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2011 RENEWABLE ENERGY: SOLAR FUELS GORDON RESEARCH CONFERENCE (open access)

2011 RENEWABLE ENERGY: SOLAR FUELS GORDON RESEARCH CONFERENCE

The conference will present and discuss current science that underlies solar fuels production, and will focus on direct production pathways for production. Thus, recent advances in design and understanding of molecular systems and materials for light capture and conversion of relevance for solar fuels will be discussed. An important set of topics will be homogeneous, heterogeneous and biological catalysts for the multi-electron processes of water oxidation, hydrogen production and carbon dioxide reduction to useful fuels. Also, progress towards integrated and scalable systems will be presented. Attached is a copy of the formal schedule and speaker program and the poster program.
Date: January 21, 2011
Creator: Hupp, Joseph
System: The UNT Digital Library
Distinguishing Realistic Military Blasts from Firecrackers in Mitigation Studies of Blast Induced Traumatic Brain Injury (open access)

Distinguishing Realistic Military Blasts from Firecrackers in Mitigation Studies of Blast Induced Traumatic Brain Injury

In their Contributed Article, Nyein et al. (1,2) present numerical simulations of blast waves interacting with a helmeted head and conclude that a face shield may significantly mitigate blast induced traumatic brain injury (TBI). A face shield may indeed be important for future military helmets, but the authors derive their conclusions from a much smaller explosion than typically experienced on the battlefield. The blast from the 3.16 gm TNT charge of (1) has the following approximate peak overpressures, positive phase durations, and incident impulses (3): 10 atm, 0.25 ms, and 3.9 psi-ms at the front of the head (14 cm from charge), and 1.4 atm, 0.32 ms, and 1.7 psi-ms at the back of a typical 20 cm head (34 cm from charge). The peak pressure of the wave decreases by a factor of 7 as it traverses the head. The blast conditions are at the threshold for injury at the front of the head, but well below threshold at the back of the head (4). The blast traverses the head in 0.3 ms, roughly equal to the positive phase duration of the blast. Therefore, when the blast reaches the back of the head, near ambient conditions exist at the …
Date: January 21, 2011
Creator: Moss, W C; King, M J & Blackman, E G
System: The UNT Digital Library
Mapping Diffuse Seismicity Using Empirical Matched Field Processing Techniques (open access)

Mapping Diffuse Seismicity Using Empirical Matched Field Processing Techniques

The objective of this project is to detect and locate more microearthquakes using the empirical matched field processing (MFP) method than can be detected using only conventional earthquake detection techniques. We propose that empirical MFP can complement existing catalogs and techniques. We test our method on continuous seismic data collected at the Salton Sea Geothermal Field during November 2009 and January 2010. In the Southern California Earthquake Data Center (SCEDC) earthquake catalog, 619 events were identified in our study area during this time frame and our MFP technique identified 1094 events. Therefore, we believe that the empirical MFP method combined with conventional methods significantly improves the network detection ability in an efficient matter.
Date: January 21, 2011
Creator: Wang, J; Templeton, D C & Harris, D B
System: The UNT Digital Library
Programmable Beam Spatial Shaping System for the National Ignition Facility (open access)

Programmable Beam Spatial Shaping System for the National Ignition Facility

A system of customized spatial light modulators has been installed onto the front end of the laser system at the National Ignition Facility (NIF). The devices are capable of shaping the beam profile at a low-fluence relay plane upstream of the amplifier chain. Their primary function is to introduce 'blocker' obscurations at programmed locations within the beam profile. These obscurations are positioned to shadow small, isolated flaws on downstream optical components that might otherwise limit the system operating energy. The modulators were designed to enable a drop-in retrofit of each of the 48 existing Pre Amplifier Modules (PAMs) without compromising their original performance specifications. This was accomplished by use of transmissive Optically Addressable Light Valves (OALV) based on a Bismuth Silicon Oxide photoconductive layer in series with a twisted nematic liquid crystal (LC) layer. These Programmable Spatial Shaper packages in combination with a flaw inspection system and optic registration strategy have provided a robust approach for extending the operational lifetime of high fluence laser optics on NIF.
Date: January 21, 2011
Creator: Heebner, J.; Borden, M.; Miller, P.; Hunter, S.; Christensen, K.; Scanlan, M. et al.
System: The UNT Digital Library
Simulating the Daylight Performance of Complex Fenestration Systems Using Bidirectional Scattering Distribution Functions within Radiance (open access)

Simulating the Daylight Performance of Complex Fenestration Systems Using Bidirectional Scattering Distribution Functions within Radiance

We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies of glazing, shading, and other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual performance evaluations of CFS, and b) accurate renderings of CFS despite the loss of spatial resolution associated with low-resolution BSDF datasets for inhomogeneous systems. Validation, accuracy, and limitations of the methods are discussed.
Date: January 21, 2011
Creator: Ward, Gregory; Mistrick, Ph.D., Richard; Lee, Eleanor; McNeil, Andrew & Jonsson, Ph.D., Jacob
System: The UNT Digital Library
TRITIUM IN-BED ACCOUNTABILITY FOR A PASSIVELY COOLED, ELECTRICALLY HEATED HYDRIDE BED (open access)

TRITIUM IN-BED ACCOUNTABILITY FOR A PASSIVELY COOLED, ELECTRICALLY HEATED HYDRIDE BED

A PAssively Cooled, Electrically heated hydride (PACE) Bed has been deployed into tritium service in the Savannah River Site (SRS) Tritium Facilities. The bed design, absorption and desorption performance, and cold (non-radioactive) in-bed accountability (IBA) results have been reported previously. Six PACE Beds were fitted with instrumentation to perform the steady-state, flowing gas calorimetric inventory method. An IBA inventory calibration curve, flowing gas temperature rise ({Delta}T) versus simulated or actual tritium loading, was generated for each bed. Results for non-radioactive ('cold') tests using the internal electric heaters and tritium calibration results are presented. Changes in vacuum jacket pressure significantly impact measured IBA {Delta}T values. Higher jacket pressures produce lower IBA {Delta}T values which underestimate bed tritium inventories. The exhaust pressure of the IBA gas flow through the bed's U-tube has little influence on measured IBA {Delta}T values, but larger gas flows reduce the time to reach steady-state conditions and produce smaller tritium measurement uncertainties.
Date: January 21, 2011
Creator: Klein, J. & Foster, P.
System: The UNT Digital Library
Absorber height effects on SWA restrictions and 'Shadow' LER (open access)

Absorber height effects on SWA restrictions and 'Shadow' LER

As extreme-ultraviolet lithography (EUVL) approaches introduction at the 22-nm half-pitch node, several key aspects of absorber height effects remain unexplored. In particular, sidewall angle (SWA) restrictions based on the height of the mask absorber has not yet been clearly defined. In addition, the effects of absorber height on line-edge roughness (LER) from shadowing has not been examined. We make an initial investigation into how tight SWA constraints are and the extent to which shadow LER alters basic LER. Our approach to SWA aims to find SWA restrictions based on 10% of the total CD error budget (10% of CD). Thus, we allot the SWA budget a {+-}0.2nm tolerance for 22nm half-pitch. New with EUVL is the off-axis illumination system. One potential pitfall that must be carefully monitored is the effect of mask absorber height blocking light from reaching, and therefore, correctly detecting, the base edge position of a feature. While mask features can correctly compensate sizing to target at the wafer, the effects of this shadowing on LER have not yet been investigated. Specifically, shadow LER may exacerbate or mitigate the inherent LER on the mask. Shadowing may also cause a difference in the observed LER on the right and …
Date: February 21, 2011
Creator: McClinton, Brittany & Naulleau, Patrick
System: The UNT Digital Library
LER control and mitigation: mask roughness induced LER (open access)

LER control and mitigation: mask roughness induced LER

In the push towards commercialization of extreme-ultraviolet lithography (EUVL), meeting the stringent requirements for line-edge roughness (LER) is increasingly challenging. For the 22-nm half-pitch node and below, the ITRS requires under 1.2 nm LER. Much of this LER is thought to arise from three significant contributors: LER on the mask absorber pattern, LER from the resist, and LER from mask roughness induced speckle. The physical mechanism behind the last contributor is becoming clearer, but how it is affected by the presence of aberrations is less well understood. Here, we conduct a full 2D aerial image simulation analysis of aberrations sensitivities of mask roughness induced LER for the first 37 fringe zernikes. These results serve as a guideline for future LER aberrations control. In examining how to mitigate mask roughness induced LER, we next consider an alternate illumination scheme whereby a traditional dipole's angular spectrum is extended in the direction parallel to the line-and-space mask absorber pattern to represent a 'strip'. While this illumination surprisingly provides merely minimal improvement to the LER as several alternate illumination schemes, overall imaging quality in terms of ILS, NILS, and contrast is improved. While the 22-nm half-pitch node can tolerate significant aberrations from a mask …
Date: February 21, 2011
Creator: McClinton, Brittany & Naulleau, Patrick
System: The UNT Digital Library
Phase Preference by Active, Acetate-Utilizing Bacteria at the Rifle, CO Integrated Field Research Challenge Site (open access)

Phase Preference by Active, Acetate-Utilizing Bacteria at the Rifle, CO Integrated Field Research Challenge Site

Previous experiments at the Rifle, Colorado Integrated Field Research Challenge (IFRC) site demonstrated that field-scale addition of acetate to groundwater reduced the ambient soluble uranium concentration. In this report, sediment samples collected before and after acetate field addition were used to assess the active microbes via {sup 13}C acetate stable isotope probing on 3 phases [coarse sand, fines (8-approximately 150 {micro}m), groundwater (0.2-8 {micro}m)] over a 24-day time frame. TRFLP results generally indicated a stronger signal in {sup 13}C-DNA in the 'fines' fraction compared to the sand and groundwater. Before the field-scale acetate addition, a Geobacter-like group primarily synthesized {sup 13}C-DNA in the groundwater phase, an alpha Proteobacterium primarily grew on the fines/sands, and an Acinetobacter sp. and Decholoromonas-like OTU utilized much of the {sup 13}C acetate in both groundwater and particle-associated phases. At the termination of the field-scale acetate addition, the Geobacter-like species was active on the solid phases rather than the groundwater, while the other bacterial groups had very reduced newly synthesized DNA signal. These findings will help to delineate the acetate utilization patterns of bacteria in the field and can lead to improved methods for stimulating distinct microbial populations in situ.
Date: February 21, 2011
Creator: Kerkhof, L.; Williams, K.H.; Long, P.E. & McGuinness, L.
System: The UNT Digital Library
Quantitative evaluation of mask phase defects from through-focus EUV aerial images (open access)

Quantitative evaluation of mask phase defects from through-focus EUV aerial images

Mask defects inspection and imaging is one of the most important issues for any pattern transfer lithography technology. This is especially true for EUV lithography where the wavelength-specific properties of masks and defects necessitate actinic inspection for a faithful prediction of defect printability and repair performance. In this paper we will present a technique to obtain a quantitative characterization of mask phase defects from EUV aerial images. We apply this technique to measure the aerial image phase of native defects on a blank mask, measured with the SEMATECH Berkeley Actinic Inspection Tool (AIT) an EUV zoneplate microscope that operates at Lawrence Berkeley National Laboratory. The measured phase is compared with predictions made from AFM top-surface measurements of those defects. While amplitude defects are usually easy to recognize and quantify with standard inspection techniques like scanning electron microscopy (SEM), defects or structures that have a phase component can be much more challenging to inspect. A phase defect can originate from the substrate or from any level of the multilayer. In both cases its effect on the reflected field is not directly related to the local topography of the mask surface, but depends on the deformation of the multilayer structure. Using the …
Date: February 21, 2011
Creator: Mochi, Iacopo; Yamazoe, Kenji; Neureuther, Andrew & Goldberg, Kenneth A.
System: The UNT Digital Library
Simplified models for mask roughness induced LER (open access)

Simplified models for mask roughness induced LER

The ITRS requires < 1.2nm line-edge roughness (LER) for the 22nm half-pitch node. Currently, we can consistently achieve only about 3nm LER. Further progress requires understanding the principle causes of LER. Much work has already been done on how both the resist and LER on the mask effect the final printed LER. What is poorly understood, however, is the extent to which system-level effects such as mask surface roughness, illumination conditions, and defocus couple to speckle at the image plane, and factor into LER limits. Presently, mask-roughness induced LER is studied via full 2D aerial image modeling and subsequent analysis of the resulting image. This method is time consuming and cumbersome. It is, therefore, the goal of this research to develop a useful 'rule-of-thumb' analytic model for mask roughness induced LER to expedite learning and understanding.
Date: February 21, 2011
Creator: McClinton, Brittany & Naulleau, Patrick
System: The UNT Digital Library
Single actomyosin motor interactions in skeletal muscle (open access)

Single actomyosin motor interactions in skeletal muscle

This article presents a study of intramuscular motion during contraction of skeletal muscle myofibrils.
Date: February 21, 2011
Creator: Földes-Papp, Zeno; Liao, Jeff Shih-Chu; Barbieri, Ben; Grycznski, Karol G.; Luchowski, Rafal; Gryczynski, Ignacy et al.
System: The UNT Digital Library
Analysis and Mitigation of X-Ray Hazard Generated From High Intensity Laser-Target Interactions (open access)

Analysis and Mitigation of X-Ray Hazard Generated From High Intensity Laser-Target Interactions

Interaction of a high intensity laser with matter may generate an ionizing radiation hazard. Very limited studies have been made, however, on the laser-induced radiation protection issue. This work reviews available literature on the physics and characteristics of laser-induced X-ray hazards. Important aspects include the laser-to-electron energy conversion efficiency, electron angular distribution, electron energy spectrum and effective temperature, and bremsstrahlung production of X-rays in the target. The possible X-ray dose rates for several femtosecond Ti:sapphire laser systems used at SLAC, including the short pulse laser system for the Matter in Extreme Conditions Instrument (peak power 4 TW and peak intensity 2.4 x 10{sup 18} W/cm{sup 2}) were analysed. A graded approach to mitigate the laser-induced X-ray hazard with a combination of engineered and administrative controls is also proposed.
Date: March 21, 2011
Creator: Qiu, R.; Liu, J. C.; Prinz, A. A.; Rokni, S. H.; Woods, M. & Xia, Z.
System: The UNT Digital Library
Ancient nature of alternative splicing and functions of introns (open access)

Ancient nature of alternative splicing and functions of introns

Using four genomes: Chamydomonas reinhardtii, Agaricus bisporus, Aspergillus carbonarius, and Sporotricum thermophile with EST coverage of 2.9x, 8.9x, 29.5x, and 46.3x respectively, we identified 11 alternative splicing (AS) types that were dominated by intron retention (RI; biased toward short introns) and found 15, 35, 52, and 63percent AS of multiexon genes respectively. Genes with AS were more ancient, and number of AS correlated with number of exons, expression level, and maximum intron length of the gene. Introns with tendency to be retained had either stop codons or length of 3n+1 or 3n+2 presumably triggering nonsense-mediated mRNA decay (NMD), but introns retained in major isoforms (0.2-6percent of all introns) were biased toward 3n length and stop codon free. Stopless introns were biased toward phase 0, but 3n introns favored phase 1 that introduced more flexible and hydrophilic amino acids on both ends of introns which would be less disruptive to protein structure. We proposed a model in which minor RI intron could evolve into major RI that could facilitate intron loss through exonization.
Date: March 21, 2011
Creator: Zhou, Kemin; Salamov, Asaf; Kuo, Alan; Aerts, Andrea & Grigoriev, Igor
System: The UNT Digital Library
Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b (open access)

Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b

Using the integral field spectrograph OSIRIS, on the Keck II telescope, broad near-infrared H and K-band spectra of the young exoplanet HR8799b have been obtained. In addition, six new narrow-band photometric measurements have been taken across the H and K bands. These data are combined with previously published photometry for an analysis of the planet's atmospheric properties. Thick photospheric dust cloud opacity is invoked to explain the planet's red near-IR colors and relatively smooth near-IR spectrum. Strong water absorption is detected, indicating a Hydrogen-rich atmosphere. Only weak CH{sub 4} absorption is detected at K band, indicating efficient vertical mixing and a disequilibrium CO/CH{sub 4} ratio at photospheric depths. The H-band spectrum has a distinct triangular shape consistent with low surface gravity. New giant planet atmosphere models are compared to these data with best fitting bulk parameters, T{sub eff} = 1100K {+-} 100 and log(g) = 3.5 {+-} 0.5 (for solar composition). Given the observed luminosity (log L{sub obs}/L{sub {circle_dot}} {approx} -5.1), these values correspond to a radius of 0.75 R{sub Jup{sub 0.12}{sup +0.17}} and mass {approx} 0.72 M{sub Jup{sub -0.6}{sup +2.6}} - strikingly inconsistent with interior/evolution models. Enhanced metallicity (up to {approx} 10 x that of the Sun) along with …
Date: March 21, 2011
Creator: Barman, T. S.; Macintosh, B. A.; Konopacky, Q. M. & Marois, C.
System: The UNT Digital Library
DUK - A Fast and Efficient Kmer Based Sequence Matching Tool (open access)

DUK - A Fast and Efficient Kmer Based Sequence Matching Tool

A new tool, DUK, is developed to perform matching task. Matching is to find whether a query sequence partially or totally matches given reference sequences or not. Matching is similar to alignment. Indeed many traditional analysis tasks like contaminant removal use alignment tools. But for matching, there is no need to know which bases of a query sequence matches which position of a reference sequence, it only need know whether there exists a match or not. This subtle difference can make matching task much faster than alignment. DUK is accurate, versatile, fast, and has efficient memory usage. It uses Kmer hashing method to index reference sequences and Poisson model to calculate p-value. DUK is carefully implemented in C++ in object oriented design. The resulted classes can also be used to develop other tools quickly. DUK have been widely used in JGI for a wide range of applications such as contaminant removal, organelle genome separation, and assembly refinement. Many real applications and simulated dataset demonstrate its power.
Date: March 21, 2011
Creator: Li, Mingkun; Copeland, Alex & Han, James
System: The UNT Digital Library
Illumina Unamplified Indexed Library Construction: An Automated Approach (open access)

Illumina Unamplified Indexed Library Construction: An Automated Approach

Manual library construction is a limiting factor in Illumina sequencing. Constructing libraries by hand is costly, time-consuming, low-throughput, and ergonomically hazardous, and constructing multiple libraries introduces risk of library failure due to pipetting errors. The ability to construct multiple libraries simultaneously in automated fashion represents significant cost and time savings. Here we present a strategy to construct up to 96 unamplified indexed libraries using Illumina TruSeq reagents and a Biomek FX robotic platform. We also present data to indicate that this library construction method has little or no risk of cross-contamination between samples.
Date: March 21, 2011
Creator: Hack, Christopher A.; Sczyrba, Alexander & Cheng, Jan-Fang
System: The UNT Digital Library
Portal 6.0 Released!! (open access)

Portal 6.0 Released!!

None
Date: March 21, 2011
Creator: Cantor, Michael & Smirnova, Tatyana
System: The UNT Digital Library
The yeast lipin orthologue Pah1p is important for biogenesis of lipid droplets (open access)

The yeast lipin orthologue Pah1p is important for biogenesis of lipid droplets

Article on yeast lipin orthologue Pah1p and its importance for biogenesis of lipid droplets.
Date: March 21, 2011
Creator: Adeyo, Oludotun; Horn, Patrick J.; Lee, SungKyung; Binns, Derk Douglas; Chandrahas, Anita; Chapman, Kent D. et al.
System: The UNT Digital Library
Atmospheric Stability Affects Wind Turbine Power Collection (open access)

Atmospheric Stability Affects Wind Turbine Power Collection

None
Date: April 21, 2011
Creator: Wharton, S & Lundquist, J K
System: The UNT Digital Library
Status of the Neutralized Drift Compression Experiment (NDCX-II) (open access)

Status of the Neutralized Drift Compression Experiment (NDCX-II)

The Neutralized Drift Compression Experiment (NDCX-II) is an 11 M$ induction accelerator project currently in construction at Lawrence Berkeley National Laboratory for warm dense matter (WDM) experiments investigating the interaction of ion beams with matter at elevated temperature and pressure. The machine consists of a lithium injector, induction accelerator cells, diagnostic cells, a neutralized drift compression line, a final focus solenoid, and a target chamber. The induction cells and some of the pulsed power systems have been reused from the decommissioned Advanced Test Accelerator at Lawrence Livermore National Laboratory after refurbishment and modification. The machine relies on a sequence of acceleration waveforms to longitudinally compress the initial ion pulse from 600 ns to less than 1 ns in {approx} 12 m. Radial confinement of the beam is achieved with 2.5 T pulsed solenoids. In the initial hardware configuration, 50 nC of Li{sup +} will be accelerated to 1.25 MeV and allowed to drift-compress to a peak current of {approx}40 A. The project started in the summer of 2009. Construction of the accelerator will be completed in the fall of 2011 and will provide a worldwide unique opportunity for ion-driven warm dense matter experiments as well as research related to novel …
Date: April 21, 2011
Creator: Waldron, W. L. & Kwan, J. W.
System: The UNT Digital Library
THE EFFECT OF VARIOUS DETECTOR GEOMETRIES ON THE PERFORMANCE OF CZT USING ONE CRYSTAL (open access)

THE EFFECT OF VARIOUS DETECTOR GEOMETRIES ON THE PERFORMANCE OF CZT USING ONE CRYSTAL

CdZnTe (CZT) continues to be a major thrust interest mainly due to its potential application as a room temperature radiation detector. The performance of CZT detectors is directly related to the charge collection ability which can be affected by the configuration of the electrical contact. The charge collection efficiency is determined in part by the specific geometry of the anode contact which serves as the readout electrode. In this report, contact geometries including single pixel, planar, coplanar, and dual anode will be systematically explored by comparing the performance efficiencies of the detector using both low and high energy gamma rays. To help eliminate the effect of crystal quality variations, the contact geometries were fabricated on the same crystal detector with minimal polishing between contact placements.
Date: June 21, 2011
Creator: Washington, A.; Duff, M. & Teague, L.
System: The UNT Digital Library
Nonequilibrium candidate Monte Carlo: A new tool for equilibrium simulation (open access)

Nonequilibrium candidate Monte Carlo: A new tool for equilibrium simulation

None
Date: June 21, 2011
Creator: Nilmeier, J P; Crooks, G E; Minh, D L & Chodera, J D
System: The UNT Digital Library
Chemistry Resolved Kinetic Flow Modeling of TATB Based Explosives (open access)

Chemistry Resolved Kinetic Flow Modeling of TATB Based Explosives

Detonation waves in insensitive, TATB based explosives are believed to have multi-time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. They use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. They term their model chemistry resolved kinetic flow as CHEETAH tracks the time dependent concentrations of individual species in the detonation wave and calculates EOS values based on the concentrations. A HE-validation suite of model simulations compared to experiments at ambient, hot, and cold temperatures has been developed. They present here a new rate model and comparison with experimental data.
Date: July 21, 2011
Creator: Vitello, P A; Fried, L E; Howard, W M; Levesque, G & Souers, P C
System: The UNT Digital Library