5 Matching Results

Search Results

Results: 1 - 5
open access

Optimization of Operating Parameters for Minimum Mechanical Specific Energy in Drilling

Description: Efficiency in drilling is measured by Mechanical Specific Energy (MSE). MSE is the measure of the amount of energy input required to remove a unit volume of rock, expressed in units of energy input divided by volume removed. It can be expressed mathematically in terms of controllable parameters; Weight on Bit, Torque, Rate of Penetration, and RPM. It is well documented that minimizing MSE by optimizing controllable factors results in maximum Rate of Penetration. Current methods for computing MS… more
Date: May 25, 2011
Creator: Hamrick, Todd
Partner: UNT Libraries Government Documents Department
open access

Measurement of the single top production cross section in proton-antiproton collisions at 1.96 TeV

Description: This thesis describes a search for singly produced top quarks via an electroweak vertex in head-on proton-antiproton collisions at a center of mass energy of √s = 1.96 TeV. The analysis uses a total of 2.3 fb<sup>-1</sup> of data collected with the D0 detector at Fermilab, corresponding to two different run periods of the Tevatron collider. Two channels contribute to single top quark production at the Tevatron, the s-channel and the t-channel. In the s-channel, a virtual W boson is produced fro… more
Date: March 25, 2010
Creator: Tanasijczuk, Andres Jorge
Partner: UNT Libraries Government Documents Department
open access

A Comparison of "Total Dust" and Inhalable Personal Sampling for Beryllium Exposure.

Description: In 2009, the American Conference of Governmental Industrial Hygienists (ACGIH) reduced the Beryllium (Be) 8-hr Time Weighted Average Threshold Limit Value (TLV-TWA) from 2.0 {micro}g/m{sup 3} to 0.05 {micro}g/m{sup 3} with an inhalable 'I' designation in accordance with ACGIH's particle size-selective criterion for inhalable mass. Currently, per the Department of Energy (DOE) requirements, the Lawrence Livermore National Laboratory (LLNL) is following the Occupational Health and Safety Administ… more
Date: April 25, 2012
Creator: Carter, C. M.
Partner: UNT Libraries Government Documents Department
open access

Much Ado about Microbunching: Coherent Bunching in High Brightness Electron Beams

Description: The push to provide ever brighter coherent radiation sources has led to the creation of correspondingly bright electron beams. With billions of electrons packed into normalized emittances (phase space) below one micron, collective effects may dominate both the preservation and use of such ultra-bright beams. An important class of collective effects is due to density modulations within the bunch, or microbunching. Microbunching may be deleterious, as in the case of the Microbunching Instability … more
Date: May 25, 2012
Creator: Ratner, Daniel & /SLAC, /Stanford U.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen