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1,349 Matching Results

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(open access)

Correspondence of the Gardner and van Genuchten/Mualem relativepermeability function parameters

The Gardner and van Genuchten models of relativepermeability are widely used in analytical and numerical solutions toflow problems. However, the applicab ility of the Gardner model to realproblems is usually limited, because empirical relative permeability datato calibrate the model are not routinely available. In contrast, vanGenuchten parameters can be estimated using more routinely availablematric potential and saturation data. However, the van Genuchten model isnot amenable to analytical solutions. In this paper, we introducegeneralized conversion formulae that reconcile these two models. Ingeneral, we find that the Gardner parameter alpha G is related to the vanGenuchten parameters alpha vG and n by alpha G=alpha vG ~; 1:3 n. Thisconversion rule will allow direct recasting of Gardner-based analyticalsolutions in the van Genuchten parameter space. The validity of theproposed formulae was tested by comparing the predicted relativepermeability of various porous media with measured values.

Date: January 3, 2007

Creator: Ghezzehei, Teamrat A.; Kneafsey, Timothy J. & Su, Grace W.

Object Type: Article

System: The UNT Digital Library

(open access)

The J-TAC (Stephenville, Tex.), Vol. 178, No. 10, Ed. 1 Thursday, November 1, 2007

Weekly student newspaper from Tarleton State University in Stephenville, Texas that includes local, state and campus news along with advertising.

Date: November 1, 2007

Creator: unknown

Object Type: Newspaper

System: The Portal to Texas History

(open access)

The J-TAC (Stephenville, Tex.), Vol. 173, No. 5, Ed. 1 Thursday, February 22, 2007

Weekly student newspaper from Tarleton State University in Stephenville, Texas that includes local, state and campus news along with advertising.

Date: February 22, 2007

Creator: unknown

Object Type: Newspaper

System: The Portal to Texas History

(open access)

Setup and Performance of the Rhic Injector Accelerators for the 2007 Run With Gold Ions

Gold ions for the 2007 run of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators is reviewed with a focus on improvements in the quality of beam delivered to RHIC. In particular, more uniform stripping foils between Booster and AGS7 and a new bunch merging scheme in AGS have provided beam bunches with reduced longitudinal emittance for RHIC.

Date: June 25, 2007

Creator: Gardner, C.; Ahrens, L.; Alessi, J.; Benjamin, J.; Blaskiewicz, M. & Al., Et

Object Type: Article

System: The UNT Digital Library

(open access)

Uniform Beam Distributions at the Target of the NSRL Beam Transfer Line

Uniform irradiation of biological or material samples with charged particle beams is desired by experimenters because it reduces radiation dose errors. In this paper we present results of uniform beams produced in the NASA SPACE RADIATION LABORATORY (NSRL) at the Brookhaven National Laboratory (BNL) by a method which was developed theoretically and was proven experimentally at BNL. A similar method which requires collimation of the beam, and also lacks the flexibility of the present method to produce beam various beam sizes at the target, was patented in the year 1988. The present method of producing uniform beam distributions on a plane transverse to the direction of the beam, is based on purely magnetic focusing of the beam and requires no collimation of the beam or any other type of beam interaction with materials. It can also generate uniform beam distributions of various sizes. The method is favorably compared with alternative methods of producing uniform beam distributions and can be applied to the whole energy spectrum of the charged particle beams that are delivered by the BNL Booster synchrotron.

Date: June 25, 2007

Creator: Tsoupas, N.; Ahrens, L.; Brown, K. Chiang, I-Hung, Gardner, C. J.; MacKay, W. W.; Pile, P. & Rusek, A.

Object Type: Article

System: The UNT Digital Library

(open access)

Summary Report of Geophysical Logging For The Seismic Boreholes Project at the Hanford Site Waste Treatment Plant.

During the period of June through October 2006, three deep boreholes and one corehole were drilled beneath the site of the Waste Treatment Plant (WTP) at the U.S. Department of Energy (DOE) Hanford Site near Richland, Washington. The boreholes were drilled to provide information on ground-motion attenuation in the basalt and interbedded sediments underlying the WTP site. This report describes the geophysical logging of the deep boreholes that was conducted in support of the Seismic Boreholes Project, defined below. The detailed drilling and geological descriptions of the boreholes and seismic data collected and analysis of that data are reported elsewhere.

Date: February 1, 2007

Creator: Gardner, Martin G. & Price, Randall K.

Object Type: Report

System: The UNT Digital Library

(open access)

Overcoming Depolarizing Resonances in the AGS With Two Helical Partial Snakes

Dual partial snake scheme has provided polarized proton beams with 1.5 x 10{sup 11} intensity and 65% polarization for the Relativistic Heavy Ion Collider (RHIC) spin program. To overcome the residual polarization loss due to horizontal resonances in the Brookhaven Alternating Gradient Synchrotron (AGS), a new string of quadrupoles have been added. The horizontal tune can then be set in the spin tune gap generated by the two partial snakes, such that horizontal resonances can also be avoided. This paper presents the accelerator setup and preliminary results.

Date: June 25, 2007

Creator: Huang, H.; Ahrens, L.; Bai, M.; Brown, K. A.; Gardner, C. J.; Glenn, J. W. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Review of the geological and structural setting near the site of the proposed Transuranic Waste Facility (TRUWF) Technical Area 52 (TA-52), Los Alamos National Laboratory

Because of Los Alamos National Laboratory’s proximal location to active geologic structures, assessment of seismic hazards, including the potential for seismic surface rupture, must occur before construction of any facilities housing nuclear or other hazardous materials. A transuranic waste facility (TRUWF) planned for construction at Technical Area 52 (TA-52) provides the impetus for this report. Although no single seismic hazards field investigation has focused specifically on TA-52, numerous studies at technical areas surrounding TA-52 have shown no significant, laterally continuous faults exhibiting activity in the last 10 ka within 3,000 ft of the proposed facility. A site-specific field study at the footprint of the proposed TRUWF would not yield further high-precision data on possible Holocene faulting at the site because post-Bandelier Tuff sediments are lacking and the shallowest subunit contacts of the Bandelier Tuff are gradational. Given the distal location of the proposed TRUWF to any mapped structures with demonstrable Holocene displacement, surface rupture potential appears minimal at TA-52.

Date: October 1, 2007

Creator: Schultz-Fellenz, Emily S. & Gardner, Jamie N.

Object Type: Report

System: The UNT Digital Library

(open access)

Rest Mass of Fully Stripped Ions in RHIC: Updated Values

N/A

Date: October 1, 2007

Creator: Brown, K. A.; Gardner, C. & Thieberger, P.

Object Type: Report

System: The UNT Digital Library

(open access)

U.S. Circuit and District Court Nominations by President George W. Bush During the 107th-109th Congresses

None

Date: January 23, 2007

Creator: unknown

Object Type: Report

System: The UNT Digital Library

(open access)

Legacies: A History Journal for Dallas and North Central Texas, Volume 19, Number 2, Fall, 2007

Biannual publication "devoted to the rich history of Dallas and North Central Texas" as a way to "examine the many historical legacies--social, ethnic, cultural, political--which have shaped the modern city of Dallas and the region around it." This issue focuses on "Dallas Pioneers."

Date: 2007

Creator: Dallas Heritage Village

Object Type: Journal/Magazine/Newsletter

System: The Portal to Texas History

(open access)

Performance of the RADPHI Detector and Trigger in a High Rate Tagged Photon Beam

We describe the design and operation of a detector system for measuring all-photon decays of mesons photoproduced in a tagged photon beam with energies between 4.3 and 5.4 GeV and a flux of 5×107 tagged photons per second. Photons from meson decays were detected with a lead-glass calorimeter with an energy resolution of 11% at 1 GeV. Various veto and trigger components were also present. Final states with as many as six photons were successfully detected and reconstructed.

Date: January 1, 2007

Creator: Jones, R. T.; Bogue, T.; Evans, B. E.; Kornicer, M.; Dzierba, A. R.; Gardner, R. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

A New Approach for the Permanent Disposal of Long Lived Fission Waste

Nuclear fission can meet humanity's disparate requirements for carbon-free energy throughout this century and for millennia to come - not only for electricity but also as a source of hydrogen for transportation fuels and a heat source for desalination. However, most countries are not pursuing fission as an option for future energy and global climate needs. One paramount reason is diminished public acceptance over concerns of waste disposal. We would also add 'fuel resources' as a major future concern, because fission is not sustainable in the long term with the present 'once-through' fuel that utilizes less than 1% of the mined uranium and consigns its fertile potential to a permanent waste repository. Accordingly, global scale fission will become attainable (i.e., doable) if and when an integrated solution to this overall 'fuel-cycle' problem is realized. It is the back-end of the fuel cycle - i.e., the need for permanent storage of spent fuel and high-level waste - that has become the focus of much of the criticism. In particular, the construction and implementation of permanent waste repositories such as Yucca Mountain is becoming increasingly problematic from a financial and political perspective. The major shortcoming of these conventional repositories is that they …

Date: March 27, 2007

Creator: Perkins, L J

Object Type: Report

System: The UNT Digital Library

(open access)

Isotopic Survey of Lake Davis and the Local Groundwater

In September 2007, California Fish and Game (CAFG) plans to eradicate the northern pike from Lake Davis. As a result of the eradication treatment, local residents have concerns that the treatment might impact the local groundwater quality. To address the concerns of the residents, Lawrence Livermore National Laboratory (LLNL) recommended measuring the naturally occurring stable oxygen isotopes in local groundwater wells, Lake Davis, and the Lake Davis tributaries. The purpose of these measurements is to determine if the source of the local groundwater is either rain/snowmelt, Lake Davis/Big Grizzly Creek water or a mixture of Lake Davis/Big Grizzly Creek and rain/snowmelt. As a result of natural evaporation, Lake Davis and the water flowing into Big Grizzly Creek are naturally enriched in {sup 18}oxygen ({sup 18}O), and if a source of a well's water is Lake Davis or Big Grizzly Creek, the well water will contain a much higher concentration of {sup 18}O. This survey will allow for the identification of groundwater wells whose water source is Lake Davis or Big Grizzly Creek. The results of this survey will be useful in the development of a water-quality monitoring program for the upcoming Lake Davis treatment. LLNL analyzed 167 groundwater wells (Table …

Date: August 21, 2007

Creator: Ridley, M N; Moran, J E & Singleton, M J

Object Type: Report

System: The UNT Digital Library

(open access)

China Spallation Neutron Source Design

The China Spallation Neutron Source (CSNS) is an accelerator-based high-power project currently in preparation under the direction of the Chinese Academy of Sciences (CAS). The complex is based on an H- linear accelerator, a rapid cycling proton synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station, and five initial instruments for spallation neutron applications. The facility will operate at 25 Hz repetition rate with a phase-I beam power of about 120 kW. The major challenge is to build a robust and reliable user's facility with upgrade potential at a fractional of ''world standard'' cost.

Date: January 29, 2007

Creator: Wei, J.

Object Type: Article

System: The UNT Digital Library

(open access)

A Split-Function Lattice for Stochastic Cooling

Lattice for a 3-GeV cooler ring with split functions is presented. The ring consists of two half-rings of different properties: in one half-ring, the phase-slip factor is near-zero; in the other half-ring, the phase-slip factor is large. The near-zero phase slip minimizes the 'bad mixing' between the stochastic-cooling pick-ups and kickers, while the high phase slip maximizes the 'good mixing' between the kickers and the next-turn pick-ups.

Date: September 10, 2007

Creator: Wei, J.

Object Type: Article

System: The UNT Digital Library

(open access)

Archaeological and Biological Analysis of World War II Shipwrecks in the Gulf of Mexico: Artificial Reef Effect in Deep Water

The objective of this research is to find, identify, and study each vessel that was a casualty of German U-boats. The second point of their research is to determine the biological effects of the boats on the environment.

Date: April 2007

Creator: Church, R.; Warren, D.; Cullimore, R.; Johnston, L.; Schroeder, W.; Patterson, W. et al.

Object Type: Report

System: The UNT Digital Library