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Fast ion-driven Bernstein instabilities (open access)

Fast ion-driven Bernstein instabilities

We investigate a new mechanism, the two-energy-stream cyclotron instability, for fast ions (e.g., fusion products) to drive electrostatic waves and to slow down. The instability comes from a relativistic effect, which dominates conventional phase overtaking as the axial phase velocity exceeds the speed of light. Both a single particle model and a dispersion relation are developed in order to illuminate the physics insights and scaling laws. We present numerical results and discuss nonlinear processes. The mechanism is essential for the dynamics of the fast ions in both D-D and D-T devices.
Date: July 20, 1992
Creator: Chen, K. R.
System: The UNT Digital Library
[Medium energy elementary particle physics]. Technical progress report (open access)

[Medium energy elementary particle physics]. Technical progress report

This report describes polarized lepton-nucleus scattering; and muonium research.
Date: July 20, 1992
Creator: unknown
System: The UNT Digital Library
Engineering design and analysis of advanced physical fine coal cleaning technologies. Quarterly technical progress report No. 11, April--June 1992 (open access)

Engineering design and analysis of advanced physical fine coal cleaning technologies. Quarterly technical progress report No. 11, April--June 1992

The changes made to the Coal Cleaning Simulator during this period were mostly aimed at correcting problems found during the flowsheet validations. one modification was made to the washability interpolation. Prior to interpolation, the feed size distribution is preprocessed by a subroutine which resets the size intervals. That subroutine was changed to ensure that standard screen sizes be used for the size intervals, with only the topsize being the actual user specified size limit. This should prevent problems such as the size range being much wider than that provided by the user (previously, this subroutine would add fine size intervals to the input size range, in some cases). Another change made was the modification of the heavy media cyclone water balance algorithm. Because of the internal calculations of both the amount of media and makeup water required, the water balance was not being made correctly in the case where a feed that was too dilute. The report writer for this model was also modified in order to correctly label the material balances reported. Other changes made were the addition of fifteen coals to the Coal Property Databank, and the referencing of utilities in the screen cost models for operating cost …
Date: July 20, 1992
Creator: Gallier, P. W.
System: The UNT Digital Library
Engineering design and analysis of advanced physical fine coal cleaning technologies (open access)

Engineering design and analysis of advanced physical fine coal cleaning technologies

The changes made to the Coal Cleaning Simulator during this period were mostly aimed at correcting problems found during the flowsheet validations. one modification was made to the washability interpolation. Prior to interpolation, the feed size distribution is preprocessed by a subroutine which resets the size intervals. That subroutine was changed to ensure that standard screen sizes be used for the size intervals, with only the topsize being the actual user specified size limit. This should prevent problems such as the size range being much wider than that provided by the user (previously, this subroutine would add fine size intervals to the input size range, in some cases). Another change made was the modification of the heavy media cyclone water balance algorithm. Because of the internal calculations of both the amount of media and makeup water required, the water balance was not being made correctly in the case where a feed that was too dilute. The report writer for this model was also modified in order to correctly label the material balances reported. Other changes made were the addition of fifteen coals to the Coal Property Databank, and the referencing of utilities in the screen cost models for operating cost …
Date: July 20, 1992
Creator: Gallier, P. W.
System: The UNT Digital Library
Fast ion-driven Bernstein instabilities (open access)

Fast ion-driven Bernstein instabilities

We investigate a new mechanism, the two-energy-stream cyclotron instability, for fast ions (e.g., fusion products) to drive electrostatic waves and to slow down. The instability comes from a relativistic effect, which dominates conventional phase overtaking as the axial phase velocity exceeds the speed of light. Both a single particle model and a dispersion relation are developed in order to illuminate the physics insights and scaling laws. We present numerical results and discuss nonlinear processes. The mechanism is essential for the dynamics of the fast ions in both D-D and D-T devices.
Date: July 20, 1992
Creator: Chen, K. R.
System: The UNT Digital Library
Low severity upgrading of F-T waxes with solid superacids. Progress report, March 1, 1992--May 30, 1992 (open access)

Low severity upgrading of F-T waxes with solid superacids. Progress report, March 1, 1992--May 30, 1992

We have previously reported the isomerization and hydrocracking of n-hexadecane and a n-C{sub 32} straight chain paraffin with a Pt/ZrO{sub 2}/SO{sub 4} catalyst at 170{degrees}C and 350 psig of hydrogen. This study has now been extended to the treatment of a Fisher-Tropsch wax with a carbon number range from C{sub 55}-C{sub 62}. The results reported in Table 1 show that the Pt/ZrO{sub 2}/SO{sub 4} catalyst is active for the isomerization and hydrocracking of this substrate. At an 88.6 wt% conversion level, an 86.1% selectivity to isoparaffins was achieved. The products consisted mainly of C{sub 4}-C{sub 9} and C{sub 10}-C{sub 14} fractions, suitable as gasoline and diesel fuels. A feed/catalyst ratio of 6:1 was used; there was no evidence of catalytic deactivation. The melted wax is viscous and there was a decrease in conversion with time, indicating that diffusion might be a limitation for chains of very high molecular weight.
Date: July 20, 1992
Creator: Wender, I. & Tierney, J. W.
System: The UNT Digital Library
(Medium energy elementary particle physics) (open access)

(Medium energy elementary particle physics)

This report describes polarized lepton-nucleus scattering; and muonium research.
Date: July 20, 1992
Creator: unknown
System: The UNT Digital Library
Low severity upgrading of F-T waxes with solid superacids (open access)

Low severity upgrading of F-T waxes with solid superacids

We have previously reported the isomerization and hydrocracking of n-hexadecane and a n-C{sub 32} straight chain paraffin with a Pt/ZrO{sub 2}/SO{sub 4} catalyst at 170{degrees}C and 350 psig of hydrogen. This study has now been extended to the treatment of a Fisher-Tropsch wax with a carbon number range from C{sub 55}-C{sub 62}. The results reported in Table 1 show that the Pt/ZrO{sub 2}/SO{sub 4} catalyst is active for the isomerization and hydrocracking of this substrate. At an 88.6 wt% conversion level, an 86.1% selectivity to isoparaffins was achieved. The products consisted mainly of C{sub 4}-C{sub 9} and C{sub 10}-C{sub 14} fractions, suitable as gasoline and diesel fuels. A feed/catalyst ratio of 6:1 was used; there was no evidence of catalytic deactivation. The melted wax is viscous and there was a decrease in conversion with time, indicating that diffusion might be a limitation for chains of very high molecular weight.
Date: July 20, 1992
Creator: Wender, I. & Tierney, J. W.
System: The UNT Digital Library
Dimerization kinetics and products of. alpha. -substituted o-quinodimethanes derived from benzene and furan (open access)

Dimerization kinetics and products of. alpha. -substituted o-quinodimethanes derived from benzene and furan

Effects of the {alpha}-substitutions on the termini of the reactive diene unit of o-quinodimethanes revealed a non-concerted mechanism for furan-based and benzene-based o-quinodimethane (o-QDM) dimerizations. In section one, the coexistence of the cisoid and transoid transition states in the diradical formation step is evidenced by the stereochemistry of the dimers. In view of the results of the furan-based o-QDM dimerizauons, it is believed that the regioselectivity in the diradical cyclization step is controlled mainly by the interaction between the active sites on the furan moieties in the diradical ring closure step, not by the intemal bond rotations of the carbon chain of the diradical intermediate. In section two, it was found that the trend of the regioselectivity. along the size of the {alpha}-substituents, of benzene-based o-QDM dimerizations is opposite to that of the Diels-Alder reactions. On the basis of the trends, it is suggested that the Diels-Alder reaction mechanism of benzene-based o-QDM's is concerted while the dimerization mechanism of benzene-based o-QDM's is stepwise. Because of their similar activation parameters, it is proposed that the parent o-xylylene and other o-xylylenes dimerize via a similar two step, diradical mechanism.
Date: July 20, 1992
Creator: Leung, Man-kit.
System: The UNT Digital Library
[Letter from Alan Levi, July 20, 1992] (open access)

[Letter from Alan Levi, July 20, 1992]

A letter from Alan Levi regarding the finances of the Texas Human Rights Foundation and the services the finances provide.
Date: July 20, 1992
Creator: Texas Human Rights Foundation, Inc.
System: The Portal to Texas History
Japan-Taiwan Economic Relations: Implications for the U.S. (open access)

Japan-Taiwan Economic Relations: Implications for the U.S.

Taiwan and Japan might seem to be two similar island economies when viewed from this side of the Pacific, but they are strikingly dissimilar. Over the twentieth century, their relationship with one another has shifted from colonial to mutual growth and recognition to the current anomaly of an intense economic interchange accompanied by severed diplomatic ties. Between Taiwan and Japan, the private sector is taking the lead in developing a relationship that is both mutually beneficial and strained.
Date: July 20, 1992
Creator: Nanto, Dick K.
System: The UNT Digital Library
Summary of All Reported Accidents in Rural Areas of Texas for June 1992 (open access)

Summary of All Reported Accidents in Rural Areas of Texas for June 1992

Monthly report providing tabular statistical information about motor vehicle accidents in rural areas of Texas during 1992, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: July 20, 1992
Creator: Texas. Department of Public Safety. Statistical Services.
System: The Portal to Texas History
Summary of All Reported Accidents in Rural Areas of Texas for [the] First Six Months [of] 1992 (open access)

Summary of All Reported Accidents in Rural Areas of Texas for [the] First Six Months [of] 1992

Semiannual report providing tabular statistical information about motor vehicle accidents in rural areas of Texas during 1992, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: July 20, 1992
Creator: Texas. Department of Public Safety. Statistical Services.
System: The Portal to Texas History
Summary of All Reported Accidents in the State of Texas for [the] First Six Months [of] 1992 (open access)

Summary of All Reported Accidents in the State of Texas for [the] First Six Months [of] 1992

Semiannual report providing tabular statistical information about motor vehicle accidents in Texas during 1992, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: July 20, 1992
Creator: Texas. Department of Public Safety. Statistical Services.
System: The Portal to Texas History
Summary of All Reported Accidents in the State of Texas for June 1992 (open access)

Summary of All Reported Accidents in the State of Texas for June 1992

Monthly report providing tabular statistical information about motor vehicle accidents in Texas during 1992, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: July 20, 1992
Creator: Texas. Department of Public Safety. Statistical Services.
System: The Portal to Texas History