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Optically-Activated GaAs Switches for Ground Penetrating Radar and Firing Set Applications (open access)

Optically-Activated GaAs Switches for Ground Penetrating Radar and Firing Set Applications

Optically activated, high gain GaAs switches are being tested for many different applications. TWO such applications are ground penetrating radar (GPR) and firing set switches. The ability of high gain GaAs Photoconductive Semiconductor Switches (PCSs) to deliver fast risetime pulses makes them suitable for their use in radars that rely on fast impulses. This type of direct time domain radar is uniquely suited for the detection of buried items because it can operate at low frequency, high average power, and close to the ground, greatly increasing power on target. We have demonstrated that a PCSs based system can be used to produce a bipolar waveform with a total duration of about 6 ns and with minimal ringing. Such a pulse is radiated and returns from a 55 gallon drum will be presented. For firing sets, the switch requirements include small size, high current, dc charging, radiation hardness and modest longevity. We have switched 1 kA at 1 kV and 2.8 kA at 3 kV dc charge.
Date: July 14, 1999
Creator: Aurand, J.; Brown, D. J.; Carin, L.; Denison, G. J.; Helgeson, W. D.; Loubriel, G. M. et al.
Object Type: Article
System: The UNT Digital Library
An overview of resid characterization by mass spectrometry and small angle scattering techniques. (open access)

An overview of resid characterization by mass spectrometry and small angle scattering techniques.

The purpose of this presentation is to discuss what is known about the molecular structures found in petroleum resid from mass spectrometry and small angle neutron and X-ray scattering methods. The question about molecular size distributions and the occurrence of aggregation in the asphaltene fraction will be examined. Our understanding of this problem has evolved with the application of new analytical methods. Also, correlations with results from other approaches will be discussed. In addition, the issue of the nature of the heteroatom-containing molecules will be examined and the challenges that remain in this area.
Date: July 14, 1999
Creator: Hunt, J. E. & Winans, R. E.
Object Type: Article
System: The UNT Digital Library
The Panola Watchman (Carthage, Tex.), Vol. 126, No. 56, Ed. 1 Wednesday, July 14, 1999 (open access)

The Panola Watchman (Carthage, Tex.), Vol. 126, No. 56, Ed. 1 Wednesday, July 14, 1999

Semiweekly newspaper from Carthage, Texas that includes local, state, and national news along with advertising.
Date: July 14, 1999
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Pawhuska Journal-Capital (Pawhuska, Okla.), Vol. 89, No. 56, Ed. 1 Wednesday, July 14, 1999 (open access)

Pawhuska Journal-Capital (Pawhuska, Okla.), Vol. 89, No. 56, Ed. 1 Wednesday, July 14, 1999

Semiweekly newspaper from Pawhuska, Oklahoma that includes local, state, and national news along with advertising.
Date: July 14, 1999
Creator: Gann, Sherry
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Penny Record (Bridge City, Tex.), Vol. 41, No. 8, Ed. 1 Wednesday, July 14, 1999 (open access)

The Penny Record (Bridge City, Tex.), Vol. 41, No. 8, Ed. 1 Wednesday, July 14, 1999

Weekly newspaper from Bridge City, Texas that includes local, state, and national news along with advertising.
Date: July 14, 1999
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Perry Daily Journal (Perry, Okla.), Vol. 106, No. 136, Ed. 1 Wednesday, July 14, 1999 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 106, No. 136, Ed. 1 Wednesday, July 14, 1999

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: July 14, 1999
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
Perspectives on Epic Physics (open access)

Perspectives on Epic Physics

An electron-proton/ion polarized beam collider (EPIC) with high luminosity and center of mass energy square root s = 25 GeV would be a valuable facility for fundamental studies of proton and nuclear structure and tests of quantum chromodynamics, I review a sample of prospective EPIC topics, particularly semi-exclusive reactions, studies of the proton fragmentation region, heavy quark electroproduction, and a new probe of odderon/pomeron interference.
Date: July 14, 1999
Creator: Brodsky, Stanley J.
Object Type: Report
System: The UNT Digital Library
Radioactive air emissions notice of construction use of a portable exhauster on single-shell tanks during salt well pumping (open access)

Radioactive air emissions notice of construction use of a portable exhauster on single-shell tanks during salt well pumping

This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.07, portable exhausters for use on singleshell tanks (SSTs) during salt well pumping. Table 1-1 lists SSTs covered by this NOC. This GOC also addresses other activities that are performed in support of salt well pumping but do not require the application of a portable exhauster. Specifically this NOC analyzes the following three activities that have the potential for emissions. (1) Salt well pumping (i.e., the actual transferring of waste from one tank to another) under nominal tank operating conditions. Nominal tank operating conditions include existing passive breathing rates. (2) Salt well pumping (the actual transferring of waste from one tank to another) with use of a portable exhauster. (3) Use of a water lance on the waste to facilitate salt well screen and salt well jet pump installation into the waste. This activity is to be performed under nominal (existing passive breathing rates) tank operating conditions. The use of portable exhausters represents a cost savings because one portable exhauster can be moved back and …
Date: July 14, 1999
Creator: Homan, N. A.
Object Type: Report
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 84, No. 259, Ed. 1 Wednesday, July 14, 1999 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 84, No. 259, Ed. 1 Wednesday, July 14, 1999

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: July 14, 1999
Creator: Horn, Richard A.
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Seminole Sentinel (Seminole, Tex.), Vol. 92, No. 77, Ed. 1 Wednesday, July 14, 1999 (open access)

The Seminole Sentinel (Seminole, Tex.), Vol. 92, No. 77, Ed. 1 Wednesday, July 14, 1999

Semiweekly newspaper from Seminole, Texas that includes local, state, and national news along with advertising.
Date: July 14, 1999
Creator: Dow, M. Gene & Fisher, David
Object Type: Newspaper
System: The Portal to Texas History
Structural design criteria for high heat flux components. (open access)

Structural design criteria for high heat flux components.

The high temperature design rules of the ITER Structural Design Criteria (ISDC), are applied to first wall designs with high heat flux. The maximum coolant pressure and surface heat flux capabilities are shown to be determined not only by the mechanical properties of the first wall material but also by the details of the blanket design. In a high power density self-cooled lithium blanket, the maximum primary stress in the first wall is controlled by many of the geometrical parameters of the blanket, such as, first wall span, first wall curvature, first wall thickness, side wall thickness, and second wall thickness. The creep ratcheting lifetime of the first wall is also shown to be controlled by many of the same geometrical parameters as well as the coolant temperature. According to most high temperature design codes, the time-dependent primary membrane stress allowable are based on the average temperature (ignoring thermal stress). Such a procedure may sometimes be unconservative, particularly for embrittled first walls with large temperature gradients. The effect of secondary (thermal) stresses on the accumulation of creep deformation is illustrated with a vanadium alloy flat plate first wall design.
Date: July 14, 1999
Creator: Majumdar, S.
Object Type: Article
System: The UNT Digital Library
Synthetic Multivariate Models to Accommodate Unmodeled Interfering Components During Quantitative Spectral Analyses (open access)

Synthetic Multivariate Models to Accommodate Unmodeled Interfering Components During Quantitative Spectral Analyses

The analysis precision of any multivariate calibration method will be severely degraded if unmodeled sources of spectral variation are present in the unknown sample spectra. This paper describes a synthetic method for correcting for the errors generated by the presence of unmodeled components or other sources of unmodeled spectral variation. If the spectral shape of the unmodeled component can be obtained and mathematically added to the original calibration spectra, then a new synthetic multivariate calibration model can be generated to accommodate the presence of the unmodeled source of spectral variation. This new method is demonstrated for the presence of unmodeled temperature variations in the unknown sample spectra of dilute aqueous solutions of urea, creatinine, and NaCl. When constant-temperature PLS models are applied to spectra of samples of variable temperature, the standard errors of prediction (SEP) are approximately an order of magnitude higher than that of the original cross-validated SEPs of the constant-temperature partial least squares models. Synthetic models using the classical least squares estimates of temperature from pure water or variable-temperature mixture sample spectra reduce the errors significantly for the variable temperature samples. Spectrometer drift adds additional error to the analyte determinations, but a method is demonstrated that can minimize …
Date: July 14, 1999
Creator: Haaland, David M.
Object Type: Article
System: The UNT Digital Library
Tank 241-SY-101 surface level rise remediation test and evaluation plan for transfer system (open access)

Tank 241-SY-101 surface level rise remediation test and evaluation plan for transfer system

The purpose of this testing and evaluation plan (TEP) is to provide the high level guidance on testing requirements for ensuring that the equipment and systems to be implemented for remediation of the SY-101 waste level rise USQ are effective.
Date: July 14, 1999
Creator: BAUER, R.E.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: JC-76 (open access)

Texas Attorney General Opinion: JC-76

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification: Whether a transit authority created under chapter 451 of the Transportation Code may purchase a railroad line, part of which extends beyond the transit authority's territory, and related question.
Date: July 14, 1999
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-77 (open access)

Texas Attorney General Opinion: JC-77

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification: Whether a van-access aisle adjacent to a van-accessible parking space is an "architectural improvement designed to aid persons with disabilities" for purposes of section 681.011(c) of the Transportation Code.
Date: July 14, 1999
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-78 (open access)

Texas Attorney General Opinion: JC-78

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification: Whether chapter 37 of the Business and Commerce Code applies to unsolicited telephone calls by licensed residential service companies to consumers for the purpose of selling residential service contracts and related questions.
Date: July 14, 1999
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-79 (open access)

Texas Attorney General Opinion: JC-79

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification: Whether a commissioners court may set a maximum speed limit on certain county roads below 30 miles an hour, and related questions.
Date: July 14, 1999
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-80 (open access)

Texas Attorney General Opinion: JC-80

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification: Whether under article III, section 52 or article XI, section 3 of the Texas Constitution a county may pay registration fees for a county official or county employee to attend a state association conference, either mandatory or voluntary, and related questions.
Date: July 14, 1999
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JC-81 (open access)

Texas Attorney General Opinion: JC-81

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Cornyn, regarding a legal question submitted for clarification: Whether a local government must collect sales taxes on beach user fees charged pursuant to chapter 61 of the Natural Resources Code and General Land Office rules.
Date: July 14, 1999
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Thermochemistry of YBa(2)Cu(3-x)M(x)O(y) (M=Ni,Zn) (open access)

Thermochemistry of YBa(2)Cu(3-x)M(x)O(y) (M=Ni,Zn)

Many studies have investigated the behavior of transition metal dopants in the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} 123 superconductors. Much of this research has focused on the effects of metal ions such as Co, Fe, Zn, Ni when they are substituted for the copper ions at Cu(1) and Cu(2) sites, commonly referred to as the chain and plane sites, respectively. Trivalent ions such as Co{sup +3} and Fe{sup +3}have been shown to behave similarly in their substitution effects, displaying site preference on the Cu(1) site [3-8]. This site preference has been established with the use of techniques such as neutron diffraction and Moessbauer spectroscopy [4,5]. Thermogravimetry, electron diffraction, and analysis of lattice parameters as a function of dopant also yield results consistent with those of the structural studies with respect to the chain site preference of both Co and Fe [3,4,6-8]. The very fast convergence of a and b lattice parameters to that of the tetragonal structure, occurring at x = 0.3 Co dopant (i.e. YBa{sub 2}Cu{sub 2.7}Co{sub 0.3}O{sub 7{minus}{delta}}) for high-oxygen-content samples, coupled with information derived from diffuse scattering and oxidation behavior of these samples, has been described in detail by several authors in terms of the Co and Fe …
Date: July 14, 1999
Creator: Licci, Francesca; Navrotsky, Alexandra & Rodriguez, Mark A.
Object Type: Article
System: The UNT Digital Library
Use of high-temperature superconducting films in superconducting bearings. (open access)

Use of high-temperature superconducting films in superconducting bearings.

We have investigated the effect of high-temperature superconductor (HTS) films deposited on substrates that are placed above bulk HTSs in an attempt to reduce rotational drag in superconducting bearings composed of a permanent magnet levitated above the film/bulk HTS combination. According to the critical state model, hysteresis energy loss is inversely proportional to critical current density, J{sub c}, and because HTS films typically have much higher J{sub c} than that of bulk HTS, the film/bulk combination was expected to reduce rotational losses by at least one order of magnitude in the coefficient of fiction, which in turn is a measure of the hysteresis losses. We measured rotational losses of a superconducting bearing in a vacuum chamber and compared the losses with and without a film present. The experimental results showed that contrary to expectation, the rotational losses are increased by the film. These results are discussed in terms of flux drag through the film, as well as of the critical state model.
Date: July 14, 1999
Creator: Cansiz, A.
Object Type: Article
System: The UNT Digital Library
Verification and validation of XSDRNPM code for tank waste calculations (open access)

Verification and validation of XSDRNPM code for tank waste calculations

This validation study demonstrates that the XSDRNPM computer code accurately calculates the infinite neutron multiplication for water-moderated systems of low enriched uranium, plutonium, and iron. Calculations are made on a 200 MHz Brvo MS 5200M personal
Date: July 14, 1999
Creator: ROGERS, C.A.
Object Type: Report
System: The UNT Digital Library
Věstník (Temple, Tex.), Vol. 87, No. 27, Ed. 1 Wednesday, July 14, 1999 (open access)

Věstník (Temple, Tex.), Vol. 87, No. 27, Ed. 1 Wednesday, July 14, 1999

Weekly Czech and English language newspaper from Temple, Texas published as the official organ of the Slavonic Benevolent Order of the State of Texas that includes news of interest to members along with advertising.
Date: July 14, 1999
Creator: Vanicek, Brian
Object Type: Newspaper
System: The Portal to Texas History
W1045 environment surf drip shield and waste package outer barrier (open access)

W1045 environment surf drip shield and waste package outer barrier

The environments on the drip shield and waste package outer barrier are controlled by the compositions of the waters that contact these components. the temperature (T) of these components, and the effective relative humidity (RH) at these components. Because the composition of the waters that are expected to enter the emplacement drifts (either by seepage flow or by episodic flow) have not been specified: well J13 water was chosen as the reference water (Harrar 1990). Section 6.2 discusses the accessible RH for the temperatures of interest at the repository horizon. Section 6.3 discusses the adsorption of water on metal alloys in the absence of hygroscopic salts. Because the temperatures of the DSs and the WPOBs are higher than those of the surrounding near-field environment, the relative humidity at the DSs and the WPOBs will be lower than that of the surrounding near-field environment. This difference is a result of the water partial pressure in the drift being constant and no higher than the equilibrium water vapor pressure at the temperature of the drift wall.
Date: July 14, 1999
Creator: Gdowski, G
Object Type: Report
System: The UNT Digital Library