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Access to Film and Video Works: Surrogates for Moving Image Documents

Description: This doctoral dissertation discusses access to film and video works. Physical and intellectual access to moving image documents is insufficient, often insignificant, at the level of the individual user. Existing access tools suffer from a lack of recognition of the differences between linguistic text communication and image communication. Browsing and relevance judgements are made difficult by the physical realities of film and video documents - one cannot flip through them - and by the habits of serial and passive viewing.
Date: 1984
Creator: O'Connor, Brian Clark
Partner: UNT College of Information

Seasonal variation in carbon dioxide exchange over a Mediterranean annual grassland in California

Description: Understanding how environmental variables affect the processes that regulate the carbon flux over grassland is critical for large-scale modeling research, since grasslands comprise almost one-third of the earth's natural vegetation. To address this issue, fluxes of CO{sub 2} (F{sub c}, flux toward the surface is negative) were measured over a Mediterranean, annual grassland in California, USA for 2 years with the eddy covariance method. To interpret the biotic and abiotic factors that modulate F{sub c} over the course of a year we decomposed net ecosystem CO{sub 2} exchange into its constituent components, ecosystem respiration (R{sub eco}) and gross primary production (GPP). Daytime R{sub eco} was extrapolated from the relationship between temperature and nighttime F{sub c} under high turbulent conditions. Then, GPP was estimated by subtracting daytime values of F{sub c} from daytime estimates of R{sub eco}. Results show that most of carbon exchange, both photosynthesis and respiration, was limited to the wet season (typically from October to mid-May). Seasonal variations in GPP followed closely to changes in leaf area index, which in turn was governed by soil moisture, available sunlight and the timing of the last frost. In general, R{sub eco} was an exponential function of soil temperature, but with season-dependent values of Q{sub 10}. The temperature-dependent respiration model failed immediately after rain events, when large pulses of R{sub eco} were observed. Respiration pulses were especially notable during the dry season when the grass was dead and were the consequence of quickly stimulated microbial activity. Integrated values of GPP, R{sub eco}, and net ecosystem exchange (NEE) were 867, 735, and -132g C m{sup -2}, respectively, for the 2000-2001 season, and 729, 758, and 29g C m{sup -2} for the 2001-2002 season. Thus, the grassland was a moderate carbon sink during the first season and a weak carbon source during the ...
Date: May 1, 2004
Creator: Xu, L & Baldocchi, D
Partner: UNT Libraries Government Documents Department

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Description: Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Partner: UNT Libraries Government Documents Department

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Description: Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Partner: UNT Libraries Government Documents Department

How plant functional-type, weather, seasonal drought and soil physical properties alter water and energy fluxes of an oak-grass savanna and an annual grassland.

Description: Savannas and open grasslands often co-exist in semi-arid regions. Questions that remain unanswered and are of interest to biometeorologists include: how do these contrasting landscapes affect the exchanges of energy on seasonal and annual time scales; and, do biophysical constraints imposed by water supply and water demand affect whether the land is occupied by open grasslands or savanna? To address these questions, and others, we examine how a number of abiotic, biotic and edaphic factors modulate water and energy flux densities over an oak-grass savanna and an annual grassland that coexist in the same climate but on soils with different hydraulic properties. The net radiation balance was greater over the oak woodland than the grassland, despite the fact that both canopies received similar sums of incoming short and long wave radiation. The lower albedo and lower radiative surface temperature of the transpiring woodland caused it to intercept and retain more long and shortwave energy over the course of the year, and particularly during the summer dry period. The partitioning of available energy into sensible and latent heat exchanged over the two canopies differed markedly. The annual sum of sensible heat exchange over the woodland was 40% greater than that over the grassland (2.05 GJ m{sup -2} per year versus 1.46 GJ m{sup -2} per year). With regards to evaporation, the oak woodland evaporated about 380mm of water per year and the grassland evaporated about 300mm per year. Differences in available energy, canopy roughness, the timing of physiological functioning, water holding capacity of the soil and rooting depth of the vegetation explained the observed differences in sensible and latent heat exchange of the contrasting vegetation surfaces. The response of canopy evaporation to diminishing soil moisture was quantified by comparing normalized evaporation rates (in terms of equilibrium evaporation) with soil water potential ...
Date: May 1, 2004
Creator: Baldocchi, DD, Xu L, Kiang N.
Partner: UNT Libraries Government Documents Department

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Description: Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Partner: UNT Libraries Government Documents Department

Liquid Metal Bond for Improved Heat Transfer in LWR Fuel Rods

Description: A liquid metal (LM) consisting of 1/3 weight fraction each of Pb, Sn, and Bi has been proposed as the bonding substance in the pellet-cladding gap in place of He. The LM bond eliminates the large AT over the pre-closure gap which is characteristic of helium-bonded fuel elements. Because the LM does not wet either UO2 or Zircaloy, simply loading fuel pellets into a cladding tube containing LM at atmospheric pressure leaves unfilled regions (voids) in the bond. The HEATING 7.3 heat transfer code indicates that these void spaces lead to local fuel hot spots.
Date: August 24, 2005
Creator: Olander, Donald
Partner: UNT Libraries Government Documents Department

A High Intensity Multi-Purpose D-D Neutron Generator for Nuclear Engineering Laboratories

Description: This NEER project involves the design, construction and testing of a low-cost high intensity D-D neutron generator for teaching nuclear engineering students in a laboratory environment without radioisotopes or a nuclear reactor. The neutron generator was designed, fabricated and tested at Lawrence Berkeley National Laboratory (LBNL).
Date: November 29, 2005
Creator: Leung, Ka-Ngo; Vujic, Jasmina L.; Morse, Edward C. & Peterson, Per F.
Partner: UNT Libraries Government Documents Department

An Improved Gamma Detector Using Gamma Moderation

Description: Abstract: "Theoretical and experimental results of the effect of gamma moderation are described. A 6.7-fold enhancement factor was obtained with a 1/8-in. - thick sodium-iodide crystal when using gamma moderation and a Co-60 gamma source. A counter was designed and built to make the most use of gamma source. A counter was designed and built to make the most use of gamma moderation. The results indicate that this counter can be made energy independent over a wide region. Though the cost of the counter is about 1/3 that of a 1-in, -diam, 1-in. -thick sodium-iodide crystal plus photomultiplier, the counting efficiency for gammas such as Na-24 is over two times greater."
Date: September 3, 1959
Creator: Fox, Raymond
Partner: UNT Libraries Government Documents Department

Coal surface control for advanced fine coal flotation

Description: The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. The results of this research are to be made available to ICF Kaiser Engineers who are currently working on the Engineering Development of Advanced Flotation under a separate contract with DOE under the Acid Rain Control Initiative program. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying degrees of weathering, namely, open to the atmosphere, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. 29 figs., 29 tabs.
Date: July 30, 1991
Creator: Fuerstenau, D. W.; Sastry, K. V. S.; Hanson, J. S.; Diao, J.; De, A.; Sotillo, F. et al.
Partner: UNT Libraries Government Documents Department

Demonstration of dual-band infrared thermal imaging at Grass Valley Creek bridges

Description: We demonstrated dual-band infrared (DBIR) thermal imaging at the Grass Valley Creek Bridges near Redding CA. DBIR thermal imaging is an enabling technology for rapid, reliable, bridge deck inspections while minimizing lane closures. bridge-deck inspections were conducted from a mobile DBIR bridge inspection laboratory during November 2-3, 1995. We drove this self-contained unit at limited highway speeds over 0.4 lane miles of bridge deck. Using two thermal IR bands, we distinguished delaminations from clutter. Clutter, or unwanted thermal detail, occurs from foreign materials or uneven shade on the bridge deck surface. By mapping the DBIR spectral- response differences at 3-5 {mu}m and 8-12 {mu}m, we removed foreign material clutter. By mapping the deck diurnal thermal inertia variations, we removed clutter from uneven shade. Thermal inertia is a bulk deck property, the square root of thermal conductivity x density x heat capacity. Delaminated decks have below-average thermal inertias, or above-average day-night temperature excursions. Compared to normal decks areas, delaminated deck areas were typically 2 or 3 {degrees}C warmer at noon, and 0.5{degrees}C cooler at night. The mobile DBIR bridge inspection laboratory is currently undergoing extensive testing to examine bridges by the Federal Highway Administration.
Date: November 1, 1996
Creator: Del Grande, N. K.; Durbin, P.F.; Logan, C.M.; Perkins, D.E. & Schich, P.C.
Partner: UNT Libraries Government Documents Department

Conversations about electricity and the future: Findings of an international seminar and lessons from a year of surprises

Description: In January 1990 thirty-two experts from twelve countries convened for a five-day working Seminar on the Berkeley Campus of the University of California to discuss electricity supply and demand. The participants brought with them deep and diverse backgrounds in energy issues. A major concern of the First 1990 Group on Electricity was the potential impact of electricity shortages on the environment, just at a time of growing awareness of environmental deterioration. These concerns extend from local problems to nations, regions and global impacts. Indeed, because of the importance of electricity in our lives, potential electric power shortages already foreseeable in this decade could overwhelm public concern for the environment, unless critical, long-leadtime measures are taken very soon. The First 1990 Group on Electricity's Findings and Conclusions, the thinking that led to them, and the impact of events in the intervening year form the content of this book.
Date: June 1, 1991
Creator: Rossin, A.D. & Fowler, K. (eds.)
Partner: UNT Libraries Government Documents Department

Experimental tracking of the evolution of foam in porous media

Description: The authors discuss the experiments that have been done to track the effects of diffusion of gas in foams trapped in porous media. They describe several types of experiments and discuss the difficulties that prevent quantitative results from being obtained in most cases. However, the experiments do help them understand the physics and diffusion-driven coarsening of foams trapped in porous media. This understanding is necessary to simulate the behavior of these foams and predict the mobilization characteristics of foam in porous media. At the end of this paper, they compare the trends and predictions resulting from the experimental work to the predictions of the models which are presented elsewhere.
Date: July 1, 1996
Creator: Cohen, D; Patzek, T.W. & Radke, C.J.
Partner: UNT Libraries Government Documents Department

Interim readiness plan

Description: This report provides rough designs and costs for 3 payloads which can be built on a relatively fast time scale. With these, Lawrence Radiation Laboratory (LRL) could measure neutrons and X-rays from high altitude shots. No measurements of soft X-rays (less than or approximately equal to 5 kev), hard X- rays (greater than or approximately equal to 60 kev), or gamma rays would be made. Plans could be made to fly the Simplex payload as part of the spring Lapwing exercise. Some interim capability exists from other sources which might compliment the above measurements. Sandia has developed a mylar sail sampler which could be used for debris experiments. There is a LASL/Sandia scan converter which could be fielded to make fast time-history measurements of the X-ray or gamma ray pulse. Interval time could be measured with a ground based EMP detector. The LRL cost of this interim rocket program is approximately 5 man years of effort and about $140,000 of major procurement. Sandia would need approximately $450,000 to stockpile payloads. I believe the necessary rockets are already stockpiled but some work on the ranges might be required. For example, more launchers are needed on Johnston Atoll. All this money and effort would be expended in FY- 1970 and these rocket experiments would be ready (`on the shelf` or close) by June 1970.
Date: March 1, 1969
Creator: Seward, F. D.
Partner: UNT Libraries Government Documents Department

Isobutanol-methanol mixtures from synthesis gas. Quarterly report, July 1 - September 30, 1996

Description: A series of CuMgCeO{sub x} catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. The bulk composition of the catalyst has been measured by atomic absorption (AA) analysis and the Cu dispersion has been determined by N{sub 2}O titration at 90 {degrees}C. CeO{sub x} does not contribute to the measured copper dispersion in K-CuO{sub 0.5}Mg{sub 5}CeO{sub x} samples and the high dispersion value indeed reflects the presence of Cu metal small crystallites. Kinetic studies of methanol and propionaldehyde coupling reactions on K-Cu/MgO/CeO{sub 2} and MgO/CeO{sub 2} catalysts indicate that Cu enhances the rates of alcohol dehydrogenation. High-pressure isobutanol synthesis from CO/H{sub 2} has been studied on CuO{sub 0.5}Mg{sub 5}O{sub x} catalysts at 593 K and 4.5 MPa. CuO{sub 0.5}Mg{sub 5}O{sub x} catalysts show high hydrocarbon and low isobutanol selectivities compared to K-CuO{sub 0.5}Mg{sub 5}CeO{sub x}, suggesting the presence of residual acidity in CuO{sub 0.5}Mg{sub 5}O{sub x}.
Date: December 1, 1996
Creator: Iglesia, E.
Partner: UNT Libraries Government Documents Department

Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 January--31 March 1996

Description: A series of CuMgCeO{sub x} catalysts have been prepared. Range of Cu dispersion, determined by N{sub 2}O titration, was 19-48% and are among the highest reported in the literature for Cu-based methanol and higher alcohol synthesis catalysts. Kinetics of MeOH and EtOH coupling reactions on Cu/ZnO and K-Cu/MgO/CeO{sub 2} catalysts indicate that Cu promotes alcohol dehydrogenation. Acetaldehyde is a reactive intermediate. High-pressure isobutanol synthesis studies have been carried out on K- and Cs-promoted Cu/MgO/CeO{sub 2} catalysts. The K promoter is more active than Cs for CO conversion, but the Cs promoter activates the C{sub 1} to C{sub 2} step more effectively. Catalysts with high alkali loading resulted in low conversions. Temperature programmed surface reaction studies of MeOH, EtOH, and acetaldehyde on MgO/CeO{sub 2}-based Cu catalysts show evolution of acetone, crotonaldehyde, methyl ethyl ketone, H2, carbon oxides. Neither EtOH nor acetaldehyde produces propionaldehyde or 1- propanol, suggesting that these C{sub 3} species can only form via reactions involving C{sub 1} and C{sub 2} oxygenate species.
Date: April 20, 1996
Partner: UNT Libraries Government Documents Department

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical progress report No. 2, December 1, 1992--February 28, 1993

Description: The rheological behavior of coal-water slurries made with Pittsburgh No. 8 coal at four solids contents was investigated with the Haake viscometer after conditioning for 16 hours at 200C. The results show that the viscosity of the slurries increases as the solids content is increased. Slurries at high solid-liquid ratios not only exhibit significant yield stresses but also viscosities which decrease with increasing in the shear rate. It was found that the empirical Heschel-Buckley equation fits the measured shear stress of slurries at different shear rates quite well. The standard deviation of the shear stress of coal-water slurries measured with the Haake viscometer was found to be less than 10%. The apparent viscosities measured with the Brookfield Synchro-Lectric LVT viscometer were comparable with values obtained with the Haake Rotovisco RV12 viscometer for slurries having solids contents of 50 and 55 wt%. In studying the effect of conditioning time on the measured viscosity of coal-water slurries (at 60 wt% solids content), it was observed that the viscosity of a slurry increases when the conditioning time is increased from 0.25 to 0.75 hour and then decreases when the conditioning time is increased further. The initial increase in viscosity with conditioning time is probably related to the penetration of water into the pores of the coal, and the decrease in the viscosity at longer conditioning times over 0.75 hour may be due to the development of a hydration layer and the electrical double layer on coal surfaces.
Date: March 1, 1993
Creator: Fuerstenau, D.W.
Partner: UNT Libraries Government Documents Department

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical progress report No. 10, December 1, 1994--February 28, 1995

Description: The research during this quarter was, directed towards: (1) systematic study of preparation of coal fines by high-pressure roll mill grinding and by high-pressure roll mill/ball mill hybrid grinding, (2) investigation of the rheological behavior of slurries prepared with fines produced by these techniques, and (3) study of the effect of coal cleaning on both short term and long term slurry rheology. Results are discussed.
Date: March 1, 1995
Creator: Fuerstenau, D.W.
Partner: UNT Libraries Government Documents Department

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical progress report number 11, March 1--May 31, 1995

Description: The objective of this research is the development of improved technology for the preparation of coal-water slurries that have potential for replacing fuel oil in direct combustion. Detailed investigations of the effect of solids content and chemical additives on the rheology of coal-water slurries, prepared with fines produced by the ball milling of Pittsburgh No. 8 coal, were conducted during the first phase of the research program. These experiments were to provide a baseline against which the rheological behavior of slurries prepared with fines produced by high-pressure roll milling or hybrid high-pressure, roll mill/ball mill grinding could be compared. The viscosity of slurries with high solids content is strongly influenced by the packing density of the feed material. The packing density can be significantly altered by mixing distributions of different median sizes, and to an extent by modifying the grinding environment. The research during this quarter was, therefore, directed towards: (1) establishing the relationship between the packing characteristic of fines and the viscosity of slurries prepared with the fines; (2) investigation of the effect of mixing distribution on the rheology; and (3) study of the effect of grinding environment in the ball mill on the rheology of coal-water slurries.
Date: June 1, 1995
Creator: Fuerstenau, D.W.
Partner: UNT Libraries Government Documents Department

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical progress report No. 12, June 1, 1995--August 31, 1995

Description: The objective of this research is the development of improved technology for the preparation of coal-water slurries that have potential for replacing fuel oil in direct combustion. This should be of major importance to the United States in its efforts to reduce dependence on imported oil and to rely more on its enormous low-cost coal resources. In accordance with this objective, in the first stage of this project, considerable work was conducted to standardize experimental procedures for sample preparation, coal grinding, and Theological measurements to assure reproducibility of the experimental results. Since a Haake RV-12 viscometer with an MV-DIN sensor system was found to give the most reproducible results for measurement of slurry viscosities, it has subsequently been used for all of our Theological measurements. Methods were developed for applying the acoustophoresis technique for studying the electrokinetic behavior of concentrated coal-water suspensions. These measurements were carried out using this technique to identify the potential of chemical additives for functioning as reagents for effective dispersion. Detailed investigations of the effect of solids content and chemical additives on the rheology of coal-water slurries, prepared with fines produced by the ball milling of Pittsburgh No. 8 coal, were conducted during the first phase of our research program. These experiments were to provide a baseline against which the rheological behavior of slurries prepared with fines produced by high-pressure roll milling or hybrid high-pressure roll mill/ball mill grinding could be compared.
Date: September 1, 1995
Creator: Fuerstenau, D.W.
Partner: UNT Libraries Government Documents Department

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical progress report No. 13, September 1, 1995--November 30, 1995

Description: The objective of this research is the development of improved technology of the preparation of coal-water slurries that have potential for replacing fuel oil in direct combustion. Research accomplishments are summarized for: standardization of experimental procedures; investigation of effect of high-pressure roll mill/ball mill grinding on the energetics of fine grinding and the rheology of coal-water slurries prepared with such fines; study of aging behavior of slurries; and ways of improving rheology of slurries. The rheological behavior of slurries is a manifestation of particle-particle and particle-fluid interactions in the slurry. Improvement in the rheology of slurries could be brought about by suitably altering these interactions. The research directed towards investigation of the influence of co-addition of sodium hexametaphosphate and vacuum oil, with CoalMaster as the primary dispersant, showed that co-addition of the reagents significantly improved the rheology of coal-water slurries. Further research conducted in this quarter indicated that co-addition of reagents also improves the long-term rheological behavior of coal-water slurries.
Date: December 1, 1995
Creator: Fuerstenau, D.W.
Partner: UNT Libraries Government Documents Department

Status report on Corsica modeling for current drive scenario development

Description: This milestone report covers the progress and status of Corsica modeling for DIII-D experiments over the past year, since our previous report in September, 1995. During this time, we have concentrated on improvements to the code in support of our ability to do self-consistent, predictive modeling of DIII-D discharges. Our interest is in obtaining a tool, benchmarked with experimental data, for developing advanced tokamak operations scenarios including simulation and analysis of high performance negative central shear (NCS) discharges and control of the current profile evolution. Our major focus has been on installing and improving the neutral beam current drive mode in Corsica; this element is critical to modeling the evolution of DIII-D discharges. The NFREYA neutral beam deposition code was installed (starting with a version consistent with GA`s ONETWO code) and the capability for following particle orbits, including the effects of drifts, was added for determining the current driven by neutral beam -injection. In addition, improved methods for more easily integrating experimental profile measurements into the code operation and for calculating Z{sub eff} either from models or from impurity density measurements have been added. We have recently begun to turn on various transport models in our simulation of discharge evolution. We have concentrated on the NCS configuration and have simulated the evolution of two different high neutron reactivity discharges; an NCS discharge with L-mode edge and a single- null, weak NCS discharge from the JET/ITER/DIII-D equivalent shape experiments. Corsica simulation results for these discharges were presented at the EPS meeting in Kiev, Ukraine in June, 1996.
Date: September 1, 1996
Creator: Casper, T. A.; Crotinger, J.; Moller, J.M. & Pearlstein, L.D.
Partner: UNT Libraries Government Documents Department