Technical Report Archive & Image Library (TRAIL) - 5,422 Matching Results

Search Results

prev Results: 31 - 54 next
open access

Fitness-for-Service Criteria for Assessing the Significance of Fatigue Cracks in Offshore Structure

Description: Abstract: Results of a research program to develop fitness-for-service criteria for assessing the significance of fatigue cracks in offshore structures are presented in five papers. Each paper describes the goals and approaches to a specific task and details the results of the study.
Date: August 1985
Creator: Cheng, Yi-Wen
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Radio-Frequency Power Delivery System: Procedures for Error Analysis and Self-Calibration

Description: Abstract: An expression is developed for net power delivered to a load in terms of the indicated forward and reflected power and the system S-parameters and reflection coefficients. The dual directional coupler is treated as nonideal with power reflections assumed between all ports. The system itself is used to evaluate the major S-parameter terms in net power computation, and uncertainty in the computed power is derived from origins in the power meter readings and incompletely known S-paramete… more
Date: August 1985
Creator: Kanda, Motohisa & Orr, R. David
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Near-Field Array of Yagi-Uda Antennas for Electromagnetic Susceptibility Testing

Description: Abstract: In electromagnetic susceptibility testing of electronic equipment, the ideal incident field is a plane wave. To approximate this condition, a seven-element array of Yagi-Uda antennas has been constructed and tested at a frequency of 500 MHz. The element weightings are determined by a near-field synthesis technique which optimizes the uniformity of the field throughout a rectangular test volume in the near field of the array. The amplitude and phase of the electric field have been meas… more
Date: June 1985
Creator: Hill, David A. & Koepke, Galen H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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

Description: 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… more
Date: June 1985
Creator: Younglove, Ben A. & Olien, Neil A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Transparent Metrology of Signal to Noise Ratios of Noisy Band-Limited Digital Signals

Description: From abstract: I propose the use of a template method for quantitative, correct, and transparent measurement of signal power to additive noise power ratios (SNR) of digital signals and systems under full operating conditions. Outer guard chips of digital templates hold intersymbol interference fixed on inner target chips in realizations of the respective template patterns in traffic. The proposed template method needs to be developed and proven as a potentially valuable metrology capability; it… more
Date: June 1985
Creator: Halford, Donald
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

VOR Calibration Services

Description: 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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Possible Estimation Methodologies for Electromagnetic Field Distributions in Complex Environments

Description: Abstract: The problem of measuring and characterizing complicated multiple-source, multiple-frequency electromagnetic environments is becoming more important and more difficult as electrical devices proliferate. This paper outlines three general approaches to the problem which are currently under investigation at the National Bureau of Standards. The three approaches are: 1) a statistical treatment of the spatial distribution of electromagnetic field intensities, 2) a numerical computation usin… more
Date: March 1985
Creator: Kanda, Motohisa; Randa, J. & Nahman, N. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Theory of Mutual Impedances and Multiple Reflections in an N-Element Array Environment

Description: Abstract: A general theoretical approach is formulated to describe the complex electromagnetic environment of an N-element array. The theory reveals the element-to-element interactions and multiple reflections within the array. From the formulation, it is found that the interaction between an excited element and an open-circuited element can be viewed as the sum of terms describing all possible signal paths within the array environment which start from the radiating element and terminate on the… more
Date: February 1985
Creator: Muth, Lorant A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mineral Investigation of the Arrastra Mountain Wilderness Study Area, La Paz, Mohave, and Yavapai Counties, and Peoples Canyon Wilderness Study Area, Yavapai County, Arizona

Description: This report presents the results of a mineral survey of the Arrastra Mountain (AZ 020-059) and Peoples Canyon (AZ 020-068) Wilderness Study Areas, La Paz, Mohove, and Yavapai Counties, Arizona.
Date: 1985
Creator: Lane, Michael E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mineral Investigation of the Sierra Ancha Wilderness and Salome Study Area, Gila County, Arizona

Description: This report presents the results of the mineral survey of the Sierra Ancha Wilderness and Salome Study Area conducted by the U.S. Bureau of Mines. A combined summary report of work done by the U.S. Geological Survey and U.S. Bureau of Mines has been previously published.
Date: 1985
Creator: Light, Thomas D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mineral Resources of a Part of the Dos Cabezas Mountains Wilderness Study Area (Az-040-065), Cochise County, Arizona

Description: From summary: In January-April 1984, the Bureau of Mines conducted a mineral survey of the Lower Burro Creek Wilderness Study Area as required by Federal Land Policy and Management Act (Public Law 94-579, October 21, 1976). The Lower Burro Creek Wilderness Study Area comprises 21,700 acres in southeastern Mohave and Yavapai Counties, Arizona. Mines and prospects are located on deposits and (or) occurrences of gold, bentonite, magnesite, and agate in the eastern and southeastern part of the stud… more
Date: 1985
Creator: Zelten, Jeanne E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mineral Resources of the Harquahala Mountains Study Area (Az-020-095), La Paz and Maricopa Counties, Arizona

Description: From summary: The Harquahala Mountains BLM Wilderness Study Area is in the Basin and Range physiographic province of west-central Arizona. The present study covers 24,735 acres of the 72,675 acre wilderness study area, preliminary recommended as suitable for inclusion in the National Wilderness Preservation System in La Paz and Maricopa Counties, Arizona. During the winter of 1983-84, under authority of the Federal Land Policy and Management Act (Public Law 94-579), the Bureau mapped and sample… more
Date: 1985
Creator: Thompson, John R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mineral Resources of the Lower Burro Creek Wilderness Study Area (Az-020-060), Mohave and Yavapai Counties, Arizona

Description: From summary: In January-April 1984, the Bureau of Mines conducted a mineral survey of the Lower Burro Creek Wilderness Study Area as required by Federal Land Policy and Management Act (Public Law 94-579, October 21, 1976). The Lower Burro Creek Wilderness Study Area comprises 21,700 acres in southeastern Mohave and Yavapai Counties, Arizona.
Date: 1985
Creator: Schreiner, Russell A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An Error Analysis for the Use of Presently Available Lunar Radio Flux Data in Broadbeam Antenna-System Measurements

Description: From introduction: Simple, precise expressions for lunar diameter, average brightness temperature, flux density, and shape factor are presented. An analysis of the relationship between these parameters and corresponding errors are included. For broadbeam (HPBW>d) antennas, results show that flux density and shape factor can be determined with errors less than 13 percent and 0.4 percent respectively at frequencies below 10 GHz. Extension of the analysis to higher frequencies is indicated.
Date: February 1984
Creator: Daywitt, William C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Theory of Near-Field Phased Arrays for Electromagnetic Susceptibility Testing

Description: From introduction: The feasibility of using a near-field array for electromagnetic susceptibility testing is studied. The basic objective is to control the element weightings such that a plane wave is generated within the test volume. The basic theory is developed for arbitrary array geometries, and numerical results are obtained for finite planar arrays. A general near-field array synthesis technique is developed, and the technique minimizes the mean square error in the test volume while const… more
Date: February 1984
Creator: Hill, D. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Coaxial Noise Standard for the 1 GHz to 12.4 GHz Frequency Range

Description: 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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Electromagnetic-Acoustic-Transducer/Synthetic-Aperture System for Thick-Weld Inspection

Description: Abstract: This report describes a system based on electromagnetic-acoustic transducers (EMATs) as an approach to automated nondestructive evaluation of thick weldments (>25 mm). Good signal-to-noise ratios, often a problem with EMATs, were possibTe through careful design of the transducers and associated electronic circuits and the use of signal averaging. At 454 kHz, the transducers produce shear-horizontal waves of approximately 7-mm wavelength in steel. The long wavelength permits determinat… more
Date: 1984
Creator: Fortunko, C. M.; Schramm, R. E.; Moulder, J. C. & McColskey, J. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Small Aperture Analysis of the Dual TEM Cell and an Investigation of Test Object Scattering in a Single TEM Cell

Description: Introduction: Small aperture theory is used to investigate the dual TEM cell. Analyzing coupling through an empty versus a loaded aperture leads to a model of dual TEM cell shielding effectiveness measurements. Small obstacle scattering yields results for both the field perturbation and the change in a cell's transmission line characteristics due to the presence of a test object in a TEM cell. In each case, theoretical values are compared to experimental data.
Date: 1984
Creator: Wilson, Perry F. & Ma, Mark T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Review of Supercritical Fluid Extraction

Description: Forward: The purpose of this report is to summarize the results obtained from a brief investigation of supercritical fluid extraction principles and applications. This study was one portion of a project funded by the U.S. Department of Energy, Office of Fossil Energy, contract nuriber DE-AI01076PR06010, in response to a preliminary proposal submitted by the authors. This report sometimes uses company trade naries to identify processes and patent holders. This usage implies no endorsement by HBS… more
Date: December 1983
Creator: Ely, James F. & Baker, Jolene K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen