ADVANCED CERAMIC MATERIALS FOR NEXT-GENERATION NUCLEAR APPLICATIONS (open access)

ADVANCED CERAMIC MATERIALS FOR NEXT-GENERATION NUCLEAR APPLICATIONS

Rising global energy demands coupled with increased environmental concerns point to one solution; they must reduce their dependence on fossil fuels that emit greenhouse gases. As the global community faces the challenge of maintaining sovereign nation security, reducing greenhouse gases, and addressing climate change nuclear power will play a significant and likely growing role. In the US, nuclear energy already provides approximately one-fifth of the electricity used to power factories, offices, homes, and schools with 104 operating nuclear power plants, located at 65 sites in 31 states. Additionally, 19 utilities have applied to the US Nuclear Regulatory Commission (NRC) for construction and operating licenses for 26 new reactors at 17 sites. This planned growth of nuclear power is occurring worldwide and has been termed the 'nuclear renaissance.' As major industrial nations craft their energy future, there are several important factors that must be considered about nuclear energy: (1) it has been proven over the last 40 years to be safe, reliable and affordable (good for Economic Security); (2) its technology and fuel can be domestically produced or obtained from allied nations (good for Energy Security); and (3) it is nearly free of greenhouse gas emissions (good for Environmental Security). Already …
Date: September 29, 2010
Creator: Marra, J.
Object Type: Article
System: The UNT Digital Library
Recovery Act: Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates (open access)

Recovery Act: Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates

III-V photovoltaics have exhibited efficiencies above 40%, but have found only a limited use because of the high cost of single crystal substrates. At the other end of the spectrum, polycrystalline and amorphous thin film solar cells offer the advantage of low-cost fabrication, but have not yielded high efficiencies. Our program is based on single-crystalline-like thin film photovoltaics on polycrystalline substrates using biaxially-textured templates made by Ion Beam-Assisted Deposition (IBAD). MgO templates made by IBAD on flexible metal substrate have been successfully used for epitaxial growth of germanium films. In spite of a 4.5% lattice mismatch, heteroepitaxial growth of Ge was achieved on CeO2 that was grown on IBAD MgO template. Room temperature optical bandgap of the Ge films was identified at 0.67 eV indicating minimal residual strain. Refraction index and extinction coefficient values of the Ge films were found to match well with that measured from a reference Ge single crystal. GaAs has been successfully grown epitaxially on Ge on metal substrate by molecular beam epitaxy. RHEED patterns indicate self annihilation of antiphase boundaries and the growth of a single domain GaAs. The GaAs is found to exhibit strong photoluminescence signal and, an existence of a relatively narrow (FWHM~20 …
Date: November 29, 2010
Creator: Selvamanickam, Venkat & Freundlich, Alex
Object Type: Report
System: The UNT Digital Library
Model Predictive Control of HVAC Systems: Implementation and Testing at the University of California, Merced (open access)

Model Predictive Control of HVAC Systems: Implementation and Testing at the University of California, Merced

A Model Predictive Control algorithm was developed for the UC Merced campus chilled water plant. Model predictive control (MPC) is an advanced control technology that has proven successful in the chemical process industry and other industries. The main goal of the research was to demonstrate the practical and commercial viability of MPC for optimization of building energy systems. The control algorithms were developed and implemented in MATLAB, allowing for rapid development, performance, and robustness assessment. The UC Merced chilled water plant includes three water-cooled chillers and a two million gallon chilled water storage tank. The tank is charged during the night to minimize on-peak electricity consumption and take advantage of the lower ambient wet bulb temperature. The control algorithms determined the optimal chilled water plant operation including chilled water supply (CHWS) temperature set-point, condenser water supply (CWS) temperature set-point and the charging start and stop times to minimize a cost function that includes energy consumption and peak electrical demand over a 3-day prediction horizon. A detailed model of the chilled water plant and simplified models of the buildings served by the plant were developed using the equation-based modeling language Modelica. Steady state models of the chillers, cooling towers and pumps …
Date: June 29, 2010
Creator: Haves, Phillip; Hencey, Brandon; Borrell, Francesco; Elliot, John; Ma, Yudong; Coffey, Brian et al.
Object Type: Report
System: The UNT Digital Library
The transverse momentum dependent distribution functions in the bag model (open access)

The transverse momentum dependent distribution functions in the bag model

Leading and subleading twist transverse momentum dependent parton distribution functions (TMDs) are studied in a quark model framework provided by the bag model. A complete set of relations among different TMDs is derived, and the question is discussed how model-(in)dependent such relations are. A connection of the pretzelosity distribution and quark orbital angular momentum is derived. Numerical results are presented, and applications for phenomenology discussed. In particular, it is shown that in the valence-x region the bag model supports a Gaussian Ansatz for the transverse momentum dependence of TMDs.
Date: January 29, 2010
Creator: Avakian, Harut; Efremov, Anatoly; Schweitzer, Peter & Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Hybrid-K-edge/X-ray Fluorescense Densitometry with Laser-Compton Scattered X-rays (open access)

Hybrid-K-edge/X-ray Fluorescense Densitometry with Laser-Compton Scattered X-rays

The quantitative verification of the accountancy of fissile nuclear materials through independent measurements represents one of the key elements of nuclear materials Safeguards. Elemental probes of materials of interest to non-proliferation are critical to research strategy in order to identify sensitive advanced instrumentation detection technologies. Advanced instrumentation for material detection and accountability are needed for use in fuel cycle facilities for real-time in-process monitoring of separations-partitioning, fuels fabrication as well as for traditional safeguards activities. Radiation-based NDA (non-destructive analysis) techniques can provide some vital information about nuclear materials much more quickly, cheaply and safely than chemical or radio chemical analysis. Hybrid K-edge densitometry (HKED) is currently the most accurate nondestructive inspection technique that provides sensitive quantification of heavy metal contamination. HKED in a technique that exploits both K-edge absorption and X-ray fluorescence (XRF) and allows simultaneously greater elemental specificity and lower detection limits
Date: August 29, 2010
Creator: Fassi, Dr. Khalid Chouffani El
Object Type: Report
System: The UNT Digital Library
Twist-three Fragmentation Function Contribution to the Single Spin Asymmetry in pp Collisions (open access)

Twist-three Fragmentation Function Contribution to the Single Spin Asymmetry in pp Collisions

We study the twist-three fragmentation function contribution to the single transverse spin asymmetries in inclusive hadron production in pp collisions, pp->h+X. In particular, we evaluate the so-called derivative contribution which dominates the spin asymmetry in the forward direction of the polarized proton. With certain parametrizations for the twist-three fragmentation function, we estimate its contribution to the asymmetry of pi0 production at RHIC energy. We find that the contribution is sizable and might be responsible for the big difference between the asymmetries in eta and pi0 productions observed by the STAR collaboration at RHIC.
Date: January 29, 2010
Creator: Kang, Zhong-Bo; Yuan, Feng & Zhou, Jian
Object Type: Article
System: The UNT Digital Library
First Quarter Hanford Seismic Report for Fiscal Year 2010 (open access)

First Quarter Hanford Seismic Report for Fiscal Year 2010

The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. The Hanford Seismic Network recorded 81 local earthquakes during the first quarter of FY 2010. Sixty-five of these earthquakes were detected in the vicinity of Wooded Island, located about eight miles north of Richland just west of the Columbia River. The Wooded Island events recorded this quarter is a continuation of the swarm events observed during fiscal year 2009 and reported in previous quarterly and annual reports (Rohay et al; 2009a, 2009b, 2009c, and 2009d). Most of the events were considered minor (coda-length magnitude [Mc] less than 1.0) with only 1 event in the 2.0-3.0 range; the maximum magnitude event (2.5 Mc) occurred on December 22 at depth 2.1 km. The average depth of the Wooded Island events during the quarter was 1.4 km with a maximum depth estimated at 3.1 km. This placed the Wooded Island events within the Columbia River Basalt Group (CRBG). The low magnitude of the Wooded Island events has made them undetectable to all but local area residents. The Hanford SMA network was triggered several times by …
Date: March 29, 2010
Creator: Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E. & Devary, Joseph L.
Object Type: Report
System: The UNT Digital Library
Sivers and Boer-Mulders functions in Light-Cone Quark Models (open access)

Sivers and Boer-Mulders functions in Light-Cone Quark Models

Results for the naive-time-reversal-odd quark distributions in a light-cone quark model are presented. The final-state interaction effects are generated via single-gluon exchange mechanism. The formalism of light-cone wave functions is used to derive general expressions in terms of overlap of wave-function amplitudes describing the different orbital angular momentum components of the nucleon. In particular, the model predictions show a dominant contribution from S- and P-wave interference in the Sivers function and a significant contribution also from the interference of P and D waves in the Boer-Mulders function. The favourable comparison with existing phenomenological parametrizations motivates further applications to describe azimuthal asymmetries in hadronic reactions.
Date: January 29, 2010
Creator: Pasquini, Barbara & Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Recovery Act: Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates (open access)

Recovery Act: Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates

III-V photovoltaics have exhibited efficiencies above 40%, but have found only a limited use because of the high cost of single crystal substrates. At the other end of the spectrum, polycrystalline and amorphous thin film solar cells offer the advantage of low-cost fabrication, but have not yielded high efficiencies. Our program is based on single-crystalline-like thin film photovoltaics on polycrystalline substrates using biaxially-textured templates made by Ion Beam-Assisted Deposition (IBAD). MgO templates made by IBAD on flexible metal substrate have been successfully used for epitaxial growth of germanium films. In spite of a 4.5% lattice mismatch, heteroepitaxial growth of Ge was achieved on CeO2 that was grown on IBAD MgO template. Room temperature optical bandgap of the Ge films was identified at 0.67 eV indicating minimal residual strain. Refraction index and extinction coefficient values of the Ge films were found to match well with that measured from a reference Ge single crystal. GaAs has been successfully grown epitaxially on Ge on metal substrate by molecular beam epitaxy. RHEED patterns indicate self annihilation of antiphase boundaries and the growth of a single domain GaAs. The GaAs is found to exhibit strong photoluminescence signal and, an existence of a relatively narrow (FWHM~20 …
Date: November 29, 2010
Creator: Selvamanickam, Venkat & Freundlich, Alex
Object Type: Report
System: The UNT Digital Library
Certification of Superconducting Solenoid-Based Focusing Lenses (open access)

Certification of Superconducting Solenoid-Based Focusing Lenses

The first production focusing lens for the HINS beam line at Fermilab has been assembled into a cryostat and tested. A total of 5 devices will be tested before they are installed in the low energy section of the HINS beam line, which uses copper Crossbar-H (CH) style RF cavities. One of the tested CH-section lens assemblies includes a pair of weak orthogonal steering dipoles nested within a strong focusing solenoid, and has six vapor cooled power leads. The other device has only the strong focusing solenoid, and utilizes a single pair of HTS power leads. The production test program is designed to measure the thermal performance of the cryostat, minimum cooling requirements for the HTS leads, quench performance of all superconducting components, and precise determination of the magnetic axis and field angles. Results and future plans for the first production device tests are presented.
Date: July 29, 2010
Creator: DiMarco, E.Joseph; Hemmati, Ali M.; Orris, Darryl F.; Page, Thomas M.; Rabehl, Roger H.; Tartaglia, Michael A. et al.
Object Type: Article
System: The UNT Digital Library
Homologous recombination contributes to the repair of DNA double-strand breaks induced by high-energy iron ions (open access)

Homologous recombination contributes to the repair of DNA double-strand breaks induced by high-energy iron ions

To test the contribution of homologous recombinational repair (HRR) in repairing DNA damaged sites induced by high-energy iron ions, we used: (1) HRR-deficient rodent cells carrying a deletion in the RAD51D gene and (2) syngeneic human cells impaired for HRR by RAD51D or RAD51 knockdown using RNA interference. We show that in response to iron ions, HRR contributes to cell survival in rodent cells, and that HRR-deficiency abrogates RAD51 foci formation. Complementation of the HRR defect by human RAD51D rescues both enhanced cytotoxicity and RAD51 foci formation. For human cells irradiated with iron ions, cell survival is decreased, and, in p53 mutant cells, the levels of mutagenesis are increased when HRR is impaired. Human cells synchronized in S phase exhibit more pronounced resistance to iron ions as compared with cells in G1 phase, and this increase in radioresistance is diminished by RAD51 knockdown. These results implicate a role for RAD51-mediated DNA repair (i.e. HRR) in removing a fraction of clustered lesions induced by charged particle irradiation. Our results are the first to directly show the requirement for an intact HRR pathway in human cells in ensuring DNA repair and cell survival in response to high-energy high LET radiation.
Date: June 29, 2010
Creator: Zafar, Faria; Seidler, Sara B.; Kronenberg, Amy; Schild, David & Wiese, Claudia
Object Type: Report
System: The UNT Digital Library
Plasticity and Failure in Nanocrystalline BCC Metals via Molecular Dynamics Simulation (open access)

Plasticity and Failure in Nanocrystalline BCC Metals via Molecular Dynamics Simulation

Advances in the ability to generate extremely high pressures in dynamic experiments such as at the National Ignition Facility has motivated the need for special materials optimized for those conditions as well as ways to probe the response of these materials as they are deformed. We need to develop a much deeper understanding of the behavior of materials subjected to high pressure, especially the effect of rate at the extremely high rates encountered in those experiments. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum at pressures less than 100 GPa to investigate the processes associated with plastic deformation for strains up to 100%. We focus on 3D polycrystalline systems with typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. …
Date: September 29, 2010
Creator: Rudd, R E
Object Type: Article
System: The UNT Digital Library
Short Wavelength Seeding through Compression for Fee Electron Lasers (open access)

Short Wavelength Seeding through Compression for Fee Electron Lasers

In this paper, we propose a seeding scheme that compresses an initial laser modulation in the longitudinal phase space of an electron beam by using two opposite sign bunch compressors and two opposite sign energy chirpers. This scheme could potentially reduce the initial modulation wavelength by a factor of C and increase the energy modulation amplitude by a factor of C , where Cis the compression factor of the first bunch compressor. Using two lasers as energy chirpers, such a modulation compression scheme can generate kilo-Ampershort wavelength current modulation with significant bunching factor from an initial a few tens Amper current. This compression scheme can also be used togenerate a prebunched single atto-second short wavelength current modulation and prebunched two color, two atto-second modulations.
Date: March 29, 2010
Creator: Qiang, Ji
Object Type: Article
System: The UNT Digital Library
Modelling off Hugoniot Loading Using Ramp Compression in Single Crystal Copper (open access)

Modelling off Hugoniot Loading Using Ramp Compression in Single Crystal Copper

The application of a ramp load to a sample is a method by which the thermodynamic variables of the high pressure state can be controlled. The faster the loading rate, the higher the entropy and higher the temperature. This paper describes moleculer dynamics (MD) simulations with 25 million atoms which investigate ramp loading of single crystal copper. The simulations followed the propagation of a 300ps ramp load to 3Mbar along the [100] direction copper. The simulations were long enough to allow the wave front to steepen into a shock, at which point the simulated copper sample shock melted.
Date: November 29, 2010
Creator: Hawreliak, J.; Remington, B. A.; Lorenzana, H.; Bringa, E. & Wark, J.
Object Type: Report
System: The UNT Digital Library
National Synchrotron Light Source 2010 Activity Report (open access)

National Synchrotron Light Source 2010 Activity Report

This is a very exciting period for photon sciences at Brookhaven National Laboratory. It is also a time of unprecedented growth for the Photon Sciences Directorate, which operates the National Synchrotron Light Source (NSLS) and is constructing NSLS-II, both funded by the Department of Energy's Office of Science. Reflecting the quick pace of our activities, we chose the theme 'Discovery at Light Speed' for the directorate's 2010 annual report, a fiscal year bookended by October 2009 and September 2010. The year began with the news that NSLS users Venki Ramakrishnan of Cambridge University (also a former employee in Brookhaven's biology department) and Thomas A. Steitz of Yale University were sharing the 2009 Nobel Prize in Chemistry with Ada E. Yonath of the Weizmann Institute of Science. Every research project has the potential for accolades. In 2010, NSLS users and staff published close to 900 papers, with about 170 appearing in premiere journals. Those are impressive stats for a facility nearly three decades old, testament to the highly dedicated team keeping NSLS at peak performance and the high quality of its user community. Our NSLS users come from a worldwide community of scientists using photons, or light, to carry out research …
Date: December 29, 2010
Creator: Rowe, M. & Snyder, K. J.
Object Type: Report
System: The UNT Digital Library
Algebraic Multigrid for Linear Systems Obtained by Explicit Element Reduction (open access)

Algebraic Multigrid for Linear Systems Obtained by Explicit Element Reduction

None
Date: June 29, 2010
Creator: Brunner, T. A. & Kolev, T. V.
Object Type: Article
System: The UNT Digital Library
Gamma Spectrum from Neutron Capture on Tungsten Isotopes (open access)

Gamma Spectrum from Neutron Capture on Tungsten Isotopes

An evaluation of thermal neutron capture on the stable tungsten isotopes is presented, with preliminary results for the compound systems 183;184;185;187W. The evaluation procedure compares the g-ray cross-section data collected at the Budapest reactor, with Monte Carlo simulations of g-ray emission following the thermal neutron-capture process. The statistical-decay code DICEBOX was used for the Monte Carlo simulations. The evaluation yields new gamma rays in 185W and the confirmation of spins in 187W, raising the number of levels below which the level schemes are considered complete, thus increasing the number of levels that can be used in neutron data libraries.
Date: April 29, 2010
Creator: Hurst, Aaron; Summers, Neil; Sleaford, Brad; Firestone, Richard B; Belgya, T. & Revay, Z.S.
Object Type: Article
System: The UNT Digital Library
What Caused the Lead burn-out in Spectrometer Magnet 2B (open access)

What Caused the Lead burn-out in Spectrometer Magnet 2B

The spectrometer solenoids are supposed to be the first magnets installed in the MICE Cooling Channel. The results of the test of Spectrometer Magnet 2B are reported in a previous MICE Note. Magnet 2B was tested with all five coils connected in series. The magnet failed because a lead to coil M2 failed before it could be trained to its full design current of 275 A. First, this report describes the condition of the magnet when the lead failure occurred. The lead that failed was between the cold mass feed-through and the heavy lead that connected to coil M2 and the quench protection diodes. It is believed that the lead failed because the minimum propagation zone (MPZ) length was too short. The quench was probably triggered by lead motion in the field external to the magnet center coil. The effect of heat transfer on quench propagation and MPZ length is discussed. The MPZ length is compared for a number of cases that apply to the spectrometer solenoid 2B as built and as it has been repaired. The required heat transfer coefficient for cryogenic stability and the quench propagation velocity along the leads are compared for various parts of the Magnet …
Date: November 29, 2010
Creator: Green, Michael A.
Object Type: Report
System: The UNT Digital Library
Development and Quantification of UV-Visible and Laser Spectroscopic Techniques for Materials Accountability and Process Control (open access)

Development and Quantification of UV-Visible and Laser Spectroscopic Techniques for Materials Accountability and Process Control

Ultraviolet-Visible Spectroscopy (UV-Visible) and Time Resolved Laser Fluorescence Spectroscopy (TRLFS) optical techniques can permit on-line, real-time analysis of the actinide elements in a solvent extraction process. UV-Visible and TRLFS techniques have been used for measuring the speciation and concentration of the actinides under laboratory conditions. These methods are easily adaptable to multiple sampling geometries, such as dip probes, fiber-optic sample cells, and flow-through cell geometries. To fully exploit these techniques for GNEP applications, the fundamental speciation of the target actinides and the resulting influence on 3 spectroscopic properties must be determined. Through this effort detection limits, process conditions, and speciation of key actinide components can be establish and utilized in a range of areas of interest to GNEP, especially in areas related to materials accountability and process control.
Date: December 29, 2010
Creator: Czerwinski, Ken; Weck, Phil & Poineau, Frederic
Object Type: Report
System: The UNT Digital Library
EFFECTS OF RADIATION ON ESTABLISHED FORENSIC EVIDENCE CONTAINMENT METHODS (open access)

EFFECTS OF RADIATION ON ESTABLISHED FORENSIC EVIDENCE CONTAINMENT METHODS

The Federal Bureau of Investigation (FBI) Laboratory is currently exploring needs and protocols for the storage of evidentiary items contaminated with radioactive material. While a large body of knowledge on the behavior of storage polymers in radiation fields exists, this knowledge has not been applied to the field of forensics and maintaining evidentiary integrity. The focus of this research was to evaluate the behavior of several traditional evidentiary containment polymers when exposed to significant alpha, beta, gamma, neutron and mixed radiation sources. Doses were designed to simulate exposures possible during storage of materials. Several products were found to be poorly suited for use in this specific application based on standardized mechanical testing results. Remaining products were determined to warrant further investigation for the storage of radiologically contaminated evidence.
Date: November 29, 2010
Creator: Ferguson, C.; Duff, M.; Clark, E. & Chapman, G.
Object Type: Article
System: The UNT Digital Library
Final Report for DoE Grant DE-FG02-06ER54878, Laboratory Studies of Reconnection in Magnetically Confined Plasmas (open access)

Final Report for DoE Grant DE-FG02-06ER54878, Laboratory Studies of Reconnection in Magnetically Confined Plasmas

The study of the collisionless magnetic reconnection constituted the primary work carried out under this grant. The investigations utilized two magnetic configurations with distinct boundary conditions. Both configurations were based upon the Versatile Toroidal Facility (VTF). The first configuration is characterized by open boundary conditions where the magnetic field lines interface directly with the vacuum vessel walls. The reconnection dynamics for this configuration has been methodically characterized and it has been shown that kinetic effects related to trapped electron trajectories are responsible for the high rates of reconnection observed. This type of reconnection has not been investigated before. Nevertheless, the results are directly relevant to observations by the Wind spacecraft of fast reconnection deep in the Earth magnetotail. The second configuration was developed to be specifically relevant to numerical simulations of magnetic reconnection, allowing the magnetic field-lines to be contained inside the device. The configuration is compatible with the presence of large current sheets in the reconnection region and reconnection is observed in fast powerful bursts. These reconnection events facilitate the first experimental investigations of the physics governing the spontaneous onset of fast reconnection. In this Report we review the general motivation of this work, the experimental set-up, and the …
Date: January 29, 2010
Creator: Egedal-Pedersen, Jan
Object Type: Report
System: The UNT Digital Library
Final Scientific Report (FSR) (open access)

Final Scientific Report (FSR)

The Flambeau River Papers “Manufacturing Conversion for Energy Efficiency” Project has identified the following goals and objectives: 1. A low pressure accumulator tank will be installed to capture low pressure gases for reuse. The estimated cost is $2.1 million with an energy savings of $500,000 annually or enough natural gas savings to heat 590 average Wisconsin homes. 2. Replace the steam turbine and upgrade Paper Machine #3, the largest of Flambeau River Papers machines, at a cost of $6.265 million. The result will save enough natural gas to heat 141 average homes, or about $1.2-million each year. 3. Install a new cyclonic and cell fracturing technology dryer to reduce moisture in both sludge and biomass wastes. The estimated cost of this task is $1.5-million with an annual energy savings of $700,000. It will also eliminate all coal burning at Flambeau River Papers (7,200 tons of coal annually).
Date: November 29, 2010
Creator: Granzin, Bill
Object Type: Report
System: The UNT Digital Library
Standing-wave excited soft x-ray photoemission microscopy: application to Co microdot magnetic arrays (open access)

Standing-wave excited soft x-ray photoemission microscopy: application to Co microdot magnetic arrays

We demonstrate the addition of depth resolution to the usual two-dimensional images in photoelectron emission microscopy (PEEM), with application to a square array of circular magnetic Co microdots. The method is based on excitation with soft x-ray standing-waves generated by Bragg reflection from a multilayer mirror substrate. Standing wave is moved vertically through sample simply by varying the photon energy around the Bragg condition. Depth-resolved PEEM images were obtained for all of the observed elements. Photoemission intensities as functions of photon energy were compared to x-ray optical calculations in order to quantitatively derive the depth-resolved film structure of the sample.
Date: October 29, 2010
Creator: Gray, Alexander; Kronast, Florian; Papp, Christian; Yang, See-Hun; Cramm, Stefan; Krug, Ingo P. et al.
Object Type: Article
System: The UNT Digital Library
Trends in U.S. Venture Capital Investments Related to Energy: 1980 through the Second Quarter of 2010 (open access)

Trends in U.S. Venture Capital Investments Related to Energy: 1980 through the Second Quarter of 2010

This report documents trends in U.S. venture capital investments over the period 1980 through the second quarter of calendar year 2010 (2010Q1+Q2). Particular attention is given to U.S. venture capital investments in the energy/industrial sector over the period 1980-2010Q1+Q2 as well as in the more recently created cross-cutting category of CleanTech over the period 1995-2010Q1+Q2. During the early 1980s, U.S. venture capital investments in the energy/industrial sector accounted for more than 20% of all venture capital investments. However subsequent periods of low energy prices, the deregulation of large aspects of the energy industry, and the emergence of fast growing new industries like computers (both hardware and software), biotechnology and the Internet quickly reduced the priority accorded to energy/industrial investments. To wit, venture capital investments related to the energy/industrial sector accounted for only 1% of the $119 billion dollars invested in 2000 by the U.S. venture capital community. The significant increase in the real price of oil that began in 2003-2004 correlates with renewed interest and increased investment by the venture capital community in energy/industrial investment opportunities. Venture capital investments for 2009 for the energy/industrial sector accounted for $2.1 billion or slightly more than 13% of all venture capital invested that …
Date: July 29, 2010
Creator: Dooley, James J.
Object Type: Report
System: The UNT Digital Library