States

[Aerial Photograph of Denton County, DFW 03-19-960]

Aerial photograph of a portion of Denton County, Texas showing roads, geography, and neighborhoods.
Date: January 10, 1990
Creator: unknown
Object Type: Photograph
System: The Portal to Texas History

[Aerial Photograph of Denton County, DFW 03-19-962]

Aerial photograph of a portion of Denton County, Texas showing roads, geography, and neighborhoods.
Date: January 10, 1990
Creator: Denton County (Tex.)
Object Type: Photograph
System: The Portal to Texas History
Analytic Multi-Regge Theory and the Pomeron in QCD (open access)

Analytic Multi-Regge Theory and the Pomeron in QCD

The formalism of Analytic Multi-Regge Theory is developed as a basis for the study of abstract Critical and Super-Critical Pomeron high-energy behavior and for related studies of the Regge behavior of spontaneously broken gauge theories and the Pomeron in QCD. Asymptotic domains of analyticity for multiparticle amplitudes are shown to follow from properties of Field Theory and S-Matrix Theory. General asymptotic dispersion relations are then derived for such amplitudes in which the spectral components are described by the graphical formalism of hexographs. Further consequences are distinct Sommerfeld-Watson representations for each hexograph spectral component, together with a complete set of angular momentum plane unitarity equations which control the form of all multi-Regge amplitudes. Because of this constraint of Reggeon Unitarity'' the Critical Pomeron solution of the Reggeon Field Theory gives the only known non-trivial'' unitary high-energy S-Matrix. By exploiting the full structure of multi-Regge amplitudes as the Pomeron becomes Super-Critical, the simultaneous modification of hadrons and the Pomeron can be studies. The result is a completely consistent description of the Super-Critical Pomeron appearing in hadron scattering. Reggeon Unitarity is satisfied in the Super-Critical Phase by the appearance of a massive gluon'' (Reggeised vector particle) coupling pair-wise to the Pomeron.
Date: May 10, 1990
Creator: White, A.R.
Object Type: Report
System: The UNT Digital Library
B-physics at CDF (open access)

B-physics at CDF

During the 1988/1989 run at the Fermilab Tevatron, the CDF detector collected {approx equal}4.1 pb{sup {minus}1} of p{bar p} data at {radical}s = 1.8 TeV. The main goals of this run being physics at high p{sub t}, the CDF trigger was tuned'' for maximizing signals from Z{sup 0}s, Ws, t-quarks, etc. As such, compared to the high p{sub t} physics, the b-physics program was of secondary importance other than that which would be used for background calculations. Also, CDF had no vertex chamber capability for seeing displaced vertices. However, significant b-quark, physics results are evident in two data samples; inclusive electrons and inclusive J/{psi} where J/{psi} {yields} {mu}{sup +}{mu}{sup {minus}}. We can then ask ourselves, given all this, why is it that CDF is able to do b-quark physics The answer is that nature has been kind enough to provide b-quarks at an extremely high rate at the Tevatron. The production cross-section for b{bar b} production is quite large. In the rest of this paper, I will try to specify the goals for b-physics using the inclusive electrons and J/{psi} signals for the 1988/1989 data set. I will then provide a brief look at the data, and will finish with …
Date: December 10, 1990
Creator: Baden, A.R. (Harvard Univ., Cambridge, MA (USA))
Object Type: Article
System: The UNT Digital Library
Characterization of the plasma-switch interaction in the LBL HIF ion source (open access)

Characterization of the plasma-switch interaction in the LBL HIF ion source

A new way to characterize the performance of the LBL HIF ion source has been found. In the LBL source, ions are drawn from an arc-generated plasma reservoir in which the electrons are confined by a negative-biased switch'' mesh. Stagnation of the plasma is prevented by absorption of the excess ion flow on this mesh. The ion beam is generated by an external negative voltage that provides Child-Langmuir extraction of the ions through the switch mesh. We elucidate the physics requirements of the source and deduce switch mesh parameters needed for successful operation. 2 refs., 2 figs.
Date: December 10, 1990
Creator: Hewett, D.W. (Lawrence Livermore National Lab., CA (USA)) & Rutkowski, H.L. (Lawrence Berkeley Lab., CA (USA))
Object Type: Article
System: The UNT Digital Library
Chemical and nuclear properties of lawrencium (element 103) and hahnium (element 105) (open access)

Chemical and nuclear properties of lawrencium (element 103) and hahnium (element 105)

The chemical and nuclear properties of Lr and Ha have been studied, using 3-minute {sup 260}Lr and 35-second {sup 262}Ha. The crystal ionic radius of Lr{sup 3+} was determined by comparing its elution position from a cation-exchange resin column with those of lanthanide elements having known ionic radii. Comparisons are made to the ionic radii of the heavy actinides, Am{sup 3+} through Es{sup 3+}, obtained by x-ray diffraction methods, and to Md{sup 3+} and Fm{sup 3+} which were determined in the same manner as Lr{sup 3+}. The hydration enthalpy of {minus}3622 kJ/mol was calculated from the crystal ionic radius using an empirical form of the Born equation. Comparisons to the spacings between the ionic radii of the heaviest members of the lanthanide series show that the 2Z spacing between Lr{sup 3+} and Md{sup 3+} is anomalously small, as the ionic radius of Lr{sup 3+} of 0.0886 nm is significantly smaller than had been expected. The chemical properties of Ha were determined relative to the lighter homologs in group 5, Nb and Ta. Group 4 and group 5 tracer activities, as well as Ha, were absorbed onto glass surfaces as a first step toward the determination of the chemical properties of …
Date: September 10, 1990
Creator: Henderson, Roger Alan
Object Type: Report
System: The UNT Digital Library
Collective Effects in Short Bunches: Summary of the Working Group on Proton Bunches (open access)

Collective Effects in Short Bunches: Summary of the Working Group on Proton Bunches

This report discusses the following topics on proton beam bunching: space charge, a collective but incoherent effect; a very short proton bunch; long proton bunches; transition energy crossing; intrabeam scattering; vacuum related effects; and the issue of mode-coupling for proton bunches. (LSP)
Date: October 10, 1990
Creator: Ruggiero, Alessandro G.
Object Type: Article
System: The UNT Digital Library
Combustion-related studies using weakly-bonded complexes (open access)

Combustion-related studies using weakly-bonded complexes

Objectives are to study binary complexes involving molecular oxygen and the photoinitiated reactions, and to study species involving oxygen atoms and small molecules and simple hydrocarbons. Attempts were made to produce O({sup 3}P) in a jet by photodissociation of NO{sub 2} and to cluster it with HCl. A new pulsed jet vacuum system with greater sensitivity is being constructed. The IR spectrum of O{sub 2}DCl complex was measured.
Date: April 10, 1990
Creator: Beaudet, R. A.
Object Type: Report
System: The UNT Digital Library
The CSMS (Configurable Seismic Monitoring System) Poorboy deployment: Seismic recording in Pinedale, Wyoming, of the Bullion NTS (Nevada Test Site) nuclear test under the verification provisions of the new TTBT protocol (open access)

The CSMS (Configurable Seismic Monitoring System) Poorboy deployment: Seismic recording in Pinedale, Wyoming, of the Bullion NTS (Nevada Test Site) nuclear test under the verification provisions of the new TTBT protocol

The Configurable Seismic Monitoring System (CSMS), developed at the Lawrence Livermore National Laboratory (LLNL) was deployed in a 13-m deep vault on the AFTAC facility at Pinedale, Wyoming to record the Bullion nuclear test. The purpose of the exercise was to meet all provisions of the new TTBT protocol on in-country seismic recording at a Designated Seismic Station (DSS). The CSMS successfully recorded the Bullion event consistent with and meeting all requirements in the new treaty protocol. In addition, desirable seismic system features not specified in the treaty protocol were determined; treaty protocol ambiguities were identified, and useful background noise recordings at the Pinedale site were obtained. 10 figs.
Date: July 10, 1990
Creator: Harben, P. E.; Rock, D. W. & Carlson, R. C.
Object Type: Report
System: The UNT Digital Library
Dielectronic recombination into Rydberg levels of lithiumlike titanium (open access)

Dielectronic recombination into Rydberg levels of lithiumlike titanium

To characterize line formation near threshold for electron-impact excitation, dielectronic capture into high-n levels in lithiumlike Ti{sup 19+} ions has been studied with high-resolution x-ray spectroscopy on the Livermore electron beam ion trap. The process is shown to result in satellite lines which are virtually indistinguishable from their dipole-allowed heliumlike parent lines. High-n satellite lines are absent from dipole-forbidden heliumlike lines.
Date: October 10, 1990
Creator: Beiersdorfer, P.; Chantrenne, S.; Chen, M. H.; Marrs, R. E.; Vogel, D. A.; Wong, K. L. et al.
Object Type: Article
System: The UNT Digital Library
DYNA3D example problem manual (open access)

DYNA3D example problem manual

This manual describes in detail the solution of ten example problems using the explicit nonlinear finite element code DYNA3D. The sample problems include solid, shell, and beam element types, and a variety of linear and nonlinear material models. For each example, there is first an engineering description of the physical problem to be studied. Next, the analytical techniques incorporated in the model are discussed and key features of DYNA3D are highlighted. INGRID commands used to generate the mesh are listed, and sample plots from the DYNA3D analysis are given. Finally, there is a description of the TAURUS post-processing commands used to generate the plots of the solution. This set of example problems is useful in verifying the installation of DYNA3D on a new computer system. In addition, these documented analyses illustrate the application of DYNA3D to a variety of engineering problems, and thus this manual should be helpful to new analysts getting started with DYNA3D. 7 refs., 56 figs., 9 tabs.
Date: October 10, 1990
Creator: Lovejoy, S.C. & Whirley, R.G.
Object Type: Report
System: The UNT Digital Library
Dynamics and pattern selection at the crystal-melt interface (open access)

Dynamics and pattern selection at the crystal-melt interface

This paper discusses dendritic sidebranching; anisotropic surface tension; light scattering at the crystal-melt interface; and succinonitrite-dye mixtures.
Date: December 10, 1990
Creator: Cummins, H. Z.
Object Type: Report
System: The UNT Digital Library
The e sup + , e sup minus background at Relativistic Heavy Ion Collider (RHIC) generated by beam crossing (open access)

The e sup + , e sup minus background at Relativistic Heavy Ion Collider (RHIC) generated by beam crossing

At the Brookhaven Relativistic Heavy Ion Collider (RHIC), fully stripped heavy ions will circulate in each of two rings up to beam energies of 250 (Z/A) GeV/u. During the beam crossing, the peripheral electromagnetic interaction between the heavy ions is sufficient to induce copious production of di-lepton pairs. These pairs are a potential source of background for the detectors at RHIC. In this paper we discuss the expected number of e{sup +},e{sup {minus}} pairs, given the accepted initial luminosity value L of the collider. More importantly, we also calculate the differential cross sections for the angle, energy, rapidity and momentum distribution of the leptons. Using the luminosity L of the collider, these differential cross sections are normalized to the expected number of leptons per second. We restrict ourselves to e{sup +},e{sup {minus}} production, a discussion of {mu}{sup +},{mu}{sup {minus}} and {tau}{sup +}{tau}{sup {minus}} distributions will be published later. The results are presented for the expected worst case, namely {sup 197}Au{sup 79+} ions at a beam kinetic energy of 100 GeV/u. This is forseen to be the heaviest ion for high luminosity experiments at RHIC. We note for a given energy, the cross section for e{sup +},e{sup {minus}} production scales as …
Date: August 10, 1990
Creator: Rhoades-Brown, M.J.; Ludlam, T. (Brookhaven National Lab., Upton, NY (USA)); Wu, J.; Bottcher, C. & Strayer, M. (Oak Ridge National Lab., TN (USA))
Object Type: Article
System: The UNT Digital Library
The effect of slightly faster strain rates and internal hydrogen on uranium-0. 8 weight percent titanium alloy mechanical properties (open access)

The effect of slightly faster strain rates and internal hydrogen on uranium-0. 8 weight percent titanium alloy mechanical properties

Mechanical testing of uranium-0.8 wt % titanium (U-0.8 wt % Ti) alloys can affect the outcome of mechanical properties, primarily ductility, by varying the crosshead velocity, which changes the strain rate. However, most specifications that govern mechanical properties of this alloy reference ASTM E-8, which limits the speed to 0.5 in./in. of gage length per minute. Our current procedure for testing U-0.8 Ti is not at the maximum speed permitted in ASTM E-8, so an experiment was designed to evaluate the effect of maximizing the crosshead velocity per ASTM E-8. In order to create a fair assessment, tensile specimens were prepared that were low in internal hydrogen (0.02 ppM) and higher in internal hydrogen (0.36 ppM). External hydrogen effects were minimized by testing in a controlled environment that contained less than 10% relative humidity. Test results showed that for the low hydrogen test group, increasing the crosshead velocity caused a significant increase in reduction in area (RA), but not in elongation. For the higher hydrogen test group, increasing the speed resulted in a significant increase in RA and an increase, though not statistically significant, in elongation. Of equal importance was an observation that strongly suggests a correlation between material defects, …
Date: October 10, 1990
Creator: Bird, E. L.
Object Type: Report
System: The UNT Digital Library
The effects of tributyl phosphate on a polymeric ultrafilter (open access)

The effects of tributyl phosphate on a polymeric ultrafilter

The purpose of this project was to determine the effects that tributyl phosphate (TBP) would have on a polysulfone crossflow ultrafilter. Aqueous simulant solutions containing TBP (100 or 1000 mg/L) and Fe(III), Si(IV), Al(III), and NaNO{sub 3} were examined. Results obtained from simulant solutions containing 100 mg/L TBP were virtually identical to those obtained in the absence of TBP. However, a solution containing higher concentrations of TBP (1000 mg/L) very rapidly reduced the permeate flow rate to nearly zero. Chemical cleaning was successful in restoring initial flow rates. Permeate flux was plotted as a function of transmembrane pressure for clean water before and after the filter had been exposed to TBP. Also, the axial pressure drop was plotted as a function of the Reynolds numbers. Linear correlation of these data suggested that the filter did not swell or become distorted. Therefore, it was concluded that TBP does not have a permanent effect on this polysulfone ultrafilter. 6 refs., 7 figs., 1 tab.
Date: August 10, 1990
Creator: Stewart, C.A.
Object Type: Report
System: The UNT Digital Library
Electromagnetic interactions with nuclei and nucleons (open access)

Electromagnetic interactions with nuclei and nucleons

This report discusses the following topics: general LEGS work; photodisintegration of the deuteron; progress towards other experiments; LEGS instrumentation; major LEGS software projects; NaI detector system; nucleon detector system; waveshifting fibers; EGN prototype detector for CEBAF; photon beam facility at CEBAF; delta electroproduction in nuclei; quasielastic scattering and excitation of the Delta by {sup 4}He(e,e{prime}); and quasielastic scattering at high Q{sup 2}.
Date: November 10, 1990
Creator: Thornton, Stephen T. & Sealock, Richard M.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of catalytic processing of synthetic liquids (open access)

Fundamental studies of catalytic processing of synthetic liquids

This project revolves around understanding the fundamental processes involved in the catalytic removal of harmful oxygenated organics present in coal liquids. We will model the complex type of sulfided Mo catalyst proposed for these reactions with a simple single crystal surfaces that display a controlled range and number of reaction sites and can be extensively characterized by surface science techniques.
Date: April 10, 1990
Creator: Watson, P. R.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of catalytic processing of synthetic liquids. Quarterly progress report, January 1, 1990--March 31, 1990 (open access)

Fundamental studies of catalytic processing of synthetic liquids. Quarterly progress report, January 1, 1990--March 31, 1990

This project revolves around understanding the fundamental processes involved in the catalytic removal of harmful oxygenated organics present in coal liquids. We will model the complex type of sulfided Mo catalyst proposed for these reactions with a simple single crystal surfaces that display a controlled range and number of reaction sites and can be extensively characterized by surface science techniques.
Date: April 10, 1990
Creator: Watson, P. R.
Object Type: Report
System: The UNT Digital Library
Hadron supercolliders: The 1-TeV scale and beyond (open access)

Hadron supercolliders: The 1-TeV scale and beyond

Greater understanding of the connection between the weak and electromagnetic interactions is central to progress in elementary-particle physics. A definitive exploration of the mechanism for electroweak symmetry breaking will require collisions between fundamental constituents at energies on the order of 1 TeV. This goal drives the design of high-energy, high-luminosity hadron colliders that will be commissioned during the next decade, but by no means completely defines their scientific potential. These three lectures are devoted to a review of the standard-model issues that motivated an experimental assault on the 1-TeV scale, an introduction to the machines and the experimental environment they will present, and a survey of possibilities for measurement and discovery with a multi-TeV hadron collider. 72 refs., 29 figs.
Date: August 10, 1990
Creator: Quigg, C.
Object Type: Article
System: The UNT Digital Library
Indirect fluorometric detection techniques on thin layer chromatography and effect of ultrasound on gel electrophoresis (open access)

Indirect fluorometric detection techniques on thin layer chromatography and effect of ultrasound on gel electrophoresis

Thin-layer chromatography (TLC) is a broadly applicable separation technique. It offers many advantages over high performance liquid chromatography (HPLC), such as easily adapted for two-dimensional separation, for whole-column'' detection and for handling multiple samples, etc. However, due to its draggy development of detection techniques comparing with HPLC, TLC has not received the attention it deserves. Therefore, exploring new detection techniques is very important to the development of TLC. It is the principal of this dissertation to present a new detection method for TLC -- indirect fluorometric detection method. This detection technique is universal sensitive, nondestructive, and simple. This will be described in detail from Sections 1 through Section 5. Section 1 and 3 describe the indirect fluorometric detection of anions and nonelectrolytes in TLC. In Section 2, a detection method for cations based on fluorescence quenching of ethidium bromide is presented. In Section 4, a simple and interesting TLC experiment is designed, three different fluorescence detection principles are used for the determination of caffeine, saccharin and sodium benzoate in beverages. A laser-based indirect fluorometric detection technique in TLC is developed in Section 5. Section 6 is totally different from Sections 1 through 5. An ultrasonic effect on the separation of …
Date: December 10, 1990
Creator: Yinfa, Ma.
Object Type: Report
System: The UNT Digital Library
Linac BPM (Beam Position Monitor) modification program status (open access)

Linac BPM (Beam Position Monitor) modification program status

In the fall of 1988 the Beam Position Monitor (BPM) Task Force recommended that linac BPM processors be pulled out of the linac, modified, adjusted for offsets, recalibrated, and reinstalled. As of the end of 1989 this process had been completed on all linac type BPM processors. This paper discusses these modifications and tests.
Date: February 10, 1990
Creator: Smith, S. & Williams, S.
Object Type: Report
System: The UNT Digital Library
Mechanisms and enhancement of flame stabilization (open access)

Mechanisms and enhancement of flame stabilization

None
Date: July 10, 1990
Creator: Law, Chung K.
Object Type: Report
System: The UNT Digital Library
Mechanisms and enhancement of flame stabilization. [Progress report] (open access)

Mechanisms and enhancement of flame stabilization. [Progress report]

None
Date: July 10, 1990
Creator: Law, C. K.
Object Type: Report
System: The UNT Digital Library
Mechanistic studies on reactivities of organometallic macrocyclic complexes of chromium and cobalt (open access)

Mechanistic studies on reactivities of organometallic macrocyclic complexes of chromium and cobalt

Reaction pathways leading to the formation and cleavage of a transition metal-carbon bond at various oxidation states of the metal occupy a central position in understanding many enzymatic reactions and designing catalysts. The report is divided into six parts that (1) focus on the homolysis vs heterolysis of a C-Cr(III) bond, (2) describes a unique chain reaction and a S{sub E}2 reaction I{sub 2} and RCrL{sup 2+}, (3) concerns the oxidation of organochromium(III) complexes by dihalide and pseudo-dihalide radical anions generated by pulse radiolysis, (4) concentrates on the oxidation mechanism of RCr(H{sub 2}O){sup 2+} and the fate of RCr(H{sub 2}O){sup 3+} as well as the corresponding reduction potentials, (5) extends study of organocobalt complexes with attention to reduction induced cleavages of a transition metal-carbon bond, and (6) describes the crystallization of ((CH{sub 3}){sub 4}N)(Co(dmgBF{sub 2}){sub 2}py) and reports its molecular structure as determined by x-ray diffraction. 182 refs., 25 figs., 16 tabs. (BM)
Date: December 10, 1990
Creator: Shi, Shu.
Object Type: Report
System: The UNT Digital Library