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The Uranium, Tin, and Copper Deposits at Majuba Hill, Pershing County, Nevada

Description: From abstract: Uranium is associated with copper and tin ores in the Majuba Hill area, Antelope mining district, in the central part of the Antelope Range, Pershing County, Nev. About 23, 000 tons of copper and 200 tons of tin ore, a small quantity of lead-silver ore, and some arsenic-silver ore have been produced from the Majuba Hill mine, the Last Chance mine, and a mine in sec. 34, T. 33 N., R. 31 E.
Date: December 1952
Creator: Thurston, Ralph H. & Trites, Albert F., Jr.

Design of the National Bureau of Standards Isotropic Magnetic Field Meter (MFM-10) 300 kHz to 100 MHz

Description: From introduction: In this report the following will he discussed: (1) design consideration of the broadband magnetic field sensor, (2) overall design of the magnetic field meter, (3) performance of the meter, (4) calibration and operating procedures, (5) alignment and adjustment procedures, and (6) summary and conclusions.
Date: October 1985
Creator: Cruz, J. E.; Driver, L. D. & Kanda, Motohisa

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 using a finite-difference (or lattice) form of the electromagnetic action functional, and 3) use of a directional probe to scan a volume. All three methods are still in the development stage, but each appears promising.
Date: March 1985
Creator: Kanda, Motohisa; Randa, J. & Nahman, N. S.

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 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.

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 element under observation. Within all paths except the most direct one, multiple reflections between subgroups of elements take place. The resulting solution is highly structured and recursive and is discussed in detail in the text. Illustrative examples are provided to facilitate understanding of these ideas.
Date: February 1985
Creator: Muth, Lorant A.

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 measured throughout the test volume with a short dipole probe, and the agreement with the theory is excellent.
Date: June 1985
Creator: Hill, David A. & Koepke, Galen H.

Pegmatites of the Crystal Mountain District, Larimer County, Colorado

Description: From abstract: The Front Range of Colorado is composed chiefly of schists of the Idaho Springs formation of pre-Cambrian age which have been intruded by a variety of granitic batholiths. In the Crystal Mountain district the Mount Olympus granite, a satellite of Fuller's Longs Peak batholith, forms sills and essentially concordant multiple intrusions in quartz-mica schist that dips southward at moderate to steep angles. A great number of pegmatites accompanied and followed the intrusion of the sills and formed concordant and discordant bodies in schist and granite.
Date: 1955
Creator: Thurston, William R.

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-parameters.
Date: August 1985
Creator: Kanda, Motohisa & Orr, R. David

A Study of Techniques for Measuring the Electromagnetic Shielding Effectiveness of Materials

Description: Abstract: Shielding effectiveness relates to a material's ability to reduce the transmission of propagating fields in order to electromagnetically isolate one region from another. Because a complex material's shielding capability is difficult to predict, it often must be measured. A number of measurement approaches are studied including the use of a shielded room, coaxial transmission line holders, time domain signals, the dual TEM cell, and an apertured TEM cell in a reverberation chamber. In each case, we consider the system's frequency range, test sample requirements, test field type, dynamic range, time required, analytical background, and present data taken on a common set of materials.
Date: May 1986
Creator: Wilson, Perry F. & Ma, Mark T.

Summary of Investigations of Uranium Deposits in the Pumpkin Buttes Area, Johnson and Campbell Counties, Wyoming

Description: From abstract: Uranium minerals were discovered in the Pumpkin Buttes area, Campbell and Johnson Counties by the U. S. Geological Survey in October 1951. From June to November 1952, an area of about 750 square miles was examined for uranium deposits, and 211 localities with abnormally high radioactivity were found; uranium minerals are visible at 121 of these localities.
Date: July 1953
Creator: Troyer, Max L.; McKay, Edward J.; Soister, Paul E. & Wallace, Stewart R.

Geology of the Freshwater Bay Area, Chichagof Island, Alaska

Description: From abstract: The Freshwater Bay area comprises about 140 square miles in the northeastern part of Chichagof Island, southeastern Alaska. A sequence of Paleozoic rocks more than 24,000 feet thick is divided into 5 formations, 4 of which are named for the first time.
Date: 1963
Creator: Loney, Robert Ahlberg; Condon, William H. & Dutro, J. Thomas, Jr.

Results of Core Drilling of Uranium-Bearing Lignite Deposits in Harding and Perkins Counties, South Dakota, and Bowman County, North Dakota

Description: Purpose: The main objective of the Dakota core drilling program was to determine reserves of uraniferous lignite based on chemical uranium and spectrographic determinations from unweathered samples, particularly from those areas where surface sampling of the beds during the previous field season indicated that significant deposits of uranium-bearing lignite might be present. A secondary objective was to obtain fresh samples and to measure the radioactivity of the overlying Oligocene White River and Miocene Arikaree formations from which the uranium in lignite is believed to have been derived.
Date: October 1952
Creator: Zeller, Howard D.

Relation of Uranium to Hypogene Mineral Zoning in the Front Range Mineral Belt, Colorado

Description: From abstract: Many of the mining districts of the Colorado Front Range mineral belt contain mesothermal sulfide ores that exhibit a zonal distribution. Present data indicate that in most of the zoned districts pitchblende and/or secondary uranium minerals are most abundant in a transition zone between central areas containing predominantly pyritic gold ores and peripheral areas containing dominantly lead-zinc-silver deposits. Copper in the form of chalcopyrite is also probably more abundant in the transition zone than in adjacent zones.
Date: August 1955
Creator: Wallace, S. R.; Leonard, B. F. & Campbell, Russell H.

Results of Diamond Drilling and Geologic Investigation of the Shirley May (Garo) Uranium Deposit, Park County, Colorado

Description: From abstract: The Shirley May (Garo) uranium deposit near Garo, Park County, Colo. , consists of tyuyamunite and carnotite that occur as disseminations and as fracture fillings in three beds of medium- to coarse-grained sandstone. The sandstones are in the Maroon formation of Permian age, This deposit was explored by means of 12 core-drill holes, totalling 2,003 feet.
Date: November 1952
Creator: Wilmarth, V. R. & Smith, L. E.

Uranium-Bearing Coal in the Central Part of the Great Divide Basin, Sweetwater County, Wyoming

Description: From abstract: Field work leading to this report was done by the U. S. Geological Survey for the Division of Raw Materials of the U. S. Atomic Energy Commission, Nearly 24 townships were mapped in the central part of the Great Divide Basin, Sweetwater County, Wyoming, Fourteen of these townships contain outcrops of uranium-bearing coal. Thirty coal beds were mapped, but only seven of them have uranium-bearing coal reserves as defined in this report.
Date: March 1956
Creator: Pipiringos, George N.

Automated Measurement of Frequency Response of Frequency-Modulated Generators Using the Bessel Null Method

Description: From abstract: This paper describes a Bessel null technique to measure the frequency response of a frequency-modulated rf carrier and a program to automate frequency response measurements of signal generators with output frequencies from 0.450 to 2000 MHz. The measurements obtained using this technique are more precise than those obtained by a highly trained technician using a manual system.
Date: March 1986
Creator: Major, J. R.; Livingston, E. M. & Adair, Robert T.

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

Description: 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.

A Statistical Characterization of Electroexplosive Devices Relevant to Electromagnetic Compatibility Assessment

Description: Abstract: Electroexplosive devices (EEDs) are electrically fired explosive initiators used in a wide variety of applications. The nature of most of these applications requires that the devices function with near certainty when required and remain inactive otherwise. Recent concern with pulsed electromagnetic interference (EMI) and nuclear electromagnetic pulse (EMP) made apparent the lack of methodology for assessing EED vulnerability. A new and rigorous approach for characterizing EED firing levels is developed in the context of statistical linear models and is demonstrated in this paper. We combine statistical theory and methodology with thermodynamic modeling to determine the probability that an EED, of a particular type, fires when excited by a pulse of a given width and amplitude. The results can be applied to any type of EED for which the hot-wire explosive binder does not melt below the firing temperature. Included are methods.for assessing model validity and for obtaining probability plots, called "Firing Likelihood Plots". A method of measuring the thermal time constant of an EED is given. This parameter is necessary to evaluate the effect of a train of pulses. These statistical methods are both more general and more efficient than previous methods for EED assessment. The results provide information which is crucial for evaluating the effects of currents induced by impulsive electromagnetic fields of short duration relative to the EEDs thermal time constant.
Date: May 1986
Creator: Friday, Dennis S. & Adams, John W.