[Magazine Article: Hypocritical Oath] (open access)

[Magazine Article: Hypocritical Oath]

A copy of a newspaper article pertaining to Califonia's Proposition 186 and the reaction of the gay and lesbian community.
Date: November 8, 1994
Creator: unknown
System: The UNT Digital Library
Search for top quark at CDF (open access)

Search for top quark at CDF

There is a vast theoretical and experimental support for idea that op quark as a weak isospin partner to b-quark should exist. Production cross section is steeply falling function of top quark mass. Therefore realistically at present only Tevatron p[anti p] collider at FNAL, with total energy 1.8 TeV in CMS system, still has a chance of top quark discovery. Dominant production mechanism for top quarks at Tevatron is pair production of t[anti t]. With almost 100% probability t ([anti t]) decays in mode t [yields] W[sup +]b. Distinct features of this decay provide very good signatures of top quark production which helps to reduce otherwise very high level of background. Based on simple combinatorial arguments one can show that W should decay in 1/9 cases into W [yields] l + [nu] where l stands for lepton (e,[mu],[tau]). Very clean signature represents case when both W's from t and [anti t] decay into e ([mu]) + [nu]. In this case experimental observation will be two isolated leptons characterized by large transverse momentum, large missing transverse energy E[sub T] and 2 b quark jets. Jets originated from b quarks can be quite frequently recognized by presence of secondary vertices associated with …
Date: November 1, 1994
Creator: unknown
System: The UNT Digital Library
The development of mechanical strength in a ceramic material during firing (open access)

The development of mechanical strength in a ceramic material during firing

This experiment was designed for high school students who have a very limited background in ceramic materials, but the experiments could also be used at the college level. The objective of the experiment is to teach students about the development of mechanical strength in a ceramic material as a result of the firing process and about testing methods used for brittle materials. In the experiment, clay-based ceramic bars of uniform circular cross section are prepared by extrusion. The bars are then fired at temperatures high enough to achieve high strength by development of a glassy bonding phase. Finally, the bars will be stressed to failure in a simple testing machine. This will quantify the increase in strength as a function of firing temperature.
Date: November 1, 1994
Creator: Bunnell, L. R. & Piippo, S. W.
System: The UNT Digital Library
Radiation-induced grain boundary segregation in austenitic stainless steels (open access)

Radiation-induced grain boundary segregation in austenitic stainless steels

Radiation-induced segregation (RIS) to grain boundaries in Fe-Ni-Cr-Si stainless alloys has been measured as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550{degrees}C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350{degrees}C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Although interfacial compositions were similar, the width of radiation-induced enrichment or depletion profiles increased consistently with increasing dose or temperature. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si peaked at levels approaching 10 at% after irradiation doses to 10 dpa at an intermediate temperature of 325{degrees}C. No evidence of grain boundary silicide precipitation was detected after irradiation at any temperature. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Comparisons to reported RIS in neutron-irradiated stainless steels revealed similar grain boundary compositional changes for both major alloying and impurity elements.
Date: November 1, 1994
Creator: Bruemmer, S. M.; Charlot, L. A.; Vetrano, J. S. & Simonen, E. P.
System: The UNT Digital Library
A survey of surveys (open access)

A survey of surveys

A new era for the field of Galactic structure is about to be opened with the advent of wide-area digital sky surveys. In this article, the author reviews the status and prospects for research for 3 new ground-based surveys: the Sloan Digital Sky Survey (SDSS), the Deep Near-Infrared Survey of the Southern Sky (DENIS) and the Two Micron AU Sky Survey (2MASS). These surveys will permit detailed studies of Galactic structure and stellar populations in the Galaxy with unprecedented detail. Extracting the information, however, will be challenging.
Date: November 1, 1994
Creator: Kent, S. M.
System: The UNT Digital Library
A spectral algorithm for the seriation problem (open access)

A spectral algorithm for the seriation problem

Given a set of objects and a correlation function f reflecting the desire for two items to be near each other, find all sequences {pi} of the items so that correlation preferences are preserved; that is if {pi}(i) < {pi}(j) < {pi}(k) then f(i,j) {ge} f(i,k) and f(j,k) {ge} f(i,k). This seriation problem has numerous applications, for instance, solving it yields a solution to the consecutive ones problem. We present a spectral algorithm for this problem that has a number of interesting features. Whereas most previous applications of spectral techniques provided bounds or heuristics, our result is an algorithm for a nontrivial combinatorial problem. Our analysis introduces powerful tools from matrix theory to the theoretical computer science community. Also, spectral methods are being applied as heuristics for a variety of sequencing problems and our result helps explain and justify these applications. Although the worst case running time for our approach is not competitive with that of existing methods for well posed problem instances, unlike combinatorial approaches our algorithm remains a credible heuristic for the important cases where there are errors in the data.
Date: November 1, 1994
Creator: Atkins, J. E.; Boman, E. G. & Hendrickson, B.
System: The UNT Digital Library
Processing and electrochemical properties of mixed conducting La{sub 1-x}A{sub x}Co{sub 1-y}Fe{sub y}O{sub 3-{delta}} (A=Sr, Ca) (open access)

Processing and electrochemical properties of mixed conducting La{sub 1-x}A{sub x}Co{sub 1-y}Fe{sub y}O{sub 3-{delta}} (A=Sr, Ca)

Powder compositions in the series La{sub 1-x}A{sub x}Co{sub 1-y}Fe{sub y}O{sub 3-{delta}} (A = Sr, Ca) have been prepared by a combustion synthesis method. Sintering of pressed powders produced high-density test specimens with the perovskite structure. The specimens exhibited high electrical conductivities with appreciable oxygen-ion conductivity that increased with Co content for the compositions studied. Oxygen permeation studies showed a significant flux of oxygen that increased with temperature for specimens in a P(O{sub 2}) gradient with no applied field. Thermogravimetric studies of the La{sub 1-x}Sr{sub x}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} system indicated a reversible mass loss with increasing temperature that increased with Sr content.
Date: November 1, 1994
Creator: Weber, W. J.; Stevenson, J. W.; Armstrong, T. R. & Pederson, L. R.
System: The UNT Digital Library
Cooling rate effects on the microstructure, critical current density, and {Tc} transition of one- and two-powder BSCCO-2223 Ag-sheathed tapes (open access)

Cooling rate effects on the microstructure, critical current density, and {Tc} transition of one- and two-powder BSCCO-2223 Ag-sheathed tapes

An important variable controlling the critical current density (J{sub c}) of Ag-sheathed BSCCO-2223 tapes is the degree of phase purity of the reacted tapes. Most correlations between J{sub c} and microstructure show that it is highly desirable to reduce the amount of non-superconducting second phases to as low a level as practical. In recent studies of the influence of cooling rate after the final reaction, we find contradictions to this general rule. The J{sub c} (77 K, 0 T) of so-called {open_quotes}one-powder{close_quotes} tapes can be raised by as much as 50% (from -8,000 A/cm{sup 2} to 12,000 A/cm{sup 2}) by slow cooling in 7.5%O{sub 2} at 0.05{degrees}C/min, even though large 2212 grains are usually seen in the slowly cooled microstructure. However, the higher J{sub c} of the slow-cooled state does correlate with a sharper T{sub c} transition. Experiments with {open_quotes}two-powder{close_quotes} tapes have produced similar results. These apparently anomalous results emphasize the important role played by the connectivity of the polycrystalline core in determining J{sub c}.
Date: November 1, 1994
Creator: Parrell, J. A.; Larbalestier, D. C. & Dorris, S. E.
System: The UNT Digital Library
Decontamination and dismantlement of Plant 7 at Fernald (open access)

Decontamination and dismantlement of Plant 7 at Fernald

Decontamination and dismantlement (D&D) tasks have been successfully completed on Plant 7 at the Fernald Environmental Management Project. The seven story facility was radiologically, chemically, and biologically contaminated. The work involved the D&D work beginning with safe shutdown and gross decontamination, and ended with removal of the structural steel. A series of lessons learned were gained which include use of explosives, bidding tactics, safe shutdown, building decontamination and lockdown, use of seam climbers, etc.
Date: November 7, 1994
Creator: Albertin, M.; Borgman, T. & Zebick, B.
System: The UNT Digital Library
Introduction to the physics of Higgs bosons (open access)

Introduction to the physics of Higgs bosons

A basic introduction to the physics of the Standard Model Higgs boson is given. We discuss Higgs boson production in e{sup +}e{sup {minus}} and hadronic collisions and survey search techniques at future accelerators. The Higgs bosons of the minimal SUSY model are briefly considered. Indirect limits from triviality arguments, vacuum stability and precision measurements at LEP are also presented.
Date: November 1, 1994
Creator: Dawson, S.
System: The UNT Digital Library
Early operating experience with large-area germanium detectors for detecting low-energy photons (open access)

Early operating experience with large-area germanium detectors for detecting low-energy photons

Intrinsic germanium (Ge) planar detector arrays have been used at Hanford for lung counting since 1983. This paper describes a counting system using an array of only four detectors, larger than those used in the past, using larger dewars and a simplified detector-positioning system. Typical detector elements have been 51 mm in diameter and 20 mm thick, with a beryllium window thickness of 0.51 mm. The resolution of the detectors has been about 560 eV for 6.4-keV x-rays and 700 eV for 122-keV gamma rays. In the past, arrays of three, four, five, and six detectors have been employed. Six detectors have been the preferred configuration for lung counting. Up to 3,000 counts annually have been performed with these systems. When detectors fail and spares are not available, calibrations and calculational algorithms are maintained for four-detector configurations. For several years, both ``bucket`` and ``stovepipe`` designs have been used for the Dewars with the 15-liter dewars proving to be much more reliable than the ``stovepipe`` designs.
Date: November 1, 1994
Creator: Rieksts, G. A.; Lynch, T. P. & Olsen, P. C.
System: The UNT Digital Library
Decoherence, determinism and chaos revisited (open access)

Decoherence, determinism and chaos revisited

We suggest that the derivation of the free space Maxwell Equations for classical electromagnetism, using a discrete ordered calculus developed by L.H. Kauffman and T. Etter, necessarily pushes the discussion of determinism in natural science down to the level of relativistic quantum mechanics and hence renders the mathematical phenomena studied in deterministic chaos research irrelevant to the question of whether the world investigated by physics is deterministic. We believe that this argument reinforces Suppes` contention that the issue of determinism versus indeterminism should be viewed as a Kantian antinomy incapable of investigation using currently available scientific tools.
Date: November 15, 1994
Creator: Noyes, H. P.
System: The UNT Digital Library
Density changes in amorphous Pd{sub 80}Si{sub 20} during low temperature ion irradiation (open access)

Density changes in amorphous Pd{sub 80}Si{sub 20} during low temperature ion irradiation

Density changes in amorphous Pd{sub 80}Si{sub 20} during ion irradiation below 100K were detected by in situ HVEM measurements of the changes in specimen length as a function of ion fluence. A decrease in mass density as a function of the ion fluence was observed. The saturation value of the change in mass density was determined to be approximately -1.2%.
Date: November 1, 1994
Creator: Schumacher, G.; Birtcher, R. C. & Rehn, L. E.
System: The UNT Digital Library
D{O} upgrade muon electronics design (open access)

D{O} upgrade muon electronics design

The planned luminosity for the upgrade is ten times higher than at present (L {approximately} 10{sup 32}cm{sup {minus}2}s{sup {minus}1}) and involves a time between collisions as small as 132 ns. To operate in this environment, completely new electronics is required for the 17,500 proportional drift tubes of the system. These electronics include a deadtimeless readout, a digital TDC with about 1 ns binning for the wire signals, fast charge integrators and pipelined ADCs for digitizing the pad electrode signals, a new wire signal triggering scheme and its associated trigger logic, and high level DSP processing. Some test results of measurements performed on prototype channels and a comparison with the existing electronics are presented.
Date: November 1, 1994
Creator: Baldin, B.; Green, D.; Haggerty, H. & Hansen, S.
System: The UNT Digital Library
Meeting on flows of granular materials in complex geometries (open access)

Meeting on flows of granular materials in complex geometries

The International Energy Agency Fossil Fuel Multiphase Flow Sciences Agreement has been in effect since 1986. The traditional mechanism for the effort has been information exchange, effected by the inclusion of scientists in annual Executive committee meetings, by exchange of reports and papers, and by visits of scientists to one another`s institutions. In a sequence of informal meetings and at the 1993 Executive committee meeting, held in Pittsburgh, US in March 1994, it was decided that more intensive interactions could be productive. A candidate for such interactions would be specific projects. Each of these would be initiated through a meeting of scientists in which feasibility of the particular project was decided, followed by relatively intense international co-operation in which the work would be done. This is a report of the first of these meetings. Official or unofficial representatives from Canada, italy, japan, mexico, the United Kingdom, and the US met in Albuquerque, New Mexico, US, to consider the subject Flows of Granular Materials in Complex Geometries. Representatives of several other countries expressed interest but were unable to attend this meeting. Sixteen lectures were given on aspects of this topic. It was decided that a co-operative effort was desirable and possible. …
Date: November 1, 1994
Creator: Passman, S. L.; Fukushima, E. & Evans, R. E.
System: The UNT Digital Library
Development of subcontractor indirect cost and other direct cost at the DOE Fernald Site (open access)

Development of subcontractor indirect cost and other direct cost at the DOE Fernald Site

The Fernald Environmental Restoration Management Corporation (FERMCO) took great strides in the development of cost estimates at Fernald. There have been many opportunities to improve on how the policies and procedures pertaining to cost estimates were to be implemented. As FERMCO took over the existing Fernald facility, the Project Controls Division began to format the estimating procedures and tools to do business at Fernald. The Estimating Department looked at the problems that pre-existed at the site. One of the key problems that FERMCO encountered was how to summarized the direct and indirect accounts of each subcontracted estimate. Direct costs were broken down by prime and sub-prime accounts. This presented a level of detail that had not been experienced at the site before; it also created many issues concerning accounts and definitions to be applied to ``all other accounts associated with a project.`` Existing subcontract indirect cost accounts were reviewed from existing historical estimates. It was found that some were very detailed and some were not. The Estimating Department was given the task of standardizing the accounts and percentages for each of the subcontractor indirect costs. Then, as the project progressed, the percentages could be revised with actual estimates, subcontract comparisons, …
Date: November 18, 1994
Creator: Cossman, R. L.
System: The UNT Digital Library
Feature-based tolerancing for advanced manufacturing applications (open access)

Feature-based tolerancing for advanced manufacturing applications

A primary requirement for the successful deployment of advanced manufacturing applications is the need for a complete and accessible definition of the product. This product definition must not only provide an unambiguous description of a product`s nominal shape but must also contain complete tolerance specification and general property attributes. Likewise, the product definition`s geometry, topology, tolerance data, and modeler manipulative routines must be fully accessible through a robust application programmer interface. This paper describes a tolerancing capability using features that complements a geometric solid model with a representation of conventional and geometric tolerances and non-shape property attributes. This capability guarantees a complete and unambiguous definition of tolerances for manufacturing applications. An object-oriented analysis and design of the feature-based tolerance domain was performed. The design represents and relates tolerance features, tolerances, and datum reference frames. The design also incorporates operations that verify correctness and check for the completeness of the overall tolerance definition. The checking algorithm is based upon the notion of satisfying all of a feature`s toleranceable aspects. Benefits from the feature-based tolerance modeler include: advancing complete product definition initiatives, incorporating tolerances in product data exchange, and supplying computer-integrated manufacturing applications with tolerance information.
Date: November 1, 1994
Creator: Brown, C. W.; Kirk, W. J. III; Simons, W. R.; Ward, R. C. & Brooks, S. L.
System: The UNT Digital Library
The influence of surface structure on the interaction of water with TiO{sub 2}(100) (open access)

The influence of surface structure on the interaction of water with TiO{sub 2}(100)

The influence of surface structure on the interaction of water with TiO{sub 2}(100) (rutile) was investigated. Two unique surface structures of the (100) crystal face can be prepared by oxidation (the bulk-terminated surface) and by vacuum reduction (the (110)- microfaceted surface). Thermal desorption profiles, which measure of the strength of the adsorbate-surface interaction, indicate that submonolayer coverages of water are more stable on the bulk-terminated surface than on the (110)-microfaceted surface. Also, subtle differences exist in the way water interacts with 2-coordinate O{sup 2{minus}} sites on these two surfaces. The implications of these results for chemistry on microcrystallines particle are considered.
Date: November 1, 1994
Creator: Henderson, M. A.
System: The UNT Digital Library
Machine recognition of navel orange worm damage in X-ray images of pistachio nuts (open access)

Machine recognition of navel orange worm damage in X-ray images of pistachio nuts

Insect infestation increases the probability of aflatoxin contamination in pistachio nuts. A non-destructive test is currently not available to determine the insect content of pistachio nuts. This paper presents the use of film X-ray images of various types of pistachio nuts to assess the possibility of machine recognition of insect infested nuts. Histogram parameters of four derived images are used in discriminant functions to select insect infested nuts from specific processing streams.
Date: November 1, 1994
Creator: Keagy, P. M.; Schatzki, T. F. & Parvin, B.
System: The UNT Digital Library
Exotic colliders (open access)

Exotic colliders

The motivation, feasibility and potential for two unconventional collider concepts - the Gamma-Gamma Collider and the Muon Collider - are described. The importance of the development of associated technologies such as high average power, high repetition rate lasers and ultrafast phase-space techniques are outlined.
Date: November 1, 1994
Creator: Chattopadhyay, S.
System: The UNT Digital Library
Electron drift velocities of Ar-CO{sub 2}-CF{sub 4} gas mixtures (open access)

Electron drift velocities of Ar-CO{sub 2}-CF{sub 4} gas mixtures

The muon spectrometer for the D0 experiment at Fermi National Accelerator Laboratory uses proportional drift tubes filled with an Ar-CO{sub 2}-CF{sub 4} gas mixture. Measurements of drift velocity as a function of electric field magnitude for 90%-5%-5% and 90%-4%-6% Ar-CO{sub 2}-CF{sub 4} mixtures are presented, and our operational experiences with these gases at D0 is discussed.
Date: November 1, 1994
Creator: Markeloff, R.; Haggerty, H. & Shao, Y.
System: The UNT Digital Library
Femtosecond X-Ray Generation Through 90° Thomson Scattering: Status of the LBL Experiment (open access)

Femtosecond X-Ray Generation Through 90° Thomson Scattering: Status of the LBL Experiment

Scattering of femotosecond laser pulses off a low energy relativistic electron beam at 90{sup o} offers the possibility to generate ultrashort X-ray pulses. Experiments are under preparation in the Beam Test Facility of the Center for Beam Physics at LBL to demonstrate the generation and detection of such pulses. The experiments involve a relativistic electron beam (tunable from 25-50 MeV) with a bunch length of 10 ps containing 1-2 nC, and an ultra short pulse (50-200 fs), high peak power (&gt;2 TW) 0.8 {mu}m Ti:Al{sub 2}O{sub 3} laser system. The electron beam, focused down to about a 50 {mu}m waist size intersects the focused laser beam at 90{sup o}. The laser field acts as an electromagnetic undulator with strength K (quiver velocity of an electron normalized to the speed of light) for the relativistic electron beam, generating radiation up-shifted by 2{gamma}{sup 2}/(1+K{sup 2}/2) and a pulse length given by the overlapped interaction length in time of the laser beam and the electron beam. Here {gamma} is the usual Lorentz factor. Wavelength tuning will be accomplished in the experiment by generating wiggler strengths on the order of one as well as by electron beam energy tuning. For a 50 MeV electron …
Date: November 1, 1994
Creator: Leemans, W.; Schoenlein, R.; Chin, A.; Glover, E.; Conde, M.; Chattopadhyay, S. et al.
System: The UNT Digital Library
Practical issues in discriminating between environmental and occupational sources in a uranium urinalysis bioassay program (open access)

Practical issues in discriminating between environmental and occupational sources in a uranium urinalysis bioassay program

Workers at two Department of Energy facilities, the Pantex Plant in Texas and the Hanford Site in Washington, are potentially exposed to class Y depleted or natural uranium. Since trace amounts of uranium are naturally present in urine excretion, site bioassay programs must be able to discern occupational exposure from naturally occurring uranium exposure. In 1985 Hanford established a 0.2-{mu}g/d environmental screening level for elemental uranium in urine; the protocol was based on log-normal probability analysis of unexposed workers. A second study of background uranium levels commenced in 1990, and experiences in the field indicated that there seemed to be an excessive number of urine samples with uranium above the screening level and that the environmental screening level should be reviewed. Due to unforeseen problems, that second study was terminated before the complete data could be obtained. Natural uranium in rock (by weight, 99.27% {sup 288}U, 0.72% {sup 235}U, and 0.006% {sup 234}U) has approximately equal activity concentrations of {sup 238}U and {sup 234}U. Earlier studies, summarized by the U.S. Environmental Protection Agency in 51 FR 32068, have indicated that {sup 234}U (via {sup 234}Th) has a greater environmental mobility than {sup 238}U and may well have a higher concentration …
Date: November 1, 1994
Creator: Long, M. P.; Carbaugh, E. H. & Fairrow, N. L.
System: The UNT Digital Library
Specification of the figure and finish of EUV mirrors in terms of performance requirements. Revision 11/94 (open access)

Specification of the figure and finish of EUV mirrors in terms of performance requirements. Revision 11/94

All manufacturing processes involve errors. In the case of bare and multilayer mirrors these unavoidable errors introduce near-field fluctuations in the reflected wavefront which propagate to the far field and degrade imaging performance. In order to specify manufacturing tolerances in terms of performance requirements we must know the connection between the two -- the finish-function relationship. This paper discusses the form of that relationship derived using elementary statistical diffraction theory. It tells us what statistical properties of the surface errors are relevant, it spells out the important role of the system parameters for EUV mirrors which is absent for conventional mirrors, and it leads to simple good-bad tests for mirror quality. These results are an extension of previous work in this area.
Date: November 1, 1994
Creator: Church, E. L. & Takacs, P. Z.
System: The UNT Digital Library