Inertial Confinement Fusion Target Component Fabrication and Technology Development Support (open access)

Inertial Confinement Fusion Target Component Fabrication and Technology Development Support

On December 31, 1990, the US Department of Energy entered into a contract with General Atomics (GA) to be the Inertial Confinement Fusion (ICF) Target Component Fabrication and Technology Development Support contractor. This report documents the technical activities of the period January 1, 1991 through September 30, 1992. During this period, GA was assigned 15 tasks in support of the Inertial Confinement Fusion program and its laboratories. These tasks included Facilities Activation, Staff Development, and Capabilities Validation to establish facilities and equipment, and demonstrate capability to perform ICF target fabrication research, development and production activities. The capabilities developed and demonstrated are those needed for fabrication and precise characterization of polymer shells and polymer coatings. We made progress toward production capability for glass shells, barrier layer coatings, and gas idling of shells. We fabricated over 1000 beam diagnostic foil targets for Sandia National Laboratory Albuquerque and provided full-time on-site engineering support for target fabrication and characterization. We initiated development of methods to fabricate polymer shells by a controlled mass microencapsulation technique, and performed chemical syntheses of several chlorine- and silicon-doped polymer materials for the University of Rochester's Laboratory for Laser Energetics (UR/LLE). We performed the conceptual design of a cryogenic target …
Date: March 1, 1993
Creator: Steinman, D. (ed.)
Object Type: Report
System: The UNT Digital Library
Processing, properties, and wear resistance of aluminides. [Fe[sub 3]Al; Al[sub 3]Ti] (open access)

Processing, properties, and wear resistance of aluminides. [Fe[sub 3]Al; Al[sub 3]Ti]

Fully dense alloys based on Fe[sub 3]Al were produced by reaction synthesis from low cost elemental powders using hot pressing, hot isostatic pressing or Ceracon process. The reaction proceeds by outward spreading of a transient liquid phase from the initial aluminum particle site and precipitation of the compound phase from the liquid. Combustion synthesized material has a very fine grain size that is resistant to coarsening at high temperature because of a high density of fine oxides from the prior particle boundaries. The fine grain size results in approximately twice the yield strength in the reaction synthesized material compared to hot extruded pre-alloyed powder. Combustion synthesis has also been successfully applied to joining Fe[sub 3]Al and to forming coatings on carbon steel substrates. Combustion synthesis has been shown to be viable for fabricating trialuminides from elemental powder compacts. Al[sub 3]Ti, Al[sub 73]Ti[sub 24]Cr[sub 3] and Al[sub 67]Ti[sub 25]Cr[sub 8] were examined. Fully dense, homogeneous materials exhibiting an equiaxed grain structure were produced by conducting reaction and homogenization under pressure, or in a furnace at ambient pressure and subsequently densifying the porous preform by hot consolidation. The tetragonal DO[sub 22] structure was the primary reaction product for all compositions. Most of …
Date: March 1, 1993
Creator: Wright, R. N.; Rabin, B. H. & Wright, J. K.
Object Type: Report
System: The UNT Digital Library
Effect of pretreating of host oil on coprocessing (open access)

Effect of pretreating of host oil on coprocessing

The principal objective of this research is to determine the role host petroleum-derived oils (1000[degrees]F+), as well as that of catalytically treated host oils, play when used as liquefaction solvents in coprocessing with coal. The host oils will be extensively characterized and then pretreated in a number of ways which involve catalytic reactions such as hydrogenation, hydrocracking, isomerization, and dehydrogenation. The pretreated oils win then be characterized. The effects of the host oil on coprocessing with coal win be compared to those obtained using catalytically modified heavy oils. When appropriate, model compounds will be used to study specific reactions brought about by the pretreatments. Highly dispersed iron catalysts modified by the addition of small amounts of other metals wig be used to modify the chemical composition of the host oils. Work continued on Task H during this quarter. In the first phase of this task, the test oil, an Amoco resid, is being treated with hydrogenation catalysts such as Mo(CO)[sub 6] and Fe[sub 2]O[sub 3]/SO[sub 4] to determine the conditions necessary to increase the hydrogen content from about 10.2 wt % to about 11.5 wt %. In the second phase, more severe hydrogenation/hydrorefining is being carried out to determine the …
Date: March 25, 1993
Creator: Wender, I. & Tierney, J.W.
Object Type: Report
System: The UNT Digital Library
Evaluation of S-101 course Supervisors' Orientation to Occupational Safety in DOE'' taught in Amarillo, Texas, November 17--20, 1992 (open access)

Evaluation of S-101 course Supervisors' Orientation to Occupational Safety in DOE'' taught in Amarillo, Texas, November 17--20, 1992

This summarizes trainee evaluations for the Safety Training Section course, Supervisors' Orientation to Occupational Safety in DOE'', (S-101) which was conducted November 17--20, 1992 at the Pantex Plant, in Amarillo, Texas. Sections 1.1 and 1.2 of this report summarize the quantitative course evaluations that trainees provided upon completion of the course. Section 1.3 provides written comments provided by the attendee, and Section 1.4 provides the examination results. Appendix A provides a transcript of the trainees' written comments and Appendix B provides the evaluation form.
Date: March 1, 1993
Creator: Wright, T. S.
Object Type: Report
System: The UNT Digital Library
The iterative Monte Carlo technique for collisionless plasma flow to a surface (open access)

The iterative Monte Carlo technique for collisionless plasma flow to a surface

A new technique for modelling the boundary plasma of magnetic fusion devices is described. The technique represents a natural extension of existing Monte Carlo codes, which are presently constrained to have the plasma background specified by either measurements or predictions from plasma fluid codes. The new approach, the Iterative Monte Carlo (IMC) technique, self-consistently determines the ambipolar electric field in the plasma by feeding back into the simulation the evolving plasma density using the Boltzmann relation. The IMC technique is applied, for demonstrative purposes, to the problem of collisionless one-dimensional plasma flow to a surface. Such a problem has previously been solved exactly using kinetic approaches in the published literature using two different particle source functions. Good agreement between the IMC results and the exact solutions is obtained.
Date: March 1, 1993
Creator: Pitcher, C. S.
Object Type: Report
System: The UNT Digital Library
State policies affecting natural gas consumption (Notice of inquiry issued on August 14, 1992) (open access)

State policies affecting natural gas consumption (Notice of inquiry issued on August 14, 1992)

On August 14, 1992, the United States Department of Energy issued a Request for Comments Concerning State Policies Affecting Natural Gas Consumption. This Notice of (NOI) noted the increasing significance of the role played by states and sought to gain better understanding of how state policies impact the gas industry. The general trend toward a. more competitive marketplace for natural gas, as well as recent regulatory and legislative changes at the Federal level, are driving State regulatory agencies to reevaluate how they regulate natural gas. State action is having a significant impact on the use of natural gas for generating electricity, as well as affecting the cost-effective trade-off between conservation expenditures and gas use. Additionally, fuel choice has an impact upon the environment and national energy security. In light of these dimensions, the Department of Energy initiated this study of State regulation. The goals of this NOI are: (1) help DOE better understand the impact of State policies on the efficient use of gas; (2) increase the awareness of the natural gas industry and Federal and State officials to the important role of State policies and regulations; (3) create an improved forum for dialogue on State and Federal natural gas …
Date: March 25, 1993
Creator: Lemon, R. & Kamphuis-Zatopa, W.
Object Type: Article
System: The UNT Digital Library
Thermodynamic properties of pulverized coal during rapid heating devolatilization processes (open access)

Thermodynamic properties of pulverized coal during rapid heating devolatilization processes

Knowledge of the thermodynamic and morphological properties of coal associated with rapid heating decomposition pathways is essential to progress in coal utilization technology. Specifically, knowledge of the heat of devolatilization, surface area and density of coal as a function of rank characteristics, temperature and extent of devolatilization in the context of rapid heating conditions is required both, for the fundamental determination of kinetic parameters of coal devolatilization, and to refine existing devolatilization sub-models used in comprehensive coal combustion codes. The objective of this research is to obtain data on the thermodynamic properties and morphology of coal under conditions of rapid heating. Specifically, the total heat of devolatilization, external surface area, BET surface area and true density will be measured for representative coal samples. In addition, for one coal, the contribution of each of the following components to the overall heat of devolatilization will be measured: the specific heat of coal/char during devolatilization, the heat of thermal decomposition of the coal, the specific heat capacity of tars, and the heat of vaporization of tars. Calibration of the heated grid calorimeter (Task 2) was completed this reporting period. Several refinements to the heated grid apparatus have been implemented which allow quantitative determination …
Date: March 1, 1993
Creator: Proscia, W. M. & Freihaut, J. D.
Object Type: Report
System: The UNT Digital Library
DNA Radiation Environments Program Spring 1991 2-meter box experiments and analyses. [DEfense Nuclear Agency (DNA)] (open access)

DNA Radiation Environments Program Spring 1991 2-meter box experiments and analyses. [DEfense Nuclear Agency (DNA)]

This report summarizes the Spring 1991 2-m Box experiments that were performed at the Army Pulse Radiation Facility (APRF) at Aberdeen Proving Ground. These studies were sponsored by the Defense Nuclear Agency (DNA) under the Radiation Environments Program to obtain measured data for benchmarking the Adjoint Monte Carlo Code System, MASH, Version 1.0. The MASH code system was developed for the Department of Defense and NATO for calculating neutron and gamma-ray radiation fields and shielding protection factors for armored vehicles and military structures against nuclear weapon radiation. In the 2-m Box experiments, neutron and gamma-ray dose rates and reduction factors were measured in the free-field and as a function of position on an anthropomorphic phantom that was placed outside and inside a borated polyethylene lined steel-walled 2-m box. The data were acquired at a distance of 400-m from the APRF reactor. The purpose of these experiments was to measure the neutron and gamma-ray dose rates as a function of detector location on the phantom for cases when the phantom was in the free-field and inside of the box. Neutron measurements were made using a BD-100R bubble detector and gamma-ray measurements were made using thermoluminescent detectors (TLD). Calculated and measured data …
Date: March 1, 1993
Creator: Santoro, R. T. & Whitaker, S. Y.
Object Type: Report
System: The UNT Digital Library
Federal Methanol Fleet Project final report (open access)

Federal Methanol Fleet Project final report

The Federal Methanol Fleet Project concluded with the termination of data collection from the three fleet sites in February 1991. The Lawrence Berkeley Laboratory (LBL) completed five years of operation, Argonne National Laboratory (ANL) completed its fourth year in the project, and Oak Ridge National Laboratory (ORNL) completed its third. Twenty of the thirty-nine vehicles in the fleet were powered by fuel methanol (typically M85, 85 % methanol, 15 % unleaded gasoline, although the LBL fleet used M88), and the remaining control vehicles were comparable gasoline vehicles. Over 2.2 million km (1.4 million miles) were accumulated on the fleet vehicles in routine government service. Data collected over the years have included vehicle mileage and fuel economy, engine oil analysis, emissions, vehicle maintenance, and driver acceptance. Fuel economies (on an energy basis) of the methanol and gasoline vehicles of the same type were comparable throughout the fleet testing. Engine oil analysis has revealed higher accumulation rates of iron and other metals in the oil of the methanol vehicles, although no significant engine damage has been attributed to the higher metal content. Vehicles of both fuel types have experienced degradation in their emission control systems, however, the methanol vehicles seem to have …
Date: March 1, 1993
Creator: West, B. H.; McGill, R. N. (Oak Ridge National Lab., TN (United States)); Hillis, S. L. & Hodgson, J. W. (Tennessee Univ., Knoxville, TN (United States))
Object Type: Report
System: The UNT Digital Library
Reduced fouling of ultrafiltration membranes via surface fluorination (open access)

Reduced fouling of ultrafiltration membranes via surface fluorination

Surface fluorination can affect significantly the performance of an ultrafiltration membrane used to concentrate a food-related stream. Membranes fluorinated and tested as flat sheets exhibit higher initial fluxes, and do not foul as rapidly as untreated membranes. This improvement is linked to increased surface hydrophilicity, as shown in decreased contact angle with water. This increased hydrophilicity, in turn, is linked to the addition of fluorine and oxygen to the surface. The pilot plant study did-not show the difference in membrane flux and fouling observed in the flat sheet study. Instead, fluorinated and unfluorinated modules behaved similarly. Fouling by potato waste feed was severe and resulted in formation of an extensive gel layer within the module on the membrane surface. XPS, SEM and FTIR indicate that buildup of organic material occurred on both fluorinated and unfluorinated membranes, but SEM indicates that a fibrous mat of material was observed only on the nonfluorinated membrane. We conclude that in the pilot study, membrane fouling and gel formation were so extensive that the surface interaction effect was overwhelmed.
Date: March 1, 1993
Creator: Sedath, R.H.; Yates, S.F. & Li, N.N.
Object Type: Report
System: The UNT Digital Library
FY 1992 Measurements and Characterization Branch annual report (open access)

FY 1992 Measurements and Characterization Branch annual report

The Measurements and Characterization Branch actively supports the advancement of DOE/NREL goals for the development and implementation of the solar photovoltaic (PV) technology. The primary focus of the laboratories is to provide state-of-the-art analytical capabilities for materials and device characterization and fabrication. The branch houses a comprehensive facility that Is capable of providing information on the full range of PV components. A major objective of the branch is to aggressively pursue collaborative research with other government laboratories, universities, and industrial firms for the advancement of Pv technologies. Members of the branch disseminate research findings to the technical community in publications and presentations. The Measurements and Characterization Branch encompasses seven coordinated research groups, providing integrated research and development that covers all aspects of photovoltaic materials/devices characterization.
Date: March 1, 1993
Creator: Dippo, P.C (ed.)
Object Type: Report
System: The UNT Digital Library
Impedance of the NSLS prototype small-gap undulator vacuum chamber (open access)

Impedance of the NSLS prototype small-gap undulator vacuum chamber

Insertion device performance is limited by the minimum magnet gap allowed by storage ring beam dynamics. In this note, we analyze the impedance of the vacuum chamber for the prototype small-gap undulator being built for the NSLS X-Ray ring, and discuss the consequent beam instability thresholds.
Date: March 1, 1993
Creator: Bane, K. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)) & Krinsky, S. (Brookhaven National Lab., Upton, NY (United States))
Object Type: Report
System: The UNT Digital Library
Composition dependence of fluid thermophysical properties: Theory and modeling (open access)

Composition dependence of fluid thermophysical properties: Theory and modeling

Objectives are studies of equilibrium/nonequilibrium properties of asymmetric fluid mixtures through computer simulation (CS), development of predictive theories of mixture equilibrium properties, development and application of selection algorithm methodology for mixture equations of state, and use of theory to develop new engineering design models for fluid mixtures. Kirwood charging method CS of Lennard-Jones mixtures with large size ratios verified the Kirkwood-Buff/Baxter method of calculating chemical potentials. CS of n-butane showed that the rheology is not a function of system size. A modified stepwise regression algorithm was developed and applied to HFC R134a. An analytical expression was developed for conformal solution size correction for mixtures. The extended corresponding states theory (ECST) can be applied to systems having large polarity differences; an accurate representation was developed of bulk phase properties of water-hydrocarbon systems. It was found how to force ECST to reach the correct virial limit.
Date: March 29, 1993
Creator: Ely, J.F.
Object Type: Report
System: The UNT Digital Library
Pilot study risk assessment for selected problems at the Fernald Environmental Management Project (FEMP) (open access)

Pilot study risk assessment for selected problems at the Fernald Environmental Management Project (FEMP)

Two important environmental problems at the USDOE Fernald Environmental Management Project (FEMP) facility in Fernald, Ohio were studied in this human health risk assessment. The problems studied were radon emissions from the K-65 waste silos, and offsite contamination of ground water with uranium. Waste from the processing of pitchblende ore is stored in the K-65 silos at the FEMP. Radium-226 in the waste decays to radon gas which escapes to the outside atmosphere. The concern is for an increase in lung cancer risk for nearby residents associated with radon exposure. Monitoring data and a gaussian plume transport model were used to develop a source term and predict exposure and risk to fenceline residents, residents within 1 and 5 miles of the silos, and residents of Hamilton and Cincinnati, Ohio. Two release scenarios were studied: the routine release of radon from the silos and an accidental loss of one silo dome integrity. Exposure parameters and risk factors were described as distributions. Risks associated with natural background radon concentrations were also estimated.
Date: March 1, 1993
Creator: Hamilton, L.D.; Meinhold, A.F.; Baxter, S.L.; Holtzman, S.; Morris, S.C.; Pardi, R. et al.
Object Type: Report
System: The UNT Digital Library
Study of Intermediates From Transition Metal Excited-State Electron- Transfer Reactions (open access)

Study of Intermediates From Transition Metal Excited-State Electron- Transfer Reactions

Progress on 6 projects is reported: excited state absorption spectrum of Ru(bpy)[sub 3][sup 2+], solvent cage model for electron transfer quenching, reductive quenching of [sup *]Cr(III) complexes, solution medium effects in oxidative quenching of [sup *]Ru(II) complexes, photosensitized oxidation of phenol in aqueous solution, and quenching of Ru(II) complexes by oxygen.
Date: March 31, 1993
Creator: Hoffman, M. Z.
Object Type: Report
System: The UNT Digital Library
Annual report on monitoring of the unsaturated zone and recharge areas at INEL to the state of Idaho INLEL Oversight COmmittee (open access)

Annual report on monitoring of the unsaturated zone and recharge areas at INEL to the state of Idaho INLEL Oversight COmmittee

This project, begun in March 1991, was originally structured as two separate research efforts: An investigation of the recharge phenomenon and surface water-ground water interactions at the INEL; and a study of water and contaminant movement through the unsaturated zone, including a review of computer models used to described this process. During the initial months of work, it became obvious to those involved in these studies that the two topic areas were intimately related, and work since that time has proceeded with no firm boundaries between the two efforts. Much of the Phase I work (March 1991--March 1992) consisted of a detailed review of available literature pertinent to the two research topics and to the INEL site. This Annual Report summarizes the other project activities during Phase III, and is organized into three sections: Section I -- an overview of the ongoing efforts related to computer model algorithms and data requirements for modeling the transport process in the unsaturated zone (Dr. Jim Liou). Section H -- a review of ongoing work to predict the growth and decay of the ground water mound beneath the INEL spreading basins, using the computer model UNSAT-2 (Dr. John Finnie). Section M -- a final …
Date: March 1, 1993
Creator: Horn, D.; Liou, J. & Finnie, J.
Object Type: Report
System: The UNT Digital Library
Sizing a water softener for aquifer thermal energy storage (open access)

Sizing a water softener for aquifer thermal energy storage

In aquifer thermal energy storage (ATES) installations, ground water is circulated between an aquifer and heat exchangers via a well field. It is often necessary to soften the water to prevent carbonate scaling in pipes, heat exchangers, and well screens. Most ATES projects requiring water softening will be best served by using synthetic ion-exchange resins. The size of the resin beds, the resin regeneration cycle, and the amount of NaCl brine used in each regeneration depend on several factors. These are (1) the chemistry of the native ground water, (2) allowable residual hardness after softening, (3) the maximum flow rate of water through the ATES plant, and (4) exchange characteristics of the resin. Example calculations are given for a three-bed water softening system.
Date: March 1, 1993
Creator: Hall, S. H. & Jenne, E. A.
Object Type: Report
System: The UNT Digital Library
Thermodynamic properties for polycyclic systems by non-calorimetric methods (open access)

Thermodynamic properties for polycyclic systems by non-calorimetric methods

A detailed vibrational spectroscopic study of furan, pyrrole, and thiophene has been completed. These compounds form part of the base of five-membered ring systems on which the rest of the research program will be built Several methyl-substituted derivatives were also studied. The results will be used to confirm the model for alkyl- substitution in the ring systems. Gas-phase spectra and fundamental- frequency assignments were completed for 2,3- and 2,5-dihydrofuran. Those compounds initiate work on ring-puckering within the research program. A paper describing the need for third virial estimation, when using the virial equation of state to derive thermodynamic properties at pressures greater than 1 bar was completed.
Date: March 1, 1993
Creator: Steele, W. V.; Chirico, R. D. & Klots, T. D.
Object Type: Report
System: The UNT Digital Library
Applications of Micellar Enzymology to Clean Coal Technology (open access)

Applications of Micellar Enzymology to Clean Coal Technology

The sequential addition of enzyme and H[sub 2]O[sub 2] during the reverse micelle incubation was found to enhance sulfoxidation, but levels of EPSn remained low. The triplicate addition of enzyme and H[sub 2]0[sub 2] during the reverse micelle incubation of EPS was found to enhance sulfoxidation to EPSn and unidentified material. Low conversion to EPSn was not due to the inability of the enzyme to oxidize EPSX in reverse micelles, since the latter was demonstrated with both commercially available and enzymatically synthesized EPSx as starting material. Chloroperoxidase in an AOT-isooctane reverse micelle solution also mediated production of a metabolite from DBT with characteristics consistent with DBTSx. The magnitude of conversion was enhanced to 10% of the starting material by triplicate addition of enyme and H[sub 2]0[sub 2]. The identity of this metabolite as DBTSx was verified by GC/MS. Chloroperoxidase in reverse micelles appears therefore to be a versatile catalyst for sulfoxidation of aliphatic and aromatic sulfur-containing model coal compounds.
Date: March 10, 1993
Creator: Walsh, C. T.
Object Type: Report
System: The UNT Digital Library
The application of X-mode reflectometry to the study of large scale fluctuations in TFTR (open access)

The application of X-mode reflectometry to the study of large scale fluctuations in TFTR

It has been suggested for some time that microwave reflectometry, has the potential for measuring the large scale structure of density fluctuations in tokamak turbulence with greatly improved spatial resolution over existing scattering techniques. The motivation for developing fluctuation diagnostics with improved spatial resolution of large scale structures is that such fluctuations may potentially account for the anomalous particle and energy transport observed in tokamaks. On TFTR we now have operational a four channel X-mode reflectometer system comprising of three fixed frequency channels at 140, 132.5, and 125 GHz and a able frequency channel scanning between 110--123 GHz. Each channel detects fluctuations from a region on the equatorial plane of the plasma torus with spatial resolution of [approx]5 cm in the poloidal direction and [approx]1 cm in the radial direction. Properties of the plasma turbulence are inferred from the amplitude and spectral coherence of phase fluctuations impressed on the reflected wave by density irregularities at or near the cutoff. Experimental results are presented which show the existence of previously unobserved large scale (k[perpendicular][rho][sub i]<<1) random and coherent density fluctuations in the Ohmic and Supershot regimes of TFTR.
Date: March 1, 1993
Creator: Mazzucato, E. & Nazikian, R.
Object Type: Article
System: The UNT Digital Library
[National Institute for Petroleum and Energy Research] monthly progress report, January 1993 (open access)

[National Institute for Petroleum and Energy Research] monthly progress report, January 1993

Accomplishments for the month of January are briefly described for the following tasks: energy production research; fuels research; and supplemental government programs. Energy production research includes: reservoir assessment and characterization; TORI research support; development of improved microbial flooding methods; development of improved chemical flooding methods; development of improved alkaline flooding methods; mobility control and sweep improvement in chemical flooding; gas flood performance prediction improvement; mobility control, profile modifications, and sweep improvement in gas flooding; three-phase relative permeability research; thermal processes for light oil recovery; thermal processes for heavy oil recovery; and imaging techniques applied to the study of fluid in porous media. Fuel research includes: development of analytical methodology for analysis of heavy crudes; and thermochemistry and thermophysical properties of organic nitrogen and diheteroatom containing compounds. supplemental Government program includes: microbial-enhanced waterflooding field project; feasibility study of heavy oil recovery in the midcontinent region--Oklahoma, Kansas, and Missouri; surfactant- enhanced alkaline flooding field project; process-engineering property measurements on heavy petroleum components; development and application of petroleum production technologies; upgrade BPO crude oil data base; simulation analysis of steam-foam projects; DOE education initiative project; field application of foams for oil production symposium; technology transfer to independent producers; and compilations and analysis of …
Date: March 1, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Innovative sputtering techniques for CIS and CdTe submodule fabrication (open access)

Innovative sputtering techniques for CIS and CdTe submodule fabrication

This report describes work done during Phase 1 of the subject subcontract. The subcontract was designed to study innovative deposition techniques, such as the rotating cylindrical magnetron sputtering system and electrodeposition for large-area, low-cost copper indium diselenide (CIS) and cadmium telluride (CdTe) devices. A key issue for photovoltaics (PV) in terrestrial and future space applications is producibility, particularly for applications using a large quantity of PV. Among the concerns for fabrication of polycrystalline thin-film PV, such as CIS and CdTe, are production volume, cost, and minimization of waste. Both rotating cylindrical magnetron (C-Mag[trademark]) sputtering and electrodeposition have tremendous potential for the fabrication of polycrystalline thin-film PV due to scaleability, efficient utilization of source materials, and inherently higher deposition rates. In the case of sputtering, the unique geometry of the C-Mae facilitates innovative cosputtering and reactive sputtering that could lead to greater throughput reduced health and safety risks, and, ultimately, lower fabrication cost. Electrodeposited films appear to be adherent and comparable with low-cost fabrication techniques. Phase I involved the initial film and device fabrication using the two techniques mentioned herein. Devices were tested by both internal facilities, as well as NREL and ISET.
Date: March 1, 1993
Creator: Armstrong, J.M.; Misra, M.S. & Lanning, B. (Martin Marietta Aerospace, Denver, CO (United States). Astronautics Group)
Object Type: Report
System: The UNT Digital Library
Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane (open access)

Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane

Amax R D will perform laboratory scale development of a promising, practical catalyst for the selective oxidation of methane to methanol. The primary component of this catalyst is vanadium-phosphate (VPO) which has shown good activity and selectivity in the partial oxidation of n-butane and propane but has not been studied in detail for methane oxidation. The goal of the project is to develop a catalyst which allows methane oxidation to methanol to be conducted at high conversion and selectivity. A low CH[sub 4]/O[sub 2] ratio will be employed with air as the source of oxygen. Temperatures below 600[degrees]C and pressures up to 20 atm are to be investigated. The use of steam in the feed gas will also be investigated. The catalyst development strategy will be to utilize promoters and supports to improve the activity and selectivity of the unmodified VPO catalyst. The catalyst testing reactor system was used to perform blank (empty) reactor runs over a wide range of temperatures, pressure, and flow rates. No methane conversion was observed at temperatures of 500[degrees]C or lower in any of the tests. At higher temperatures, significant methane conversion to carbon dioxide was observed. At 550[degrees]C, 300 psig, and the highest flow …
Date: March 4, 1993
Creator: McCormick, Robert L. & Jha, Mahesh C.
Object Type: Report
System: The UNT Digital Library
Steady-state and transient modeling of tracer and nutrient distributions in the global ocean (open access)

Steady-state and transient modeling of tracer and nutrient distributions in the global ocean

The balance of stable and decaying tracers was incorporated into a latitude-depth ocean circulation model which resolves the major ocean basin and is coupled to an atmospheric energy balance model. The modern distribution of radiocarbon and the analysis of artificial color tracers enabled the census of the deep water masses. We show that good agreement with the observation can be achieved if the surface forcing is modified. The same process could also account for long-term, large-scale changes of the global thermohaline circulation. Uptake rates of carbon are investigated using an inorganic carbon cycle model and performing 2 [times] CO[sub 2]-experiments. We prescribe the industrial evolution of pCO[sub 2] in the atmosphere from 1792 to 1988 and calculate the total flux of carbon into the world ocean. Results are in good agreement with two recent 3-dimensional model simulation. First results using an organic carbon cycle in this model are presented. Changes in the hydrological cycle can stabilize the thermohaline circulation in the Atlantic and enable simulation of climate events resembling the Younger Dryas. By adding the balance of radiocarbon the evolution of its atmospheric concentration is studied during rapid changes of deep ocean ventilation. A resumption of ventilation creates a rapid …
Date: March 8, 1993
Creator: Stocker, T.F. & Broecker, W.S.
Object Type: Report
System: The UNT Digital Library