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A Coaxial Noise Standard for the 1 GHz to 12.4 GHz Frequency Range
From introduction: This note describes the design and construction of a coaxial thermal noise standard. The standard is designed to operate at the boiling point of liquid nitrogen with a noise temperature accurate to t 1 K in the frequency range from 1 GHz to 12.4 GHz.
Date:
1984
Creator:
Daywitt, William C.
Object Type:
Report
System:
The UNT Digital Library
Tests of Commercial Densimeters for LNG Service
Abstract: Densimeters for liquefied natural gas (LNG) from four manufacturers were tested in liquid methane and an LNG-like mixture of methane, propane, and nitrogen in the density reference system (DRS). The calibration and performance of one type tested for the first time are reported. The stability of the calibrations and performances of three densimeters of a type previously tested have been examined and are also reported here.
Date:
June 1982
Creator:
Siegwarth, J. D. & LaBrecque, J. F.
Object Type:
Report
System:
The UNT Digital Library
Beam-Profile Measurement of Laser Pulses Using a Spatial Filter to Sample the Hermite Modes of a String of Pulses
Abstract: As a first step in the development of a beam-profile measuring instrument for laser sources that is capable of determining the distribution of low-order (less than 25) Hermitian modes in a series of laser pulses, I designed and evaluated the three key parts of such an instrument. First, there is the telescope system which allows the incident laser beam to be phase, beamwidth, and beam center matched to the optical spatial filter. Second, there is a brief error analysis of the structure of the mismatch function between the beam out of the telescope and that expected by the filter. Finally, there is the detailed analysis and design of the computer-generated spatial filter that will cause the incident-laser beam to be cross correlated with the low-order Hermite modes and will create an array of light spots in the detector (Fourier transform) plane each of which can be uniquely related to a particular Hermite mode of the original laser pulse. The principal conclusion is that the Hermite mode analysis can be done with better than 99 percent separation between modes, provided the phase between modes is uncorrelated from pulse to pulse when the filter has been fabricated with a two-level, gray-scale …
Date:
September 1982
Creator:
Johnson, Eric Gunnar, Jr.
Object Type:
Report
System:
The UNT Digital Library
A System for Measuring Energy and Peak Power of Low-Level 1.064 [mu]m Laser Pulses
From introduction: For the first time, transfer standards have been developed for measuring 1.064 Pm laser pulses of duration about 10-100 ns, peak irradiance of about 10-8-10-4 W/cm2, and fluences of about 10-16-10-11 J/cm2 . These energy and power measurement devices use PIN and APD silicon detectors, respectively, and can be used as stable transfer standards with total uncertainties (random errors computed at the 95 percent confidence level) of 10 to 15 percent. The system for calibrating these transfer standards is also described and consists of a cw Nd:YAG laser beam acousto-optically modulated to provide low-level laser pulses of known peak power and energy. A detailed evaluation of systematic and random errors is also shown.
Date:
October 1982
Creator:
Sanders, A. A. & Rasmussen, A. L.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
The Fundamental Basis for the Standardization of Electrical Instruments and Meters
Description of the standards used by the electrical power industry for the measurement of the electrical quantities.
Date:
May 7, 1948
Creator:
Silsbee, Francis B.
Object Type:
Report
System:
The UNT Digital Library
Excitation of a TEM Cell by a Vertical Electric Hertzian Dipole
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 offering more flexibility of increasing the size of the test area to accommodate larger pieces of test equipment.
Date:
March 1981
Creator:
Wilson, Perry F.; Chang, David C. & Ma, Mark T.
Object Type:
Report
System:
The UNT Digital Library
Cryogenic Fluids Density Reference System: Provisional Accuracy Statement (1980)
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 to be the sum of the systematic and random errors. This applies to the density range of 400 to 480 kg/m at pressures from 0.8 to 4 bar absolute and temperatures between 109 and 128 K. This accuracy statement is expected to apply over ranges of at least 400 to 1000 kg/m3 in density, 77 to 300 K in temperature, and 0.8 to 7 bar in pressure though the accuracy over these ranges has not been verified.
Date:
April 1981
Creator:
Siegwarth, J. D. & LaBrecque, J. F.
Object Type:
Report
System:
The UNT Digital Library
Proceedings of the Joint Panel Conference of the U.S.-Japan Cooperative Program in Natural Resources: 1982
Abstract: The 14th Joint Meeting of the U.S. - Japan Panel on Wind and Seismic Effects was held in Washington, D. C., United States front May 17 through 20, 1982. This publication, which is the proceedings of the Joint Meeting, includes the program, list of members, formal resolutions, technical papers, and the task committee report:. Subjects covered in the papers presented to the panel include: (l) characteristics of strong winds, (2) wind loads on structures and design criteria, (3) earthquake ground motions and dynamic analysis of embankment dams, (4) soil liquefaction study and methods to improve liquefaction resistance. (5) seismic loads on structures and design criteria, (6) stress analyses of pipelines during earthquakes, (7) full-scale seismic experiments, (8) earthquake hazard reduction program, (9) use of microcomputer for earthquake studies, (10) quantitative evaluation of damages caused by winds and earthquakes, and (11) tsunami research projects.
Date:
April 1983
Creator:
United States-Japan Cooperative Program in Natural Resources. Panel on Wind and Seismic Effects.
Object Type:
Report
System:
The UNT Digital Library
Annual Report and Directory of Accredited Laboratories: 1982
Annual report describing the activities and goals of the National Voluntary Laboratory Accreditation Program (NVLAP) during 1982, and a directory list of laboratories including the test methods for which they are accredited.
Date:
September 1983
Creator:
NVLAP (Program : U.S.)
Object Type:
Report
System:
The UNT Digital Library
Ozone Reactions in Aqueous Solutions: a Bibliography
Abstract: A reaction oriented list of references is provided for published papers and reports containing rate data or information on mechanism for reactions of ozone with various substrates in aqueous solutions. Catalyzed, as well as uncatalyzed, reactions are included. One hundred and sixty-four papers are listed. The period covered extends from 1913 to 1981.
Date:
August 1983
Creator:
Westley, Francis
Object Type:
Report
System:
The UNT Digital Library
Low-Sloped Roofing Research Plan
Abstract: This report presents a long-range plan for roofing research. The plan was developed in response to a need for roofing research addressing major materials problems and changes in low-sloped roofing materials technology. The intent of the plan is to establish the technical basis for developing standards and minimum levels of performance to assist in the selection of cost-effective and durable roofing materials. Four major areas of needed research are identified: (1) low-sloped roofing systems, (2) roofing membranes including single-ply and built-up, (3) thermal insulation for roofing systems, and (4) condition assessment and repair of roofs. Within each research area, a goal is given as well as a number of objectives to achieve the goal. A recommended approach to accomplish each objective is also given.
Date:
July 1983
Creator:
Cullen, William C.; Rossiter, Walter J., Jr.; Mathey, Robert G. & Clifton, James R.
Object Type:
Report
System:
The UNT Digital Library
Measurement & Analysis of Productivity Growth: a Synthesis of Thought
Abstract: Productivity is one of the most important factors influencing our economic well-being. Productivity growth is essential to a higher standard of living and is vital to a sound economic and political environment. However, there has been a slowdown in the growth of productivity in the United States since the mid-1960s. This slowdown has caused concern among policy makers and researchers. Accordingly, several questions persist both in policy and academic circles. Why has productivity been slowing? and What can be done to reverse this trend? The purpose of this report is to address broadly the first of these two questions by surveying and synthesizing the vast literature on the measurement and determinants of productivity. This review is intended to be a source document for those interested in the measurement and analysis of productivity growth. The report is divided into five sections. In the first section, the importance of productivity growth on economic activity is discussed. In the second section, the so called "facts" about patterns of measured productivity growth in the United States are presented. In the third section, the methods currently used for calculating productivity indices are summarized. In the fourth section, the literature related to the determinants of …
Date:
September 1983
Creator:
Link, Albert N.
Object Type:
Report
System:
The UNT Digital Library
DATAPLOT: Introduction and Overview
Abstract: This manual provides DATAPLOT code solution to a variety of commonly occurring graphical problems. A line-by-line explanation of code is given, along with illustrations and general discussion.
Date:
June 1984
Creator:
Filliben, James J.
Object Type:
Report
System:
The UNT Digital Library
Standards Committee Activities of the National Bureau of Standards: 1983 Highlights
Abstract: This report summarizes NBS standards committee activities and accomplishments during calendar year 1983. It profiles NBS state participation on outside standards committees and highlights significant technical and individual contributions made by NBS staff. In 1983, 446 staff members (or 28% of NBS' professionals, scientific, and technical staff) participated in 989 standards committees of 87 national and international standards organizations.
Date:
April 1984
Creator:
Newell, Karl G., Jr.
Object Type:
Report
System:
The UNT Digital Library
National Bureau of Standards
This is an article on the center for materials science, the National Bureau Standards (NBS). From ceramic tiles that shield the space shuttle to dental adhesives which replace metal fillings, new materials are revolutionizing technology and everyday life. NBS is at the forefront of materials technology with its broad-based research effort conducted by the Center for Materials Science (CMS). The Center provides measurements, data, standards, reference materials, and other technical information regarding materials to industry, government agencies, universities, and other scientific organizations. CMS research supports development of new and improved materials which can be used safely, efficiently, and economically.
Date:
1986
Creator:
United States. National Bureau of Standards.
Object Type:
Report
System:
The UNT Digital Library
Facilities of the National Bureau of Standards
From forward: Every laboratory in this country is a valuable national resource. Along with the people who work in these facilities, U.S. laboratories constitute the basic foundation of this country's scientific and industrial strength. As the nation's foremost science and engineering measurement laboratory, the National Bureau of Standards has some of the premier research and testing facilities in the United States, and several of our laboratories are unequaled anywhere in the world. Bureau scientists and engineers use these special facilities to pursue the measurement-related work that U.S. science and industry need to grow and prosper. This brochure highlights only a small number of the special facilities available at NBS and provides information about their availability for collaborative or independent research and testing.
Date:
December 19, 1984
Creator:
United States. National Bureau of Standards.
Object Type:
Report
System:
The UNT Digital Library
Compiled Thermodynamic Data Sources for Aqueous and Biochemical Systems: an Annotated Bibliography (1930-1983)
Abstract: This is a selected and annotated bibliography of sources of compiled and evaluated chemical thermodynamic data relevant to biochemical and aqueous systems. The principal thermodynamic properties considered herein are Gibbs energy and equilibrium data, enthalpies of formation and reaction, heat capacities and entropies, and the corresponding partial molar and excess properties. Derived quantities used in calculating the above are also included. Transport and mechanical data have also been identified to a lesser degree. Included in the annotations to the data sources are brief descriptions of the types of properties tabulated, the classes of materials dealt with, and the degree of completeness of the compilations.
Date:
December 1984
Creator:
Goldberg, Robert N.
Object Type:
Report
System:
The UNT Digital Library
State Measurement Laboratories
Abstract: The National Bureau of Standards receives repeated requests from industry and Federal agencies (e.g. , Department of Defense, Nuclear Regulatory Commission) for information about the capabilities of and services provided by State measurement laboratories. This directory is a compilation of such information by State, including a description of the services available and fees charged. The directory will be updated annually in January of each year to coincide with the issuance of annual certification of these laboratories.
Date:
November 1984
Creator:
Oppermann, H. V.
Object Type:
Report
System:
The UNT Digital Library
Directory of Accredited Laboratories: 1984
Abstract: Laboratories accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) are identified along with the specific test methods for which they are accredited. The current status of existing accreditation programs is given for laboratories that test thermal insulation, freshly mixed concrete, carpet, wood burning stoves, paint, and personnel radiation dosimeters, and that provide acoustical testing services. Indexes are provided for searching the Directory for laboratories accredited in specific testing areas or for specific test methods.
Date:
February 1985
Creator:
NVLAP (Program : U.S.)
Object Type:
Report
System:
The UNT Digital Library
Computerizing Materials Data -- A Workshop for the Nuclear Power Industry
Abstract: This report summarizes the recommendations of a Workshop in Computerized Materials Data as related to engineers in the Nuclear Power Industry. Four areas of discussion are featured: the content of a proposed data system; its size and data sources; the user interfaces and system capabilities; and ways of making further progress. In addition, changes in the use of materials data in the Nuclear Power Industry and progress-to-date in computerizing these data are presented.
Date:
January 1985
Creator:
Rumble, John, Jr. & Westbrook, Jack H.
Object Type:
Report
System:
The UNT Digital Library
Steel Research Needs for Buildings
Abstract: This report identifies experimental and analytical research needed to advance the state-of-the-art and improve safety and economy in the design, fabrication and construction of steel buildings. A five year plan for a coordinated research program is included. Recommendations for research projects dealing with the following topics are presented: total building systems, connections and members, frames, seismic design, load and resistance factor design, fire protection, and design loads. The recommendations were developed at a workshop involving participation by steel industry representatives, design professionals, Federal agency representatives and university researchers.
Date:
May 1985
Creator:
Culver, Charles G.; Iwankiw, Nestor & Kuentz, Albert
Object Type:
Report
System:
The UNT Digital Library
Research and Innovation in the Building Regulatory Process
This document contains the Proceedings of the Sixth NBS/NCSBCS Joint Conference on Research and Innovation in the Building Regulatory Process, held on September 11, 1984, in Denver, CO. This conference addressed streamlined administrative procedures, computers in construction, and fire safety technology. These Proceedings contain the 10 papers selected for presentation at the conference.
Date:
April 1985
Creator:
Beavers, Linda
Object Type:
Report
System:
The UNT Digital Library