Metastability and Delta-Phase Retention in Plutonium Alloys Final Report of LDRD Project 01-ERD-029 (open access)

Metastability and Delta-Phase Retention in Plutonium Alloys Final Report of LDRD Project 01-ERD-029

The {delta} to {alpha}' phase transformation in Pu-Ga alloys is intriguing for both scientific and technological reasons. On cooling, the ductile fcc {delta}-phase transforms martensitically to the brittle monoclinic {alpha}'-phase at approximately -120 C (depending on composition). This exothermic transformation involves a 20% volume contraction and a significant increase in resistivity. The reversion of {alpha}' to {delta} involves a large temperature hysteresis beginning just above room temperature. In an attempt to better understand the underlying thermodynamics and kinetics responsible for these unusual features, we have investigated the {delta} {leftrightarrow} {alpha}' phase transformations in a Pu-0.6 wt% Ga alloy using a combination of experimental and modeling techniques.
Date: February 11, 2004
Creator: Wong, J; Schwartz, A J; Blobaum, K M; Krenn, C R; Wall, M A; Wolfer, W G et al.
Object Type: Report
System: The UNT Digital Library
A Multiplex PCR-coupled Liquid Bead Array for the Simultaneous Detection of Four Biothreat Agents (open access)

A Multiplex PCR-coupled Liquid Bead Array for the Simultaneous Detection of Four Biothreat Agents

We have developed a 10-plexed PCR assay coupled to a 12-plexed liquid bead array to rapidly screen environmental samples for B. anthracis, Y. pestis, F. tularensis, and B. melitensis. Highly validated species -specific primer sets were used to simultaneously amplify multiple diagnostic regions unique to each individual pathogen. Resolution of the mix of amplified products was achieved by PCR product hybridization to corresponding probe sequences, attached to unique sets of fluorescent beads. The hybridized beads were processed through a flow cytometer, which detected presence and quantity of each PCR product. The assay was optimized to allow for maximum sensitivity in a multiplexed format. A high- throughput demonstration was performed where 384 simulated environmental samples were spiked with different amounts of B. thuringensis spores and pathogen DNA. The samples were robotically processed to extract DNA and arrayed for multiplexed PCR-liquid bead detection. The assay correctly identified the presence or absence of each pathogen and collected over 3,000 individual data points within a single 8-hour shift for approximately $1.20 per sample in a 10-plexed assay.
Date: February 4, 2004
Creator: Wilson, W. J.; Erler, A. M.; Nasarabadi, S. L.; Skowronski, E. W. & McCready, P. M.
Object Type: Article
System: The UNT Digital Library
Magnetically responsive microparticles for targeted drug and radionuclide delivery. (open access)

Magnetically responsive microparticles for targeted drug and radionuclide delivery.

We are currently investigating the use of magnetic particles--polymeric-based spheres containing dispersed magnetic nanocrystalline phases--for the precise delivery of drugs via the human vasculature. According to this review, meticulously prepared magnetic drug targeting holds promise as a safe and effective method of delivering drugs to specific organ, tissue or cellular targets. We have critically examined the wide range of approaches in the design and implementation of magnetic-particle-based drug delivery systems to date, including magnetic particle preparation, drug encapsulation, biostability, biocompatibility, toxicity, magnetic field designs, and clinical trials. However, we strongly believe that there are several limitations with past developments that need to be addressed to enable significant strides in the field. First, particle size has to be carefully chosen. Micrometer-sized magnetic particles are better attracted over a distance than nanometer sized magnetic particles by a constant magnetic field gradient, and particle sizes up to 1 {micro}m show a much better accumulation with no apparent side effects in small animal models, since the smallest blood vessels have an inner diameter of 5-7 {micro}m. Nanometer-sized particles <70 nm will accumulate in organ fenestrations despite an effective surface stabilizer. To be suitable for future human applications, our experimental approach synthesizes the magnetic drug …
Date: February 16, 2004
Creator: Kaminski, M. D.; Ghebremeskel, A. N.; Nunez, L.; Kasza, K. E.; Chang, F.; Chien, T. H. et al.
Object Type: Report
System: The UNT Digital Library
Science and Technology Review April 2004 (open access)

Science and Technology Review April 2004

This months issue has the following articles: (1)''Computing Science: One Arrow in the Quiver for Homeland Security''--Commentary by Wayne Shotts; (2) ''On the Front Lines of Biodefense''--The Laboratory's pathogen bioinformatics group is developing ways to rapidly identify microbes that could pose a threat to the nation's citizens, livestock, and crops. (3) ''Defending against Corrosion''--Livermore researchers are designing a rugged system to prevent nuclear wastes from seeping into the environment at the proposed underground repository at Yucca Mountain, Nevada. (4) ''Engine Shows Diesel Efficiency without the Emissions''--Computer models are helping Laboratory engineers better understand the homogeneous compression charge ignition engine, a fuel-efficient engine with reduced emissions.
Date: February 24, 2004
Creator: McMahon, D H
Object Type: Report
System: The UNT Digital Library
Spectroscopic Confirmation of A Radio-Selected Galaxy Overdensity at z = 1.11 (open access)

Spectroscopic Confirmation of A Radio-Selected Galaxy Overdensity at z = 1.11

We report the discovery of a galaxy overdensity at z = 1.11 associated with the z = 1.110 high-redshift radio galaxy MG 0442+0202. The group, CL 0442+0202, was found in a near-infrared survey of z > 1 radio galaxies undertaken to identify spatially-coincident regions with a high density of objects red in I - K' color, typical of z > 1 elliptical galaxies. Spectroscopic observations from the Keck I telescope reveal five galaxies within 35'' of MG 0442+0202 at 1.10 < z < 1.11. These member galaxies have broad-band colors and optical spectra consistent with passively-evolving elliptical galaxies formed at high redshift. Archival ROSAT observations reveal a 3{sigma} detection of soft X-ray emission coincident with CL 0442+0202 at a level five times greater than expected for the radio galaxy. These data are suggestive of a rich galaxy cluster and inspired a 45 ks Chandra X-Ray Observatory observation. As expected, the radio galaxy is unresolved to Chandra, but is responsible for approximately half of the observed X-ray flux. The remaining ROSAT flux is resolved into four point sources within 15'' of the radio galaxy, corresponding to a surface density two orders of magnitude higher than average for X-ray sources at these …
Date: February 26, 2004
Creator: Stanford, S; Stern, D; Holden, B & Spinrad, H
Object Type: Article
System: The UNT Digital Library
Immigration: The Labor Market Effects of a Guest Worker Program for U.S. Farmers (open access)

Immigration: The Labor Market Effects of a Guest Worker Program for U.S. Farmers

This report provides an overview of the labor market effects of a guest worker program for U.S. farmers.
Date: February 20, 2004
Creator: Levine, Linda
Object Type: Report
System: The UNT Digital Library
Immigration: The Labor Market Effects of a Guest Worker Program for U.S. Farmers (open access)

Immigration: The Labor Market Effects of a Guest Worker Program for U.S. Farmers

Temporary alien worker programs are meant to assure employers, including growers, of an adequate supply of labor when and where it is needed without adding permanent residents to the U.S. population. Guest worker programs are not supposed to harm the wage and job opportunities of U.S. workers while they alleviate spot labor shortages. President Bush’s proposal of a broad guest worker program has reignited interest in legislation introduced during the 108th Congress that relates specifically to the agricultural industry.
Date: February 20, 2004
Creator: Levine, Linda
Object Type: Report
System: The UNT Digital Library
Partnering for Success (open access)

Partnering for Success

Partnering for Success features the R & D and industrial energy management best practices and accomplishments of manufacturers who are partnering with DOE.
Date: February 1, 2004
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Measuring the top anti-t Production Cross-Section in the Electron + Jets Channel in Proton - Anti-proton Collisions at s**(1/2) = 1.96-TeV with the D0 Detector at the Tevatron: A Monte Carlo Study (open access)

Measuring the top anti-t Production Cross-Section in the Electron + Jets Channel in Proton - Anti-proton Collisions at s**(1/2) = 1.96-TeV with the D0 Detector at the Tevatron: A Monte Carlo Study

The measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV using the final state with an electron and jets is studied with Monte Carlo event samples. All methods used in the real data analysis to measure efficiencies and to estimate the background contributions are examined. The studies focus on measuring the electron reconstruction efficiencies as well as on improving the electron identification and background suppression. With a generated input cross section of 7 pb the following result is obtained: {sigma}{sub t{bar t}} = (7 {+-} 1.63(stat){sub -1.14}{sup +0.94} (syst)) pb.
Date: February 1, 2004
Creator: Park, Su-Jung
Object Type: Report
System: The UNT Digital Library
Geothermal Money Book [Geothermal Outreach and Project Financing] (open access)

Geothermal Money Book [Geothermal Outreach and Project Financing]

Small business lending is big business and growing. Loans under $1 million totaled $460 billion in June 2001, up $23 billion from 2000. The number of loans under $100,000 continued to grow at a rapid rate, growing by 10.1%. The dollar value of loans under $100,000 increased 4.4%; those of $100,000-$250,000 by 4.1%; and those between $250,000 and $1 million by 6.4%. But getting a loan can be difficult if a business owner does not know how to find small business-friendly lenders, how to best approach them, and the specific criteria they use to evaluate a loan application. This is where the Geothermal Money Book comes in. Once a business and financing plan and financial proposal are written, the Geothermal Money Book takes the next step, helping small geothermal businesses locate and obtain financing. The Geothermal Money Book will: Explain the specific criteria potential financing sources use to evaluate a proposal for debt financing; Describe the Small Business Administration's (SBA) programs to promote lending to small businesses; List specific small-business friendly lenders for small geothermal businesses, including those which participate in SBA programs; Identify federal and state incentives which are relevant to direct use and small-scale (< 1 megawatt) power …
Date: February 1, 2004
Creator: Battocletti, Elizabeth
Object Type: Report
System: The UNT Digital Library
UZ Flow Models and Submodels (open access)

UZ Flow Models and Submodels

The purpose of this Model Report is to document the unsaturated zone (UZ) fluid flow and tracer transport models and submodels as well as the flow fields generated utilizing the UZ Flow and Transport Model of Yucca Mountain (UZ Model), Nevada. This work was planned in ''Technical Work Plan (TWP) for: Performance Assessment Unsaturated Zone'' (BSC 2002 [160819], Section 1.10, Work Package AUZM06). The UZ Model has revised, updated, and enhanced the previous UZ Flow Model REV 00 ICN 01 (BSC 2001 [158726]) by incorporation of the conceptual repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates and their spatial distributions as well as moisture conditions in the UZ system. These 3-D UZ flow fields are used directly by Performance Assessment (PA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic conditions. In addition, this Model Report supports several PA activities, including abstractions, particle-tracking transport simulations, and the …
Date: February 11, 2004
Creator: Dixon, P.
Object Type: Report
System: The UNT Digital Library
Engineered Barrier System: Physical and Chemical Environment Model (open access)

Engineered Barrier System: Physical and Chemical Environment Model

The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are …
Date: February 9, 2004
Creator: Jolley, D. M.; Jarek, R. & Mariner, P.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 29, Number 7, Pages 1269-1474, February 13, 2004 (open access)

Texas Register, Volume 29, Number 7, Pages 1269-1474, February 13, 2004

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: February 13, 2004
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History