A Preliminary Improved Test of the Flavor Independence of Strong Interactions (open access)

A Preliminary Improved Test of the Flavor Independence of Strong Interactions

The authors present an improved comparison of the strong couplings of gluons to light (u, d, and s), c, and b quarks, determined from multijet rates in flavor-tagged samples of hadronic Z{sup 0} decays recorded with the SLC Large Detector at the SLAC Linear Collider between 1993 and 1995. Flavor separation on the basis of lifetime and decay multiplicity differences among hadrons containing light, c, and b quarks was made using the SLD precision tracking system, yielding tags with high purity and low bias against {ge} 3-jet final states. They find: {alpha}{sub s}{sup uds}/{alpha}{sub s}{sup all} = 0.997 {+-} 0.011(stat) {+-} 0.011(syst) {+-} 0.005(theory), {alpha}{sub s}{sup c}/{alpha}{sub s}{sup all} = 0.984 {+-} 0.042 {+-} 0.053 {+-} 0.022, {alpha}{sub s}{sup b}/{alpha}{sub s}{sup all} = 1.022 {+-} 0.019 {+-} 0.023 {+-} 0.012.
Date: June 1, 1997
Creator: Abe, K.; Abe, K.; Akagi, T. & Collaboration, SLD
Object Type: Article
System: The UNT Digital Library
Production of {pi}{sup {+-}}, K{sup {+-}}, K{sup 0}, K*{sup 0}, {phi}, p and {Lambda}{sup 0} in Hadronic Z{sup 0} Decays (open access)

Production of {pi}{sup {+-}}, K{sup {+-}}, K{sup 0}, K*{sup 0}, {phi}, p and {Lambda}{sup 0} in Hadronic Z{sup 0} Decays

The authors have measured production rates as a function of momentum of the identified hadrons {pi}{sup +}, K{sup +}, K{sup 0}, K*{sup 0}, {phi}, p, {Lambda}{sup 0} and their antihadrons in inclusive hadronic Z{sup 0} decays, as well as separately in decays into light, c and b flavors. In addition they have compared hadron and antihadron production rates in light quark (rather than antiquark) jets. The SLD Cherenkov Ring Imaging Detector was used to identify charged hadrons. The vertex detector was used to tag high-purity samples of light- and b-flavor events. The electron beam polarization was used to tag samples of quark and antiquark jets. Clear flavor dependences are observed, consistent with expectations based upon measured production and decay properties of heavy hadrons. They use the light-flavor results to test the predictions of MLLA QCD and of various fragmentation models. Differences between hadron and antihadron production in light quark jets are observed at high momentum fraction, providing direct evidence that higher-momentum particles are more likely to contain a primary quark or antiquark, and they use these results to make a new direct measurement of strangeness suppression in the jet fragmentation process.
Date: June 1, 1997
Creator: Abe, K.; Abe, K.; Akagi, T. & Collaboration, SLD
Object Type: Article
System: The UNT Digital Library
Stratigraphy of the Mississippian System, South-Central Colorado and North-Central New Mexico (open access)

Stratigraphy of the Mississippian System, South-Central Colorado and North-Central New Mexico

From abstract: In the Sawatch, Mosquito and Front Ranges of central Colorado and the Sangre de Cristo Mountains of south-central Colorado, Tournaisian beds of the Mississippian Leadville Limestone overlie rocks of Early Mississippian and Late Devonian age. In the Sangre de Cristo Mountains in north-central New Mexico, the oldest beds are the Tournaisian (zone 9) Espiritu Santo Formation. In west-central New Mexico, in the Magdalena, Lemitar, and Ladron Mountains, the Kelly Limestone of Tournaisian and Visean age rests unconformably on Proterozoic metamorphic and igneous rocks. This report examines the stratigraphy of this area.
Date: 1992
Creator: Armstrong, Augustus K.; Mamet, Bernard L. & Repetski, John E.
Object Type: Report
System: The UNT Digital Library
[Evolution of Sedimentary Basins--San Juan Basin: Chapters J and K] (open access)

[Evolution of Sedimentary Basins--San Juan Basin: Chapters J and K]

From introduction to each respective report: Report J summarizes the results of several studies concerning the stratigraphy and sedimentology of uppermost Jurassic to lowermost Upper Cretaceous rocks in the San Juan basin and adjacent areas. Report K describes using X-ray diffraction techniques to determine the occurrence and distribution of clay minerals in the upper part of the Brushy Basin Member and in the Burro Canyon Formation in the Four Corners area.
Date: 1992
Creator: Aubrey, William M. & Skipp, Gary
Object Type: Report
System: The UNT Digital Library
The production of {pi}{sup {+-}}, K{sup {+-}}, p, k{sup 0} and {Lambda}{sup 0} in hadronic Z{sup 0} decays (open access)

The production of {pi}{sup {+-}}, K{sup {+-}}, p, k{sup 0} and {Lambda}{sup 0} in hadronic Z{sup 0} decays

The authors have measured production fractions and spectra for {pi}{sup {+-}}, K{sup {+-}} and p, and production spectra for K{sup 0} and {Lambda}{sup 0} in both hadronic Z{sup 0} decays and a Z{sup 0} {yields} light quark (uds) subset at SLD. The SLD Cherenkov Ring Imaging Detector was used to identify charged hadrons. The CCD vertex detector was used to select the enriched uds sample. For the global sample, the results are consistent with previous experiments. The authors observe a clear flavor dependence in production spectra, but only a small effect in hadron fractions and {xi} = ln(1/x{sub p}) peak positions.
Date: August 1, 1995
Creator: Baird, K.
Object Type: Article
System: The UNT Digital Library
Effects of Vegetation of Radon Transport Processes in Soil: The Origins and Pathways of {Sup 222}Rn Entering Into Basement Structures. Final Report, March 15, 1987--May 15, 1993 (open access)

Effects of Vegetation of Radon Transport Processes in Soil: The Origins and Pathways of {Sup 222}Rn Entering Into Basement Structures. Final Report, March 15, 1987--May 15, 1993

The entry rate of {sup 22}Rn into a basement structure was measured continuously. These measurements demonstrated that radon entry did not vanish even when the structure was slightly pressurized. This persistent entry has been determined to be dominated by diffusion through the floor and walls and a combination of diffusion and convection through the floor-wall joint. The highest indoor radon concentrations occurred during calm periods when the pressure differentials between the inside and outside of the structure were small. The objectives of this work were to identify the origins of the radon and investigate the entry pathways. The radon could originate either in the concrete or in the soil surrounding the structure. Entry pathways into the basement were through the concrete floor and walls as well as through the floor-wall joint. The contributions of the origins and entry pathways were determined by continuously measuring the radon entry rate into the basement, using a trace gas system, and the flux density through portions of the floor and walls. Radon entry through the floor-wall joint could be controlled using a baseboard barrier system. Results indicated that, during calm conditions with wind speeds less than 1 m s{sup {minus}1}, 25 % of the …
Date: August 1, 1992
Creator: Borak, T. B.
Object Type: Report
System: The UNT Digital Library
Effects of Vegetation on Radon Transport Processes in Soil (open access)

Effects of Vegetation on Radon Transport Processes in Soil

A large component of radon entry cannot be explained by pressure differences between the soil and inside the structures. The persistence of this radon entry even when the house is pressurized by 1 Pa indicates that it must be due to molecular diffusion. The radon entry rate as measured by accumulators below ground level (soil + concrete) is roughly 2 times greater than that measured above ground level (concrete alone). The soil permeability is about 10{sup {minus}12} m{sup 2} and does not change dramatically with depth down to 2 m. The diffusion component of radon entry is reduced by about 30% when the floor wall joint is sealed. The Rn3D model is operating on our computer system and is being modified to accommodate the geometrical configurations of the underground test structure.
Date: January 1, 1991
Creator: Borak, T.B.
Object Type: Report
System: The UNT Digital Library
VXD3: The SLD Vertex Detector Upgrade Based on a 307 MPixel CCD System (open access)

VXD3: The SLD Vertex Detector Upgrade Based on a 307 MPixel CCD System

The SLD upgrade CCD vertex detector (VXD3) is described. Its 307 million pixels are assembled from 96 3.2 Mpixel CCDs of 13 cm{sup 2} each. The system has evolved from the pioneering CCD vertex detector VXD2, which has operated in SLD since 1992. The CCDs of VXD3 are mounted on beryllium ladders in three cylinders, providing three space point measurements along each track of about 5 microns resolution in all three co-ordinates. Significant improvements are achieved with VXD3 in impact parameter resolution (about a factor of two) and acceptance ({approximately}20%) through optimized geometry and reduced material. New readout electronics have been developed for this system.
Date: December 1995
Creator: Brau, James E.
Object Type: Article
System: The UNT Digital Library
Long-Term Risk From Actinides in the Environment: Modes of Mobility. 1998 Annual Progress Report (open access)

Long-Term Risk From Actinides in the Environment: Modes of Mobility. 1998 Annual Progress Report

'The mobility of actinides in surface soils is a key issue of concern at several DOE facilities in arid and semiarid environments, including Rocky Flats, Hanford, Nevada Test Site, Idaho National Engineering Laboratory, and Los Alamos National Laboratory and the Waste Isolation Pilot Plant (WIPP). Key sources of uncertainty in assessing Pu mobility are the magnitudes of mobility resulting from three modes of transport: (1) wind erosion, (2) water erosion, and (3) vertical migration. Each of these three processes depend on numerous environmental factors and they compete with one another, particularly for actinides in very shallow soils ({approximately} 1 \265m). The overall goal of the study is to quantify the mobility of soil actinides from all three modes. The authors study is using field measurements, laboratory experiments, and ecological modeling to address these three processes at three DOE facilities where actinide kinetics are of concern: WIPP, Rocky Flats, and Hanford. Wind erosion is being measured with suite of monitoring equipment, water erosion is being studied with rainfall simulation experiments, vertical migration is being studied in controlled laboratory experiments, and the three processes are being integrated using ecological modeling. Estimates for clean up of soil actinides for the extensive tracts of …
Date: June 1, 1998
Creator: Breshears, D. D.; Whicker, J. J.; Ibrahim, S. A.; Whicker, F. W.; Hakonson, T. E. & Kirchner, T.
Object Type: Report
System: The UNT Digital Library
Carbon Dioxide in Mississippian Rocks of the Paradox Basin and Adjacent Areas, Colorado, Utah, New Mexico, and Arizona (open access)

Carbon Dioxide in Mississippian Rocks of the Paradox Basin and Adjacent Areas, Colorado, Utah, New Mexico, and Arizona

From abstract: This report is about six gas samples that were obtained from the Mississippian Leadville Limestone in the McElmo field, Colorado, and the Lisbon field, Utah. These samples were recorded to contain a high reading of carbon dioxide and the report investigates these results.
Date: 1995
Creator: Cappa, James A. & Rice, Dudley D.
Object Type: Report
System: The UNT Digital Library
Geology of Pre-Pennsylvanian Rocks in the Paradox Basin and Adjacent Areas, Southeastern Utah and Southwestern Colorado (open access)

Geology of Pre-Pennsylvanian Rocks in the Paradox Basin and Adjacent Areas, Southeastern Utah and Southwestern Colorado

From abstract: This report is about the geology of pre-Pennsylvanian rocks in the Paradox basin and its adjacent areas--such as the Mississippian strata, the Upper Devonian rocks, and the Upper Cambrian--in southeastern Utah and southwestern Colorado.
Date: 1995
Creator: Condon, Steven M.
Object Type: Report
System: The UNT Digital Library
Geology of the Pennsylvanian and Permian Cutler Group and Permian Kaibab Limestone in the Paradox Basin, Southeastern Utah and Southwestern Colorado (open access)

Geology of the Pennsylvanian and Permian Cutler Group and Permian Kaibab Limestone in the Paradox Basin, Southeastern Utah and Southwestern Colorado

From abstract: This report talks about the geology of the Pennsylvanian and Permian Cutler Group that consists of the lower Cutler beds, Cedar Mesa Sandstone, Organ Rock Formation, White Rim Sandstone, and De Chelly Sandstone. The report also talks about the Permian Kaibab Limestone in the Paradox Basin that overlays the Cutler.
Date: 1997
Creator: Condon, Steven M.
Object Type: Report
System: The UNT Digital Library
Parameterization of Convective Clouds Mesoscale Convective Systems, and Convective-Generated Cirrus. Final Report, September 15, 1990--October 31, 1993 (open access)

Parameterization of Convective Clouds Mesoscale Convective Systems, and Convective-Generated Cirrus. Final Report, September 15, 1990--October 31, 1993

The overall goal of this research is to develop a scheme to parameterize diabatic heating, moisture/water substance, and momentum transports, and precipitation from mesoscale convective systems (MCSs) for use in general circulation models (GCMs). Our approach is to perform explicit cloud-resolving simulations of MCSs in the spirit of the GEWEX Cloud Systems Study (GCSS), by using the Regional Atmospheric Modeling System (RAMS) developed at Colorado State University (CSU). We then perform statistical analyses (conditional sampling, ensemble-averages, trajectory analyses) of simulated MCSs to assist in fabricating a parameterization scheme, calibrating coefficients, and provide independent tests of the efficacy of the parameterization scheme. A cloud-resolving simulation of ordinary cumulonimbi forced by sea breeze fronts has been completed. Analysis of this case and comparison with parameterized convection simulations has resulted in a number of refinements in the scheme. Three three-dimensional, cloud-resolving simulations of MCSs have been completed. Statistical analyses of model-output data are being performed to assist in developing a parameterization scheme of MCSs in general circulation models.
Date: November 5, 1993
Creator: Cotton, W. R.
Object Type: Report
System: The UNT Digital Library
National Institute for Global Environmental Change. Final Report (open access)

National Institute for Global Environmental Change. Final Report

Over the past decade or so the evolution and equilibria of persistent decks of stratocumulus climatologically clinging to the edge of summertime subtropical highs has been an issue of increased scientific inquiry. The particular interest in the microphysical structure of these clouds stems from a variety of hypotheses which suggest that anthropogenic influences or biogenic feedbacks may alter the structure of these clouds in a manner which may be climatically significant. Most hypotheses regarding boundary layer influences on climate have been formulated by an examination of the solution space of simple models. The earliest hypothesis of this sort (and the one on the most solid footing) is due to Twomey (1974), who posited that enhanced concentrations of CCN could lead to enhanced droplet reflectivity and enhanced albedos in clouds of modest optical depths. In low lying clouds where the albedo effect dominates, the climate sensitivity to a robust perturbation in cloud albedo may be significant. One of the primary objectives of this current research has been to explore the hypothesis of Twomey. The basic approach was to couple radiative calculations with detailed representations of the droplet spectra. The detailed representation of the droplet spectra was generated by the Large Eddy …
Date: March 9, 1995
Creator: Cotton, W.R.; Stevens, B.; Duda, D.; Richardson, W. & Feingold, G.
Object Type: Report
System: The UNT Digital Library
Grassland/Atmosphere Response to Changing Climate: Coupling Regional and Local Scales. Final Report (open access)

Grassland/Atmosphere Response to Changing Climate: Coupling Regional and Local Scales. Final Report

The objectives of the study were: to evaluate the response of grassland ecosystems to atmospheric change at regional and site scales, and to develop multiscaled modeling systems to relate ecological and atmospheric models with different spatial and temporal resolutions. A menu-driven shell was developed to facilitate use of models at different temporal scales and to facilitate exchange information between models at different temporal scales. A detailed ecosystem model predicted that C{sub 3} temperate grasslands wig respond more strongly to elevated CO{sub 2} than temperate C{sub 4} grasslands in the short-term while a large positive N-PP response was predicted for a C{sub 4} Kenyan grassland. Long-term climate change scenarios produced either decreases or increases in Colorado plant productivity (NPP) depending on rainfall, but uniform increases in N-PP were predicted in Kenya. Elevated CO{sub 2} is likely to have little effect on ecosystem carbon storage in Colorado while it will increase carbon storage in Kenya. A synoptic climate classification processor (SCP) was developed to evaluate results of GCM climate sensitivity experiments. Roughly 80% agreement was achieved with manual classifications. Comparison of lx and 2xCO{sub 2} GCM Simulations revealed relatively small differences.
Date: October 1, 1993
Creator: Coughenour, M. B.; Kittel, T. G. F.; Pielke, R. A. & Eastman, J.
Object Type: Report
System: The UNT Digital Library
Extraction and Recovery of Mercury and Lead From Aqueous Waste Streams Using Redox-Active Layered Metal Chalcogenides. 1998 Annual Progress Report (open access)

Extraction and Recovery of Mercury and Lead From Aqueous Waste Streams Using Redox-Active Layered Metal Chalcogenides. 1998 Annual Progress Report

'Mercury and other highly-toxic heavy metals such as cadmium and lead are present in many aquatic environments, and the remediation of such environments or the avoidance of heavy-metal contamination in the first place is an area of active interest. In recent years tougher environmental regulations and the high initial cost of new, more effective, and more selective extractants has made the reuse of extractant materials and the minimization of secondary waste volume a focus of their scientific effort. The authors research has involved the investigation of redox-active layered metal chalcogenides as selective, effective, and redox-recyclable extractants for heavy metals from aqueous solution.'
Date: June 1, 1998
Creator: Dorhout, P.K. & Strauss, S.H.
Object Type: Report
System: The UNT Digital Library
Extraction and Recovery of Mercury and Lead From Aqueous Waste Streams Using Redox-Active Layered Metal Chalcogenides. Annual Progress Report, September 15, 1996--September 14, 1997 (open access)

Extraction and Recovery of Mercury and Lead From Aqueous Waste Streams Using Redox-Active Layered Metal Chalcogenides. Annual Progress Report, September 15, 1996--September 14, 1997

'The authors have begun to examine the extraction and recovery of heavy elements from aqueous waste streams using redox-active metal chalcogenides. They have been able to prepare extractants from known chalcogenide starting materials, studied the efficacy of the extractants for selective removal of soft metal ions from aqueous phases, studied the deactivation of extractants and the concomitant recovery of soft metal ions from the extractants, and characterized all of the solids and solutions thus far in the study. The study was proposed as two parallel tasks: Part 1 and Part 2 emphasize the study and development of known metal chalcogenide extractants and the synthesis and development of new metal chalcogenide extractants, respectively. The two tasks were divided into sub-sections that study the extractants and their chemistry as detailed below: Preparation and reactivity of metal chalcogenide host solids Extraction of target waste (guest) ions from simulated waste streams Examination of the guest-host solids recovery of the guest metal and reuse of extractant Each section of the two tasks was divided into focused subsections that detail the specific problems and solutions to those problems that were proposed. The extent to which those tasks have been accomplished and the continued efforts of the …
Date: January 1, 1997
Creator: Dorhout, P.K. & Strauss, S.H.
Object Type: Report
System: The UNT Digital Library
Chemically modified electrodes and related solution studies. Final technical report, January 15, 1991--January 14, 1992 (open access)

Chemically modified electrodes and related solution studies. Final technical report, January 15, 1991--January 14, 1992

This report is divided into 5 sections: Ru{sub 4}/Fe complexes of tetra(4{prime}-methyl-2,2{prime}-bipyridine)porphyrin--catalytic epoxidation of olefins; water oxidation catalysis by doubly linked {mu}-oxo ruthenium complexes; polymer films formed by oxidation of transition metal electrodes into solutions of bisbipyridinealkane ligands; polymer films containing [CpMo({mu}-S)]{sub 2}S{sub 2}CHR dinuclear clusters;and conducting polymer films for catalyst incorporation.
Date: April 1, 1993
Creator: Elliott, C. M.
Object Type: Report
System: The UNT Digital Library
Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems. Progress Report, September 1, 1993--May 31, 1993 (open access)

Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems. Progress Report, September 1, 1993--May 31, 1993

Focus has been mainly on preparation and characterization of triply bridged dinuclear complexes containing a tris-2-2`- bipyridineruthenium chromophore and a second tris-bipyridine metal complex which is to serve as electron donor or acceptor, and of linked RuL{sub 3}-containing D-C-A complexes where D is a phenothiazine donor and A is a diquat type acceptor. (DLC)
Date: June 1, 1993
Creator: Elliott, C. M.
Object Type: Report
System: The UNT Digital Library
Chemically modified electrodes and related solution studies (open access)

Chemically modified electrodes and related solution studies

This report is divided into 5 sections: Ru[sub 4]/Fe complexes of tetra(4[prime]-methyl-2,2[prime]-bipyridine)porphyrin--catalytic epoxidation of olefins; water oxidation catalysis by doubly linked [mu]-oxo ruthenium complexes; polymer films formed by oxidation of transition metal electrodes into solutions of bisbipyridinealkane ligands; polymer films containing [CpMo([mu]-S)][sub 2]S[sub 2]CHR dinuclear clusters;and conducting polymer films for catalyst incorporation.
Date: April 1, 1993
Creator: Elliott, C.M.
Object Type: Report
System: The UNT Digital Library
Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems (open access)

Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems

Focus has been mainly on preparation and characterization of triply bridged dinuclear complexes containing a tris-2-2'- bipyridineruthenium chromophore and a second tris-bipyridine metal complex which is to serve as electron donor or acceptor, and of linked RuL[sub 3]-containing D-C-A complexes where D is a phenothiazine donor and A is a diquat type acceptor. (DLC)
Date: June 1, 1993
Creator: Elliott, C.M.
Object Type: Report
System: The UNT Digital Library
Properties of molecular solids and fluids at high pressure and temperature. Final report, March 1, 1986--October 31, 1993 (open access)

Properties of molecular solids and fluids at high pressure and temperature. Final report, March 1, 1986--October 31, 1993

The main thrust of this work was directed to the task of determining the thermodynamic behavior of condensed solids and fluids containing simple molecules. Properties calculated include specific heats, equations of state, compressibilities, sound velocities, virial coefficients, viscosities, and thermal expansion. In addition, details of the structural, orientational, and magnetic phase transitions were determined. Dynamical quantities calculated include the lattice, libron, and vibron mode frequencies at various pressures and temperatures. Also, we developed new techniques required to meet our objectives. One was a method for accurately calculating the Gibbs free energy of various phases. Another is the multiple-histogram Monte Carlo which can dramatically reduce computing time and can provide a continuous map of thermodynamic averages over a range of some thermodynamical variable.
Date: June 1, 1994
Creator: Etters, R. D.
Object Type: Report
System: The UNT Digital Library
Zeolite Membranes for Gas Separations (open access)

Zeolite Membranes for Gas Separations

Silicalite-1, a pure silica zeolite, was deposited on a tubular, asymmetric, {gamma}-alumina support. Single gas permeation experiments with N{sub 2}, CH{sub 4}, and CO{sub 2} were carried out on the membrane. Separation experiments for N{sub 2}/CH{sub 4} mixtures were also conducted. Single-gas permeation of H{sub 2} and separation of H{sub 2}/SF{sub 6} mixture were also carried out with the membrane. Composite membranes of silicalite and Ni-SAPO-34 were also fabricated, but no CO{sub 2}/H{sub 2} selectivity was found. It is proposed to use these membranes for methanol synthesis and separation, and for separating H{sub 2} from gasification products for use as fuel cell fuel, etc.
Date: June 1, 1995
Creator: Falconer, J. & Noble, R.
Object Type: Article
System: The UNT Digital Library
Direct Methane Conversion to Methanol (open access)

Direct Methane Conversion to Methanol

Objective is to demonstrate the effectiveness of a catalytic membrane reactor (ceramic membrane combined with catalyst) to selectively produce methanol by partial oxidation of methane. None of the membranes tested in a high pressure system could selectively remove methanol, until a cooling tube was inserted inside the membrane reactor to quench the product stream; this effectively increased methanol selectivity 2[times] during methane oxidation. For both conditions, combined selectivity for methanol and CO is constant, 85%. The remaining product is CO[sub 2]. The membranes were broken when removed from the system; this was remedied when a cooling tube with a smaller diameter was used.
Date: December 3, 1992
Creator: Falconer, J. L. & Noble, R. D.
Object Type: Report
System: The UNT Digital Library