ACRF Instrumentation Status: New, Current, and Future March 2009 (open access)

ACRF Instrumentation Status: New, Current, and Future March 2009

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: March 15, 2009
Creator: Voyles, J. W.
Object Type: Report
System: The UNT Digital Library
Analysis of background distributions of metals in the soil at Lawrence Berkeley National Laboratory (open access)

Analysis of background distributions of metals in the soil at Lawrence Berkeley National Laboratory

As part of its Resource Conservation and Recovery Act (RCRA) Corrective Action Program (CAP), the Lawrence Berkeley National Laboratory (LBNL) Environmental Restoration Program conducted an evaluation of naturally occurring metals in soils at the facility. The purpose of the evaluation was to provide a basis for determining if soils at specific locations contained elevated concentrations of metals relative to ambient conditions. Ambient conditions (sometimes referred to as 'local background') are defined as concentrations of metals in the vicinity of a site, but which are unaffected by site-related activities (Cal-EPA 1997). Local background concentrations of 17 metals were initially estimated by LBNL using data from 498 soil samples collected from borings made during the construction of 71 groundwater monitoring wells (LBNL 1995). These concentration values were estimated using the United States Environmental Protection Agency's (USEPA's) guidance that was available at that time (USEPA 1989). Since that time, many more soil samples were collected and analyzed for metals by the Environmental Restoration Program. In addition, the California Environmental Protection Agency (Cal-EPA) subsequently published a recommended approach for calculating background concentrations of metals at hazardous waste sites and permitted facilities (Cal-EPA 1997). This more recent approach differs from that recommended by the USEPA …
Date: March 15, 2009
Creator: Diamond, David; Baskin, David; Brown, Dennis; Lund, Loren; Najita, Julie & Javandel, Iraj
Object Type: Report
System: The UNT Digital Library
Assessments of Environmental Impacts and Beneficial Use of Coalbed Methane Produced Water in the Powder River Basin (open access)

Assessments of Environmental Impacts and Beneficial Use of Coalbed Methane Produced Water in the Powder River Basin

Impact on water quality and the beneficial use of the coal bed methane (CBM) produced water are imminent questions to be answered due to the rapidly growing CBM exploration in the Powder River Basin (PRB). The practice of discharging large volumes of water into drainage channels or using it to irrigate rangeland areas has the potential of causing serious problems. The elevated salinity and sodicity in the CBM water may be detrimental to soils, plants and the associated microbial communities. There are limited studies on CBM water characterization; however, a comprehensive understanding of CBM water influence on the local ecosystem is lacking. It is very important that the water applied to soils meets the favorable combination of salinity and sodicity that will allow the plants to grow at good production levels and that will maintain the structure of the soils. The purpose of this study was to access various CBM water treatment technologies and the influence of the treated water on local biogeochemical settings in order to evaluate and identify the proper technologies to treat the CBM produced water from CBM operations, and use it in an environmentally safe manner. Unfortunately, a suitable field site was not identified and the …
Date: March 15, 2009
Creator: Morris, Jeff
Object Type: Report
System: The UNT Digital Library
First Quarter Hanford Seismic Report for Fiscal Year 2009 (open access)

First Quarter Hanford Seismic Report for Fiscal Year 2009

The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. 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. This includes three recently acquired Transportable Array stations located at Cold Creek, Didier Farms, and Phinney Hill. For the Hanford Seismic Network, ten local earthquakes were recorded during the first quarter of fiscal year 2009. All earthquakes were considered as “minor” with magnitudes (Mc) less than 1.0. Two earthquakes were located at shallow depths (less than 4 km), most likely in the Columbia River …
Date: March 15, 2009
Creator: Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E. & Devary, Joseph L.
Object Type: Report
System: The UNT Digital Library
JV Task-130 Technological Synergies for Recovery of Organic Pollutants from a Coal Seam at Garrison, North Dakota (open access)

JV Task-130 Technological Synergies for Recovery of Organic Pollutants from a Coal Seam at Garrison, North Dakota

The Energy & Environmental Research Center (EERC) initiated remediation of hydrocarbon-contaminated soils and groundwater associated with gasoline release at the Farmers Union Oil station in Garrison, North Dakota. The remedial strategy implemented is based on application of two innovative concepts: (1) simultaneous operation of soil vapor and multiphase extraction systems allowing for water table control in challenging geotechnical conditions and (2) controlled hot-air circulation between injection and extraction wells to accelerated in situ volatilization and stripping of contaminants of concern (COC) alternatively using the same wells as either extraction or injection points. A proactive remedial approach is required to reduce high COC levels in the source and impacted areas and to eliminate long-term health risks associated with contaminant migration to water-bearing zones used as a regional water supply source. This report compiles results of Phase I focused on design, construction, and start-up of remediation systems.
Date: March 15, 2009
Creator: Solc, Jaroslav
Object Type: Report
System: The UNT Digital Library
Modeling of thermally driven hydrological processes in partially saturated fractured rock (open access)

Modeling of thermally driven hydrological processes in partially saturated fractured rock

This paper is a review of the research that led to an in-depth understanding of flow and transport processes under strong heat stimulation in fractured, porous rock. It first describes the anticipated multiple processes that come into play in a partially saturated, fractured porous volcanic tuff geological formation, when it is subject to a heat source such as that originating from the decay of radionuclides. The rationale is then given for numerical modeling being a key element in the study of multiple processes that are coupled. The paper outlines how the conceptualization and the numerical modeling of the problem evolved, progressing from the simplified to the more realistic. Examples of numerical models are presented so as to illustrate the advancement and maturation of the research over the last two decades. The most recent model applied to in situ field thermal tests is characterized by (1) incorporation of a full set of thermal-hydrological processes into a numerical simulator, (2) realistic representation of the field test geometry, in three dimensions, and (3) use of site-specific characterization data for model inputs. Model predictions were carried out prior to initiation of data collection, and the model results were compared to diverse sets of measurements. …
Date: March 15, 2009
Creator: Tsang, Yvonne; Birkholzer, Jens & Mukhopadhyay, Sumit
Object Type: Article
System: The UNT Digital Library
Modeling preferential water flow and solute transport in unsaturated soil using the active region model (open access)

Modeling preferential water flow and solute transport in unsaturated soil using the active region model

Preferential flow and solute transport are common processes in the unsaturated soil, in which distributions of soil water content and solute concentrations are often characterized as fractal patterns. An active region model (ARM) was recently proposed to describe the preferential flow and transport patterns. In this study, ARM governing equations were derived to model the preferential soil water flow and solute transport processes. To evaluate the ARM equations, dye infiltration experiments were conducted, in which distributions of soil water content and Cl{sup -} concentration were measured. Predicted results using the ARM and the mobile-immobile region model (MIM) were compared with the measured distributions of soil water content and Cl{sup -} concentration. Although both the ARM and the MIM are two-region models, they are fundamental different in terms of treatments of the flow region. The models were evaluated based on the modeling efficiency (ME). The MIM provided relatively poor prediction results of the preferential flow and transport with negative ME values or positive ME values less than 0.4. On the contrary, predicted distributions of soil water content and Cl- concentration using the ARM agreed reasonably well with the experimental data with ME values higher than 0.8. The results indicated that the …
Date: March 15, 2009
Creator: Sheng, F.; Wang, K.; Zhang, R. & Liu, H.H.
Object Type: Article
System: The UNT Digital Library
Subtask 4.4 - North Dakota Lignite Fuel Upgrading (open access)

Subtask 4.4 - North Dakota Lignite Fuel Upgrading

This project will add the capability for the Energy & Environmental Research Center (EERC) to conduct Fischer-Tropsch (FT) catalyst testing at a scale consistent with the benchscale continuous fluid-bed reactor. This capability will enable various vendors to test their FT catalysts on actual coal-derived syngas. The project goals were to also develop some EERC expertise with issues associated with FT liquid production. A study by Dr. Calvin Bartholmew at Brigham Young University (BYU) is further apparent that it is possible to build a single reactor (rather than multiple reactors of different sizes) consisting of three 1-inch-diameter, 10 foot-long tubes to accommodate the anticipated range of catalytic activities and process conditions. However, this single reactor should ideally be designed to operate over a significant range of recycle ratio (e.g., 1-10), temperature (25-400 C), pressure (10-25 bar), flow rate (1-6 scfm), and cooling duty (0.2-1.5 kW). It should have the flexibility of flowing gas to one, two, or three tubes. Based on the recommended design specifications provided by BYU while staying within the approved budget, the EERC decided to build a two fixed-bed reactor system with the capability to add a third reactor at a later time. This system was constructed to …
Date: March 15, 2009
Creator: Swanson, Michael
Object Type: Report
System: The UNT Digital Library
Use of Gene Probes to Assess the Impact and Effectiveness of Aerobic in Situ Bioremediation of Tce (open access)

Use of Gene Probes to Assess the Impact and Effectiveness of Aerobic in Situ Bioremediation of Tce

Gene probe hybridization was used to determine distribution and expression of co-metabolic genes at a contaminated site as it underwent in situ methanotrophic bioremediation of trichloroethylene (TCE). The bioremediation strategies tested included a series of air, air:methane, and air:methane:nutrient pulses of the test plot using horizontal injection wells. During the test period, the levels of TCE reduced drastically in almost all test samples. Sediment core samples (n = 367) taken from 0 m (surface)-43 m depth were probed for gene coding for methanotrophic soluble methane monooxygenase (sMMO) and heterotrophic toluene dioxygenase (TOD), which are known to co-metabolize TCE. The same sediment samples were also probed for genes coding for methanol dehydrogenase (MDH) (catalyzing the oxidation of methanol to formaldehyde) to assess specifically changes in methylotrophic bacterial populations in the site. Gene hybridization results showed that the frequency of detection of sMMO genes were stimulated approximately 250% following 1% methane:air (v/v) injection. Subsequent injection of 4% methane:air (v/v) resulted in an 85% decline probably due to nutrient limitations, since addition of nutrients (gaseous nitrogen and phosphorus) thereafter caused an increase in the frequency of detection of sMMO genes. Detection of TOD genes declined during the process, and eventually they were non-detectable …
Date: March 15, 2009
Creator: Hazen, T. C.; Chakraborty, R.; Fleming, J. M.; Gregory, I. R.; Bowman, J. P.; Jimenez, L. et al.
Object Type: Article
System: The UNT Digital Library
Variation in soil moisture and N availability modulates carbon and water exchange in a California grassland experiment (open access)

Variation in soil moisture and N availability modulates carbon and water exchange in a California grassland experiment

Variability in the magnitude and timing of precipitation is predicted to change under future climate scenarios. The primary objective of this study was to understand how variation in precipitation patterns consisting of soil moisture pulses mixed with intermittent dry down events influence ecosystem gas fluxes. We characterized the effects of precipitation amount and timing, N availability, and plant community composition on whole ecosystem and leaf gas exchange in a California annual grassland mesocosm study system that allowed precise control of soil moisture conditions. Ecosystem CO2 and fluxes increased significantly with greater precipitation and were positively correlated with soil moisture. A repeated 10 day dry down period following 11 days of variable precipitation inputs strongly depressed net ecosystem CO2 exchange (NEE) across a range of season precipitation totals, and plant community types. Ecosystem respiration (Re), evapotranspiration (ET) and leaf level photosynthesis (Amax) showed greatest sensitivity to dry down periods in low precipitation plots. Nitrogen additions significantly increased NEE, Re and Amax, particularly as water availability was increased. These results demonstrate that N availability and intermittent periods of soil moisture deficit (across a wide range of cumulative season precipitation totals) strongly modulate ecosystem gas exchange.
Date: March 15, 2009
Creator: Clair, S.B., St.; Sudderth, E.; Fischer, M. L.; Torn, M. S.; Stuart, S.; Salve, R. et al.
Object Type: Article
System: The UNT Digital Library
Annual Report to the Congressional Defense Committees (open access)

Annual Report to the Congressional Defense Committees

2008 Annual Report measuring and updating the accomplishments and priorities of the Department of Defense (DoD) in regards to business transformation and the Military Health System. The report offers extensive documentation of the DoD Business Enterprise Priorities, reporting on milestones, modernization, property accountability, and visibility in regards to personnel, acquisitions, and finances.
Date: March 15, 2008
Creator: United States. Department of Defense.
Object Type: Report
System: The UNT Digital Library
Basalt weathering rates on Earth and the duration of liquid water on the plains of Gusev Crater, Mars (open access)

Basalt weathering rates on Earth and the duration of liquid water on the plains of Gusev Crater, Mars

Where Martian rocks have been exposed to liquid water, chemistry versus depth profiles could elucidate both Martian climate history and potential for life. The persistence of primary minerals in weathered profiles constrains the exposure time to liquid water: on Earth, mineral persistence times range from {approx}10 ka (olivine) to {approx}250 ka (glass) to {approx}1Ma (pyroxene) to {approx}5Ma (plagioclase). Such persistence times suggest mineral persistence minima on Mars. However, Martian solutions may have been more acidic than on Earth. Relative mineral weathering rates observed for basalt in Svalbard (Norway) and Costa Rica demonstrate that laboratory pH trends can be used to estimate exposure to liquid water both qualitatively (mineral absence or presence) and quantitatively (using reactive transport models). Qualitatively, if the Martian solution pH > {approx}2, glass should persist longer than olivine; therefore, persistence of glass may be a pH-indicator. With evidence for the pH of weathering, the reactive transport code CrunchFlow can quantitatively calculate the minimum duration of exposure to liquid water consistent with a chemical profile. For the profile measured on the surface of Humphrey in Gusev Crater, the minimum exposure time is 22 ka. If correct, this estimate is consistent with short-term, episodic alteration accompanied by ongoing surface …
Date: March 15, 2008
Creator: Steefel, Carl; Hausrath, E. M.; Navarre-Sitchler, A. K.; Sak, P. B.; Steefel, C. & Brantley, S. L.
Object Type: Article
System: The UNT Digital Library
Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems (open access)

Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems

Fenton's reagent, a solution of hydrogen peroxide and ferrous iron catalyst, is used for an in-situ chemical oxidation of organic contaminants. Sulfuric acid is commonly used to create an acidic condition needed for catalytic oxidation. Fenton's reaction often involves pressure buildup and precipitation of reaction products, which can cause safety hazards and diminish efficiency. We selected citric acid, a food-grade substance, as an acidifying agent to evaluate its efficiencies for organic contaminant removal in Fenton's reaction, and examined the impacts of using citric acid on the unwanted reaction products. A series of batch and column experiments were performed with varying H{sub 2}O{sub 2} concentrations to decompose selected chlorinated ethylenes. Either dissolved iron from soil or iron sulfate salt was added to provide the iron catalyst in the batch tests. Batch experiments revealed that both citric and sulfuric acid systems achieved over 90% contaminant removal rates, and the presence of iron catalyst was essential for effective decontamination. Batch tests with citric acid showed no signs of pressure accumulation and solid precipitations, however the results suggested that an excessive usage of H{sub 2}O{sub 2} relative to iron catalysts (Fe{sup 2+}/H{sub 2}O{sub 2} < 1/330) would result in lowering the efficiency of contaminant …
Date: March 15, 2008
Creator: Seol, Yongkoo & Javandel, Iraj
Object Type: Article
System: The UNT Digital Library
Exact Averaging of Stochastic Equations for Flow in Porous Media (open access)

Exact Averaging of Stochastic Equations for Flow in Porous Media

It is well known that at present, exact averaging of the equations for flow and transport in random porous media have been proposed for limited special fields. Moreover, approximate averaging methods--for example, the convergence behavior and the accuracy of truncated perturbation series--are not well studied, and in addition, calculation of high-order perturbations is very complicated. These problems have for a long time stimulated attempts to find the answer to the question: Are there in existence some, exact, and sufficiently general forms of averaged equations? Here, we present an approach for finding the general exactly averaged system of basic equations for steady flow with sources in unbounded stochastically homogeneous fields. We do this by using (1) the existence and some general properties of Green's functions for the appropriate stochastic problem, and (2) some information about the random field of conductivity. This approach enables us to find the form of the averaged equations without directly solving the stochastic equations or using the usual assumption regarding any small parameters. In the common case of a stochastically homogeneous conductivity field we present the exactly averaged new basic nonlocal equation with a unique kernel-vector. We show that in the case of some type of global …
Date: March 15, 2008
Creator: Karasaki, Kenzi; Shvidler, Mark & Karasaki, Kenzi
Object Type: Article
System: The UNT Digital Library
Porous ceramic scaffolds with complex architectures (open access)

Porous ceramic scaffolds with complex architectures

This work compares two novel techniques for the fabrication of ceramic scaffolds for bone tissue engineering with complex porosity: robocasting and freeze casting. Both techniques are based on the preparation of concentrated ceramic suspensions with suitable properties for the process. In robocasting, the computer-guided deposition of the suspensions is used to build porous materials with designed three dimensional (3-D) geometries and microstructures. Freeze casting uses ice crystals as a template to form porous lamellar ceramic materials. Preliminary results on the compressive strengths of the materials are also reported.
Date: March 15, 2008
Creator: Saiz, Eduardo; Munch, Etienne; Franco, Jaime; Deville, Sylvain; Hunger, Phillip; Saiz, Eduardo et al.
Object Type: Article
System: The UNT Digital Library
Temperature dependence of the interface moments in Co2MnSi thin films (open access)

Temperature dependence of the interface moments in Co2MnSi thin films

X-ray magnetic circular dichroism (XMCD) is utilized to explore the temperature dependence of the interface moments in Co{sub 2}MnSi (CMS) thin films capped with aluminium. By increasing the thickness of the capping layer we demonstrate enhanced interface sensitivity of the measurements and the existence of a thin Mn oxide layer at the CMS/Al interface even when a thick capping layer is used. We show that for well ordered L2{sub 1} CMS films there is no significant variation in either the Co or Mn interface moments as a function of temperature. However, a dramatic reduction in the interface moments at low temperature is observed in a disordered CMS film that is likely to be caused by increased Mn-Mn antiferromagnetic coupling. It is suggested that for ordered L2{sub 1} CMS films the temperature dependence of the tunneling magnetoresistance is not related to changes in the interface moments. However, the existence of residual Mn oxide at the CMS/barrier interface could be a contributing factor.
Date: March 15, 2008
Creator: Arenholz, Elke; Telling, N.; Keatley, P.; Shelford, L.; Arenholz, E.; van der Laan, G. et al.
Object Type: Article
System: The UNT Digital Library
Test of the consistency of various linearized semiclassical initial value time correlation functions in application to inelastic neutron scattering from liquid para-hydrogen (open access)

Test of the consistency of various linearized semiclassical initial value time correlation functions in application to inelastic neutron scattering from liquid para-hydrogen

The linearized approximation to the semiclassical initial value representation (LSC-IVR) is used to calculate time correlation functions relevant to the incoherent dynamic structure factor for inelastic neutron scattering from liquid para-hydrogen at 14 K. Various time correlations functions were used which, if evaluated exactly, would give identical results, but they do not because the LSC-IVR is approximate. Some of the correlation functions involve only linear operators, and others involve non-linear operators. The consistency of the results obtained with the various time correlation functions thus provides a useful test of the accuracy of the LSC-IVR approximation and its ability to treat correlation functions involving both linear and nonlinear operators in realistic anharmonic systems. The good agreement of the results obtained from different correlation functions, their excellent behavior in the spectral moment tests based on the exact moment constraints, and their semi-quantitative agreement with the inelastic neutron scattering experimental data all suggest that the LSC-IVR is indeed a good short-time approximation for quantum mechanical correlation functions.
Date: March 15, 2008
Creator: Miller, William; Liu, Jian & Miller, William H.
Object Type: Article
System: The UNT Digital Library
Agricultural Export and Food Aid Programs (open access)

Agricultural Export and Food Aid Programs

This report discusses the recent development in different programs administered by U.S. Department of Agriculture (USDA) with the goal to promote agricultural exports and to provide food aid. These programs include direct export subsidies, export market development, export credit guarantees, and foreign food aid.
Date: March 15, 2007
Creator: Hanrahan, Charles E.
Object Type: Report
System: The UNT Digital Library
Animal Agriculture: Selected Issues for Congress (open access)

Animal Agriculture: Selected Issues for Congress

None
Date: March 15, 2007
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
The Animal Welfare Act: Background and Selected Legislation (open access)

The Animal Welfare Act: Background and Selected Legislation

This report is on The Animal Welfare Act: Background and Selected Legislation.
Date: March 15, 2007
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Assistance to Firefighters Program (open access)

Assistance to Firefighters Program

This report discusses the Assistance to Firefighters Grant (AFG) Program, also known as the FIRE Act grant program, which provides federal grants directly to local fire departments and Emergency Medical Services (EMS) organizations.
Date: March 15, 2007
Creator: Kruger, Lennard G.
Object Type: Report
System: The UNT Digital Library
Broadband over Powerlines: Regulatory and Policy Issues (open access)

Broadband over Powerlines: Regulatory and Policy Issues

This report provides information about the Regulatory and Policy Issues Broadband over Power lines.
Date: March 15, 2007
Creator: Moloney Figliola, Patricia
Object Type: Report
System: The UNT Digital Library
Confinement and Local Transport in the National Spherical Torus Experiment NSTX (open access)

Confinement and Local Transport in the National Spherical Torus Experiment NSTX

NSTX operates at low aspect ratio (R/a~1.3) and high beta (up to 40%), allowing tests of global confinement and local transport properties that have been established from higher aspect ratio devices. NSTX plasmas are heated by up to 7 MW of deuterium neutral beams with preferential electron heating as expected for ITER. Confinement scaling studies indicate a strong ΒΤ dependence, with a current dependence that is weaker than that observed at higher aspect ratio. Dimensionless scaling experiments indicate a strong increase of confinement with decreasing collisionality and a weak degradation with beta. The increase of confinement with ΒΤ is due to reduced transport in the electron channel, while the improvement with plasma current is due to reduced transport in the ion channel related to the decrease in the neoclassical transport level. Improved electron confinement has been observed in plasmas with strong reversed magnetic shear, showing the existence of an electron internal transport barrier (eITB). The development of the eITB may be associated with a reduction in the growth of microtearing modes in the plasma core. Perturbative studies show that while L-mode plasmas with reversed magnetic shear and an eITB exhibit slow changes of LΤe across the profile after the pellet …
Date: March 15, 2007
Creator: Kaye, S. M.; Stutman, D.; Tritz, K.; Yuh, H.; Bell, M. G.; Bell, R. E. et al.
Object Type: Article
System: The UNT Digital Library
Cruise Missile Defense (open access)

Cruise Missile Defense

None
Date: March 15, 2007
Creator: Bolkcom, Christopher
Object Type: Report
System: The UNT Digital Library