EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT (open access)

EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT

The concept of an effective porosity is widely used in solute transport modeling to account for the presence of a fraction of the medium that effectively does not influence solute migration, apart from taking up space. This non-participating volume or ineffective porosity plays the same role as the gas phase in single-phase liquid unsaturated transport: it increases pore velocity, which is useful towards reproducing observed solute travel times. The prevalent use of the effective porosity concept is reflected by its prominent inclusion in popular texts, e.g., de Marsily (1986), Fetter (1988, 1993) and Zheng and Bennett (2002). The purpose of this commentary is to point out that proper application of the concept for sorbing solutes requires more than simply reducing porosity while leaving other material properties unchanged. More specifically, effective porosity implies the corresponding need for an effective bulk density in a conventional single-porosity model. The reason is that the designated non-participating volume is composed of both solid and fluid phases, both of which must be neglected for consistency. Said another way, if solute does not enter the ineffective porosity then it also cannot contact the adjoining solid. Conceptually neglecting the fluid portion of the non-participating volume leads to a …
Date: February 27, 2012
Creator: Flach, G.
Object Type: Article
System: The UNT Digital Library
Well Completion Report for Well ER-20-11, Corrective Action Units 101 and 102: Central and Western Pahute Mesa (open access)

Well Completion Report for Well ER-20-11, Corrective Action Units 101 and 102: Central and Western Pahute Mesa

Well ER-20-11 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Management Operations Underground Test Area (UGTA) Activity at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The well was drilled in September 2012 as part of the Central and Western Pahute Mesa Corrective Action Unit Phase II drilling program. Well ER-20-11 was constructed to further investigate the nature and extent of radionuclidecontaminated groundwater encountered in two nearby UGTA wells, to help define hydraulic and transport parameters for the contaminated Benham aquifer, and to provide data for the UGTA hydrostratigraphic framework model. The 44.5-centimeter (cm) surface hole was drilled to a depth of 520.0 meters (m) and cased with 34.0-cm casing to 511.5 m. The hole diameter was then decreased to 31.1 cm, and the borehole was drilled to a total depth of 915.6 m. The hole was completed to allow access for hydrologic testing and sampling in the target aquifer, which is a lava-flow aquifer known as the Benham aquifer. The completion casing string, set to the depth of 904.3 m, consists of a string of 6⅝-inch (in.) stainless-steel casing hanging from a …
Date: February 27, 2013
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
2011 Annual Ecological Survey: Pacific Northwest National Laboratory Site (open access)

2011 Annual Ecological Survey: Pacific Northwest National Laboratory Site

The U.S. Department of Energy (DOE) Pacific Northwest Site Office (PNSO) oversees and manages the DOE contract for the Pacific Northwest National Laboratory (PNNL), a DOE Office of Science multi-program laboratory located in Richland, Washington. PNSO is responsible for ensuring that all activities conducted on the PNNL site comply with applicable laws, policies, and DOE Orders. The DOE Pacific Northwest Site Office Cultural and Biological Resources Management Plan (DOE/PNSO 2008) addresses the requirement for annual surveys and monitoring for species of concern and to identify and map invasive species. In addition to the requirement for an annual survey, proposed project activities must be reviewed to assess any potential environmental consequences of conducting the project. The assessment process requires a thorough understanding of the resources present, the potential impacts of a proposed action to those resources, and the ultimate consequences of those actions. The PNNL site is situated on the southeastern corner of the DOE Hanford Site, located at the north end of the city of Richland in south-central Washington. The site is bordered on the east by the Columbia River, on the west by Stevens Drive, and on the north by the Hanford Site 300 Area (Figure 1). The environmental …
Date: February 27, 2012
Creator: Becker, James M. & Chamness, Michele A.
Object Type: Report
System: The UNT Digital Library
Nevada National Security Site 2011 Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site (open access)

Nevada National Security Site 2011 Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site

This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS). The data have been collected since 1993 and include calendar year 2011 results. During 2011, groundwater samples were collected and static water levels were measured at the three pilot wells surrounding the Area 5 RWMS. Samples were collected at UE5PW-1 on March 8, August 2, August 24, and October 19, 2011; at UE5PW-2 on March 8, August 2, August 23, and October 19, 2011; and at UE5PW-3 on March 8, August 2, August 23, and October 19, 2011. Static water levels were measured at each of the three pilot wells on March 1, June 7, August 1, and October 17, 2011. Groundwater samples were analyzed for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. Indicators of general water chemistry (cations and anions) were also measured. Initial total organic carbon and total organic halides results for samples collected in August 2011 were above previous measurements and, in some cases, above the established investigation limits. However, after field sample pumps and tubing were disinfected with Clorox solution, the results returned to normal levels. Final results …
Date: February 27, 2012
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
User Guide for the STAYSL PNNL Suite of Software Tools (open access)

User Guide for the STAYSL PNNL Suite of Software Tools

The STAYSL PNNL software suite provides a set of tools for working with neutron activation rates measured in a nuclear fission reactor, an accelerator-based neutron source, or any neutron field to determine the neutron flux spectrum through a generalized least-squares approach. This process is referred to as neutron spectral adjustment since the preferred approach is to use measured data to adjust neutron spectra provided by neutron physics calculations. The input data consist of the reaction rates based on measured activities, an initial estimate of the neutron flux spectrum, neutron activation cross sections and their associated uncertainties (covariances), and relevant correction factors. The output consists of the adjusted neutron flux spectrum and associated covariance matrix, which is useful for neutron dosimetry and radiation damage calculations.
Date: February 27, 2013
Creator: Greenwood, Lawrence R. & Johnson, Christian D.
Object Type: Report
System: The UNT Digital Library
Analysis of the Younger Dryas Impact Layer (open access)

Analysis of the Younger Dryas Impact Layer

We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden disappearance of the megafauna and Clovis people. The distribution pattern of the Younger Dryas boundary (YDB) ejecta layer is consistent with an impact near the Great Lakes that deposited terrestrial-like ejecta near the impact site and unusual, titanium-rich projectile-like ejecta further away. High water content associated with the ejecta, up to 28 at. percent hydrogen (H), suggests the impact occurred over the Laurentide Ice Sheet. YDB microspherules and magnetic grains are highly enriched in TiO{sub 2}. Magnetic grains from several sites are enriched in iridium (Ir), up to 117 ppb. The TiO{sub 2}/FeO, K/Th, TiO{sub 2}/Zr, Al{sub 2}O{sub 3}/FeO+MgO, CaO/Al{sub 2}O{sub 3}, REE/ chondrite, FeO/MnO ratios and SiO{sub 2}, Na{sub 2}O, K{sub 2}O, Cr{sub 2}O{sub 3}, …
Date: February 27, 2010
Creator: Firestone, Richard B.; West, Allen; Revay, Zsolt; Hagstrum, Jonathon T,; Belgya, Thomas; Hee, Shane S. Que et al.
Object Type: Article
System: The UNT Digital Library
Nano Structured Activated Carbon for Hydrogen Storge (open access)

Nano Structured Activated Carbon for Hydrogen Storge

Development of a nanostructured synthetic carbons materials that have been synthesized by thermal-decomposition of aromatic rich polyether such as poly(ether ether ketone) (PEEK) is reported. These polymers based nanostructured carbons efficacious for gas adsorption and storage and have Brunauer-Emmett-Teller (BET) surface area of more than 3000 m2/g, and with average pore diameter of < 2nm. Surface-area, pore characteristics, and other critical variables for selecting porous materials of high gas adsorption capacities are presented. Analysis of the fragments evolved under various carbonization temperatures, and the correlation between the activation and carbonization temperatures provides a mechanistic perspective of the pore evolution during activation. Correlations between gas (N2 and H2) adsorption capacity and porous texture of the materials have been established. The materials possess excellent hydrogen storage properties, with hydrogen storage capacity up to 7.4 wt% (gravimetric) and ~ 45 g H2 L-1 (volumetric) at -196oC and 6.0 MPa.
Date: February 27, 2013
Creator: Cabasso, Israel & Yuan, Youxin
Object Type: Text
System: The UNT Digital Library
Structural and Kinetic Studies of Novel Cytochrome P450 Small-Alkane Hydroxylases (open access)

Structural and Kinetic Studies of Novel Cytochrome P450 Small-Alkane Hydroxylases

The goals of this project are to investigate (1) the kinetics and stabilities of engineered cytochrome P450 (P450) small alkane hydroxylases and their evolutionary intermediates, (2) the structural basis for catalytic proficiency on small alkanes of these engineered P450s, and (3) the changes in redox control resulting from protein engineering. To reach these goals, we have established new methods for determining the kinetics and stabilities of multicomponent P450s such as CYP153A6. Using these, we were able to determine that CYP153A6 is proficient for hydroxylation of alkanes as small as ethane, an activity that has never been observed previously in any natural P450. To elucidate the structures of the engineered P450s, we obtained x-ray diffraction data for two variants in the P450PMO (propane monooxygenase) lineage and a preliminary structure for the most evolved variant. This structure shows changes in the substrate binding regions of the enzyme and a reduction in active site volume that are consistent with the observed changes in substrate specificity from fatty acids in the native enzyme to small alkanes in P450PMO. We also constructed semi-rational designed libraries mutating only residues in the enzyme active site that in one round of mutagenesis and screening produced variants that achieved …
Date: February 27, 2012
Creator: Arnold, Frances H.
Object Type: Report
System: The UNT Digital Library
Constraining the initial temperature and shear viscosity in a hybrid hydrodynamic model of sNN=200 GeV Au+Au collisions using pion spectra, elliptic flow, and femtoscopic radii (open access)

Constraining the initial temperature and shear viscosity in a hybrid hydrodynamic model of sNN=200 GeV Au+Au collisions using pion spectra, elliptic flow, and femtoscopic radii

None
Date: February 27, 2013
Creator: Soltz, R; Garishvili, I; Abelev, B & Glenn, A
Object Type: Article
System: The UNT Digital Library
California GAMA Special Study: Stable Isotopic Composition of Boron in Groundwater - San Diego County Domestic Well Data (open access)

California GAMA Special Study: Stable Isotopic Composition of Boron in Groundwater - San Diego County Domestic Well Data

None
Date: February 27, 2012
Creator: Eppich, G. R.; Wimpenny, J. B.; Yin, Q. Z. & Esser, B. K.
Object Type: Report
System: The UNT Digital Library
HHFW Power Flow Along Magnetic Field Lines In The Scrape-off Layer of NSTX (open access)

HHFW Power Flow Along Magnetic Field Lines In The Scrape-off Layer of NSTX

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast wave heating and current drive.
Date: February 27, 2012
Creator: Perkins, Rory; Bell, R. E.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A. et al.
Object Type: Report
System: The UNT Digital Library
A Three-Dimensional Gas Migration Model for the Leroy Natural Gas Storage Facility (open access)

A Three-Dimensional Gas Migration Model for the Leroy Natural Gas Storage Facility

None
Date: February 27, 2012
Creator: Chen, M.; Buscheck, T. A.; Wagoner, J. L.; Sun, Y.; White, J. A. & Chiaramonte, L.
Object Type: Article
System: The UNT Digital Library
DOE_EE0003592_HEL-SR-PR-0027 Rev 1 20130227 Final Report_Public Release (open access)

DOE_EE0003592_HEL-SR-PR-0027 Rev 1 20130227 Final Report_Public Release

To develop a high temperature Thermal Storage System (TES) based on graphite and able to provide both economical and technical advantages with respect to existing solutions contributing to increase the share of Concentrated Solar Plants (CSP).
Date: February 27, 2013
Creator: Eduardo Villarroel, Carlos Fernandez-Pello, Jeff Lenartz, Karen Parysek
Object Type: Report
System: The UNT Digital Library
Energy Saving Glass Lamination via Selective Radio Frequency Heating (open access)

Energy Saving Glass Lamination via Selective Radio Frequency Heating

This project focused on advancing radio-frequency (RF) lamination technology closer to commercial implementation, in order to reduce the energy intensity of glass lamination by up to 90%. Lamination comprises a wide range of products including autoglass, architectural safety and innovative design glass, transparent armor (e.g. bullet proof glass), smart glass, mirrors, and encapsulation of photovoltaics. Lamination is also the fastest growing segment of glass manufacturing, with photovoltaics, architectural needs, and an anticipated transition to laminated side windows in vehicles. The state-of-the-art for glass lamination is to use autoclaves, which apply heat and uniform gas pressure to bond the laminates over the course of 1 to 18 hours. Laminates consist of layers of glass or other materials bonded with vinyl or urethane interlayers. In autoclaving, significant heat energy is lost heating the chamber, pressurized air, glass racks, and the glass. In RF lamination, the heat is generated directly in the vinyl interlayer, causing it to heat and melt quickly, in just 1 to 10 minutes, without significantly heating the glass or the equipment. The main purpose of this project was to provide evidence that low energy, rapid RF lamination quality met the same standards as conventionally autoclaved windows. The development of …
Date: February 27, 2012
Creator: Allan, Shawn M.; Baranova, Inessa; Poley, Joseph & Reis, Henrique
Object Type: Report
System: The UNT Digital Library
Modeling the Performance of an Algebraic Multigrid Cycle Using Hybrid MPI/OpenMP (open access)

Modeling the Performance of an Algebraic Multigrid Cycle Using Hybrid MPI/OpenMP

None
Date: February 27, 2012
Creator: Gahvari, H.; Gropp, W.; Jordan, K. E.; Schulz, M. & Yang, U. M.
Object Type: Article
System: The UNT Digital Library
Analysis of 2011 Meteorological Data from the Knolls Atomic Power Laboratory and Kesselring Site Operations Facilities (open access)

Analysis of 2011 Meteorological Data from the Knolls Atomic Power Laboratory and Kesselring Site Operations Facilities

Both the Knolls Atomic Power Laboratory (KAPL) in Schenectady, NY and the Kesselring Site Operations (KSO) facility near Ballston Spa, NY are required to estimate the effects of hypothetical emissions of radiological material from their respective facilities by the US Environmental Protection Agency (EPA), which regulates these facilities. An atmospheric dispersion model known as CAP88, which was developed and approved by the EPA for such purposes, is used by KAPL and KSO to meet this requirement. CAP88 calculations over a given time period are based on statistical data on the meteorological conditions for that period. Both KAPL and KSO have on-site meteorological towers which take atmospheric measurements at a frequency ideal for EPA regulatory model input. However, an independent analysis and processing of the meteorological data from each tower is required to derive a data set appropriate for use in the CAP88 model. The National Atmospheric Release Advisory Center (NARAC) was contracted by KAPL to process the on-site data for the calendar year 2011. The purpose of this document is to: (1) summarize the procedures used in the preparation/analysis of the 2011 meteorological data; and (2) document adherence of these procedures to the guidance set forth in 'Meteorological Monitoring Guidance …
Date: February 27, 2012
Creator: Aluzzi, F J
Object Type: Report
System: The UNT Digital Library
Energy Saving Glass Lamination via Selective Radio Frequency Heating (open access)

Energy Saving Glass Lamination via Selective Radio Frequency Heating

This project focused on advancing radio-frequency (RF) lamination technology closer to commercial implementation, in order to reduce the energy intensity of glass lamination by up to 90%. Lamination comprises a wide range of products including autoglass, architectural safety and innovative design glass, transparent armor (e.g. bullet proof glass), smart glass, mirrors, and encapsulation of photovoltaics. Lamination is also the fastest growing segment of glass manufacturing, with photovoltaics, architectural needs, and an anticipated transition to laminated side windows in vehicles. The state-of-the-art for glass lamination is to use autoclaves, which apply heat and uniform gas pressure to bond the laminates over the course of 1 to 18 hours. Laminates consist of layers of glass or other materials bonded with vinyl or urethane interlayers. In autoclaving, significant heat energy is lost heating the chamber, pressurized air, glass racks, and the glass. In RF lamination, the heat is generated directly in the vinyl interlayer, causing it to heat and melt quickly, in just 1 to 10 minutes, without significantly heating the glass or the equipment. The main purpose of this project was to provide evidence that low energy, rapid RF lamination quality met the same standards as conventionally autoclaved windows. The development of …
Date: February 27, 2012
Creator: Allan, Shawn M.
Object Type: Report
System: The UNT Digital Library
Final Report: Detection and Characterization of Underground Facilities by Stochastic Inversion and Modeling of Data from the New Generation of Synthetic Aperture Satellites (open access)

Final Report: Detection and Characterization of Underground Facilities by Stochastic Inversion and Modeling of Data from the New Generation of Synthetic Aperture Satellites

Many clandestine development and production activities can be conducted underground to evade surveillance. The purpose of the study reported here was to develop a technique to detect underground facilities by broad-area search and then to characterize the facilities by inversion of the collected data. This would enable constraints to be placed on the types of activities that would be feasible at each underground site, providing a basis the design of targeted surveillance and analysis for more complete characterization. Excavation of underground cavities causes deformation in the host material and overburden that produces displacements at the ground surface. Such displacements are often measurable by a variety of surveying or geodetic techniques. One measurement technique, Interferometric Synthetic Aperture Radar (InSAR), uses data from satellite-borne (or airborne) synthetic aperture radars (SARs) and so is ideal for detecting and measuring surface displacements in denied access regions. Depending on the radar frequency and the acquisition mode and the surface conditions, displacement maps derived from SAR interferograms can provide millimeter- to centimeter-level measurement accuracy on regional and local scales at spatial resolution of {approx}1-10 m. Relatively low-resolution ({approx}20 m, say) maps covering large regions can be used for broad-area detection, while finer resolutions ({approx}1 m) can …
Date: February 27, 2012
Creator: Foxall, W; Cunningham, C; Mellors, R; Templeton, D; Dyer, K & White, J
Object Type: Report
System: The UNT Digital Library
Photon Linear Collider Gamma-Gamma Summary (open access)

Photon Linear Collider Gamma-Gamma Summary

High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.
Date: February 27, 2012
Creator: Gronberg, J
Object Type: Article
System: The UNT Digital Library
Correction of the spin chromaticity in RHIC (open access)

Correction of the spin chromaticity in RHIC

N/A
Date: February 27, 2013
Creator: Kewisch, J.; Bai, M.; Bruno, D.; Meot, F. & Roser, T.
Object Type: Report
System: The UNT Digital Library
Crystallization In High Level Waste (HLW) Glass Melters: Operational Experience From The Savannah River Site (open access)

Crystallization In High Level Waste (HLW) Glass Melters: Operational Experience From The Savannah River Site

processing strategy for the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The basis of this alternative approach is an empirical model predicting the crystal accumulation in the WTP glass discharge riser and melter bottom as a function of glass composition, time, and temperature. When coupled with an associated operating limit (e.g., the maximum tolerable thickness of an accumulated layer of crystals), this model could then be integrated into the process control algorithms to formulate crystal tolerant high level waste (HLW) glasses targeting higher waste loadings while still meeting process related limits and melter lifetime expectancies. This report provides a review of the scaled melter testing that was completed in support of the Defense Waste Processing Facility (DWPF) melter. Testing with scaled melters provided the data to define the DWPF operating limits to avoid bulk (volume) crystallization in the un-agitated DWPF melter and provided the data to distinguish between spinels generated by K-3 refractory corrosion versus spinels that precipitated from the HLW glass melt pool. This report includes a review of the crystallization observed with the scaled melters and the full scale DWPF melters (DWPF Melter 1 and DWPF Melter 2). Examples of actual DWPF melter attainment with Melter 2 …
Date: February 27, 2014
Creator: Fox, K. M.
Object Type: Report
System: The UNT Digital Library
Analysis Of Tank 38H (HTF-38-14-6, 7) And Tank 43H (HTF-43-14-8, 9) Samples For Support Of The Enrichment Control And Corrosion Control Programs (open access)

Analysis Of Tank 38H (HTF-38-14-6, 7) And Tank 43H (HTF-43-14-8, 9) Samples For Support Of The Enrichment Control And Corrosion Control Programs

SRNL performed analysis on Tanks 38H and 43H surface and subsurface supernate samples to support ECP and CCP. The U-235 mass divided by the total U mass ranged from 0.0059 to 0.0060. Uranium concentration ranged from 53.1 mg/L in the Tank 43H surface sample to the 85.1 mg/L in the Tank 38H subsurface sample. The U-235/U and uranium concentration are in line with the prior 2H-Evaporator System ECP samples.
Date: February 27, 2014
Creator: Martino, C. J.
Object Type: Report
System: The UNT Digital Library
Recent BaBar Studies of Bottomonium States (open access)

Recent BaBar Studies of Bottomonium States

None
Date: February 27, 2014
Creator: Guido, Elisa
Object Type: Article
System: The UNT Digital Library
Low density biodegradable shape memory polyurethane foams for embolic biomedical applications (open access)

Low density biodegradable shape memory polyurethane foams for embolic biomedical applications

None
Date: February 27, 2013
Creator: Singhal, P.; Small, W.; Cosgriff-Hernandez, E.; Maitland, D. & Wilson, T.
Object Type: Article
System: The UNT Digital Library