Award Nomination Information for Lawrence Livermore National Laboratory SkillSoft Perspectives Conference 2011 (open access)

Award Nomination Information for Lawrence Livermore National Laboratory SkillSoft Perspectives Conference 2011

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Date: April 6, 2011
Creator: Positeri, L A; Molyneaux, B R & Morley, M B
Object Type: Article
System: The UNT Digital Library
Hybrid Organic-Inorganic Composite Solar Cells for Efficient, Low Cost, Photoelectric Energy Conversion (open access)

Hybrid Organic-Inorganic Composite Solar Cells for Efficient, Low Cost, Photoelectric Energy Conversion

Cadmium selenide nanoparticles and nanoclusters were prepared and added to polymer solar cells to improve their photon capture ability. These nanoparticles did exhibit some beneficial effects on the photon conversion efficiencies of selected polymer solar cells. Ternary bulk heterojunction systems based on composites of methyl viologen-doped, CdSe nanoparticles blended with poly (3-hexothiopene) (P3HT) and 6, 6-phenyl C{sub 61}-butyric acid methyl ester (PCBM) were also tested. It was found that the devices with methyl viologen-doped CdSe nanoparticles do produce more photocurrent in a region surrounding the absorption peak of the particles (560 to 660nm) when compared to pristine P3HT:PCBM devices. Gold nanorods were also prepared and tested in some solar cells. These nanorods did produce a very small enhancement in photon absorbance, but the observed increase the photon conversion efficiency was not sufficient to make the effort worthwhile. Our goals were (1) to prepare cadmium sulfide and cadmium selenide clusters and nanoparticles to be tested as photon absorbers to enhance the photon conversion efficiency of polymer solar polymer solar cells and (2) to prepare gold and silver nanorods to be added to polymer solar cells to enhance their photon capture capability. The cadmium sulfide and cadmium selenide nanoparticles and some new …
Date: April 6, 2011
Creator: Adams, Richard D.
Object Type: Report
System: The UNT Digital Library
Hybrid Plasma Reactor/Filter for Transportable Collective Protection Systems (open access)

Hybrid Plasma Reactor/Filter for Transportable Collective Protection Systems

Pacific Northwest National Laboratory (PNNL) has performed an assessment of a Hybrid Plasma/Filter system as an alternative to conventional methods for collective protection. The key premise of the hybrid system is to couple a nonthermal plasma (NTP) reactor with reactive adsorption to provide a broader envelope of protection than can be provided through a single-solution approach. The first step uses highly reactive species (e.g. oxygen radicals, hydroxyl radicals, etc.) created in a nonthermal plasma (NTP) reactor to destroy the majority (~75% - 90%) of an incoming threat. Following the NTP reactor an O3 reactor/filter uses the O3 created in the NTP reactor to further destroy the remaining organic materials. This report summarizes the laboratory development of the Hybrid Plasma Reactor/Filter to protect against a ‘worst-case’ simulant, methyl bromide (CH3Br), and presents a preliminary engineering assessment of the technology to Joint Expeditionary Collective Protection performance specifications for chemical vapor air purification technologies.
Date: April 6, 2011
Creator: Josephson, Gary B.; Tonkyn, Russell G.; Frye, J. G.; Riley, Brian J. & Rappe, Kenneth G.
Object Type: Report
System: The UNT Digital Library
It's Who You Know: Graph Mining Using Recursive Structural Features (open access)

It's Who You Know: Graph Mining Using Recursive Structural Features

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Date: April 6, 2011
Creator: Henderson, K.; Gallagher, B.; Li, L.; Akoglu, L.; Eliassi-Rad, T.; Tong, H. et al.
Object Type: Article
System: The UNT Digital Library
Neutron source capability assessment for cumulative fission yields measurements (open access)

Neutron source capability assessment for cumulative fission yields measurements

A recent analysis of high-quality cumulative fission yields data for Pu-239 published in the peer-reviewed literature showed that the quoted experimental uncertainties do not allow a clear statement on how the fission yields vary as a function of energy. [Prussin2009] To make such a statement requires a set of experiments with well 'controlled' and understood sources of experimental errors to reduce uncertainties as low as possible, ideally in the 1 to 2% range. The Inter Laboratory Working Group (ILWOG) determined that Directed Stockpile Work (DSW) would benefit from an experimental program with the stated goal to reduce the measurement uncertainties significantly in order to make a definitive statement of the relationship of energy dependence to the cumulative fission yields. Following recent discussions between Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), there is a renewed interest in developing a concerted experimental program to measure fission yields in a neutron energy range from thermal energy (0.025 eV) to 14 MeV with an emphasis on discrete energies from 0.5 to 4 MeV. Ideally, fission yields would be measured at single energies, however, in practice there are only 'quasi-monoenergetic' neutrons sources of finite width. This report outlines a capability assessment …
Date: April 6, 2011
Creator: Descalle, M A; Dekin, W & Kenneally, J
Object Type: Report
System: The UNT Digital Library
Optical modeling of Fresnel zoneplate microscopes (open access)

Optical modeling of Fresnel zoneplate microscopes

Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes rou tinely used in the synchrotron community.
Date: April 6, 2011
Creator: Naulleau, Patrick; Mochi, Iacopo & Goldberg, Kenneth A.
Object Type: Article
System: The UNT Digital Library
The Products of the Thermal Decomposition of CH3CHO (open access)

The Products of the Thermal Decomposition of CH3CHO

We have used a heated 2 cm x 1 mm SiC microtubular (mu tubular) reactor to decompose acetaldehyde: CH3CHO + DELTA --> products. Thermal decomposition is followed at pressures of 75 - 150 Torr and at temperatures up to 1700 K, conditions that correspond to residence times of roughly 50 - 100 mu sec in the mu tubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: VUV photoionization mass spectroscopy (PIMS) and infrared (IR) absorption spectroscopy after isolation in a cryogenic matrix. Besides CH3CHO, we have studied three isotopologues, CH3CDO, CD3CHO, and CD3CDO. We have identified the thermal decomposition products CH3(PIMS), CO (IR, PIMS), H (PIMS), H2 (PIMS), CH2CO (IR, PIMS), CH2=CHOH (IR, PIMS), H2O (IR, PIMS), and HC=CH (IR, PIMS). Plausible evidence has been found to support the idea that there are at least three different thermal decomposition pathways for CH3CHO: Radical decomposition: CH3CHO + DELTA --> CH3 + [HCO] --> CH3 + H + CO Elimination: CH3CHO + DELTA --> H2 + CH2=C=O. Isomerization/elimination: CH3CHO + DELTA --> [CH2=CH-OH] --> HC=CH + H2O. Both PIMS and IR spectroscopy show compelling evidence for the participation of vinylidene, CH2=C:, as an intermediate in the decomposition of vinyl …
Date: April 6, 2011
Creator: Vasiliou, AnGayle; Piech, Krzysztof M.; Zhang, Xu; Nimlos, Mark R.; Ahmed, Musahid; Golan, Amir et al.
Object Type: Article
System: The UNT Digital Library
Scaling hypre's multigrid solvers to 100,000 cores (open access)

Scaling hypre's multigrid solvers to 100,000 cores

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Date: April 6, 2011
Creator: Baker, A H; Falgout, R D; Kolev, T V & Yang, U M
Object Type: Article
System: The UNT Digital Library
Surface Currents and Winds at the Delaware Bay Mouth (open access)

Surface Currents and Winds at the Delaware Bay Mouth

Knowledge of the circulation of estuaries and adjacent shelf waters has relied on hydrographic measurements, moorings, and local wind observations usually removed from the region of interest. Although these observations are certainly sufficient to identify major characteristics, they lack both spatial resolution and temporal coverage. High resolution synoptic observations are required to identify important coastal processes at smaller scales. Long observation periods are needed to properly sample low-frequency processes that may also be important. The introduction of high-frequency (HF) radar measurements and regional wind models for coastal studies is changing this situation. Here we analyze synoptic, high-resolution surface winds and currents in the Delaware Bay mouth over an eight-month period (October 2007 through May 2008). The surface currents were measured by two high-frequency radars while the surface winds were extracted from a data-assimilating regional wind model. To illustrate the utility of these monitoring tools we focus on two 45-day periods which previously were shown to present contrasting pictures of the circulation. One, the low-outflow period is from 1 October through 14 November 2007; the other is the high-outflow period from 3 March through 16 April 2008. The large-scale characteristics noted by previous workers are clearly corroborated. Specifically the M2 tide …
Date: April 6, 2011
Creator: Muscarella, P A; Barton, N P; Lipphardt, B L; Veron, D E; Wong, K C & Kirwan, A D
Object Type: Article
System: The UNT Digital Library