UNT Libraries Government Documents Department - 4 Matching Results

Search Results

The Fermilab computing farms in 1997

Description: The farms in 1997 went through a variety of changes. First, the farms expansion, begun in 1996, was completed. This boosted the computing capacity to something like 20,000 MIPS (where a MIP is a unit defined by running a program, TINY, on the machine and comparing the machine performance to a VAX 11/780). In SpecInt92, it would probably rate close to 40,000. The use of the farms was not all that large. The fixed target experiments were not generally in full production in 1997, but spent time tuning up code. Other users processed on the farms, but tended to come and go and not saturate the resource. Some of the old farms were retired, saving the lab money on maintenance and saving the farms support staff effort.
Date: February 15, 1998
Creator: Wolbers, S.

Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report

Description: A laser sampling system was attached to a Perkin Elmer Optima 3000 inductively-coupled plasma, atomic emission spectrometer that was already installed and operating in the Chemistry and Geochemistry Department at the Colorado School of Mines. The use of the spectrometer has been highly successful. Graduate students and faculty from at least four different departments across the CSM campus have used the instrument. The final report to NSF is appended to this final report. Appendices are included which summarize several projects utilizing this instrument: acquisition of an inductively-coupled plasma atomic emission spectrometer for the geochemistry program; hydrogen damage susceptibility assessment for high strength steel weldments through advanced hydrogen content analysis, 1996 and 1997 annual reports; and methods for determination of hydrogen distribution in high strength steel welds.
Date: February 15, 1998

Pyrite oxidation in saturated and Unsaturated Porous Media Flow: AComparison of alternative mathematical modeling approaches

Description: Pyrite (FeS{sub 2}) is one of the most common naturally occurring minerals that is present in many subsurface environments. It plays an important role in the genesis of enriched ore deposits through weathering reactions, is the most abundant sulfide mineral in many mine tailings, and is the primary source of acid drainage from mines and waste rock piles. The pyrite oxidation reaction serves as a prototype for oxidative weathering processes with broad significance for geoscientific, engineering, and environmental applications. Mathematical modeling of these processes is extremely challenging because aqueous concentrations of key species vary over an enormous range, oxygen inventory and supply are typically small in comparison to pyrite inventory, and chemical reactions are complex, involving kinetic control and microbial catalysis. We present the mathematical formulation of a general multi-phase advective-diffusive reactive transport model for redox processes. Two alternative implementations were made in the TOUGHREACT and TOUGH2-CHEM simulation codes which use sequential iteration and simultaneous solution, respectively. The simulators are applied to reactive consumption of pyrite in (1) saturated flow of oxidizing water, and (2) saturated-unsaturated flow in which oxygen transport occurs in both aqueous and gas phases. Geochemical evolutions predicted from different process models are compared, and issues of numerical accuracy and efficiency are discussed.
Date: February 15, 1998
Creator: Xu, Tianfu; White, Stephen P. & Pruess, Karsten

Recent results from CDF

Description: We first present recent CDF results on the top quark, covering the measurement of the t{anti t} production cross section and the top quark mass, the observation of hadronic W decays in top events, the measurement of V{sub tb}, the search for flavor changing neutral current decays, and kinematical properties of t{anti t} production. Then we present one topic from CDF exotic physics results, i.e., the search for first-generation leptoquarks, and one topic from CDF B physics results, i.e., the measurement of time-dependent B{sup 0}-{anti B}{sup 0} mixing. Finally we conclude by briefly mentioning the prospects for Run II.
Date: February 15, 1998
Creator: Takikawa, K. & CDF