Domain wall dynamics in a spin-reorientation transition system Au/Co/Au (open access)

Domain wall dynamics in a spin-reorientation transition system Au/Co/Au

We report measurements of domain wall dynamics in an ultrathin Au/Co/Au system that exhibits a spin reorientation phase transition as a function of temperature.The domain walls exhibit cooperative motion throughout the temperature range of 150 - 300 K. The decay times were found to exhibit a maximum at the transition temperature. The slowdown has been explained as due to formation of a double well in the energy landscape by the different competing interactions. Our results show that the complex, slow dynamics can provide a more fundamental understanding of magnetic phase transitions.
Date: May 14, 2009
Creator: Roy, Sujoy; Seu, Keoki; Turner, Joshua J.; Park, Sungkyun; Kevan, Steve & Falco, Charles M.
Object Type: Article
System: The UNT Digital Library
FIFTY-FIVE GALLON DRUM STANDARD STUDY (open access)

FIFTY-FIVE GALLON DRUM STANDARD STUDY

Fifty-five gallon drums are routinely used within the U.S. for the storage and eventual disposal of fissionable materials as Transuranic or low-level waste. To support these operations, criticality safety evaluations are required. A questionnaire was developed and sent to selected Endusers at Hanford, Idaho National Laboratory, Lawrence Livermore National Laboratory, Oak Ridge and the Savannah River Site to solicit current practices. This questionnaire was used to gather information on the kinds of fissionable materials packaged into drums, the models used in performing criticality safety evaluations in support of operations involving these drums, and the limits and controls established for the handling and storage of these drums. The completed questionnaires were reviewed and clarifications solicited through individual communications with each Enduser to obtain more complete and consistent responses. All five sites have similar drum operations involving thousands to tens of thousands of fissionable material waste drums. The primary sources for these drums are legacy (prior operations) and decontamination and decommissioning wastes at all sites except Lawrence Livermore National Laboratory. The results from this survey and our review are discussed in this paper.
Date: May 14, 2009
Creator: RJ, PUIGH
Object Type: Article
System: The UNT Digital Library
FIRST NEUTRINO POINT-SOURCE RESULTS FROM THE 22-STRING ICECUBE DETECTOR (open access)

FIRST NEUTRINO POINT-SOURCE RESULTS FROM THE 22-STRING ICECUBE DETECTOR

We present new results of searches for neutrino point sources in the northern sky, using data recorded in 2007-08 with 22 strings of the IceCube detector (approximately one-fourth of the planned total) and 275.7 days of livetime. The final sample of 5114 neutrino candidate events agrees well with the expected background of atmospheric muon neutrinos and a small component of atmospheric muons. No evidence of a point source is found, with the most significant excess of events in the sky at 2.2 {sigma} after accounting for all trials. The average upper limit over the northern sky for point sources of muon-neutrinos with E{sup -2} spectrum is E{sup 2} {Phi}{sub {nu}{sub {mu}}} < 1.4 x 10{sup -1} TeV cm{sup -2}s{sup -1}, in the energy range from 3 TeV to 3 PeV, improving the previous best average upper limit by the AMANDA-II detector by a factor of two.
Date: May 14, 2009
Creator: Collaboration, IceCube & Klein, Spencer
Object Type: Article
System: The UNT Digital Library
The Open Source Stochastic Building Simulation Tool SLBM and Its Capabilities to Capture Uncertainty of Policymaking in the U.S. Building Sector (open access)

The Open Source Stochastic Building Simulation Tool SLBM and Its Capabilities to Capture Uncertainty of Policymaking in the U.S. Building Sector

The increasing concern about climate change as well as the expected direct environmental economic impacts of global warming will put considerable constraints on the US building sector, which consumes roughly 48percent of the total primary energy, making it the biggest single source of CO2 emissions. It is obvious that the battle against climate change can only be won by considering innovative building approaches and consumer behaviors and bringing new, effective low carbon technologies to the building / consumer market. However, the limited time given to mitigate climate change is unforgiving to misled research and / or policy. This is the reason why Lawrence Berkeley National Lab is working on an open source long range Stochastic Lite Building Module (SLBM) to estimate the impact of different policies and consumer behavior on the market penetration of low carbon building technologies. SLBM is designed to be a fast running, user-friendly model that analysts can readily run and modify in its entirety through a visual interface. The tool is fundamentally an engineering-economic model with technology adoption decisions based on cost and energy performance characteristics of competing technologies. It also incorporates consumer preferences and passive building systems as well as interactions between technologies (such as …
Date: May 14, 2009
Creator: Stadler, Michael; Marnay, Chris; Azevedo, Ines Lima; Komiyama, Ryoichi & Lai, Judy
Object Type: Article
System: The UNT Digital Library
Photoinitiated Processes in Small Hydrides Final Technical Report DE-FG02-04ER15509 (open access)

Photoinitiated Processes in Small Hydrides Final Technical Report DE-FG02-04ER15509

This grant was in effect for a quite long time: 1984-2008. This period saw a broad range of research activities transpire in my group, and these enlisted the participation of many students, postdoctorals, and visitors. The earliest participants have since enjoyed full careers: faculty members here and abroad, government laboratories, successful entrepreneurs, and so on. Some have even retired! Consequently, during the past few months I have repeatedly asked myself: how can a coherent, readable report be prepared that covers so long a period of time and so varied a collection of projects? On the one hand, the work has evolved — a sensible progression of experimental techniques and strategies, as well as a parallel deepening of our theoretical understanding. On the other hand, there is a distinctive¬ness to many of the projects that enables them to be arranged into groups. In the end a compromise was struck. Areas and topics that received the most focused attention are identified. Our main contributions and how they relate to the field of chemical dynamics, in general, are organized according to these groups. Publications are listed but not explained per se, as this would produce a manifestly unreadable document. They are all available …
Date: May 14, 2009
Creator: Wittig, Curt
Object Type: Report
System: The UNT Digital Library
Pulling of 3 mm diameter AlSb rods by micro-pulling down method (open access)

Pulling of 3 mm diameter AlSb rods by micro-pulling down method

We designed and supplied special crucibles for AlSb material. Thermal insulation and limitation of Sb losses were our first work. The protection of the growth environment was also one of our priority to avoid any pollution of the Fibercryst {mu}PD facility. When this work was achieved, the next step was the calibration of the heating power for these new crucibles. Then, it was the definition of single crystal growth conditions that oriented our research. Following our proposal, many growths attempts were performed. We started from Al & Sb pure powder or from LBNL AlSb crystal as expected. We used different crucibles and different seeds.
Date: May 14, 2009
Creator: Bourret-Courchesne, Edith & Perrodin, Didier
Object Type: Report
System: The UNT Digital Library
Transition to ELM-free Improved H-mode by Lithium Deposition on NSTX Graphite Divertor Surfaces (open access)

Transition to ELM-free Improved H-mode by Lithium Deposition on NSTX Graphite Divertor Surfaces

Lithium evaporated onto plasma facing components in the NSTX lower divertor has made dramatic improvements in discharge performance. As lithium accumulated, plasmas previously exhibiting robust Type 1 ELMs gradually transformed into discharges with intermittent ELMs and finally into continuously evolving ELM-free discharges. During this sequence, other discharge parameters changed in a complicated manner. As the ELMs disappeared, energy confinement improved and remarkable changes in edge and scrape-off layer plasma properties were observed. These results demonstrate that active modification of plasma surface interactions can preempt large ELMs.
Date: May 14, 2009
Creator: Mansfield, D. K.; Kugel, H. W.; Maingi, R.; Bell, M. G.; Bell, R.; Kaita, R. et al.
Object Type: Report
System: The UNT Digital Library
Updated Probabilistic and Deterministic Seismic Hazard Analyses for the University of California, Berkeley and Lawrence Berkeley National Laboratory (open access)

Updated Probabilistic and Deterministic Seismic Hazard Analyses for the University of California, Berkeley and Lawrence Berkeley National Laboratory

Probabilistic seismic hazard analyses of ground motion levels having specified frequencies of exceedance (return periods) for UCB campus and LBNL.
Date: May 14, 2009
Creator: Wong, Ivan; Thomas, Patricia & Somerville, Paul
Object Type: Report
System: The UNT Digital Library
2006 Hanford Site Annual Illness and Injury Surveillance Report (open access)

2006 Hanford Site Annual Illness and Injury Surveillance Report

The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: May 14, 2008
Creator: United States. Department of Energy. Office of Health, Safety, and Security.
Object Type: Report
System: The UNT Digital Library
BLACKFEET NATION FIRST STEPS TO RENEWABLE ENERGY – ENERGY ORGANIZATION DEVELOPMENT PROJECT FINAL REPORT (open access)

BLACKFEET NATION FIRST STEPS TO RENEWABLE ENERGY – ENERGY ORGANIZATION DEVELOPMENT PROJECT FINAL REPORT

The Blackfeet Nation Energy Organization Development project, which was funded through the auspices of the Department of Energy First Steps to Renewable Energy Grant, has produced a centralized effort that assists the Blackfeet Tribal Business Council in the proper management, development, and informed decision making ability to negotiate and develop Blackfeet Renewable Energy opportunities, with a special emphasis on wind energy development. In addition, the Blackfeet Nation has been armed with an enhanced ability to examine environmental and legal issues, perform market research, identify additional lands for possible acquisition and development, and examine wind energy projects by other tribes that serve as models. The product of this effort has been that the Blackfeet Nation formerly petitioned the Bureau of Indian Affairs to approve and charter an Indian Reorganization Act, Section 17 Corporation, the Blackfeet Renewable Energy Inc. Please See Attachment.
Date: May 14, 2008
Creator: Lawrence, Jeri
Object Type: Report
System: The UNT Digital Library
Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to eta K gamma (open access)

Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to eta K gamma

The authors present measurements of the CP-violation parameters S and C for the radiative decay B{sup 0} {yields} {eta}K{sub S}{sup 0}{gamma}; for B {yields} {eta}K{gamma} they also measure the branching fractions and for B{sup +} {yields} {eta}K{sup +}{gamma} the time-integrated charge asymmetry {Alpha}{sub ch}. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation. The results are S = -0.18{sub -0.46}{sup +0.49} {+-} 0.12, C = -0.32{sub -0.39}{sup +0.40} {+-} 0.07, {Beta}(B{sup 0} {yields} {eta}K{sup 0}{gamma}) = (7.1{sub -2.0}{sup +2.1} {+-} 0.4) x 10{sup -6}, {Beta}(B{sup +} {yields} {eta}K{sup +}{gamma}) = (7.7 {+-} 1.0 {+-} 0.4) x 10{sup -6}, and {Alpha}{sub ch} = (-9.0{sub -9.8}{sup +10.4} {+-} 1.4) x 10{sup -2}. The first error quoted is statistical and the second systematic.
Date: May 14, 2008
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS USING ARP PRODUCT SIMULANT AND SB4 TANK 40 SLUDGE SLURRY (open access)

DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS USING ARP PRODUCT SIMULANT AND SB4 TANK 40 SLUDGE SLURRY

The radioactive startup of two new SRS processing facilities, the Actinide Removal Process (ARP) and the Modular Caustic-Side-Solvent-Extraction Unit (MCU) will add two new waste streams to the Defense Waste Processing Facility (DWPF). The ARP will remove actinides from the 5.6 M salt solution resulting in a sludge-like product that is roughly half monosodium titanate (MST) insoluble solids and half sludge insoluble solids. The ARP product will be added to the Sludge Receipt and Adjustment Tank (SRAT) at boiling and dewatered prior to pulling a SRAT receipt sample. The cesium rich MCU stream will be added to the SRAT at boiling after both formic and nitric acid have been added and the SRAT contents concentrated to the appropriate endpoint. A concern was raised by an external hydrogen review panel that the actinide loaded MST could act as a catalyst for hydrogen generation (Mar 15, 2007 report, Recommendation 9). Hydrogen generation, and it's potential to form a flammable mixture in the off-gas, under SRAT and Slurry Mix Evaporator (SME) processing conditions has been a concern since the discovery that noble metals catalyze the decomposition of formic acid. Radiolysis of water also generates hydrogen, but the radiolysis rate is orders of magnitude …
Date: May 14, 2008
Creator: Lambert, D; John Pareizs, J; Bradley Pickenheim, B; Cj Bannochie, C; Michael Stone, M; Damon Click, D et al.
Object Type: Report
System: The UNT Digital Library
Electronic structure and conductivity of nanocomposite metal (Au,Ag,Cu,Mo)-containing amorphous carbon films (open access)

Electronic structure and conductivity of nanocomposite metal (Au,Ag,Cu,Mo)-containing amorphous carbon films

In this work, we study the influence of the incorporation of different metals (Me = Au, Ag, Cu, Mo) on the electronic structure of amorphous carbon (a-C:Me) films. The films were produced at room temperature using a novel pulsed dual-cathode arc deposition technique. Compositional analysis was performed with secondary neutral mass spectroscopy whereas X-ray diffraction was used to identify the formation of metal nanoclusters in the carbon matrix. The metal content incorporated in the nanocomposite films induces a drastic increase in the conductivity, in parallel with a decrease in the band gap corrected from Urbach energy. The electronic structure as a function of the Me content has been monitored by x-ray absorption near edge structure (XANES) at the C K-edge. XANES showed that the C host matrix has a dominant graphitic character and that it is not affected significantly by the incorporation of metal impurities, except for the case of Mo, where the modifications in the lineshape spectra indicated the formation of a carbide phase. Subtle modifications of the spectral lineshape are discussed in terms of nanocomposite formation.
Date: May 14, 2008
Creator: Endrino, Jose L.; Horwat, David; Gago, Raul; Andersson, Joakim; Liu, Y. S.; Guo, Jinghua et al.
Object Type: Article
System: The UNT Digital Library

Ethanol Production, Distribution, and Use: Discussions on Key Issues

From production to the environment, presentation discusses issues surrounding ethanol as a transportation fuel.
Date: May 14, 2008
Creator: Harrow, G.
Object Type: Presentation
System: The UNT Digital Library
Final Progress Report: Developing Ethical Practices for Genetics Testing in the Workplace (open access)

Final Progress Report: Developing Ethical Practices for Genetics Testing in the Workplace

Our multidisciplinary research team for this project involved collaboration between the Department of Psychiatry and Behavioral Medicine at the Medical College of Wisconsin (MCW) and the Department of Family and Community Medicine at the University of New Mexico Health Sciences Center (UNM HSC). Our research team in Wisconsin was led by Laura Roberts, M.D., Principal Investigator, and included Scott Helberg, MLS (Project Coordinator), Kate Green Hammond, Ph.D. (Consultant), Krisy Edenharder (Research Coordinator), and Mark Talatzko (Research Assistant). Our New Mexico-based team was led by Teddy Warner, Ph.D., Co-Principal Investigator and UNM Site Principal Investigator, and included Suzanne Roybal (Project Assistant), Darlyn Mabon (Project Assistant), Kate Green Hammond, PhD (Senior Research Scientist on the UNM team from 2004 until January, 2007), and Paulette Christopher (Research Assistant). In addition, computer technical and web support for the web-based survey conducted on a secure server at the University of New Mexico was provided by Kevin Wiley and Kim Hagen of the Systems and Programming Team of the Health Sciences Center Library and Information Center. We stated 3 aims in the grant proposal: (1) To collect web survey reports of the ethical perspectives, concerns, preferences and decision-making related to genetic testing using surveys from employees …
Date: May 14, 2008
Creator: Roberts, Laura & Warner, Teddy
Object Type: Text
System: The UNT Digital Library
IMPLEMENTATION OF THE SEISMIC DESIGN CRITERIA OF DOE-STD-1189-2008 APPENDIX A [FULL PAPER] (open access)

IMPLEMENTATION OF THE SEISMIC DESIGN CRITERIA OF DOE-STD-1189-2008 APPENDIX A [FULL PAPER]

This paper describes the approach taken by two Fluor Hanford projects for implementing of the seismic design criteria from DOE-STD-1189-2008, Appendix A. The existing seismic design criteria and the new seismic design criteria is described, and an assessment of the primary differences provided. The gaps within the new system of seismic design criteria, which necessitate conduct of portions of work to the existing technical standards pending availability of applicable industry standards, is discussed. Two Hanford Site projects currently in the Control Decision (CD)-1 phase of design have developed an approach to implementation of the new criteria. Calculations have been performed to determine the seismic design category for one project, based on information available in early CD-1. The potential effects of DOE-STD-1189-2008, Appendix A seismic design criteria on the process of project alternatives analysis is discussed. Present of this work is expected to benefit others in the DOE Complex that may be implementing DOE-STD-1189-2008.
Date: May 14, 2008
Creator: SK, OMBERG
Object Type: Article
System: The UNT Digital Library
Literature Review of Data on the Incremental Costs to Design and Build Low-Energy Buildings (open access)

Literature Review of Data on the Incremental Costs to Design and Build Low-Energy Buildings

This document summarizes findings from a literature review into the incremental costs associated with low-energy buildings. The goal of this work is to help establish as firm an analytical foundation as possible for the Building Technology Program's cost-effective net-zero energy goal in the year 2025.
Date: May 14, 2008
Creator: Hunt, W. D.
Object Type: Report
System: The UNT Digital Library
A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro (open access)

A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro

Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region (l {element_of} [65{sup o}, 85{sup o}]). For the Cygnus region, the flux is twice the predicted value. This excess can be explained by the presence of active cosmic ray sources accelerating hadrons which interact with the local dense interstellar medium and produce gamma rays through pion decay.
Date: May 14, 2008
Creator: Abdo, A. A.; Allen, B.; Aune, T.; Berley, D.; Blaufuss, E.; Casanova, S. et al.
Object Type: Article
System: The UNT Digital Library
Observation of B+ to b_1+K0 and Search for B-meson Decays to b_10K0 and b_1pi0 (open access)

Observation of B+ to b_1+K0 and Search for B-meson Decays to b_10K0 and b_1pi0

We present the results of searches for decays of B mesons to final states with a b{sub 1} meson and a neutral pion or kaon. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation. The results for the branching fractions are, in units of 10{sup -6}, {Beta}(B{sup +} {yields} b{sub 1}{sup +}K{sup 0}) = 9.6 {+-} 1.7 {+-} 0.9, {Beta}(B{sup 0} {yields} b{sub 1}{sup 0}K{sup 0}) = 5.1 {+-} 1.8 {+-} 0.5 (< 7.8), {Beta}(B{sup +} {yields} b{sub 1}{sup +} {pi}{sup 0}) = 1.8 {+-} 0.9 {+-} 0.2 (<3.3), and {Beta}(B{sup 0} {yields} b{sub 1}{sup 0}{pi}{sup 0}) = 0.4 {+-} 0.8 {+-} 0.2 (<1.9), with the assumption that {Beta}(b{sub 1} {yields} {omega}{pi}) = 1. They also measure the charge asymmetry {Alpha}{sub ch} (B{sup +} {yields} b{sub 1}{sup +}K{sup 0}) = -0.03 {+-} 0.15 {+-} 0.02. The first error quoted is statistical, the second systematic, and the upper limits in parentheses indicate the 90% confidence level.
Date: May 14, 2008
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh (open access)

Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

Several reactions producing odd-Z transactinide compound nuclei were studiedwith the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the LawrenceBerkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via differentnuclear reactions. In doing so, it can be determined if there is a preference in entrancechannel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's"Fusion By Diffusion" model is nearly identical forthe two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs' cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrancechannel in these paired reactions. Charge equilibration immediately prior to fusionleading to a decreased fusion barrier is the likely cause of this phenomenon. In addition …
Date: May 14, 2008
Creator: Nelson, Sarah L & Nelson, Sarah L
Object Type: Thesis or Dissertation
System: The UNT Digital Library
On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies (open access)

On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies

Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of cosmic rays (CRs) with energies >57 EeV that suggests a correlation with the positions of active galactic nuclei (AGN) located within {approx}75 Mpc. However, this analysis does not take into account AGN morphology. A detailed study of the sample of AGN whose positions correlate with the CR events shows that most of them are classified as Seyfert 2 and low-ionization nuclear emission-line region (LINER) galaxies which do not differ from other local AGN of the same types. Therefore, the claimed correlation between the CR events observed by the Pierre Auger Observatory and local active galaxies should be considered as resulting from a chance coincidence, if the production of the highest energy CRs is not episodic in nature, but operates in a single object on long ({ge} Myr) timescales. Additionally, most of the selected sources do not show significant jet activity, and hence--in the framework of the jet paradigm--there are no reasons for expecting them to accelerate CRs up to the highest energies, {approx}10{sup 20} eV, at all. If the extragalactic magnetic fields and the sources of these CRs are coupled with matter, it is …
Date: May 14, 2008
Creator: Moskalenko, Igor V.; Stawarz, Lukasz; Porter, Troy A. & Cheung, Chi C.
Object Type: Article
System: The UNT Digital Library
Planning meeting to form the CMSN Team: Building a unified computational model for the resonant X-ray scattering of strongly correlated materials (open access)

Planning meeting to form the CMSN Team: Building a unified computational model for the resonant X-ray scattering of strongly correlated materials

The planning meeting was held May 21-23 2008 at Argonne National Laboratory (ANL). The purpose of the meeting was to establish a network on building computational model for resonant elastic and inelastic x-ray scattering. This course of action was recommended by program officer Dale Koelling after the initial submission of a proposal for a Computational Materials Science Network to Basic Energy Sciences. The meeting consisted of talks and discussion. At the end of the meeting three subgroups were formed. After the successful formation of the team, a new proposal was written which was funded by BES. Since this was a planning meeting there were no proceedings. The program and titles of talks are given below.
Date: May 14, 2008
Creator: Veenendaal, M. van
Object Type: Text
System: The UNT Digital Library
Plastic deformation in Al (Cu) interconnects stressed by electromigration and studied by synchrotron polychromatic X-ray microdiffraction (open access)

Plastic deformation in Al (Cu) interconnects stressed by electromigration and studied by synchrotron polychromatic X-ray microdiffraction

We report here an in-depth synchrotron radiation based white beam X-ray microdiffraction study of plasticity in individual grains of an Al (Cu) interconnect during the early stage of electromigration. The study shows a rearrangement of the geometrically necessary dislocations (GND) in bamboo typed grains during that stage. We find that about 90percent of the GNDs are oriented so that their line direction is the closest to the current flow direction. In non-bamboo typed grains, the Laue peak positions shift, indicating that the grains rotate. An analysis in terms of force directions has been carried out and is consistent with observed electromigration induced grain rotation and bending.
Date: May 14, 2008
Creator: Source, Advanced Light; UCLA; Chen, Kai; Chen, Kai; Tamura, Nobumichi; Valek, Bryan C. et al.
Object Type: Article
System: The UNT Digital Library
Q1Report for CADWR Project: Desalination Using Carbon NAnotube Membranes (open access)

Q1Report for CADWR Project: Desalination Using Carbon NAnotube Membranes

In this research and development project, LLNL will leverage the process for fabrication of the membranes developed by our internally funded effort (LLNL Laboratory Directed Research and Development). LLNL will then employ chemical manipulations to modify charge at the ends of the nanotubes and make the membranes more selective to either positive or negative ions through a combination of size and charge selectivity. LLNL's goal is to demonstrate ion exclusion while preserving high permeabilities and low energy use. Success of this research and development project may warrant further developments in the fabrication of membranes.
Date: May 14, 2008
Creator: Bakajin, O
Object Type: Report
System: The UNT Digital Library