Arsenic Removal From Gaseous Streams (open access)

Arsenic Removal From Gaseous Streams

Uranium feed materials, depending on the production process, have been found to contain arsenic (As) as a contaminant. Analyses show the As to be present as As pentafluoride (AsF{sub 5}) and/or hexafluoroarsenic acid (HAsF{sub 6}) and enter the enrichment cycle through contaminated hydrogen fluoride (HF). Problems related to corrosion of cylinder valves and plugging of feed lines and valves have been attributed to the As. Techniques to separate AsF{sub 5} from uranium hexafluoride (UF{sub 6}) using sodium fluoride (NaF) as a trapping media were successful and will be discussed. Procedures to significantly reduce (up to 97%) the level of As in HF will also be reported. 5 figs., 9 tabs.
Date: November 22, 1989
Creator: Russell, R. G. & Otey, M. G.
Object Type: Report
System: The UNT Digital Library
Improved methods for computing masses from numerical simulations (open access)

Improved methods for computing masses from numerical simulations

An important advance in the computation of hadron and glueball masses has been the introduction of non-local operators. This talk summarizes the critical signal-to-noise ratio of glueball correlation functions in the continuum limit, and discusses the case of (q{bar q} and qqq) hadrons in the chiral limit. A new strategy for extracting the masses of excited states is outlined and tested. The lessons learned here suggest that gauge-fixed momentum-space operators might be a suitable choice of interpolating operators. 15 refs., 2 tabs.
Date: November 22, 1989
Creator: Kronfeld, A.S.
Object Type: Article
System: The UNT Digital Library
Direct conversion of methane to C sub 2 's and liquid fuels (open access)

Direct conversion of methane to C sub 2 's and liquid fuels

Objectives of the project are to discover and evaluate novel catalytic systems for the conversion of methane or by-product light hydrocarbon gases either indirectly (through intermediate light gases rich in C{sub 2}'s) or directly to liquid hydrocarbon fuels, and to evaluate, from an engineering perspective, different conceptualized schemes. The approach is to carry out catalyst testing on several specific classes of potential catalysts for the conversion of methane selectively to C{sub 2} products. Promoted metal oxide catalysts were tested. Several of these exhibited similar high ethylene to ethane ratios and low carbon dioxide to carbon monoxide ratios observed for the NaCl/{alpha}-alumina catalyst system reported earlier. Research on catalysts containing potentially activated metals began with testing of metal molecular sieves. Silver catalysts were shown to be promising as low temperature catalysts. Perovskites were tested as potential methane coupling catalysts. A layered perovskite (K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}) gave the highest C{sub 2} yield. Work continued on the economic evaluation of a hypothetical process converting methane to ethylene. An engineering model of the methane coupling system has been prepared. 47 refs., 17 figs., 57 tabs.
Date: November 22, 1989
Creator: Warren, B.K. & Campbell, K.D.
Object Type: Report
System: The UNT Digital Library
Response to Congressional inquiry regarding seepage basins at the Savannah River Site (open access)

Response to Congressional inquiry regarding seepage basins at the Savannah River Site

This report has been prepared in response to the request by the House Appropriations Committee to address the permanent isolation and containment/removal of the contaminants associated with the seepage basins at the Savannah River Site (SRS). Many of the activities regarding groundwater monitoring and status referred to in this report will be discussed in detail in a companion report on the Groundwater Monitoring Program at the SRS [(U), WSRC-RP-89-889].
Date: November 22, 1989
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Response to Congressional inquiry regarding seepage basins at the Savannah River Site (open access)

Response to Congressional inquiry regarding seepage basins at the Savannah River Site

This report has been prepared in response to the request by the House Appropriations Committee to address the permanent isolation and containment/removal of the contaminants associated with the seepage basins at the Savannah River Site (SRS). Many of the activities regarding groundwater monitoring and status referred to in this report will be discussed in detail in a companion report on the Groundwater Monitoring Program at the SRS [(U), WSRC-RP-89-889].
Date: November 22, 1989
Creator: unknown
Object Type: Report
System: The UNT Digital Library