properties of Isobutane from 114 to 700 K at Pressures to 70 MPa (open access)

Thermophysical Properties of Isobutane from 114 to 700 K at Pressures to 70 MPa

Abstract: Using a modified version of the nonanalytic equation of state, thermophysical properties of isobutane are derived from physical properties data and are tabulated at integral temperatures over the entire range of fluid states from 114 to 700 K along isobars at pressures to 70 MPa. Results include dielectric constants, densities, enthalpies, entropies, equation of state, internal energies, isobars, isochores, isotherms, Joule-Thomson inversion, heats of vaporization, melting line, orthobaric densities, specific heats, sound velocities, vapor pressures, and virial coefficients. In addition to the equation of state, equations are given for vapor pressures, orthobaric vapor and liquid densities, ideal gas properties, second virial coefficients, dielectric constants, heats of vaporization, melting pressures, and orthobaric liquid specific heats, enthalpies, and entropies. Several new sets of data have been used in this correlation; comparisons between experimental and calculated values are given.
Date: January 1982
Creator: Goodwin, Robert D. & Haynes, William M.
System: The UNT Digital Library
Trapped Ions and Laser Cooling: Selected Publications of the Ion Storage Group of the Time and Frequency Division, NBS, Boulder, Colorado (open access)

Trapped Ions and Laser Cooling: Selected Publications of the Ion Storage Group of the Time and Frequency Division, NBS, Boulder, Colorado

Abstract: Selected publications of the Ion Storage Group of the Time and Frequency Division, NBS, Boulder, Colorado.
Date: July 1985
Creator: Wineland, David J.; Itano, Wayne M.; Bergquist, James Charles & Bollinger, John J.
System: The UNT Digital Library
Provisional Thermodynamic Functions for Para-Hydrogen (open access)

Provisional Thermodynamic Functions for Para-Hydrogen

The need for thermodynamic functions of para hydrogen, especially in compressed liquid and dense fluid states, prompts the tabulation of these provisional properties, computed by approximate methods utilizing the new PVT data of these reports. Computation and preparation of the tables is discussed under the following: Approximate Computational Methods; Correlation Methods; Discussion of Errors; and Tables of Functions.
Date: December 1961
Creator: Roder, Hans M. & Goodwin, Robert D.
System: The UNT Digital Library
Design, Evaluation, and Use of a Reverberation Chamber for Performing Electromagnetic Susceptibility/Vulnerability Measurements (open access)

Design, Evaluation, and Use of a Reverberation Chamber for Performing Electromagnetic Susceptibility/Vulnerability Measurements

Abstract: This report presents the results of work at the National Bureau of Standards, Boulder, Colorado, to carefully evaluate, document, develop (when necessary), and describe the methodology for performing radiated susceptibility/vulnerability measurements using a reverberation chamber. The report describes the reverberation chamber theory of operation, construction, evaluation, functional operation, and use for performing immunity measurements. It includes an estimate of measurement uncertainties derived empirically from test results and from comparisons with anechoic chamber measurements. Finally, it discusses the limitations and advantages of the measurement technique to assist potential users in determining the applicability for this technique to their electromagnetic compatibility (EMC) measurement needs.
Date: April 1986
Creator: Crawford, M. L. & Koepke, Galen H.
System: The UNT Digital Library
Electrical Properties of Materials and Their Measurement at Low Temperatures (open access)

Electrical Properties of Materials and Their Measurement at Low Temperatures

Abstract: A review is given of the electrical resistance of materials at cryogenic temperatures. Measurement techniques, the data base, and uses of the data are presented. The emphasis is on metals and alloys of technological importance; a toxic which covers a large range of materials. Similarly, the treatment of theory and of measurement techniques is primarily for the user interested in the more practical aspects of the subject. In every instance, however, references are given which allow the reader to pursue the subject at any level.
Date: March 1982
Creator: Fickett, F. R.
System: The UNT Digital Library
A Method to Quantify the Radiation Characteristics of an Unknown Interference Source (open access)

A Method to Quantify the Radiation Characteristics of an Unknown Interference Source

From introduction: A new method for determining the radiation characteristics of leakage from electronic equipment for interference studies is described in this report. Basically, an unintentional leakage source is considered to be electrically small, and may be characterized by three equivalent orthogonal electric dipole moments and three equivalent orthogonal magnetic dipole moments. When an unknown source object is placed at the center of a transverse electromagnetic (TEM) cell, its radiated energy couples into the fundamental transmission mode and propagates toward the two output ports of the TEM cell. With a hybrid junction inserted into a loop connecting the cell output ports, one is able to measure the sum and difference powers and the relative phase between the sum and difference outputs. Systematic measurements of these powers and phases at six different source object positions, based on a well-developed theory, are sufficient to determine the amplitudes and phases of the unknown component dipole moments, from which the detailed free-space radiation pattern of the unknown source and the total radiated power can be determined. Results of simulated theoretical examples and an experiment using a spherical dipole radiator are given to illustrate the theory and measurement procedure.
Date: October 1982
Creator: Ma, Mark T. & Koepke, Galen H.
System: The UNT Digital Library
Interactive FORTRAN Programs for Micro Computers to Calculate the Thermophysical Properties of Twelve Fluids (MIPROPS) (open access)

Interactive FORTRAN Programs for Micro Computers to Calculate the Thermophysical Properties of Twelve Fluids (MIPROPS)

From abstract: The thermophysical and transport properties of selected fluids have been programmed in FORTRAN 77 which is available for micro computers. The input variables are any two of P, p, T (pressure, density, and temperature) in the single phase regions, and either P or T for the saturated liquid or vapor states. The output is pressure, density, temperature, internal energy, enthalpy, entropy, specific heat capacities (Cp and Cv), speed of sound and, in most cases, viscosity, thermal conductivity and dielectric constant.
Date: May 1986
Creator: McCarty, Robert D.
System: The UNT Digital Library
Tables of Industrial Gas Container Contents and Density for Oxygen, Argon, Nitrogen, Helium, and Hydrogen (open access)

Tables of Industrial Gas Container Contents and Density for Oxygen, Argon, Nitrogen, Helium, and Hydrogen

Abstract: Custody transfer tables are presented for oxygen, argon, nitrogen, helium, and hydrogen. The tables are based on standard reference data previously compiled by the National Bureau of Standards. Two sets of tables are provided for each fluid. Tables in engineering units cover the range -40 to 130*F with pressures from 100 to 10,000 prig. Tables in SI units (density versus pressure and temperature) cover the range 200 to 370 K with pressures from 0.5 to 70 MPa. The tables in engineering units are designed to provide a means of determining the volume of gas at standard conditions contained in a tank given the volume of the tank and the pressure and temperature of the gas within the tank. The publication also includes four examples of use of the tables in calculating tank quantities.
Date: June 1985
Creator: Younglove, Ben A. & Olien, Neil A.
System: The UNT Digital Library