Hedberg Research Conference on Fundamental Controls on Flow in Carbonates: Request for Travel Support for Post-Doctoral Fellows (open access)

Hedberg Research Conference on Fundamental Controls on Flow in Carbonates: Request for Travel Support for Post-Doctoral Fellows

Carbonate reservoirs pose a scientific and engineering challenge to geophysical prediction and monitoring of fluid flow in the subsurface. Difficulties in interpreting hydrological, reservoir and other exploration data arise because carbonates are composed of a hierarchy of geological structures, constituents and processes that span a wide spectrum of length and time scales. What makes this problem particularly challenging is that length scales associated with physical structure and processes are often not discrete, but overlap, preventing the definition of discrete elements at one scale to become the building blocks of the next scale. This is particularly true for carbonates where complicated depositional environments, subsequent post-deposition diagenesis and geochemical interactions result in pores that vary in scale from submicron to centimeters to fractures, variation in fabric composition with fossils, minerals and cement, as well as variations in structural features (e.g., oriented inter- and intra layered - interlaced bedding and/or discontinuous rock units). In addition, this complexity is altered by natural and anthropogenic processes such as changes in stress, fluid content, reactive fluid flow, etc. Thus an accurate geophysical assessment of the flow behavior of carbonate reservoirs requires a fundamental understanding of the interplay of textural and structural features subjected to physical processes …
Date: April 28, 2013
Creator: Pyrak-Nolte, Laura J.
Object Type: Report
System: The UNT Digital Library
A Hybrid Forming System: Electrical-Assisted Double Side Incremental Forming (EADSIF) Process for Enhanced Formability and Geometrical Flexibility (open access)

A Hybrid Forming System: Electrical-Assisted Double Side Incremental Forming (EADSIF) Process for Enhanced Formability and Geometrical Flexibility

The objectives of this project are to establish the scientific bases, engineering technologies and energy/emission impact of a novel dieless forming process, Double side Incremental Forming (DSIF), and to explore the effectiveness of its hybrid variation, Electrical-Assisted Double Side Incremental Forming (EADSIF), on increasing the formability of metallic sheets. The scope of this project includes: (1) the analysis of environmental performance of the proposed new process as compared to conventional sheet metal forming processes; (2) the experimental investigation of the process capabilities of DSIF and EADSIF via the self-designed and newly established lab-scale EADSIF equipment; (3) the development of the essential software in executing the new proposed process, i.e., the toolpath generation algorithms; and finally (4) the exploration of the electricity effect on material deformation. The major accomplishments, findings and conclusions obtained through this one and a half years exploratory project are: (1) The first industrial medium-size-scale DSIF machine using two hexapods, capable of handling a sheet area up to 675 mm x 675 mm, was successfully completed at Ford. (2) The lab-scale of the DSIF machine was designed, fabricated and assembled to form a workpiece up to 250 mm x 250 mm. (3) Parts with arbitrary freeform double-curvatures using …
Date: April 28, 2012
Creator: Cao, Jian; Xia, Z. Cedric; Gutowski, Timothy G. & Roth, John
Object Type: Report
System: The UNT Digital Library
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters (open access)

Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters

Integrated energy, environment and economics modeling suggests that worldwide electrical energy use will increase from 2.4 TWe today to ~12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources derived from natural energy flows. Thus nuclear power may be needed to provide ~30%, 3600 GWe, by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century global nuclear proliferation risks are much greater, and more resistant to mitigation. Fusion energy, if successfully demonstrated to be economically competitive, would provide a source of nuclear power with much lower proliferation risks than fission.
Date: April 28, 2011
Creator: Goldston, Robert J.
Object Type: Report
System: The UNT Digital Library
The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants (open access)

The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants

We report the genome sequence of the nonseed vascular plant, Selaginella moellendorffii, and by comparative genomics identify genes that likely played important roles in the early evolution of vascular plants and their subsequent evolution
Date: April 28, 2011
Creator: Grigoriev, Igor V.; Banks, Jo Ann; Nishiyama, Tomoaki; Hasebe, Mitsuyasu; Bowman, John L.; Gribskov, Michael et al.
Object Type: Article
System: The UNT Digital Library
Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88 (open access)

Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome …
Date: April 28, 2011
Creator: Grigoriev, Igor V.; Baker, Scott E.; Andersen, Mikael R.; Salazar, Margarita P.; Schaap, Peter J.; Vondervoot, Peter J.I. van de et al.
Object Type: Article
System: The UNT Digital Library
Determination of the Fe magnetic anisotropies and the CoO frozen spins in epitaxial CoO/Fe/Ag(001) (open access)

Determination of the Fe magnetic anisotropies and the CoO frozen spins in epitaxial CoO/Fe/Ag(001)

CoO/Fe/Ag(001) films were grown epitaxially and studied by X-ray Magnetic Circular Dichroism (XMCD) and X-ray Magnetic Linear Dichroism (XMLD). After field cooling along the Fe[100] axis to 80 K, exchange bias, uniaxial anisotropy, and 4-fold anisotropy of the films were determined by hysteresis loop and XMCD measurements by rotating the Fe magnetization within the film plane. The CoO frozen spins were determined by XMLD measurement as a function of CoO thickness.We find that among the exchange bias, uniaxial anisotropy, and 4-fold anisotropy, only the uniaxial magnetic anisotropy follows thickness dependence of the CoO frozen spins.
Date: April 28, 2011
Creator: Meng, J. Li, Y.; Park, J. S.; Jenkins, C. A.; Arenholz, E.; Scholl, A.; Tan, A. et al.
Object Type: Article
System: The UNT Digital Library
Inertial Confinement Fusion R&D and Nuclear Proliferation (open access)

Inertial Confinement Fusion R&D and Nuclear Proliferation

In a few months, or a few years, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory may achieve fusion gain using 192 powerful lasers to generate x-rays that will compress and heat a small target containing isotopes of hydrogen. This event would mark a major milestone after decades of research on inertial confinement fusion (ICF). It might also mark the beginning of an accelerated global effort to harness fusion energy based on this science and technology. Unlike magnetic confinement fusion (ITER, 2011), in which hot fusion fuel is confined continuously by strong magnetic fields, inertial confinement fusion involves repetitive fusion explosions, taking advantage of some aspects of the science learned from the design and testing of hydrogen bombs. The NIF was built primarily because of the information it would provide on weapons physics, helping the United States to steward its stockpile of nuclear weapons without further underground testing. The U.S. National Academies' National Research Council is now hosting a study to assess the prospects for energy from inertial confinement fusion. While this study has a classified sub-panel on target physics, it has not been charged with examining the potential nuclear proliferation risks associated with ICF R&D. We …
Date: April 28, 2011
Creator: Goldston, Robert J.
Object Type: Report
System: The UNT Digital Library
Ion-beam-driven HEDP experiments at HIFS-VNL (open access)

Ion-beam-driven HEDP experiments at HIFS-VNL

None
Date: April 28, 2011
Creator: Bieniosek, F. M.; Barnard, J. J.; Henestroza, E.; Jung, J. Y.; Leitner, M. A.; Lidia, S. et al.
Object Type: Article
System: The UNT Digital Library
Microarrays for Pathogen Detection and Analysis (open access)

Microarrays for Pathogen Detection and Analysis

None
Date: April 28, 2011
Creator: McLoughlin, K S
Object Type: Article
System: The UNT Digital Library
Novel Approaches to Wide Bandgap CuInSe2 Based Absorbers (open access)

Novel Approaches to Wide Bandgap CuInSe2 Based Absorbers

This project targeted the development of high performance wide bandgap solar cells based on thin film alloys of CuInSe2 to relax constraints on module design and enable tandem solar cell structures. This addressed goals of the Solar Energy Technologies Program for Next Generation PV to develop technology needed for higher thin film module efficiency as a means to reduce costs. Specific objectives of the research project were: 1) to develop the processes and materials required to improve the performance of wide bandgap thin film solar cells based on alloys of CuInSe2, and 2) to provide the fundamental science and engineering basis for the material, electronic, and device properties required to effectively apply these processes and materials to commercial manufacture. CuInSe2-based photovoltaics have established the highest efficiencies of the thin film materials at both the cell and module scales and are actively being scaled up to commercialization. In the highest efficiency cells and modules, the optical bandgap, a function of the CuInSe2-based alloy composition, is relatively low compared to the optimum match to the solar spectrum. Wider bandgap alloys of CuInSe2 produce higher cell voltages which can improve module performance and enable the development of tandem solar cells to boost the …
Date: April 28, 2011
Creator: Shafarman, William N.
Object Type: Report
System: The UNT Digital Library
Simulations of NDCX-II Targets for Warm Dense Matter and Heavy Ion Fusion Physics (open access)

Simulations of NDCX-II Targets for Warm Dense Matter and Heavy Ion Fusion Physics

None
Date: April 28, 2011
Creator: Barnard, J. J.; Friedman, A.; Perkins, L. J.; Bieniosek, F. M.; Hay, M.; Henestroza, E. et al.
Object Type: Article
System: The UNT Digital Library
Task 1 Steam Oxidation (NETL-US) (open access)

Task 1 Steam Oxidation (NETL-US)

Some conclusions are: (1) Increased flow rates can lower chromia activity in alloys with Ti and Mn - (a) Reduced chromia activity reduces equilibrium CrO{sub 2}(OH){sub 2}(g) vapor pressures; (2) Model is very sensitive to small decreases in chromia activity at the HP turbine - (a) Upstream partial saturation of the gas phase with CrO{sub 2}(OH){sub 2}(g) can become nearly or fully saturated at the HP turbine, (b) Can radically change breakaway oxidation times from less than a year to never happening; and (3) Thus even small chromia activity reductions from Ti and Mn additions can make evaporation issues self-correcting.
Date: April 28, 2011
Creator: Holcomb, G. R.; Tylczak, J. & R. Hu,
Object Type: Article
System: The UNT Digital Library
Task 2—Materials for Advanced Boiler and Oxy-combustion Systems (NETL-US) (open access)

Task 2—Materials for Advanced Boiler and Oxy-combustion Systems (NETL-US)

None
Date: April 28, 2011
Creator: Holcomb, G. R. & Tylczak, J.
Object Type: Article
System: The UNT Digital Library
Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan (open access)

Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan

During the period 1980 to 2002, China experienced a 5% average annual reduction in energy consumption per unit of gross domestic product (GDP). The period 2002-2005 saw a dramatic reversal of the historic relationship between energy use and GDP growth: energy use per unit of GDP increased an average of 3.8% per year during this period (NBS, various years). China's 11th Five Year Plan (FYP), which covers the period 2006-2010, required all government divisions at different levels to reduce energy intensity by 20% in five years in order to regain the relationship between energy and GDP growth experienced during the 1980s and 1990s. This report provides an assessment of selected policies and programs that China has instituted in its quest to fulfill the national goal of a 20% reduction in energy intensity by 2010. The report finds that China has made substantial progress toward its goal of achieving 20% energy intensity reduction from 2006 to 2010 and that many of the energy-efficiency programs implemented during the 11th FYP in support of China's 20% energy/GDP reduction goal appear to be on track to meet - or in some cases even exceed - their energy-saving targets. It appears that most of the …
Date: April 28, 2010
Creator: Levine, Mark D.; Price, Lynn; Zhou, Nan; Fridley, David; Aden, Nathaniel; Lu, Hongyou et al.
Object Type: Report
System: The UNT Digital Library
Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler (open access)

Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler

The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________
Date: April 28, 2010
Creator: Qin, Hong; Davidson, Ronald C. & Logan, B. Grant
Object Type: Report
System: The UNT Digital Library
Measurement of the gamma gamma* to eta_c transition form factor (open access)

Measurement of the gamma gamma* to eta_c transition form factor

The authors study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sub c}, {eta}{sub c} {yields} K{sub S}K{sup {+-}}{pi}{sup {-+}} and obtain {eta}{sub c} mass and width values 2982.2 {+-} 0.4 {+-} 1.6 MeV/c{sup 2} and 31.7 {+-} 1.2 {+-} 0.8 MeV, respectively. They find {Lambda}({eta}{sub c} {yields} {gamma}{gamma}){Beta}({eta}{sub c} {yields} K{bar K}{pi}) = 0.374 {+-} 0.009 {+-} 0.031 keV, and measure the {gamma}{gamma}* {yields} {eta}{sub c} transition form factor in the momentum transfer range from 2 to 50 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Date: April 28, 2010
Creator: Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E. et al.
Object Type: Article
System: The UNT Digital Library
Non-diffusive spin dynamics in a two-dimensional electron gas (open access)

Non-diffusive spin dynamics in a two-dimensional electron gas

We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs/GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves in the wavevector range from zero to 6 x 10{sup 4} cm{sup -1}. We find that the spin polarization lifetime is maximal at nonzero wavevector, in contrast with expectation based on ordinary spin diffusion, but in quantitative agreement with recent theories that treat diffusion in the presence of spin-orbit coupling.
Date: April 28, 2010
Creator: Weber, C.P.
Object Type: Article
System: The UNT Digital Library
Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons (open access)

Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic …
Date: April 28, 2010
Creator: Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P. et al.
Object Type: Report
System: The UNT Digital Library
Phytoremediation of ionic and methylmercury pollution (open access)

Phytoremediation of ionic and methylmercury pollution

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and . water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and to aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.
Date: April 28, 2010
Creator: Meagher, Richard B
Object Type: Report
System: The UNT Digital Library
Quantum Detection and Invisibility in Coherent Nanostructures (open access)

Quantum Detection and Invisibility in Coherent Nanostructures

We address quantum invisibility in the context of electronics in nanoscale quantum structures. In analogy with metamaterials, we use the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with respect to inelastic electron scattering spectroscopy in combination with scanning tunneling microscopy, and we propose a design strategy. A simple illustration of the invisibility is given in terms of an elliptic quantum corral containing a molecule, with a local vibrational mode, at one of the foci. Our work has implications to quantum information technology and presents new tools for nonlocal quantum detection and distinguishing between different molecules.
Date: April 28, 2010
Creator: Fransson, J.
Object Type: Article
System: The UNT Digital Library
Quantum Phase Extraction in Isospectral Electronic Nanostructures (open access)

Quantum Phase Extraction in Isospectral Electronic Nanostructures

Quantum phase is not a direct observable and is usually determined by interferometric methods. We present a method to map complete electron wave functions, including internal quantum phase information, from measured single-state probability densities. We harness the mathematical discovery of drum-like manifolds bearing different shapes but identical resonances, and construct quantum isospectral nanostructures possessing matching electronic structure but divergent physical structure. Quantum measurement (scanning tunneling microscopy) of these 'quantum drums' [degenerate two-dimensional electron states on the Cu(111) surface confined by individually positioned CO molecules] reveals that isospectrality provides an extra topological degree of freedom enabling robust quantum state transplantation and phase extraction.
Date: April 28, 2010
Creator: Moon, Christopher
Object Type: Article
System: The UNT Digital Library
Science & Technology Review June 2010 (open access)

Science & Technology Review June 2010

This month's issue has the following articles: (1) A Leader in High-Pressure Science--Commentary by William H. Goldstein; (2) Diamonds Put the Pressure on Materials--New experimental capabilities are helping Livermore scientists better understand how extreme pressure affects a material's structure; (3) Exploring the Unusual Behavior of Granular Materials--Livermore scientists are developing new techniques for predicting the response of granular materials under pressure; (4) A 1-Ton Device in a Briefcase--A new briefcase-sized tool for nuclear magnetic resonance is designed for onsite analysis of suspected chemical weapons; and (5) Targets Designed for Ignition--A series of experiments at the National Ignition Facility is helping scientists finalize the ignition target design.
Date: April 28, 2010
Creator: Blobaum, K. J.
Object Type: Report
System: The UNT Digital Library
Semiconductor Nanowires: What's Next? (open access)

Semiconductor Nanowires: What's Next?

In this perspective, we take a critical look at the research progress within the nanowire community for the past decade. We discuss issues on the discovery of fundamentally new phenomena versus performance benchmarking for many of the nanowire applications. We also notice that both the bottom-up and top-down approaches have played important roles in advancing our fundamental understanding of this new class of nanostructures. Finally we attempt to look into the future and offer our personal opinions on what the future trends will be in nanowire research.
Date: April 28, 2010
Creator: Yang, Peidong; Yan, Ruoxue & Fardy, Melissa
Object Type: Article
System: The UNT Digital Library
Single-Atom Gating of Quantum State Superpositions (open access)

Single-Atom Gating of Quantum State Superpositions

The ultimate miniaturization of electronic devices will likely require local and coherent control of single electronic wavefunctions. Wavefunctions exist within both physical real space and an abstract state space with a simple geometric interpretation: this state space - or Hilbert space - is spanned by mutually orthogonal state vectors corresponding to the quantized degrees of freedom of the real-space system. Measurement of superpositions is akin to accessing the direction of a vector in Hilbert space, determining an angle of rotation equivalent to quantum phase. Here we show that an individual atom inside a designed quantum corral1 can control this angle, producing arbitrary coherent superpositions of spatial quantum states. Using scanning tunnelling microscopy and nanostructures assembled atom-by-atom we demonstrate how single spins and quantum mirages can be harnessed to image the superposition of two electronic states. We also present a straightforward method to determine the atom path enacting phase rotations between any desired state vectors. A single atom thus becomes a real-space handle for an abstract Hilbert space, providing a simple technique for coherent quantum state manipulation at the spatial limit of condensed matter.
Date: April 28, 2010
Creator: Moon, Christopher
Object Type: Article
System: The UNT Digital Library