Three-Dimensional Imaging and Quantification of Biomass and Biofilms in Porous Media (open access)

Three-Dimensional Imaging and Quantification of Biomass and Biofilms in Porous Media

A new method to resolve biofilms in three dimensions in porous media using high-resolution synchrotron-based x-ray computed microtomography (CMT) has been developed. Imaging biofilms in porous media without disturbing the natural spatial arrangement of the porous media and associated biofilm has been a challenging task, primarily because porous media generally precludes conventional imaging via optical microscopy; x-ray tomography offers a potential alternative. One challenge for using this method is that most conventional x-ray contrast agents are water-soluble and easily diffuse into biofilms. To overcome this problem, silver-coated microspheres were added to the fluid phase to create an x-ray contrast that does not diffuse into the biofilm mass. Using this approach, biofilm imaging in porous media was accomplished with sufficient contrast to differentiate between the biomass- and fluid-filled pore spaces. The method was validated by using a two-dimensional micro-model flow cell where both light microscopy and CMT imaging were used to im age the biofilm. The results of this work has been published in Water Resources Research (Iltis et al., 2010). Additional work needs to be done to optimize this imaging approach, specifically, we find that the quality of the images are highly dependent on the coverage of the biofilm with …
Date: October 10, 2012
Creator: Wildenschild, Dorthe
Object Type: Report
System: The UNT Digital Library
Effects of remediation amendments on vadose zone microorganisms (open access)

Effects of remediation amendments on vadose zone microorganisms

Surfactant-based foam delivery technology has been studied to remediate Hanford 200 area deep vadose zone sediment. However, the surfactants and remediation amendments have an unknown effect on indigenous subsurface microorganisms. Microbial populations are important factors to consider in remediation efforts due to their potential to alter soil geochemistry. This project focuses on measuring microbial metabolic responses to remediation amendments in batch and column studies using Deep Vadose Zone Sediments. Initial studies of the microbes from Hanford 200 area deep vadose zone sediment showed surfactants sodium dodecyl sulfate (SDS) and cocamidopropyl betaine (CAPB) and remediation amendment calcium polysulfide (CPS) had no affect on microbial growth using BiologTM Ecoplates. To move towards a more realistic field analog, soil columns were packed with Hanford 200 Area sediment. Once microbial growth in the column was verified by observing growth of the effluent solution on tryptic soy agar plates, remedial surfactants were injected into the columns, and the resulting metabolic diversity was measured. Results suggest surfactant sodium dodecyl sulfate (SDS) stimulates microbial growth. The soil columns were also visualized using X-ray microtomography to inspect soil packing and possibly probe for evidence of biofilms. Overall, BiologTM Ecoplates provide a rapid assay to predict effects of remediation …
Date: August 10, 2012
Creator: Miller, Hannah M. & Tilton, Fred A.
Object Type: Report
System: The UNT Digital Library
Importance of Final-State Fluctuations in Radiative Capture Reactions and Applications to Surrogate Reaction Measurements (open access)

Importance of Final-State Fluctuations in Radiative Capture Reactions and Applications to Surrogate Reaction Measurements

None
Date: October 10, 2012
Creator: Dietrich, F S
Object Type: Article
System: The UNT Digital Library
Laser wakefield acceleration self-guiding in noble gas mixes (open access)

Laser wakefield acceleration self-guiding in noble gas mixes

None
Date: August 10, 2012
Creator: Kesler, L.
Object Type: Report
System: The UNT Digital Library
Comparison of Waste Feed Delivery Small Scale Mixing Demonstration Simulant to Hanford Waste (open access)

Comparison of Waste Feed Delivery Small Scale Mixing Demonstration Simulant to Hanford Waste

The Hanford double-shell tank (DST) system provides the staging location for waste that will be transferred to the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Specific WTP acceptance criteria for waste feed delivery describe the physical and chemical characteristics of the waste that must be met before the waste is transferred from the DSTs to the WTP. One of the more challenging requirements relates to the sampling and characterization of the undissolved solids (UDS) in a waste feed DST because the waste contains solid particles that settle and their concentration and relative proportion can change during the transfer of the waste in individual batches. A key uncertainty in the waste feed delivery system is the potential variation in UDS transferred in individual batches in comparison to an initial sample used for evaluating the acceptance criteria. To address this uncertainty, a number of small-scale mixing tests have been conducted as part of Washington River Protection Solutions' Small Scale Mixing Demonstration (SSMD) project to determine the performance of the DST mixing and sampling systems. A series of these tests have used a five-part simulant composed of particles of different size and density and designed to be equal or more challenging than …
Date: July 10, 2012
Creator: Wells, Beric E.; Gauglitz, Phillip A. & Rector, David R.
Object Type: Report
System: The UNT Digital Library
NIF Ignition Campaign Target Performance and Requirements: Status May 2012 (open access)

NIF Ignition Campaign Target Performance and Requirements: Status May 2012

None
Date: September 10, 2012
Creator: Haan, S. W.; Atherton, J.; Clark, D. S.; Hammel, B. A.; Callahan, D. A.; Cerjan, C. J. et al.
Object Type: Article
System: The UNT Digital Library
Source fabrication and lifetime for Li{sup +} ion beams extracted from alumino-silicate sources (open access)

Source fabrication and lifetime for Li{sup +} ion beams extracted from alumino-silicate sources

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm{sup 2} have been measured from lithium alumino-silicate ion sources at a temperature of ∼1275{degrees}C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm{sup 2}, and J increases weakly with the applied voltage. A source with an alumino-silicate coating 6.35 mm in diameter and ≤0.25 mm thick, has a lifetime of ∼40 hours at ∼1275{degrees}C, when pulsed at 0.05 Hz and with pulse length of ∼6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Furthermore, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be extended if the temperature is reduced between pulses.
Date: February 10, 2012
Creator: Greenway, W. G. & Kwan, J. W.
Object Type: Article
System: The UNT Digital Library
Longitudinal Emittance Growth Due to Nonlinear Space Charge Effect (open access)

Longitudinal Emittance Growth Due to Nonlinear Space Charge Effect

None
Date: May 10, 2012
Creator: Lau, Y. Y.; Yu, S. S.; Barnard, J. J. & Seidl, P. A.
Object Type: Article
System: The UNT Digital Library
Multiplexed gas spectroscopy using tunable VCSELs (open access)

Multiplexed gas spectroscopy using tunable VCSELs

Detection and identification of gas species using tunable laser diode laser absorption spectroscopy has been performed using vertical cavity surface emitting lasers (VCSEL). Two detection methods are compared: direct absorbance and wavelength modulation spectroscopy (WMS). In the first, the output of a DC-based laser is directly monitored to detect for any quench at the targeted specie wavelength. In the latter, the emission wavelength of the laser is modulated by applying a sinusoidal component on the drive current of frequency {omega}, and measuring the harmonics component (2{omega}) of the photo-detected current. This method shows a better sensitivity measured as signal to noise ratio, and is less susceptible to interference effects such as scattering or fouling. Gas detection was initially performed at room temperature and atmospheric conditions using VCSELs of emission wavelength 763 nm for oxygen and 1392 nm for water, scanning over a range of approximately 10 nm, sufficient to cover 5-10 gas specific absorption lines that enable identification and quantization of gas composition. The amplitude and frequency modulation parameters were optimized for each detected gas species, by performing two dimensional sweeps for both tuning current and either amplitude or frequency, respectively. We found that the highest detected signal is observed …
Date: April 10, 2012
Creator: Bond, T; Bond, S; McCarrick, J; Zumstein, J; Chang, A; Moran, B et al.
Object Type: Article
System: The UNT Digital Library
NEAMS Update. Quarterly Report for April - June 2012 (open access)

NEAMS Update. Quarterly Report for April - June 2012

None
Date: August 10, 2012
Creator: Bradley, K. S.; Hayes, S.; Pointer, D.; Summers, R.; Sadasivan, P.; Sun, X. et al.
Object Type: Report
System: The UNT Digital Library
The Secret Life of Quarks, Final Report for the University of North Carolina at Chapel Hill (open access)

The Secret Life of Quarks, Final Report for the University of North Carolina at Chapel Hill

This final report summarizes activities and results at the University of North Carolina as part of the the SciDAC-2 Project The Secret Life of Quarks: National Computational Infrastructure for Lattice Quantum Chromodynamics. The overall objective of the project is to construct the software needed to study quantum chromo- dynamics (QCD), the theory of the strong interactions of subatomic physics, and similar strongly coupled gauge theories anticipated to be of importance in the LHC era. It built upon the successful efforts of the SciDAC-1 project National Computational Infrastructure for Lattice Gauge Theory, in which a QCD Applications Programming Interface (QCD API) was developed that enables lat- tice gauge theorists to make effective use of a wide variety of massively parallel computers. In the SciDAC-2 project, optimized versions of the QCD API were being created for the IBM Blue- Gene/L (BG/L) and BlueGene/P (BG/P), the Cray XT3/XT4 and its successors, and clusters based on multi-core processors and Infiniband communications networks. The QCD API is being used to enhance the performance of the major QCD community codes and to create new applications. Software libraries of physics tools have been expanded to contain sharable building blocks for inclusion in application codes, performance analysis and …
Date: December 10, 2012
Creator: Fowler, Robert
Object Type: Report
System: The UNT Digital Library
Fuel from Bacteria, CO2, Water, and Solar Energy (open access)

Fuel from Bacteria, CO2, Water, and Solar Energy

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to generate liquid fuels from bacteria, carbon dioxide, water, and sunlight (project title "Engineering a Bacterial Reverse Fuel Cell") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 10, 2012
Creator: Harvard Medical School. Wyss Institute
Object Type: Text
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter (2012) (open access)

Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter (2012)

N/A
Date: August 10, 2012
Creator: D., Kharzeev; Liao, J.; Shuryak, E. & Yee, H.-U.
Object Type: Report
System: The UNT Digital Library
2012 ELECTRON DONOR-ACCEPTOR INTERACTIONS GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012 (open access)

2012 ELECTRON DONOR-ACCEPTOR INTERACTIONS GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012

The upcoming incarnation of the Gordon Research Conference on Electron Donor Acceptor Interactions will feature sessions on classic topics including proton-coupled electron transfer, dye-sensitized solar cells, and biological electron transfer, as well as emerging areas such as quantum coherence effects in donor-acceptor interactions, spintronics, and the application of donor-acceptor interactions in chemical synthesis.
Date: August 10, 2012
Creator: McCusker, James
Object Type: Article
System: The UNT Digital Library
Edge Turbulence Velocity Changes with Lithium Coating on NSTX (open access)

Edge Turbulence Velocity Changes with Lithium Coating on NSTX

Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________
Date: August 10, 2012
Creator: A. Cao, S.J. Zweben, D.P. Stotler, M. Bell, A. Diallo, S.M. Kaye and B. LeBlanc
Object Type: Report
System: The UNT Digital Library
Blending Of Radioactive Salt Solutions In Million Gallon Tanks (open access)

Blending Of Radioactive Salt Solutions In Million Gallon Tanks

Research was completed at Savannah River National Laboratory (SRNL) to investigate processes related to the blending of radioactive, liquid waste, salt solutions in 4920 cubic meter, 25.9 meter diameter storage tanks. One process was the blending of large salt solution batches (up to 1135 ? 3028 cubic meters), using submerged centrifugal pumps. A second process was the disturbance of a settled layer of solids, or sludge, on the tank bottom. And a third investigated process was the settling rate of sludge solids if suspended into slurries by the blending pump. To investigate these processes, experiments, CFD models (computational fluid dynamics), and theory were applied. Experiments were performed using simulated, non-radioactive, salt solutions referred to as supernates, and a layer of settled solids referred to as sludge. Blending experiments were performed in a 2.44 meter diameter pilot scale tank, and flow rate measurements and settling tests were performed at both pilot scale and full scale. A summary of the research is presented here to demonstrate the adage that, ?One good experiment fixes a lot of good theory?. Experimental testing was required to benchmark CFD models, or the models would have been incorrectly used. In fact, CFD safety factors were established by …
Date: December 10, 2012
Creator: Leishear, Robert A.; Lee, Si Y.; Fowley, Mark D. & Poirier, Michael R.
Object Type: Article
System: The UNT Digital Library
On the Lack of Evolution in Galaxy Star Formation Efficiency (open access)

On the Lack of Evolution in Galaxy Star Formation Efficiency

None
Date: December 10, 2012
Creator: Behroozi, Peter S.; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC; Conroy, Charlie & /UC, Santa Cruz, Astron. Astrophys.
Object Type: Article
System: The UNT Digital Library
Satellite Re-entry Modeling and Uncertainty Quantification (open access)

Satellite Re-entry Modeling and Uncertainty Quantification

None
Date: September 10, 2012
Creator: Horsley, M
Object Type: Article
System: The UNT Digital Library
ACTUAL-WASTE TESTING OF ULTRAVIOLET LIGHT TO AUGMENT THE ENHANCED CHEMICAL CLEANING OF SRS SLUDGE (open access)

ACTUAL-WASTE TESTING OF ULTRAVIOLET LIGHT TO AUGMENT THE ENHANCED CHEMICAL CLEANING OF SRS SLUDGE

In support of Savannah River Site (SRS) tank closure efforts, the Savannah River National Laboratory (SRNL) conducted Real Waste Testing (RWT) to evaluate Enhanced Chemical Cleaning (ECC), an alternative to the baseline 8 wt% oxalic acid (OA) chemical cleaning technology for tank sludge heel removal. ECC utilizes a more dilute OA solution (2 wt%) and an oxalate destruction technology using ozonolysis with or without the application of ultraviolet (UV) light. SRNL conducted tests of the ECC process using actual SRS waste material from Tanks 5F and 12H. The previous phase of testing involved testing of all phases of the ECC process (sludge dissolution, OA decomposition, product evaporation, and deposition tank storage) but did not involve the use of UV light in OA decomposition. The new phase of testing documented in this report focused on the use of UV light to assist OA decomposition, but involved only the OA decomposition and deposition tank portions of the process. Compared with the previous testing at analogous conditions without UV light, OA decomposition with the use of UV light generally reduced time required to reach the target of <100 mg/L oxalate. This effect was the most pronounced during the initial part of the decomposition …
Date: July 10, 2012
Creator: Martino, C.; King, W. & Ketusky, E.
Object Type: Report
System: The UNT Digital Library
Biofuels from E. coli (open access)

Biofuels from E. coli

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses the modification of E. coli to consume carbon dioxide and produce liquid fuel as part of the "Engineering E. coli as an Electrofuels Chassis for Isooctane Production" project.
Date: May 10, 2012
Creator: Ginkgo Bioworks
Object Type: Text
System: The UNT Digital Library
Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings (open access)

Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings

None
Date: December 10, 2012
Creator: Cai, Y
Object Type: Article
System: The UNT Digital Library
Genetically Modified Bacteria for Fuel Production (open access)

Genetically Modified Bacteria for Fuel Production

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses a new program to develop a bacteria that uses electricity to convert carbon dioxide into liquid fuels as part of the "Development of Rhodobacter as a Versatile Platform for Fuels Production" project.
Date: May 10, 2012
Creator: Pennsylvania State University
Object Type: Text
System: The UNT Digital Library
Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012 (open access)

Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012

Individual datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile research sites are collected and routed to the Data Management Facility (DMF) for processing in near-real-time. Instrument and processed data are then delivered approximately daily to the ARM Data Archive, where they are made freely available to the research community. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Data Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.
Date: October 10, 2012
Creator: Voyles, JW
Object Type: Text
System: The UNT Digital Library
Scalable Load Balancing for Massively Parallel Distributed Monte Carlo Particle Transport (open access)

Scalable Load Balancing for Massively Parallel Distributed Monte Carlo Particle Transport

None
Date: December 10, 2012
Creator: O'Brien, M. J.; Brantley, P. S. & Joy, K. I.
Object Type: Article
System: The UNT Digital Library