Influence of ammonium availability on expression of nifD and amtB genes during biostimulation of a U(VI) contaminated aquifer: implications for U(VI) removal and monitoring the metabolic state of Geobacteraceae (open access)

Influence of ammonium availability on expression of nifD and amtB genes during biostimulation of a U(VI) contaminated aquifer: implications for U(VI) removal and monitoring the metabolic state of Geobacteraceae

The influence of ammonium availability on bacterial community structure and the physiological status of Geobacter species during in situ bioremediation of uranium-contaminated groundwater was evaluated. Ammonium concentrations varied by 2 orders of magnitude (<4 to 400 ?M) across the study site. Analysis of 16S rRNA sequences suggested that ammonium may have been one factor influencing the community composition prior to acetate amendment with Rhodoferax species predominating over Geobacter species with higher ammonium and Dechloromonas species dominating at the site with lowest ammonium. However, once acetate was added and dissimilatory metal reduction was stimulated, Geobacter species became the predominant organisms at all locations. Rates of U(VI) reduction appeared to be more related to acetate concentrations rather than ammonium levels. In situ mRNA transcript abundance of the nitrogen fixation gene, nifD, and the ammonium transporter gene, amtB, in Geobacter species indicated that ammonium was the primary source of nitrogen during uranium reduction. The abundance of amtB was inversely correlated to ammonium levels, whereas nifD transcript levels were similar across all sites examined. These results suggest that nifD and amtB expression are closely regulated in response to ammonium availability to ensure an adequate supply of nitrogen while conserving cell resources. Thus, quantifying nifD …
Date: March 25, 2009
Creator: Mouser, Paula J.; N'Guessan, A. Lucie; Elifantz, Hila; Holmes, Dawn E.; Williams, Kenneth H; Wilkins, Michael J. et al.
Object Type: Article
System: The UNT Digital Library
Axial-Torsion Testing Plastic-Bonded Explosives to Failure (open access)

Axial-Torsion Testing Plastic-Bonded Explosives to Failure

None
Date: March 25, 2009
Creator: Gagliardi, F J & Cunningham, B J
Object Type: Article
System: The UNT Digital Library
Identification and Characterization of Hydrogeologic Units at the Nevada Test Site Using Geophysical Logs: Examples from the Underground Test Area Project (open access)

Identification and Characterization of Hydrogeologic Units at the Nevada Test Site Using Geophysical Logs: Examples from the Underground Test Area Project

The diverse and complex geology of the Nevada Test Site region makes for a challenging environment for identifying and characterizing hydrogeologic units penetrated by wells drilled for the U.S. Department of Energy, National Nuclear Security Administration, Underground Test Area (UGTA) Environmental Restoration Sub-Project. Fortunately, UGTA geoscientists have access to large and robust sets of subsurface geologic data, as well as a large historical knowledge base of subsurface geological analyses acquired mainly during the underground nuclear weapons testing program. Of particular importance to the accurate identification and characterization of hydrogeologic units in UGTA boreholes are the data and interpretation principles associated with geophysical well logs. Although most UGTA participants and stakeholders are probably familiar with drill hole data such as drill core and cuttings, they may be less familiar with the use of geophysical logs; this document is meant to serve as a primer on the use of geophysical logs in the UGTA project. Standard geophysical logging tools used in the UGTA project to identify and characterize hydrogeologic units are described, and basic interpretation principles and techniques are explained. Numerous examples of geophysical log data from a variety of hydrogeologic units encountered in UGTA wells are presented to highlight the use …
Date: March 25, 2009
Creator: Lance Prothro, Sigmund Drellack, Margaret Townsend
Object Type: Report
System: The UNT Digital Library
Hydrogen Production by Water Dissociation Using Ceramic Membranes - Annual Report for Fy 2008. (open access)

Hydrogen Production by Water Dissociation Using Ceramic Membranes - Annual Report for Fy 2008.

The objective of this project is to develop dense ceramic membranes that, without using an external power supply or circuitry, can produce hydrogen via coal/coal gas-assisted water dissociation. This project grew from an effort to develop a dense ceramic membrane for separating hydrogen from gas mixtures such as those generated during coal gasification, methane partial oxidation, and water-gas shift reactions. That effort led to the development of various cermet (i.e., ceramic/metal composite) membranes that enable hydrogen production by two methods. In one method, a hydrogen transport membrane (HTM) selectively removes hydrogen from a gas mixture by transporting it through either a mixed protonic/electronic conductor or a hydrogen transport metal. In the other method, an oxygen transport membrane (OTM) generates hydrogen mixed with steam by removing oxygen that is generated through water splitting. This project focuses on the development of OTMs that efficiently produce hydrogen via the dissociation of water. Supercritical boilers offer very high-pressure steam that can be decomposed to provide pure hydrogen by means of OTMs. Oxygen resulting from the dissociation of steam can be used for coal gasification, enriched combustion, or synthesis gas production. Hydrogen and sequestration-ready CO{sub 2} can be produced from coal and steam by using …
Date: March 25, 2009
Creator: Balachandran, U.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y. et al.
Object Type: Report
System: The UNT Digital Library
MODELING THE IMPACT OF ELEVATED MERCURY IN DEFENSE WASTE PROCESSING FACILITY MELTER FEED ON THE MELTER OFF-GAS SYSTEM - PRELIMINARY REPORT (open access)

MODELING THE IMPACT OF ELEVATED MERCURY IN DEFENSE WASTE PROCESSING FACILITY MELTER FEED ON THE MELTER OFF-GAS SYSTEM - PRELIMINARY REPORT

The Defense Waste Processing Facility (DWPF) is currently evaluating an alternative Chemical Process Cell (CPC) flowsheet to increase throughput. It includes removal of the steam-stripping step, which would significantly reduce the CPC processing time and lessen the sampling needs. However, its downside would be to send 100% of the mercury that come in with the sludge straight to the melter. For example, the new mercury content in the Sludge Batch 5 (SB5) melter feed is projected to be 25 times higher than that in the SB4 with nominal steam stripping of mercury. This task was initiated to study the impact of the worst-case scenario of zero-mercury-removal in the CPC on the DWPF melter off-gas system. It is stressed that this study is intended to be scoping in nature, so the results presented in this report are preliminary. In order to study the impact of elevated mercury levels in the feed, it is necessary to be able to predict how mercury would speciate in the melter exhaust under varying melter operating conditions. A homogeneous gas-phase oxidation model of mercury by chloride was developed to do just that. The model contains two critical parameters pertaining to the partitioning of chloride among HCl, …
Date: March 25, 2009
Creator: Zamecnik, J. & Choi, A.
Object Type: Report
System: The UNT Digital Library
EMSL Operations Manual (open access)

EMSL Operations Manual

This manual is a general resource tool to assist EMSL users and Laboratory staff within EMSL locate official policy, practice and subject matter experts. It is not intended to replace or amend any formal Battelle policy or practice. Users of this manual should rely only on Battelle’s Standard Based Management System (SBMS) for official policy. No contractual commitment or right of any kind is created by this manual. Battelle management reserves the right to alter, change, or delete any information contained within this manual without prior notice.
Date: March 25, 2009
Creator: Foster, Nancy S.
Object Type: Report
System: The UNT Digital Library
TANK 12 SLUDGE CHARACTERIZATION AND ALUMINUM DISSOLUTION DEMONSTRATION (open access)

TANK 12 SLUDGE CHARACTERIZATION AND ALUMINUM DISSOLUTION DEMONSTRATION

A 3-L sludge slurry sample from Tank 12 was characterized and then processed through an aluminum dissolution demonstration. The dominant constituent of the sludge was found to be aluminum in the form of boehmite. The iron content was minor, about one-tenth that of the aluminum. The salt content of the supernatant was relatively high, with a sodium concentration of {approx}7 M. Due to these characteristics, the yield stress and plastic viscosity of the unprocessed slurry were relatively high (19 Pa and 27 cP), and the settling rate of the sludge was relatively low ({approx}20% settling over a two and a half week period). Prior to performing aluminum dissolution, plutonium and gadolinium were added to the slurry to simulate receipt of plutonium waste from H-Canyon. Aluminum dissolution was performed over a 26 day period at a temperature of 65 C. Approximately 60% of the insoluble aluminum dissolved during the demonstration, with the rate of dissolution slowing significantly by the end of the demonstration period. In contrast, approximately 20% of the plutonium and less than 1% of the gadolinium partitioned to the liquid phase. However, about a third of the liquid phase plutonium became solubilized prior to the dissolution period, when the …
Date: March 25, 2009
Creator: Reboul, S; Michael Hay, M; Kristine Zeigler, K & Michael Stone, M
Object Type: Report
System: The UNT Digital Library
Energy Supply- Production of Fuel from Agricultural and Animal Waste (open access)

Energy Supply- Production of Fuel from Agricultural and Animal Waste

The Society for Energy and Environmental Research (SEER) was funded in March 2004 by the Department of Energy, under grant DE-FG-36-04GO14268, to produce a study, and oversee construction and implementation, for the thermo-chemical production of fuel from agricultural and animal waste. The grant focuses on the Changing World Technologies (CWT) of West Hempstead, NY, thermal conversion process (TCP), which converts animal residues and industrial food processing biproducts into fuels, and as an additional product, fertilizers. A commercial plant was designed and built by CWT, partially using grant funds, in Carthage, Missouri, to process animal residues from a nearby turkey processing plant. The DOE sponsored program consisted of four tasks. These were: Task 1 Optimization of the CWT Plant in Carthage - This task focused on advancing and optimizing the process plant operated by CWT that converts organic waste to fuel and energy. Task 2 Characterize and Validate Fuels Produced by CWT - This task focused on testing of bio-derived hydrocarbon fuels from the Carthage plant in power generating equipment to determine the regulatory compliance of emissions and overall performance of the fuel. Task 3 Characterize Mixed Waste Streams - This task focused on studies performed at Princeton University to better …
Date: March 25, 2009
Creator: Miller, Gabriel
Object Type: Report
System: The UNT Digital Library
Domain-wall oscillations studies by time-resolved soft x-ray mircorscopy (open access)

Domain-wall oscillations studies by time-resolved soft x-ray mircorscopy

Fast magnetization dynamics in the micro- and nanometer regime are an interesting field of research. On these length scales magnetic structures can be designed to contain a single vortex or a single domain wall. Both size and speed of these patterns are of great interest in todays research for prospective non-volatile data storage devices. Especially the possibility to move domain-walls by spin-polarized current gained a lot of interest. Magnetic configurations can be imaged by soft X-ray magnetic microscopy with a spatial resolution down to 15 nm. By a stroboscopic pump and probe measurement scheme a temporal resolution below 100 ps is achieved. This provides the opportunity to directly image changes in magnetic domains and domain-wall motion. We image oscillations of a single domain wall in a confining potential in time steps of 200 ps by time resolved X-ray microscopy at the full-field soft X-ray transmission microscope at the Advanced Light Source in Berkeley (beamline 6.1.2). Domain walls are prepared in permalloy nanostructures with a restoring potential. The oscillation of a 180{sup o} domain wall is triggered by nanosecond current pulses. The spin-polarized current and the accompanying Oersted field can contribute to the motion of the wall. By analysis of the …
Date: March 25, 2009
Creator: Bocklage, L.; Kruger, B.; Eiselt, R.; Bolte, M.; Fischer, P. & Meier, G.
Object Type: Article
System: The UNT Digital Library
Deposition Velocities of Newtonian and Non-Newtonian Slurries in Pipelines (open access)

Deposition Velocities of Newtonian and Non-Newtonian Slurries in Pipelines

The WTP pipe plugging issue, as stated by the External Flowsheet Review Team (EFRT) Executive Summary, is as follows: “Piping that transports slurries will plug unless it is properly designed to minimize this risk. This design approach has not been followed consistently, which will lead to frequent shutdowns due to line plugging.” A strategy was employed to perform critical-velocity tests on several physical simulants. Critical velocity is defined as the point where a stationary bed of particles deposits on the bottom of a straight horizontal pipe during slurry transport operations. Results from the critical velocity testing provide an indication of slurry stability as a function of fluid rheological properties and transport conditions. The experimental results are compared to the WTP design guide on slurry transport velocity in an effort to confirm minimum waste velocity and flushing velocity requirements as established by calculations and critical line velocity correlations in the design guide. The major findings of this testing is discussed below. Experimental results indicate that the use of the Oroskar and Turian (1980) correlation in the design guide is conservative—Slurry viscosity has a greater affect on particles with a large surface area to mass ratio. The increased viscous forces on these …
Date: March 25, 2009
Creator: Poloski, Adam P.; Adkins, Harold E.; Abrefah, John; Casella, Andrew M.; Hohimer, Ryan E.; Nigl, Franz et al.
Object Type: Report
System: The UNT Digital Library
Novel Intergrated Process to Process to Produce Fuels from Coal and Other Carbonaceous Feedstocks (open access)

Novel Intergrated Process to Process to Produce Fuels from Coal and Other Carbonaceous Feedstocks

BioConversion Technology, LLC has developed a novel gasifier design that produces a clean, medium to high BTU synthesis gas that can be utilized for a variety of applications. The staged, indirectly heated design produces high quality synthesis gas without the need for costly pure oxygen. This design also allows for extreme flexibility with respect to feedstocks (including those with high moisture contents) in addition to high throughputs in a small gasifier footprint. A pilot scale testing project was proposed to assist BCT with commercializing the process. A prototype gasifier constructed by BCT was transported to WRI for installation and testing. After troubleshooting, the gasifier was successfully operated with both coal and biomass feedstocks. Instrument upgrades are recommended for further testing.
Date: March 25, 2009
Creator: Lucero, Andrew
Object Type: Report
System: The UNT Digital Library
JV Task 119 - Effects of Aging on Treated Activated Carbons (open access)

JV Task 119 - Effects of Aging on Treated Activated Carbons

For both the United States and Canada, testing has been under way for electric utilities to find viable and economical mercury control strategies to meet pending future mercury emission limits. The technology that holds the most promise for mercury control in low-chlorine lignite to meet the needs of the Clean Air Act in the United States and the Canada-Wide Standards in Canada is injection of treated activated carbon (AC) into the flue gas stream. Most of the treated carbons are reported to be halogenated, often with bromine. Under a previous multiyear project headed by the Energy & Environmental Research Center (EERC), testing was performed on a slipstream unit using actual lignite-derived flue gas to evaluate various sorbent technologies for their effectiveness, performance, and cost. Testing under this project showed that halogenated ACs performed very well, with mercury capture rates often {ge} 90%. However, differences were noted between treated ACs with respect to reactivity and capacity, possibly as a result of storage conditions. Under certain conditions (primarily storage in ambient air), notable performance degradation had occurred in mercury capture efficiency. Therefore, a small exploratory task within this project evaluated possible differences resulting from storage conditions and subsequent effects of aging that …
Date: March 25, 2009
Creator: Olson, Edwin; Hamre, Lucinda; Pavlish, John & Mibeck, Blaise
Object Type: Report
System: The UNT Digital Library