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United States Geological Survey Reports
12
Trace elements investigations report
5
Water Resources Investigations Reports
3
United States Bureau of Mines Reports
2
Geological Survey bulletin
1
Geological Survey professional paper
1
Report of investigations (United States. Bureau of Mines)
1
Trace elements memorandum report
1
U.S. Geological Survey bulletin
1
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Geology of the Copper King Mine area, Prairie Divide, Larimer County, Colorado
"This report, prepared principally to aid in the interpretation of the core drilling, presents the principal results of the field and preliminary laboratory work by the U.S. Geological Survey; it does not contain information obtained from the core drilling."
Date:
December 1952
Creator:
Sims, P. K. & Phair, George
Object Type:
Report
System:
The UNT Digital Library
Geology of the Copper King uranium mine, Larimer County, Colorado
A report regarding the geology of the Copper King Uranium Mine, in Larimer County, Colorado.
Date:
June 1955
Creator:
Sims, P. K.; Phair, George & Moench, Robert Hadley
Object Type:
Report
System:
The UNT Digital Library
Report of factual data obtained during examination of Copper King shaft, Black Hawk claim no. 1, Larimer County, Colorado
A report regarding factual data obtained during an examination of the copper King Shaft, Black Hawk Claim no. 1, Larimer County, Colorado. This report is designed to provide the owners with the factual data obtained from their property in accordance with the Agreement for Mineral Exploration with them.
Date:
May 1950
Creator:
Granger, H. C. & King, Robert Ugstad
Object Type:
Report
System:
The UNT Digital Library
Rehabilitation Potential and Practices of Colorado Oil Shale Lands. Progress Report, June 1, 1976--May 31, 1977
Substantial progress has been made towards implementing all of the prescribed studies and satisfying the stated objectives since the Oil Shale Rehabilitation Project was actively initiated in June 1976. Concurrent with implementation, research objectives were substantively defined and supplemented without distracting or departing from the original purpose. Current studies are designed to fill voids in the present status of knowledge regarding lands disturbed by an impending oil shale industry in Colorado. The efforts of all contributing investigators have therefore been integrated and directed toward the goal of developing methodologies requisite for restoring diverse and complex ecosystems which will require only a minimal amount of maintenance or input of scarce resources. An intensive study site southeast of the Oil Shale Tract C-a has been obtained through a Cooperative Agreement with the Bureau of Land Management. Following this agreement, most subprojects were initiated at the intensive site. Additional programs will be implemented as spent shale becomes available this summer. Studies conducted principally in the laboratory and greenhouse, such as the microbiological and plant genetic studies, have achieved significant results.
Date:
February 1, 1977
Creator:
Sims, P. L.
Object Type:
Report
System:
The UNT Digital Library
Fluxes of Tracers in Wind and Water Tunnels
The absorption process of particulate matter at an air-water interface was studied by means of a Monte Carlo Simulation. This absorption process does not appear to be significantly different from similar processes over stationary boundaries. Especially an increased flux toward the boundary as the result of more effective particle removal due to wave action could not be observed. The particular nature of the tracer prevents this from happening.
Date:
March 1, 1976
Creator:
Gessler, J.
Object Type:
Report
System:
The UNT Digital Library
General Circulation of the Atmosphere and Weather in the Mediterranean
The occurrence of mistral winds in the Mediterranean shows a correlation with blocking activity over the eastern Atlantic. Apparently for this reason periods with a ''midwinter dip'' in the zonal available potential energy of the northern hemisphere are favored by mistral occurrence. There also is a tendency for a 22- to 26-day cycle to appear in pressure gradients at the 500- and 100-mb surfaces along the southern coast of France. Such pressure gradients, if they exceed a certain magnitude, are indicative of mistral episodes.
Date:
January 1, 1976
Creator:
Reiter, Elmar R.
Object Type:
Article
System:
The UNT Digital Library
Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas and Lpg Vehicles
This study was designed to evaluate the effectiveness of aftermarket fuel delivery systems for vehicles fueled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Most of the CNG and LPG vehicles studied were converted to the alternative fuel after purchase. There are wide variations in the quality of the conversion hardware and the installation. This leads to questions about the overall quality of the converted vehicles, in terms of emissions, safety, and performance. There is a considerable body of emissions data for converted light-duty vehicles, and a smaller amount for medium- and heavy-duty vehicles. However, very few of these data involve real world conditions, and there is growing concern about in-use emissions. This report also attempts to assess factors that could allow in-use emissions to vary from the best-case'' results normally reported. The study also addresses issues of fuel supply, fuel composition, performance, safety, and warranty waivers. The report is based on an extensive literature and product survey and on the author's experience with fuel delivery systems for light-duty vehicles.
Date:
September 1, 1992
Creator:
Willson, B. (Colorado State Univ., Fort Collins, CO (United States))
Object Type:
Report
System:
The UNT Digital Library
Capillary discharge extreme ultraviolet lasers. Progress report, December 15, 1991--December 14, 1992
The project objective is to explore the generation of soft X-ray laser radiation in a plasma column created by a fast capillary discharge. The proposed capillary lasing scheme offers the potential for compact, simple and efficient soft X-ray laser sources. For this purpose a compact, fast pulse generator which produces 100 kA current pulses with a risetime of 11 ns was constructed. Initial experiments were conducted in evacuated capillaries, in which the plasma is produced by ablation of the capillary walls. The soft X-ray emission from discharges in polyethylene capillary channels was studied to investigate the possibility of amplification in the 3-2 transition of C VI, at {lambda} = 18.2 nm. Time-resolved spectra in which this transition appears anomalously intense with respect to the 4--2 transition of the same ion were obtained. To date, however, this phenomenoa could not be confirmed as gain, as the intensity of the 18.2 nm line has not been observed to increase exponentially as a function of the capillary length. Encouraging results were obtained by fast pulse discharge excitation of capillaries filled with preionized gas. High temperature (Te > 150 eV), small diameter ({approximately}200 {mu}m) plasma columns were efficiently generated. Fast current pulse excitation of …
Date:
August 1, 1992
Creator:
Rocca, J. J.
Object Type:
Report
System:
The UNT Digital Library
Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas and Lpg Vehicles
This study was designed to evaluate the effectiveness of aftermarket fuel delivery systems for vehicles fueled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Most of the CNG and LPG vehicles studied were converted to the alternative fuel after purchase. There are wide variations in the quality of the conversion hardware and the installation. This leads to questions about the overall quality of the converted vehicles, in terms of emissions, safety, and performance. There is a considerable body of emissions data for converted light-duty vehicles, and a smaller amount for medium- and heavy-duty vehicles. However, very few of these data involve real world conditions, and there is growing concern about in-use emissions. This report also attempts to assess factors that could allow in-use emissions to vary from the ``best-case`` results normally reported. The study also addresses issues of fuel supply, fuel composition, performance, safety, and warranty waivers. The report is based on an extensive literature and product survey and on the author`s experience with fuel delivery systems for light-duty vehicles.
Date:
September 1, 1992
Creator:
Willson, B.
Object Type:
Report
System:
The UNT Digital Library
Capillary discharge extreme ultraviolet lasers. Final report, December 15, 1990--February 28, 1994. Demonstration of a discharge pumped table-top soft x-ray laser
None
Date:
June 1, 1994
Creator:
Rocca, J. J.
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
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
Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1991--31 March 1992
The limiting role of polycrystallinity in thin-film solar calls has been reduced somewhat during the past year, and efficiencies of both CdTe and CuInSe{sub 2} cells are approaching 15%. Quantitative separation of loss mechanisms shows that individual losses, with the exception of forward recombination current, can be made comparable to their single crystal counterparts. One general manifestation of the extraneous trapping states in that the voltage of all polycrystalline thin-film cells drifts upward by 10--50 mV following the onset of illumination.
Date:
November 1, 1992
Creator:
Sites, J. R.
Object Type:
Report
System:
The UNT Digital Library
Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1992--31 March 1993
This report describes work to conduct several investigations of thin-film polycrystalline solar cells. (1) An analysis of high-efficiency solar cells fabricated at the University of South Florida showed significant reduction in forward recombination current, and the cells were stable over a 3-month test period. (2) Transient voltage effects were documented in a large number of polycrystalline cells and were attributed to long-lived trapping states sensitive to voltage changes near one-half open-circuit voltage. (3) Collection efficiency and its voltage dependence were carefully calculated. The typical effect on photocurrent at operating voltages is about 2% for CuInSe{sub 2}, and less for other cells.
Date:
February 1, 1994
Creator:
Sites, J. R.
Object Type:
Report
System:
The UNT Digital Library
Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes. Final report
Assignment of the vibrational modes Of Os{sub 2}(CO){sub 8}(CHCH{sub 3}) and Os(CO){sub 4}(C{sub 2}H{sub 4)} has given fingerprint vibrational spectra for the following species when chemisorbed on metal catalyst surfaces: ethylidene and ethylene bound in a metallacyclopropane mode. The formation and fragmentation of diosmacyclobutanes have been shown to involve slippage of the outgoing olefin onto a single osmium, and associative exchange of the olefin from that site. The incorporation of vinylcyclopropane without rearrangement has confirmed the absence of a diradical intermediate. The anomalous stability of the diosmacyclobutane derived from trans-2-butene has proven due to greater destabilization (by the substituent methyls) of the slipped intermediate than of the ground state. Reaction of an osmacyclobutane with 1,3- or 1,2-dienes (allenes) gives 1,2 rather than 1,4 addition to the diosmium unit. Treatment of Os(CO){sub 4}(C{sub 2}H{sub 4}) with triflic acid results in the formation of Os(CO){sub 4}(C{sub 2}H{sub 5})OTf. The authors have found that the reaction of an aryl iodine(III) reagent with propargyl stannanes or silanes results in o-iodo propargyl arenes.
Date:
April 25, 1994
Creator:
Norton, J. R.
Object Type:
Report
System:
The UNT Digital Library
Diosmacycloalkanes as Models for the Formation of Hydrocarbons From Surface Methylenes. Progress Report, November 1, 1991--October 31, 1992
We are making progress on our investigation of the mechanism of olefin exchange with Os{sub 2}(C{sub 2}H{sub 4})(CO){sub 8}. We are probing this system by kinetic study of the reaction of Os{sub 2}(C{sub 2}H{sub 4})(CO){sub 8} with butyl acrylate (BA) under various pressures of ethylene.
Date:
May 1, 1992
Creator:
Norton, J. R.
Object Type:
Report
System:
The UNT Digital Library
Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes. Progress report, April 1, 1988--March 31, 1989
We have obtained a neutron diffraction data set for Os{sub 2}(CO){sub 8}({mu}-C{sub 2}H{sub 4}). While the structure is still being solved, it is already clear that the hybridization at both of the ethylene carbons is sp{sup 3}. Our first interpretation of our liquid crystal NMR results had suggested a very acute H-C-H angle. We have also obtained {sup 13}C liquid crystal data for Os{sub 2}(CO){sub 8}({mu}-C{sub 2}H{sub 4}). Liquid crystal NMR ({sup 13}C as well as {sup 1}H) spectra have been obtained for Os(CO){sub 4}(C{sub 2}H{sub 4}) and its solution structure determined, in order to test our methodology on a molecule with a rigid structure. The normal modes of Os(CO){sub 4}({mu}-C{sub 2}H{sub 4}) and its deuterated and {sup 13}C-labelled isotopomers have been completely assigned. A partial vibrational analysis of Os{sub 2}(CO){sub 8}({mu}-propene), Os{sub 2}(CO){sub 8}(trans-2-butene), and Os{sub 2}(CO){sub 8}(1-butene) has been completed. We have prepared Os(CO){sub 4}({mu}-CH{sub 2}CH{sub 2}CH{sub 2}) and its 3,3-dideuterio analog. In the course of this work the reaction of Na{sub 2}Os(CO){sub 4} with a number of 1,3-propanediol derivatives has been examined. 1,3-Propanediol ditosylate afforded much better yields of the osmacycle than did either the ditriflate or diiodide. 2,2-Dideutero-1,3-propanediol ditosylate was used to prepare the deuterium-labelled osmacyclobutane.
Date:
January 1, 1989
Creator:
Norton, J. R.
Object Type:
Report
System:
The UNT Digital Library
Diosmacycloalkanes as Models for the Formation of Hydrocarbons From Surface Methylenes. Progress Report, November 1, 1992--October 31, 1993
The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO){sub 4}(C{sub 2}H{sub 4}), an osmacyclopropane; and reaction of {mu}-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.
Date:
May 1, 1993
Creator:
Norton, J. R.
Object Type:
Report
System:
The UNT Digital Library
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
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
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
Development of a gas-to-particle conversion model for use in three-dimensional global sulfur budget studies. Final report, 1 August 1991--30 June 1992
A fully-parameterized model for the formation and growth of aerosols via gas-to-particle conversion has been developed and tested. A particularly significant contribution is a new method for the prediction of numbers of particles nucleated using information on the vapor source rate, relative humidity, and preexisting aerosol alone, thus eliminating the need to solve a system of coupled ODEs. Preliminary tests indicate substantial reduction in computational costs, but it is recommended that the BIMODAM model be incorporated into a large-scale model of the sulfur cycle in order to more fully test its computational feasibility.
Date:
August 1, 1993
Creator:
Kreidenweis, S. M.
Object Type:
Report
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
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
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
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