Comparing FRACHEM and TOUGHREACT for reactive transport modelingof brine-rock interactions in enhanced geothermal systems (EGS) (open access)

Comparing FRACHEM and TOUGHREACT for reactive transport modelingof brine-rock interactions in enhanced geothermal systems (EGS)

Coupled modelling of fluid flow and reactive transport ingeothermal systems is challenging because of reservoir conditions such ashigh temperatures, elevated pressures and sometimes high salinities ofthe formation fluids. Thermal hydrological-chemical (THC) codes, such asFRACHEM and TOUGHREACT, have been developed to evaluate the long-termhydrothermal and chemical evolution of exploited reservoirs. In thisstudy, the two codes were applied to model the same geothermal reservoir,to forecast reservoir evolution using respective thermodynamic andkinetic input data. A recent (unreleased) TOUGHREACT version allows theuse of either an extended Debye-Hu?ckel or Pitzer activity model forcalculating activity coefficients, while FRACHEM was designed to use thePitzer formalism. Comparison of models results indicate that differencesin thermodynamic equilibrium constants, activity coefficients andkinetics models can result in significant differences in predictedmineral precipitation behaviour and reservoir-porosity evolution.Differences in the calculation schemes typically produce less differencein model outputs than differences in input thermodynamic and kineticdata, with model results being particularly sensitive to differences inion-interaction parameters for highsalinity systems.
Date: November 15, 2005
Creator: Andre, L.; Spycher, N.; Xu, T.; Pruess, K. & Vuataz, F.-D.
Object Type: Article
System: The UNT Digital Library
Avian Field Guide and Checklist for Kunsan Air Base, Korea. (open access)

Avian Field Guide and Checklist for Kunsan Air Base, Korea.

This report summarizes the results of the avian surveys conducted at Kunsan Air Base (AB). This on-going survey is conducted to comply with requirements of the Environmental Governing Standards (EGS) for the Republic of Korea, the Integrated Natural Resources Management Plan (INRMP) for Kunsan AB, and the 8th Fighter Wing's Bird Aircraft Strike Hazard (BASH) Plan. One hundred sixteen bird species representing 34 families were identified and recorded. Seven species are designated as Cultural Property Monuments, and their protection is accorded by the Korean Ministry of Culture and Tourism. Six species appear on the Korean Association for Conservation of Nature's(KACN's) list of Reserved Wild Species and are protected by the Korean Ministry of Environment. Combined, only ten different species are Republic of Korea (ROK)-protected because the Eurasian Spoonbill, Peregrine Falcon, and Eurasian Oystercatcher are listed by both agencies. The primary objective of the avian survey at Kunsan AB was to determine what species of birds are present on the airfield and their respective habitat requirements during the critical seasons of the year. This requirement is specified in Annex C.4.a.(1-4) of the 8th Fighter Wing BASH Plan(8FWOPLAN 91-202). The second objective was to initiate surveys to determine what bird species are …
Date: November 15, 2005
Creator: Levenson, J. B. & Assessment, Environmental
Object Type: Report
System: The UNT Digital Library
Motivation, description, and summary status of geomechanical andgeochemical modeling studies in Task D of the InternationalDECOVALEX-THMC Project (open access)

Motivation, description, and summary status of geomechanical andgeochemical modeling studies in Task D of the InternationalDECOVALEX-THMC Project

The DECOVALEX project is an international cooperativeproject initiated by SKI, the Swedish Nuclear Power Inspectorate, withparticipation of about 10 international organizations. The general goalof this project is to encourage multidisciplinary interactive andcooperative research on modelling coupledthermo-hydro-mechanical-chemical (THMC) processes in geologic formationsin support of the performance assessment for underground storage ofradioactive waste. One of the research tasks, initiated in 2004 by theU.S. Department of Energy (DOE), addresses the long-term impact ofgeomechanical and geochemical processes on the flow conditions near wasteemplacement tunnels. Within this task, four international research teamsconduct predictive analysis of the coupled processes in two genericrepositories, using multiple approaches and different computer codes.Below, we give an overview of the research task and report its currentstatus.
Date: November 15, 2005
Creator: Birkholzer, J.T.; Barr, D.; Rutqvist, J. & Sonnenthal, E.
Object Type: Article
System: The UNT Digital Library
Design and Synthesis of Oriented Guest-Host Nanostructures for Enhanced Membrane Performances (open access)

Design and Synthesis of Oriented Guest-Host Nanostructures for Enhanced Membrane Performances

This project has demonstrated a novel nanomaterial design concept and a synthesis method for ''guesthost'' type superionic-conducting nanocomposite membranes. This concept consists of nanophases of oxide electrolyte nanograins (guest) encapsulated inside the nanopore channels of an oxide layer matrix (host), with channels oriented perpendicular to the layer surface. Using ionic conducting YSZ (yttrium stabilized zirconia) as a special case, we have shown that the host-guest design allows orientation of a large number channels, allowing a high density of nanograin boundaries/interfaces to be built into the film to enhance cross-membrane conductivity. This structure allowed conductivity measurements with impedance spectroscopy to be performed for the first time at room temperature. Cross-membrane conductivity values at low temperature ranges of interest are the higher than any reported values. The conductivity-enhancing mechanisms could be attributed to (1) controlled orientation and increased number density of YSZ nanograin-host interfaces and (2) creation and stabilization of YSZ nanocrystalline phases inside nanopore channels (<10 nm dia.). This successful initial demonstration of host-guest nanostructures is expected to have direct impact on fuel cell technologies, and may also have beneficial use in a broad range of applications such as in solar cells, sensors, chemical/gas separations, catalysis, and magnetic memory devices. This …
Date: November 15, 2005
Creator: Hu, M.Z.
Object Type: Report
System: The UNT Digital Library
2005 Annual Report Summer Research Institute Interfacial and Condensed Phase Chemical Physics (open access)

2005 Annual Report Summer Research Institute Interfacial and Condensed Phase Chemical Physics

The Pacific Northwest National Laboratory (PNNL) hosted its second annual Summer Research Institute in Interfacial and Condensed Phase Chemical Physics from May through September 2005. During this period, sixteen PNNL scientists hosted fourteen young scientists from eleven different universities. Of the fourteen participants, twelve were graduate students; one was a postdoctoral fellow; and one was a university faculty member.
Date: November 15, 2005
Creator: Barlow, Stephan E.
Object Type: Report
System: The UNT Digital Library
Geophysical Techniques for Monitoring CO2 Movement During Sequestration (open access)

Geophysical Techniques for Monitoring CO2 Movement During Sequestration

The relative merits of the seismic, gravity, and electromagnetic (EM) geophysical techniques are examined as monitoring tools for geologic sequestration of carbon dioxide (CO{sub 2}). This work does not represent an exhaustive study, but rather demonstrates the capabilities of a number of geophysical techniques for two synthetic modeling scenarios. The first scenario represents combined CO{sub 2} enhanced oil recovery (EOR) and sequestration in a producing oil field, the Schrader Bluff field on the north slope of Alaska, USA. EOR/sequestration projects in general and Schrader Bluff in particular represent relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and CO{sub 2}). This model represents the most difficult end member of a complex spectrum of possible sequestration scenarios. The time-lapse performance of seismic, gravity, and EM techniques are considered for the Schrader Bluff model. The second scenario is a gas field that in general resembles conditions of Rio Vista reservoir in the Sacramento Basin of California. Surface gravity, and seismic measurements are considered for this model.
Date: November 15, 2005
Creator: Gasperikova, Erika & Hoversten, G. Michael
Object Type: Report
System: The UNT Digital Library
Determination of Fissile Loadings onto Monosodium Titanate (MST) under Conditions Relevant to the Actinide Removal Process Facility (open access)

Determination of Fissile Loadings onto Monosodium Titanate (MST) under Conditions Relevant to the Actinide Removal Process Facility

This report describes the results of an experimental study to measure the sorption of fissile actinides on monosodium titanate (MST) at conditions relevant to operation of the Actinide Removal Process (ARP). The study examined the effect of a single contact of a large volume of radionuclide-spiked simulant solution with a small mass of MST. The volume of simulant to MST (8.5 L to 0.2 g of MST solids) was designed to mimic the maximum phase ratio that occurs between the multiple contacts of MST and waste solution and washing of the accumulated solids cycle of ARP. This work provides the following results. (1) After a contact time of {approx}2 weeks, we measured the following actinide loadings on the MST (average of solution and solids data), Pu: 2.79 {+-} 0.197 wt %, U: 14.0 {+-} 1.04 wt %, and Np: 0.839 {+-} 0.0178 wt %. (2) The plutonium and uranium loadings reported above are considerably higher than previously reported values. The higher loading result from the very high phase ratio and the high initial mass concentrations of uranium and plutonium. A separate upcoming document details the predicted values for this system versus the results. (3) The strontium DF values measured in …
Date: November 15, 2005
Creator: Peters, T
Object Type: Report
System: The UNT Digital Library
Fostering a Renewable Energy Technology Industry: An InternationalComparison of Wind Industry Policy Support Mechanisms (open access)

Fostering a Renewable Energy Technology Industry: An InternationalComparison of Wind Industry Policy Support Mechanisms

This article examines the importance of national and sub-national policies in supporting the development of successful global wind turbine manufacturing companies. We explore the motivations behind establishing a local wind power industry, and the paths that different countries have taken to develop indigenous large wind turbine manufacturing industries within their borders. This is done through a cross-country comparison of the policy support mechanisms that have been employed to directly and indirectly promote wind technology manufacturing in twelve countries. We find that in many instances there is a clear relationship between a manufacturer's success in its home country market and its eventual success in the global wind power market. Whether new wind turbine manufacturing entrants are able to succeed will likely depend in part on the utilization of their turbines in their own domestic market, which in turn will be influenced by the annual size and stability of that market. Consequently, policies that support a sizable, stable market for wind power, in conjunction with policies that specifically provide incentives for wind power technology to be manufactured locally, are most likely to result in the establishment of an internationally competitive wind industry.
Date: November 15, 2005
Creator: Lewis, Joanna & Wiser, Ryan
Object Type: Article
System: The UNT Digital Library
Radiation Damage and Fission Product Release in Zirconium Nitride (open access)

Radiation Damage and Fission Product Release in Zirconium Nitride

None
Date: November 15, 2005
Creator: Egeland, G.W.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Spectra Observed Following Cargo Interrogation (open access)

Spectra Observed Following Cargo Interrogation

The authors present calculations of photon spectra observed following irradiation of bare HEU, HEU embedded in steel and wood cargos, and steel and wood alone. These spectra might be useful starting points for statistical detection efforts aimed at determining whether fissile material is present in a cargo. Detailed comparisons between calculations and experiments are presented and overall quite good (small {chi}{sup 2}) agreement is found. they do not present a complete solution to the problem of determining whether a given spectrum contains contributions from post-fission photons. However, it is shown that a brute-force fitting of observed spectra in terms of a few calculated ''basis'' spectra gives meaningful predictions about the presence of {sup 235}U in cargo. Though this may not be the most powerful method, it does give well defined confidence limits and seems to have strong predictive power.
Date: November 15, 2005
Creator: Pruet, J; Prussin, S; Descalle, M & Hall, J
Object Type: Article
System: The UNT Digital Library
Novel Pulping Technology: Directed Green Liquor Utilization (D-GLU) Pulping (open access)

Novel Pulping Technology: Directed Green Liquor Utilization (D-GLU) Pulping

The general objectives of this new project are the same as those described in the original proposal. Conventional kraft pulping technologies will be modified for significant improvements in pulp production, such as strength, bleachability, and yield by using green liquor, a naturally high, kraft mill-derived sulfidity source. Although split white liquor sulfidity and other high sulfidity procedures have the promise of addressing several of the latter important economic needs of pulp mills, they require considerable engineering/capital retrofits, redesigned production methods, and thus add to overall mill expenditures. Green liquor use, however, possesses the required high sulfidity to obtain in general the benefits attributable to higher sulfidity cooking, without the required capital constraints for implementation. Before introduction of green liquor in our industrial operations, a stronger understanding of its fundamental chemical interaction with the lignin and carbohydrates in US hardwood and softwoods must be obtained. In addition, its effect on bleachability, enhancement of pulp properties, and influence on the overall energy and recovery of the mill requires further exploration before the process witnesses widespread mill use in North America. Thus, proof of principle will be accomplished in this work and the consequent effect of green liquor and other high sulfide sources …
Date: November 15, 2005
Creator: Lucia, Lucian A.
Object Type: Report
System: The UNT Digital Library
High Selectivity Oxygen Delignification (open access)

High Selectivity Oxygen Delignification

Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.
Date: November 15, 2005
Creator: Lucia, Lucian A.
Object Type: Report
System: The UNT Digital Library
High-Tech Means High-Efficiency: The Business Case for EnergyManagement in High-Tech Industries (open access)

High-Tech Means High-Efficiency: The Business Case for EnergyManagement in High-Tech Industries

In the race to apply new technologies in ''high-tech'' facilities such as data centers, laboratories, and clean rooms, much emphasis has been placed on improving service, building capacity, and increasing speed. These facilities are socially and economically important, as part of the critical infrastructure for pharmaceuticals,electronics, communications, and many other sectors. With a singular focus on throughput, some important design issues can be overlooked, such as the energy efficiency of individual equipment (e.g., lasers, routers and switches) as well as the integration of high-tech equipment into the power distribution system and the building envelope. Among technology-based businesses, improving energy efficiency presents an often untapped opportunity to increase profits, enhance process control,maximize asset value, improve the work place environment, and manage a variety of business risks. Oddly enough, the adoption of energy efficiency improvements in this sector lags behind many others. As a result, millions of dollars are left on the table with each year ofoperation.
Date: November 15, 2005
Creator: Shanshoian, Gary; Blazek, Michele; Naughton, Phil; Seese, RobertS.; Mills, Evan & Tschudi, William
Object Type: Report
System: The UNT Digital Library
Energy Assurance Technical Training and Awareness Program/Energy Infrastructure Training and Analysis Center: Final Report, FY2004 (open access)

Energy Assurance Technical Training and Awareness Program/Energy Infrastructure Training and Analysis Center: Final Report, FY2004

This report covers the work completed during Year One (Year One has a 16 month project period) of a five- year Cooperative Agreement (DE-FC26-03NT41895) between the International Union of Operating Engineers (IUOE) National Hazmat Program (OENHP) and the U. S. Department of Energy (DOE) National Energy Technology Laboratory (NETL). This final technical report is being submitted, as required by the Cooperative Agreement, within 90 (calendar) days after the project period ends (December 31, 2004). The resources allocated to Year One of the Cooperative Agreement were adequate for the completion of the required deliverables. All deliverables have been completed and sent to AAD Document Control as directed in the cooperative agreement. The allocation for Year One required 20-25 trainers to be trained in each of five Train-the-Trainer courses and a total of 6,000 workers trained throughout the country. Through cost savings employed for the scheduling and conduct of Train-the-Trainer, instructor refreshers, and direct training classes, 3171 workers have been trained to date. This total incorporates 159 trainers and members from management, local, county, state and federal organizations identified in the Strategic Plan. The largest percentage of personnel trained is heavy equipment operators, and building engineers, which is the largest targeted population …
Date: November 15, 2005
Creator: McCabe, Barbara
Object Type: Report
System: The UNT Digital Library
PID Tuning Using Extremum Seeking (open access)

PID Tuning Using Extremum Seeking

Although proportional-integral-derivative (PID) controllers are widely used in the process industry, their effectiveness is often limited due to poor tuning. Manual tuning of PID controllers, which requires optimization of three parameters, is a time-consuming task. To remedy this difficulty, much effort has been invested in developing systematic tuning methods. Many of these methods rely on knowledge of the plant model or require special experiments to identify a suitable plant model. Reviews of these methods are given in [1] and the survey paper [2]. However, in many situations a plant model is not known, and it is not desirable to open the process loop for system identification. Thus a method for tuning PID parameters within a closed-loop setting is advantageous. In relay feedback tuning [3]-[5], the feedback controller is temporarily replaced by a relay. Relay feedback causes most systems to oscillate, thus determining one point on the Nyquist diagram. Based on the location of this point, PID parameters can be chosen to give the closed-loop system a desired phase and gain margin. An alternative tuning method, which does not require either a modification of the system or a system model, is unfalsified control [6], [7]. This method uses input-output data to …
Date: November 15, 2005
Creator: Killingsworth, Nick J. & Krstic, Miroslav
Object Type: Article
System: The UNT Digital Library
EM Telemetry Tool for Deep Well Drilling Applications: Final Report (open access)

EM Telemetry Tool for Deep Well Drilling Applications: Final Report

This final report discusses the successful development and testing of a deep operational electromagnetic (EM) telemetry system, produced under a cooperative agreement with the United States Department of Energy's National Energy Technology Laboratory. This new electromagnetic telemetry system provides a wireless communication link between sensors deployed deep within oil and gas wells and data acquisition equipment located on the earth's surface. EM based wireless telemetry is a highly appropriate technology for oil and gas exploration in that it avoids the need for thousands of feet of wired connections. In order to achieve the project performance objectives, significant improvements over existing EM telemetry systems were made. These improvements included the development of new technologies that have improved the reliability of the communications link while extending operational depth. A key element of the new design is the incorporation of a data-fusion methodology which enhances the communication receiver's ability to extract very weak signals from large amounts of ambient environmental noise. This innovative data-fusion receiver based system adapts advanced technologies, not normally associated with low-frequency communications, and makes them work within the harsh drilling environments associated with the energy exploration market. Every element of a traditional EM telemetry system design, from power efficiency …
Date: November 15, 2005
Creator: Gabelmann, Jeffrey M.
Object Type: Report
System: The UNT Digital Library
Suppression of mutagenesis by Rad51D-mediated homologous recombination (open access)

Suppression of mutagenesis by Rad51D-mediated homologous recombination

Homologous recombinational repair (HRR) restores chromatid breaks arising during DNA replication and prevents chromosomal rearrangements that can occur from the misrepair of such breaks. In vertebrates, five Rad51 paralogs are identified that contribute in a nonessential but critical manner to HRR efficiency. We constructed and characterized a Rad51D knockout cell line in widely studied CHO cells. The rad51d mutant (51D1) displays sensitivity to a wide spectrum of induced DNA damage, indicating the broad relevance of HRR to genotoxicity. Untreated 51D1 cells exhibit {approx}5-fold elevated chromosomal breaks, a 12-fold increased rate of hprt mutation, and 4- to 10-fold increased rates of gene amplification at the dhfr and CAD loci, respectively. These results explicitly show the quantitative importance of HHR in preventing these types genetic alterations, which are associated with carcinogenesis. Thus, HRR copes in an error-free manner with spontaneous DNA damage encountered during DNA replication, and Rad51D is essential for this fidelity.
Date: November 15, 2005
Creator: Hinz, J M; Tebbs, R S; Wilson, P F; Nham, P B; Salazar, E P; Nagasawa, H et al.
Object Type: Article
System: The UNT Digital Library
Methods for increasing the efficiency of Compton imagers (open access)

Methods for increasing the efficiency of Compton imagers

A Compton scatter camera based on position sensitive, planar Ge and Si(Li) detectors with segmented electrodes is being developed at LLNL. This paper presents various methods that were developed to increase the position resolution of the detectors, the granularity and capability to reconstruct the scattering sequence of the gamma-ray within the detectors. All these methods help to increase the efficiency of the imager, by accepting more photons in the final image. The initial extent and diffusion of charge-carrier clouds inside the semiconductor detectors are found to affect profoundly the fraction of interactions that deposit charge in multiple adjacent electrodes. An accurate identification of these charge-shared interactions is a key factor in correctly reconstructing the position of interactions in the detector.
Date: November 15, 2005
Creator: Mihailescu, L; Vetter, K; Burks, M; Chivers, D; Cunningham, M; Gunter, D et al.
Object Type: Article
System: The UNT Digital Library
Corrosion Enhanced Enrichment of Sulfur and Implications for Alloy 22 (open access)

Corrosion Enhanced Enrichment of Sulfur and Implications for Alloy 22

The uniform corrosion rate of Alloy 22 will define the lifetime of a component such as a waste container if all other degradation modes are not operative. This represents the best-case scenario because the experimentally determined uniform corrosion rates from multi-year tests is 0.01 {micro}m/yr or 0.1 mm in 10,000 years. This lifetime depends on the stability of the passive film over the lifetime of the container; however, this stability is unknown. One potential breakdown mechanism is corrosion-enhanced enrichment of sulfur to the surface leading to sulfur induced breakdown of the passive film. There are numerous studies that confirm that sulfur causes passive film breakdown in nickel based alloys and evidence exists for corrosion enhanced enrichment of sulfur in nickel and nickel alloys. However, neither sulfur enrichment nor sulfur induced breakdown of the passive film on Alloy 22 has been demonstrated. The results of preliminary studies suggest sulfur enrichment does occur at the alloy surface and that sulfur shifts the corrosion potential to more active potentials. No clear affect of sulfur was noted on the corrosion rate but the sulfur concentrations were about only 2-3% of a monolayer, well below the concentrations that are possible.
Date: November 15, 2005
Creator: Jones, R H; Baer, D R; Windisch Jr., C F & Rebak, R B
Object Type: Article
System: The UNT Digital Library
CLEAN HYDROGEN TECHNOLOGY FOR 3-WHEEL TRANSPORTATION IN INDIA (open access)

CLEAN HYDROGEN TECHNOLOGY FOR 3-WHEEL TRANSPORTATION IN INDIA

Hydrogen is a clean burning, non-polluting transportation fuel. It is also a renewable energy carrier that can be produced from non-fossil fuel resources such as solar, wind and biomass. Utilizing hydrogen as an alternative fuel for vehicles will diversify the resources of energy, and reduce dependence on oil in the transportation sector. Additionally, clean burning hydrogen fuel will also alleviate air pollution that is a very severe problem in many parts of world, especially major metropolitan areas in developing countries, such as India and China. In our efforts to foster international collaborations in the research, development, and demonstration of hydrogen technologies, through a USAID/DOE cost-shared project, Energy Conversion Devices, Inc.,(www.ovonic.com) a leading materials and alternative energy company, in collaboration with Bajaj Auto Limited, India's largest three-wheeler taxi manufacturer, has successfully developed and demonstrated prototype hydrogen ICE three-wheelers in the United States and India. ECD's proprietary Ovonic solid-state hydrogen storage technology is utilized on-board to provide a means of compact, low pressure, and safe hydrogen fuel. These prototype hydrogen three-wheelers have demonstrated comparable performance to the original CNG version of the vehicle, achieving a driving range of 130 km. The hydrogen storage system capable of storing 1 kg hydrogen can be …
Date: November 15, 2005
Creator: Sapru, Krishna
Object Type: Report
System: The UNT Digital Library
FY04 LDRD Final Report Stroke Sensor Development Using Microdot Sensor Arrays (open access)

FY04 LDRD Final Report Stroke Sensor Development Using Microdot Sensor Arrays

Stroke is a major cause of mortality and is the primary cause of long-term disability in the United States. A recent study of Stroke incidence, using conservative calculations, suggests that over 700,000 people annually in this country will have a stroke. Of these 700,000, approximately 150,000 will die and 400,000 will be left with a significant deficit; only one quarter will return to an independent--although not necessarily baseline--level of functioning. The costs of caring for victims of stroke in the acute phase, chronic care, and lost productivity amount to 40 billion per year. Of all strokes, approximately 20% are hemorrhagic and 20% are due to small vessel disease. Thus, the number of people with large vessel thromboembolic disease and the target population of this research is greater than 400,000. Currently, the only approved therapy for treatment of acute ischemic stroke is intravenous thrombolytic drugs. While stroke patients who receive these drugs are more likely to have better outcomes than those who do not, their improvement is highly dependent on the initiation of treatment within three hours of the onset of symptoms, with an increased risk of intracranial hemorrhage if the medication is begun outside this time window. With this rigid …
Date: November 15, 2005
Creator: Carter, J. C.; Wilson, T. S.; Alvis, R. M.; Paulson, C. N.; Setlur, U. S.; McBride, M. T. et al.
Object Type: Report
System: The UNT Digital Library
In-Service Design & Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation (open access)

In-Service Design & Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation

This final report on "In-Service Design & Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation" (DE-FG03-01ER54632) consists of a series of summaries of work that has been published, or presented at meetings, or both. It briefly describes results on the following topics: 1) A Transport and Fate Model for Helium and Helium Management; 2) Atomistic Studies of Point Defect Energetics, Dynamics and Interactions; 3) Multiscale Modeling of Fracture consisting of: 3a) A Micromechanical Model of the Master Curve (MC) Universal Fracture Toughness-Temperature Curve Relation, KJc(T - To), 3b) An Embrittlement DTo Prediction Model for the Irradiation Hardening Dominated Regime, 3c) Non-hardening Irradiation Assisted Thermal and Helium Embrittlement of 8Cr Tempered Martensitic Steels: Compilation and Analysis of Existing Data, 3d) A Model for the KJc(T) of a High Strength NFA MA957, 3e) Cracked Body Size and Geometry Effects of Measured and Effective Fracture Toughness-Model Based MC and To Evaluations of F82H and Eurofer 97, 3-f) Size and Geometry Effects on the Effective Toughness of Cracked Fusion Structures; 4) Modeling the Multiscale Mechanics of Flow Localization-Ductility Loss in Irradiation Damaged BCC Alloys; and 5) A Universal Relation Between Indentation Hardness and True Stress-Strain Constitutive Behavior. Further details can …
Date: November 15, 2005
Creator: Odette, G. R. & Lucas, G. E.
Object Type: Report
System: The UNT Digital Library
Quantifying Silica Reactivity in Subsurface Environments: An Integrated Experimental Study of Quartz and Amorphous Silica to Establish a baseline for Glass Durability (open access)

Quantifying Silica Reactivity in Subsurface Environments: An Integrated Experimental Study of Quartz and Amorphous Silica to Establish a baseline for Glass Durability

An immediate EM science need is a reliable kinetic model that predicts long-term waste glass performance.
Date: November 15, 2005
Creator: Dove, Patricia; Han, Nizhou & He, Y. Thomas
Object Type: Report
System: The UNT Digital Library
IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED IN STABLE NANOPOROUS HOST (open access)

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED IN STABLE NANOPOROUS HOST

Composite materials of SBA-15/zeolite Y were synthesized from zeolite Y precursor and a synthesis mixture of mesoporous silicate SBA-15 via a hydrothermal process in the presence of a slightly acidic media of pH 4-6 with 2M H{sub 2}SO{sub 4}. The SBA-15/ZY composites showed Type IV adsorption isotherms, narrow BJH average pore size distribution of 4.9 nm, surface areas up to 800 m{sup 2}2/g and pore volumes 1.03 cm{sup 3}, all comparable to pure SBA-15 synthesized under similar conditions. Chemical analysis revealed Si/Al ratio down to 8.5 in the most aluminated sample, and {sup 27}AlSS MAS NMR confirmed aluminum was in tetrahedral coordination. This method of introduction of Al in pure T{sub d} coordination is effective in comparison to other direct and post synthesis alumination methods. Bronsted acid sites were evident from a pyridinium peak at 1544 cm-1 in the FTIR spectrum after pyridine adsorption, and from NH{sub 3} -TPD experiments. SBA-15/ZY composites showed significant catalytic activities for the dealkylation of isopropylbenzene to benzene and propene, similar to those of commercial zeolite Y. It was observed that higher conversion for catalysts synthesized with high amount of ZY precursor mixture added to the SBA-15. Over all the composites has shown good catalytic …
Date: November 15, 2005
Creator: Ingram, Conrad & Mitchell, Mark
Object Type: Report
System: The UNT Digital Library