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
Catalytic applications of mono- and dinuclear complexes containing metal-carbon sigma bonds. Final report, November 1, 1993--October 31, 1996 (open access)

Catalytic applications of mono- and dinuclear complexes containing metal-carbon sigma bonds. Final report, November 1, 1993--October 31, 1996

This report discusses results from several studies involved in the project. Investigations include: vibrational models for surface olefins and alkylidenes; mechanism of the formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; determination by nematic phase NMR of the structure of mononuclear and dinuclear ethylene complexes of osmium; and generation of ``coordinatively unsaturated`` complexes by protonation of methyl osmium complexes.
Date: December 31, 1996
Creator: Norton, J.R.
Object Type: Report
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
Surface and subsurface cleanup protocol for radionuclides, Gunnison, Colorado, UMTRA project processing site. Final report: Revision 1 (open access)

Surface and subsurface cleanup protocol for radionuclides, Gunnison, Colorado, UMTRA project processing site. Final report: Revision 1

Surface and subsurface soil cleanup protocols for the Gunnison, Colorado, processing site are summarized as follows: In accordance with EPA-promulgated land cleanup standards, in situ Ra-226 is to be cleaned up based on bulk concentrations not exceeding 5 and 15 pCi/g in 15-cm surface and subsurface depth increments, averaged over 100m{sup 2} grid blocks, where the parent Ra-226 concentrations are greater than, or in secular equilibrium with, the Th-230 parent. In locations where Th-230 has differentially migrated in subsoil relative to Ra-226, a Th-230 clean up protocol has been developed. The cleanup of other radionuclides or nonradiological hazards that pose a significant threat to the public and the environment will be determined and implemented in accordance with pathway analysis to assess impacts and the implications of ALARA specified in 40 CFR Part 192 relative to supplemental standards.
Date: December 1993
Creator: Gonzales, D.
Object Type: Report
System: The UNT Digital Library
Finding of No Significant Impact, Proposed Remediation of the Maybell Uranium Mill Processing Site, Maybell, Colorado (open access)

Finding of No Significant Impact, Proposed Remediation of the Maybell Uranium Mill Processing Site, Maybell, Colorado

The U.S. Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-0347) on the proposed surface remediation of the Maybell uranium mill processing site in Moffat County, Colorado. The mill site contains radioactively contaminated materials from processing uranium ore that would be stabilized in place at the existing tailings pile location. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, Public Law 91-190 (42 U.S.C. {section}4321 et seq.), as amended. Therefore, preparation of an environmental impact statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).
Date: December 31, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Economic Impact Study of the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado State Fiscal Year 1994. Revision 1 (open access)

Economic Impact Study of the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado State Fiscal Year 1994. Revision 1

The Colorado economic impact study summarizes employment and economic benefits to the state from activities associated with the Uranium Mill Tailings Remedial Action (UMTRA) Project during Colorado state fiscal year 1994 (1 July 1993 through 30 June 1994). To capture employment information, a questionnaire was distributed to subcontractor employees at the active UMTRA Project sites of Grand Junction, Naturita, Gunnison, and Rifle, Colorado. Economic data were requested from each site prime subcontractor, as well as from the Remedial Action Contractor. Information on wages, taxes, and subcontract expenditures in combination with estimates and economic multipliers is used to estimate the dollar economic benefits to Colorado during the state fiscal year. Finally, the fiscal year 1994 estimates are compared to fiscal year 1993 employment and economic information.
Date: December 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Waste minimization opportunities at the U.S. Uranium Mill Tailings Remedial Action (UMTRA) Project, Rifle, Colorado, site (open access)

Waste minimization opportunities at the U.S. Uranium Mill Tailings Remedial Action (UMTRA) Project, Rifle, Colorado, site

At two uranium mill sites in Rifle, Colorado, the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project is removing uranium mill tailings and contaminated subgrade soils. This remediation activity will result in the production of groundwater contaminated with uranium, heavy metals, ammonia, sulfates, and total dissolved solids (TDS). The initial remediation plan called for a wastewater treatment plant for removal of the uranium, heavy metals, and ammonia, with disposal of the treated water, which still includes the sulfates and TDSS, to the Colorado River. The National Pollutant Discharge Elimination (NPDES) permit issued by the Colorado Department of Health for the two Rifle sites contained more restrictive discharge limits than originally anticipated. During the detailed review of alternate treatment systems to meet these more restrictive limits, the proposed construction procedures were reviewed emphasizing the methods to minimize groundwater production to reduce the size of the water treatment facility, or to eliminate it entirely. It was determined that with changes to the excavation procedures and use of the contaminated groundwater for use in dust suppression at the disposal site, discharge to the river could be eliminated completely.
Date: December 31, 1993
Creator: Hartmann, George L.; Arp, Sharon & Hempill, Hugh
Object Type: Report
System: The UNT Digital Library
Economic Impact Study of the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado State Fiscal Year 1993 (open access)

Economic Impact Study of the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado State Fiscal Year 1993

The Colorado economic impact study summarizes employment and economic benefits to the state from activities associated with the Uranium Mill Tailings Remedial Action (UMTRA) Project during Colorado state fiscal year 1993 (July 1, 1992, through June 30, 1993). To capture employment benefits, a questionnaire was distributed to subcontractor employees at the active UMTRA Project sites of Grand Junction, Rifle, and Gunnison, Colorado. An estimated 52 percent of the employees working on the UMTRA Project responded to this information request. Economic data were requested from each site prime subcontractor, as well as from the Remedial Action Contractor. The most significant benefits associated with the UMTRA Project in Colorado are summarized.
Date: December 1, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado (open access)

Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado

This Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells. This risk assessment evaluates the most contaminated monitor wells at the processing site. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.
Date: December 1, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Mitigation and Monitoring Plan for Impacted Wetlands at the Gunnison Umtra Project Site, Gunnison, Colorado. Revision 1 (open access)

Mitigation and Monitoring Plan for Impacted Wetlands at the Gunnison Umtra Project Site, Gunnison, Colorado. Revision 1

The Gunnison, Colorado, abandoned uranium mill site is one site being cleaned up by the DOE under UMTRCA authority. This site`s contaminated material is being transported to a disposal site on US Bureau of Land Management (BLM) land east of Gunnison. Remedial action activities have temporarily disturbed 0.8 acre (ac) (0.3 hectares [ha]) of wetlands and permanently eliminated 4.3 ac (1.7 ha). As required by the Clean Water Act, the US Army Corps of Engineers (USACE) prepared a Section 404 Permit that addresses the loss of wetlands as a result of remedial action at the Gunnison UMTRA Project site. The 404 permit includes this report as an attachment and it describes the wetland mitigation and monitoring plan. The DOE formulated this plan in consultation with the BLM and the USACE. This report represents a revised version of the mitigation and monitoring plan (DOE, 1992b).
Date: December 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Direct Conversion of Methane to Methanol in a Non-Isothermal Catalytic Membrane Reactor (open access)

Direct Conversion of Methane to Methanol in a Non-Isothermal Catalytic Membrane Reactor

The direct partial oxidation of CH{sub 4} to CH{sub 3}OH has been studied in a non-permselective, non-isothermal catalytic membrane reactor system. A cooling tube introduced coaxially inside a tubular membrane reactor quenches the product stream rapidly so that further oxidation of CH{sub 3}OH is inhibited. Selectivity for CH{sub 3}OH formation is significantly higher with quenching than in experiments without quenching. For CH{sub 4} conversion of 4% to 7% CH{sub 3}OH selectivity is 40% to 50% with quenching and 25% to 35% without quenching.
Date: December 31, 1993
Creator: Noble, R. D. & Falconer, J. L.
Object Type: Article
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale. Technical Progress Report, April 1, 1991--June 30, 1991 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. Technical Progress Report, April 1, 1991--June 30, 1991

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain data useful to develop a process more economic than existing processes and to report all findings. Quarter summary: all modifications previously planned where completed and a reaction experiment was run. A couple design flaws were discovered, improvements were designed, and all parts are expected in the first week of July. Experiment {number_sign}6 is expected to run the following Monday. Barring further mishap, experiments will be run one each week thereafter. The project is behind schedule, but the project is well positioned to make significant and considerable progress.
Date: December 1, 1991
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library
Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991 (open access)

Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991

The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.
Date: December 31, 1991
Creator: Sites, J. R.
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale (open access)

Chemically Assisted in Situ Recovery of Oil Shale

The purpose of the research project was to investigate the feasibility of the chemically assisted in situ retort method for recovering shale oil from Colorado oil shale. The chemically assisted in situ procedure uses hydrogen chloride (HCl), steam (H{sub 2}O), and carbon dioxide (CO{sub 2}) at moderate pressure to recovery shale oil from Colorado oil shale at temperatures substantially lower than those required for the thermal decomposition of kerogen. The process had been previously examined under static, reaction-equilibrium conditions, and had been shown to achieve significant shale oil recoveries from powdered oil shale. The purpose of this research project was to determine if these results were applicable to a dynamic experiment, and achieve penetration into and recovery of shale oil from solid oil shale. Much was learned about how to perform these experiments. Corrosion, chemical stability, and temperature stability problems were discovered and overcome. Engineering and design problems were discovered and overcome. High recovery (90% of estimated Fischer Assay) was observed in one experiment. Significant recovery (30% of estimated Fischer Assay) was also observed in another experiment. Minor amounts of freed organics were observed in two more experiments. Penetration and breakthrough of solid cores was observed in six experiments.
Date: December 31, 1993
Creator: Ramierz, W. F.
Object Type: Report
System: The UNT Digital Library
Direct Methane Conversion to Methanol. Quarterly Project Status Report, July 1, 1992--September 30, 1992 (open access)

Direct Methane Conversion to Methanol. Quarterly Project Status Report, July 1, 1992--September 30, 1992

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
Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], April 1, 1990--June 30, 1990 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], April 1, 1990--June 30, 1990

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain-data useful to develop a process more economic than existing processes and to report all findings. The technical progress of the project is reported. The progress of the project is that experiment preparations are underway. Reactor design, process design, and experiment design have been completed. The laboratory to be used has required extensive clean-up, and is nearly ready. Safety considerations are underway. Finally, an initial literature search has revealed some important aspects that need to be considered.
Date: December 31, 1990
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], October 1, 1991--December 31, 1991 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], October 1, 1991--December 31, 1991

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain data useful to develop a process more economic than existing processes and to report all findings. The technical progress of the project is reported. The project status is that the solutions to the problems discussed in the third quarter status, were found to function satisfactorily. Future needs have been considered, and appropriate equipment and instrumentation changes have been designed. Only one experiment was performed this quarter, with some improvement over the previous experiments. The increase in shale oil recovery followed directly from the changes discussed last quarter, but the improvement could have been larger with wider-spread implementation of the changes. Equipment was purchased to rectify the need, and will be installed shortly. Further, a minor change in the design was necessary to account for the brittleness of high temperature electrical resistance heating tapes. The focus of the work this quarter has been on the development of computer software to enable the use of on-line parameter identification, the design of the instrumentation necessary to adequately …
Date: December 31, 1991
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library