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Failure of sheathed thermocouples due to thermal cycling

Description: Open circuit failures (up to 100%) in small-diameter thermocouples used in electrically heated nuclear fuel rod simulator prototypes during thermal cycling tests were investigated to determine the cause(s) of the failures. The experiments conducted to determine the relative effects of differential thermal expansion, wire size, grain size, and manufacturing technology are described. It was concluded that the large grain size and embrittlement which result from certain common manufacturing anneal… more
Date: March 1, 1982
Creator: Anderson, R.L. & Ludwig, R.L.
Partner: UNT Libraries Government Documents Department
open access

US Atom-Resolving Microscope Project

Description: The largest project in transmission electron microscopy in this country has recently been initiated. This project has been given the name Atomic Resolution Microscopy and its goal is to provide the instrumentation and expertise necessary to conduct materials research directly at the atomic level. Taking advantage of the best available technology in electron-optical design, its core instrumentation is a unique machine, the Atomic Resolution Microscope (ARM), which is to be built by commercial ma… more
Date: March 1, 1980
Creator: Gronsky, R.
Partner: UNT Libraries Government Documents Department
open access

Circular intensity differential scattering (CIDS) measurements in the soft x-ray region of the spectrum (@16 eV to 500 eV)

Description: We propose the use of recently developed techniques of circular intensity differential scattering (CIDS), as extended to the soft x-ray region of the spectrum (16 eV to 500 eV), to study the higher order organization of the eukaryotic chromosome. CIDS is the difference in scattering power of an object when illuminated by right circularly polarized vs. left circularly polarized electromagnetic radiation of arbitrary wavelength. CIDS has been shown to be a very sensitive measure of the helical or… more
Date: March 1, 1991
Creator: Maestre, M .F.; Bustamante, C.; Snyder, P.; Rowe, E. & Hansen, R.
Partner: UNT Libraries Government Documents Department
open access

Proposal for a cryogenic magnetic field measurement system for SSC dipole magnets

Description: This proposal describes the research and development required, and the subsequent fabrication of, a system capable of making integrated magnetic multipole measurements of cryogenic 40-mm-bore SSC dipole magnets utilizing a cryogenic probe. Our experience and some preliminary studies indicate that it is highly unlikely that a 16-meter-long probe can be fabricated that will have a twist below several milliradians at cryogenic temperatures. We would anticipate a twist of several milliradians just … more
Date: March 1, 1991
Creator: Green, M.I. & Hansen, L.
Partner: UNT Libraries Government Documents Department
open access

MICROFLUIDIC MIXERS FOR THE INVESTIGATION OF PROTEIN FOLDING USING SYNCHROTRON RADIATION CIRCULAR DICHROISM SPECTROSCOPY

Description: The purpose of this study is to design, fabricate and optimize microfluidic mixers to investigate the kinetics of protein secondary structure formation with Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy. The mixers are designed to rapidly initiate protein folding reaction through the dilution of denaturant. The devices are fabricated out of fused silica, so that they are transparent in the UV. We present characterization of mixing in the fabricated devices, as well as the initial… more
Date: March 20, 2006
Creator: Kane, A; Hertzog, D; Baumgartel, P; Lengefeld, J; Horsley, D; Schuler, B et al.
Partner: UNT Libraries Government Documents Department
open access

Biomonitoring with Wireless Communications

Description: This review is divided into three sections: technologies for monitoring physiological parameters; biosensors for chemical assays and wireless communications technologies including image transmissions. Applications range from monitoring high risk patients for heart, respiratory activity and falls to sensing levels of physical activity in military, rescue, and sports personnel. The range of measurements include, heart rate, pulse wave form, respiratory rate, blood oxygen, tissue pCO2, exhaled car… more
Date: March 1, 2003
Creator: Budinger, Thomas F.
Partner: UNT Libraries Government Documents Department
open access

EVALUATING ROBOT TECHNOLOGIES AS TOOLS TO EXPLORE RADIOLOGICAL AND OTHER HAZARDOUS ENVIRONMENTS

Description: There is a general consensus that robots could be beneficial in performing tasks within hazardous radiological environments. Most control of robots in hazardous environments involves master-slave or teleoperation relationships between the human and the robot. While teleoperation-based solutions keep humans out of harms way, they also change the training requirements to accomplish a task. In this paper we present a research methodology that allowed scientists at Idaho National Laboratory to iden… more
Date: March 1, 2008
Creator: Nielsen, Curtis W.; Gertman, David I.; Bruemmer, David J.; Hartley, R. Scott & Walton, Miles C.
Partner: UNT Libraries Government Documents Department
open access

ELECTRONICS UPGRADE OF HIGH RESOLUTION MASS SPECTROMETERS

Description: High resolution mass spectrometers are specialized systems that allow researchers to determine the exact mass of samples to four significant digits by using magnetic and electronic sector mass analyzers. Many of the systems in use today at research laboratories and universities were designed and built more than two decades ago. The manufacturers of these systems have abandoned the support for some of the mass spectrometers and parts to power and control them have become scarce or obsolete. The … more
Date: March 10, 2008
Creator: Mcintosh, J & Joe Cordaro, J
Partner: UNT Libraries Government Documents Department
open access

Electron sputtering in the analytical electron microscope: Calculations and experimental data

Description: The environment of the electron microscope is particularly severe when one considers the energy deposited in a specimen during typical experimental conditions. Conventional imaging experiments tend to employ electron current densities ranging from approx.0.1 to 1 A/cm/sup 2/ while during microanalysis conditions probe current densities can range from 10 to values as high as 10/sup 5/ A/cm/sup 2/. At 100 kV this corresponds to power densities from 100 Kilowatts/cm/sup 2/ to 10/sup 4/ Megawatts/c… more
Date: March 1, 1987
Creator: Zaluzec, N.J. & Mansfield, J.F.
Partner: UNT Libraries Government Documents Department
open access

Rupture-safe pressure transducers

Description: The design, fabrication and testing of a rupture-safe transducer for measuring gas pressures in a manned-area field environment are described. (LCL)
Date: March 13, 1979
Creator: Holten, D.C.
Partner: UNT Libraries Government Documents Department
open access

Magnetic fields, current densities, melt velocities and current efficiencies in Hall-Heroult cells: computations and comparison with measurements

Description: The magnetic fields, current densities, metal and electrolyte velocities, and current efficiencies within the Hall-Heroult cells used to produce aluminum have been predicted from first principles. The computation of current densities was carried out by solving Ohms law enabling the calculation of magnetic field vectors from the Biot-Savart law. The cross product of the current densities and magnetic fields then yielded the electromagnetic stirring forces acting on the molten metal and electroly… more
Date: March 1, 1979
Creator: Evans, J. W.; Zundelevich, Y.; Tarapore, E. D. & Sharma, D.
Partner: UNT Libraries Government Documents Department
open access

Large area 200 psec gated microchannel plate detector

Description: Results are presented with a 15 mm wide gated microchannel plate uv and x-ray detector. The active area is part of a 6 ohm transmission line driven by an electronically generated gate pulse. The microchannel plate is coated with CsI allowing tests with a frequency quadrupled, high repetition rate 1.05 ..mu..m laser. Results showing optical gate widths as short as 100 psec are presented.
Date: March 1, 1986
Creator: Eckart, M. J.; Hanks, R. L.; Kilkenny, J. D.; Pasha, R.; Wiedwald, J. D. & Hares, J. D.
Partner: UNT Libraries Government Documents Department
open access

Nanosecond fluorescence spectroscopy

Description: This article is a summary of a short course lecture given in conjunction with the 1984 Nuclear Science Symposium. Measuring systems for nanosecond fluorescence spectroscopy using single-photon counting techniques are presented. These involve systems based on relaxation-type spark gap light pulser and synchronously pumped mode-locked dye lasers. Furthermore, typical characteristics and optimization of operating conditions of the critical components responsible for the system time resolution are … more
Date: March 1, 1985
Creator: Leskovar, B.
Partner: UNT Libraries Government Documents Department
open access

Field measuring probe for SSC (Superconducting Super Collider) magnets

Description: The field probe developed for measuring the field in SSC dipole magnets is an adaptation of the rotating tangential coil system in use at Brookhaven for several years. Also known as the MOLE, it is a self-contained room-temperature mechanism that is pulled through the aperture of the magnet with regular stops to measure the local field. Several minutes are required to measure the field at each point. The probe measures the multipole components of the field as well as the field angle relative to… more
Date: March 1, 1987
Creator: Ganetis, G.; Herrera, J.; Hogue, R.; Skaritka, J.; Wanderer, P. & Willen, E.
Partner: UNT Libraries Government Documents Department
open access

A resonant beam detector for TEVATRON tune monitoring

Description: An inductively resonated, balanced stripline pickup has been constructed for observing tune spectra. The device is a sensitive betatron oscillation and Schottky noise pickup, providing 25 dB gain over untuned detectors of like geometry. The electrodes are motorized so the device center and aperture may be remotely adjusted. To tune the resonator onto the 21.4 MHz operating frequency, a motorized capacitor is employed. Quadrature signals from a pair of detectors has enabled observation of indivi… more
Date: March 1, 1989
Creator: Martin, D.; Fellenz, B.; Hood, C.; Johnson, M.; Shafer, R.; Siemann, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

Description: Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we appro… more
Date: March 1, 1993
Creator: Bluestein, H. B.; LaDue, J. G.; Stein, H.; Speheger, D. & Unruh, W. P.
Partner: UNT Libraries Government Documents Department
open access

Laser probing of interfaces

Description: In the past decade, the possibility of using lasers to probe surfaces and interfaces has attracted a great of attention. Such techniques have the advantages of being able to interrogate a surface or interface in a non-detrimental and remote sensing way. Optical second harmonic generation (SHG) and sum frequency generation (SFG) have turned out to be most effective and versatile. By symmetry, these second-order nonlinear optical processes are forbidden (under the electric dipole approximation) i… more
Date: March 1, 1994
Creator: Shen, Y. R.
Partner: UNT Libraries Government Documents Department
open access

Design of a fieldable laser system for a sodium guide star

Description: The design and background data for a sodium layer laser guide star system to be installed on the 3 meter telescope at Lick Observatory is presented. A 30 W dye laser at 589 nm and 10 kHz will be mounted on the telescope and will be pumped by fiber coupled frequency doubled YAG laser located in a separate room.
Date: March 17, 1994
Creator: Friedman, H.; Erbert, G.; Kuklo, T.; Salmon, T.; Smauley, D.; Thompson, G. et al.
Partner: UNT Libraries Government Documents Department
open access

Portable, solid state, fiber optic coupled Doppler interferometer system for detonation and shock diagnostics

Description: VISAR (Velocity Interferometer System for Any Reflector) is a specialized Doppler interferometer system that is gaining world-wide acceptance as the standard for shock phenomena analysis. The VISAR`s large power and cooling requirements, and the sensitive and complex nature of the interferometer cavity have restricted the traditional system to the laboratory. This paper describes the new portable VISAR, its peripheral sensors, and the role it played in optically measuring ground shock of an und… more
Date: March 1, 1994
Creator: Fleming, K. J. & Crump, O. B.
Partner: UNT Libraries Government Documents Department
open access

Issues in the design and optimization of adaptive optics and laser guide stars for the Keck Telescopes

Description: We discuss issues in optimizing the design of adaptive optics and laser guide star systems for the Keck Telescope. The initial tip-tilt system will use Keck`s chopping secondary mirror. We describe design constraints, choice of detector, and expected performance of this tip-tilt system as well as its sky coverage. The adaptive optics system is being optimized for wavelengths of I-2.2{mu}m. We are studying adaptive optics concepts which use a wavefront sensor with varying numbers of subapertures… more
Date: March 1, 1994
Creator: Max, C. E.; Gavel, D. T. & Olivier, S. S.
Partner: UNT Libraries Government Documents Department
open access

Portable fiber optic coupled doppler interferometer system for detonation and shock wave diagnostics

Description: Testing and analysis of shock wave characteristics such as produced by detonators and ground shock propagation frequently require a method of measuring velocity and displacement of the surface of interest. One method of measurement is doppler interferometry. The VISAR (Velocity Interferometer System for Any Reflector) uses doppler interferometry and has pined wide acceptance as the preferred tool for shock measurement. An important asset of VISAR is that it measures velocity and displacement no… more
Date: March 1, 1993
Creator: Fleming, K. J.
Partner: UNT Libraries Government Documents Department
open access

Fiber-optic currents measurements

Description: Polarization maintaining pigtailed laser diodes have greatly increased the ease with which fiber-optic sensors for Faraday current measurements on large pulsed experiments can be deployed. 670, 830, and 1300 nm units are readily available. Such diode lasers can easily be mounted in an RF shielded box along with the simple electronics and batteries to power them. Our units measure 16.5 {times} 8 {times} 6 cm. and have a single external control; an on off switch. They use two 1.5 volt ``C`` cell … more
Date: March 1, 1993
Creator: Forman, P. R.; Looney, L. D. & Tabaka, L. J.
Partner: UNT Libraries Government Documents Department
open access

Single sided tomography of extremely large dense objects

Description: One can envision many circumstances where radiography could be valuable but is frustrated by the geometry of the object to be radiographed. For example, extremely large objects, the separation of rocket propellants from the skin of solid fuel rocket motor, the structural integrity of an underground tank or hull of a ship, the location of buried objects, inspection of large castings etc. The author has been investigating ways to do this type of radiography and as a result has developed a techniq… more
Date: March 24, 1993
Creator: Thoe, R. S.
Partner: UNT Libraries Government Documents Department
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