Development of improved iron Fischer-Tropsch catalysts (open access)

Development of improved iron Fischer-Tropsch catalysts

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: April 30, 1990
Creator: Bukur, D.B.; Patel, S.A.; Dalai, A.K.; Jayanthi, G. & Ledakowicz, S.
Object Type: Report
System: The UNT Digital Library
A 5-cm dipole for the SSC-DE-1 (open access)

A 5-cm dipole for the SSC-DE-1

A 5cm SSC superconducting dipole that develops 6.6 tesla at 5790 A is proposed. The two layer magnet has 12% more transfer function than the present design as a result of using thin collars and close in'' iron. The thin collars provide precise positioning of the coils; they also provide minimum prestress (perhaps 2000 psi) as aid for magnet assembly. A welded skin around the iron provides the final prestress and shapes and the coil geometry. A prestressed aluminum bar placed between the vertically split iron yokes provides precise control of the gap between yokes halves and is designed to allow gap to close tightly during cooldown so that there is no decrease of prestress. In order to reduce the effect of iron saturation on the field multipoles the iron ID has been optimized to an elliptical shape. The coil inner layer is a 30 strand cable with 1.3:1 cu/sc. The outer layer is a 36 strand cable wit 1.8:1 cu/sc. At the operating field of 6.6 tesla the current density in the copper is 666 A/mm{sup 2} and 760 A/mm{sup 2} in the inner and outer layers respectively. The magnet short sample performance is limited by the inner layer. …
Date: April 30, 1990
Creator: Caspi, S.
Object Type: Report
System: The UNT Digital Library
Hanford Site Waste Management and Environmental Restoration Integration Plan (open access)

Hanford Site Waste Management and Environmental Restoration Integration Plan

The Hanford Site Waste Management and Environmental Restoration Integration Plan'' describes major actions leading to waste disposal and site remediation. The primary purpose of this document is to provide a management tool for use by executives who need to quickly comprehend the waste management and environmental restoration programs. The Waste Management and Environmental Restoration Programs have been divided into missions. Waste Management consists of five missions: double-shell tank (DST) wastes; single-shell tank (SST) wastes (surveillance and interim storage, stabilization, and isolation); encapsulated cesium and strontium; solid wastes; and liquid effluents. Environmental Restoration consists of two missions: past practice units (PPU) (including characterization and assessment of SST wastes) and surplus facilities. For convenience, both aspects of SST wastes are discussed in one place. A general category of supporting activities is also included. 20 refs., 14 figs., 7 tabs.
Date: April 30, 1990
Creator: Merrick, D.L.
Object Type: Report
System: The UNT Digital Library
Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report (open access)

Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report

Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, induced the precipitation of calcium carbonate under controlled conditions. Crusts, the largest features formed, are composed of 5--200{mu}m diameter bundles which are, in turn, composed of numerous individual crystals. The smallest observed features are 0.1--0.4{mu}m spheres and rods which comprise some individual crystals and crystal bundles. Crystal bundles resembling rhombohedra, tetragonal disphenoids, tetragonal dipyramids, and calcite dumbbells appear to be uniquely bacterial in origin, and they have all been observed in recent sediments. Swollen rods, discs, curved dumbbells, and 50--200{mu}m optically continuous crystals resembling brushes may be uniquely bacterial in origin, however, they have not been reported by other laboratories nor observed in natural settings. Presence of any of these forms in recent sediments should be taken as strong evidence for bacterial influence. Spheres and aragonite dumbbells have also been …
Date: April 30, 1990
Creator: Chafetz, H. S.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Argon Spill Trough Bellows - Leak Test (open access)

Argon Spill Trough Bellows - Leak Test

The four argon spill trough bellows were leak tested with helium during the week of March 12, 1990. Three passed without incident, but the fourth was found to have a leak in the weld at one of the ring/clamps. The hole was approximately 1/32-inch in diameter (a likely result of a welding burn through) and located on an inflexible portion of the bellows, the ring/clamp. Frank Juravic, who conducted the tests, suggested using grey structural epoxy to plug the leak. The epoxy is metallic with some inherent flexibility. The epoxy was applied and the bellows retested in the same manner as before. The repair was a success as the bellows proved to be leaktight. The bellows were then put in their original shipping crates and placed in storage at Lab C. Included in this report is the manufacturer's spec sheets on the bellows, a copy of the Quality Control Report form and a sketch of the test setup with an explanation of the procedure. On the bellows data sheet entitled 'Analysis of Stress in Bellows', the analysis output is obtained through a theoretical bellows program that uses quadratic equations to approximate characteristic curves for such data as axial, lateral and …
Date: April 30, 1990
Creator: Jaques, A.
Object Type: Report
System: The UNT Digital Library
Bacterially induced precipitation of CaCO sub 3 : An example from studies of cyanobacterial mats (open access)

Bacterially induced precipitation of CaCO sub 3 : An example from studies of cyanobacterial mats

Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, induced the precipitation of calcium carbonate under controlled conditions. Crusts, the largest features formed, are composed of 5--200{mu}m diameter bundles which are, in turn, composed of numerous individual crystals. The smallest observed features are 0.1--0.4{mu}m spheres and rods which comprise some individual crystals and crystal bundles. Crystal bundles resembling rhombohedra, tetragonal disphenoids, tetragonal dipyramids, and calcite dumbbells appear to be uniquely bacterial in origin, and they have all been observed in recent sediments. Swollen rods, discs, curved dumbbells, and 50--200{mu}m optically continuous crystals resembling brushes may be uniquely bacterial in origin, however, they have not been reported by other laboratories nor observed in natural settings. Presence of any of these forms in recent sediments should be taken as strong evidence for bacterial influence. Spheres and aragonite dumbbells have also been …
Date: April 30, 1990
Creator: Chafetz, H. S.
Object Type: Report
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1990--31 March 1990 (open access)

Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1990--31 March 1990

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: April 30, 1990
Creator: Bukur, D. B.; Patel, S. A.; Dalai, A. K.; Jayanthi, G. & Ledakowicz, S.
Object Type: Report
System: The UNT Digital Library
Develop and Test an Internally Cooled, Cabled Superconductor (ICCS) for Large Scale MHD Magnets (open access)

Develop and Test an Internally Cooled, Cabled Superconductor (ICCS) for Large Scale MHD Magnets

The work conducted under DOE/PETC Contract DE-AC22-84PC70512 has included four principal tasks, (1) development of a Design Requirements Definition for a retrofit MHD magnet system, (2) analysis of an internally cooled, cabled superconductor (ICCS) to use in that design, (3) design of an experiment to test a subscale version of that conductor, which is a NbTi, copper stabilized superconductor, and (4) proof-of-concept testing of the conductor. The program was carried forth through the third task with very successful development and test of a conventional ICCS conductor with 27 multifilamentary copper-superconductor composite strands and a new concept conductor in which, in each triplet, two strands were pure copper and the third strand was a multifilamentary composite. In reviewing the magnet design and the premises for the conductor design it became obvious that, since the principal source of perturbation in MHD magnets derives from slippage between coils, or between turns in a coil, thereby producing frictional heat which must flow through the conductor sheath and the helium to the superconductor strands, an extra barrier might be highly effective in enhancing magnet stability and protection. This concept was developed and a sample conductor manufactured and tested in comparison with an identical conductor lacking …
Date: April 30, 1990
Creator: Marston, P.G.; Hale, J.R. & Dawson, A.M.
Object Type: Report
System: The UNT Digital Library