Opportunities and Challenges for Development of a Mature Concentrating Photovoltaic Power Industry (Revision) (open access)

Opportunities and Challenges for Development of a Mature Concentrating Photovoltaic Power Industry (Revision)

This report summarizes the current status of the CPV industry and is updated from previous versions to include information from the last year. New information presented at the CPV-8 conference is included along with the addition of new companies that have announced their interest in CPV, and estimates of production volumes for 2011 and 2012.
Date: November 1, 2012
Creator: Kurtz, S.
Object Type: Report
System: The UNT Digital Library
Microstructural Studies of Uranium-7wt%Molybdenum/Aluminum-2wt%Silicon Dispersion Fuel (open access)

Microstructural Studies of Uranium-7wt%Molybdenum/Aluminum-2wt%Silicon Dispersion Fuel

Document is a thesis.
Date: November 1, 2010
Creator: Miller, Brandon D.
Object Type: Report
System: The UNT Digital Library
Some Specific CASL Requirements for Advanced Multiphase Flow Simulation of Light Water Reactors (open access)

Some Specific CASL Requirements for Advanced Multiphase Flow Simulation of Light Water Reactors

Because of the diversity of physical phenomena occuring in boiling, flashing, and bubble collapse, and of the length and time scales of LWR systems, it is imperative that the models have the following features: • Both vapor and liquid phases (and noncondensible phases, if present) must be treated as compressible. • Models must be mathematically and numerically well-posed. • The models methodology must be multi-scale. A fundamental derivation of the multiphase governing equation system, that should be used as a basis for advanced multiphase modeling in LWR coolant systems, is given in the Appendix using the ensemble averaging method. The remainder of this work focuses specifically on the compressible, well-posed, and multi-scale requirements of advanced simulation methods for these LWR coolant systems, because without these are the most fundamental aspects, without which widespread advancement cannot be claimed. Because of the expense of developing multiple special-purpose codes and the inherent inability to couple information from the multiple, separate length- and time-scales, efforts within CASL should be focused toward development of a multi-scale approaches to solve those multiphase flow problems relevant to LWR design and safety analysis. Efforts should be aimed at developing well-designed unified physical/mathematical and high-resolution numerical models for compressible, …
Date: November 1, 2010
Creator: Berry, R. A.
Object Type: Report
System: The UNT Digital Library
Advanced inactive materials for improved lithium-ion battery safety. (open access)

Advanced inactive materials for improved lithium-ion battery safety.

None
Date: November 1, 2012
Creator: Orendorff, Christopher J.; Nagasubramanian, Ganesan; Lambert, Timothy N.; Fenton, Kyle Ross; Apblett, Christopher Alan; Shaddix, Christopher R. et al.
Object Type: Report
System: The UNT Digital Library
Meeting Summary Advanced Light Water Reactor Fuels Industry Meeting Washington DC October 27 - 28, 2011 (open access)

Meeting Summary Advanced Light Water Reactor Fuels Industry Meeting Washington DC October 27 - 28, 2011

The Advanced LWR Fuel Working Group first met in November of 2010 with the objective of looking 20 years ahead to the role that advanced fuels could play in improving light water reactor technology, such as waste reduction and economics. When the group met again in March 2011, the Fukushima incident was still unfolding. After the March meeting, the focus of the program changed to determining what we could do in the near term to improve fuel accident tolerance. Any discussion of fuels with enhanced accident tolerance will likely need to consider an advanced light water reactor with enhanced accident tolerance, along with the fuel. The Advanced LWR Fuel Working Group met in Washington D.C. on October 72-18, 2011 to continue discussions on this important topic.
Date: November 1, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
PRODUCTION TPBAR INPUTS FOR CORE DESIGNERS TTQP-1-116 Rev 15 (open access)

PRODUCTION TPBAR INPUTS FOR CORE DESIGNERS TTQP-1-116 Rev 15

The purpose of this controlled document is to provide a convenient reference for tritiumproducing burnable absorber rod (TPBAR) parameters used by reactor core designers.
Date: November 1, 2012
Creator: Collins, Brian A.; Love, Edward F. & Thornhill, Cheryl K.
Object Type: Report
System: The UNT Digital Library
Energy and water in the Great Lakes. (open access)

Energy and water in the Great Lakes.

The nexus between thermoelectric power production and water use is not uniform across the U.S., but rather differs according to regional physiography, demography, power plant fleet composition, and the transmission network. That is, in some regions water demand for thermoelectric production is relatively small while in other regions it represents the dominate use. The later is the case for the Great Lakes region, which has important implications for the water resources and aquatic ecology of the Great Lakes watershed. This is today, but what about the future? Projected demographic trends, shifting lifestyles, and economic growth coupled with the threat of global climate change and mounting pressure for greater U.S. energy security could have profound effects on the region's energy future. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decisionmaking is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place. Based on these confounding needs, the objective of this effort is to develop Great Lakes-specific methods and tools to integrate energy and water resource planning and thereby support the …
Date: November 1, 2011
Creator: Tidwell, Vincent Carroll
Object Type: Report
System: The UNT Digital Library
LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE (open access)

LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cell and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at …
Date: November 1, 2011
Creator: O'Brien, J. E.; O'Brien, R. C.; Zhang, X.; Tao, G. & Butler, B. J.
Object Type: Article
System: The UNT Digital Library
Real-Time Dynamic Brake Assessment Proof of Concept Final Report (open access)

Real-Time Dynamic Brake Assessment Proof of Concept Final Report

This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes …
Date: November 1, 2011
Creator: Lascurain, Mary Beth; Franzese, Oscar & Capps, Gary J
Object Type: Report
System: The UNT Digital Library
Assessment of Geochemical Environment for the Proposed INL Remote-Handled Low-Level Waste Disposal Facility (open access)

Assessment of Geochemical Environment for the Proposed INL Remote-Handled Low-Level Waste Disposal Facility

Conservative sorption parameters have been estimated for the proposed Idaho National Laboratory Remote-Handled Low-Level Waste Disposal Facility. This analysis considers the influence of soils, concrete, and steel components on water chemistry and the influence of water chemistry on the relative partitioning of radionuclides over the life of the facility. A set of estimated conservative distribution coefficients for the primary media encountered by transported radionuclides has been recommended. These media include the vault system, concrete-sand-gravel mix, alluvium, and sedimentary interbeds. This analysis was prepared to support the performance assessment required by U.S. Department of Energy Order 435.1, 'Radioactive Waste Management.' The estimated distribution coefficients are provided to support release and transport calculations of radionuclides from the waste form through the vadose zone. A range of sorption parameters are provided for each key transport media, with recommended values being conservative. The range of uncertainty has been bounded through an assessment of most-likely-minimum and most-likely-maximum distribution coefficient values. The range allows for adequate assessment of mean facility performance while providing the basis for uncertainty analysis.
Date: November 1, 2011
Creator: Cooper, D. Craig
Object Type: Report
System: The UNT Digital Library
International perspectives on mitigating laboratory biorisks. (open access)

International perspectives on mitigating laboratory biorisks.

The International Perspectives on Mitigating Laboratory Biorisks workshop, held at the Renaissance Polat Istanbul Hotel in Istanbul, Republic of Turkey, from October 25 to 27, 2010, sought to promote discussion between experts and stakeholders from around the world on issues related to the management of biological risk in laboratories. The event was organized by Sandia National Laboratories International Biological Threat Reduction program, on behalf of the US Department of State Biosecurity Engagement Program and the US Department of Defense Cooperative Biological Engagement Program. The workshop came about as a response to US Under Secretary of State Ellen O. Tauscher's statements in Geneva on December 9, 2009, during the Annual Meeting of the States Parties to the Biological Weapons Convention (BWC). Pursuant to those remarks, the workshop was intended to provide a forum for interested countries to share information on biorisk management training, standards, and needs. Over the course of the meeting's three days, participants discussed diverse topics such as the role of risk assessment in laboratory biorisk management, strategies for mitigating risk, measurement of performance and upkeep, international standards, training and building workforce competence, and the important role of government and regulation. The meeting concluded with affirmations of the utility …
Date: November 1, 2010
Creator: Pinard, William J. & Salazar, Carlos A.
Object Type: Report
System: The UNT Digital Library
Wireless Sensing, Monitoring and Optimization for Campus-Wide Steam Distribution (open access)

Wireless Sensing, Monitoring and Optimization for Campus-Wide Steam Distribution

The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize energy delivery within the steam distribution system. Our approach leverages an integrated wireless sensor and real-time monitoring capability. We make real time state assessment on the steam trap health and steam flow estimate of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observing measurements of these sensors with state estimators for system health. Our assessments are based on a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps status. Experimental results show that the energy signature scheme has the potential to identify different steam trap states and it has sufficient sensitivity to estimate flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy …
Date: November 1, 2011
Creator: Olama, Mohammed M.; Allgood, Glenn O.; Kuruganti, Phani Teja; Sukumar, Sreenivas R.; Woodworth, Ken & Lake, Joe E.
Object Type: Report
System: The UNT Digital Library
Small-Scale Spray Releases: Initial Aerosol Test Results (open access)

Small-Scale Spray Releases: Initial Aerosol Test Results

One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic …
Date: November 1, 2012
Creator: Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C. et al.
Object Type: Report
System: The UNT Digital Library
A study of algal biomass potential in selected Canadian regions. (open access)

A study of algal biomass potential in selected Canadian regions.

A dynamic assessment model has been developed for evaluating the potential algal biomass and extracted biocrude productivity and costs, using nutrient and water resources available from waste streams in four regions of Canada (western British Columbia, Alberta oil fields, southern Ontario, and Nova Scotia). The purpose of this model is to help identify optimal locations in Canada for algae cultivation and biofuel production. The model uses spatially referenced data across the four regions for nitrogen and phosphorous loads in municipal wastewaters, and CO{sub 2} in exhaust streams from a variety of large industrial sources. Other data inputs include land cover, and solar insolation. Model users can develop estimates of resource potential by manipulating model assumptions in a graphic user interface, and updated results are viewed in real time. Resource potential by location can be viewed in terms of biomass production potential, potential CO{sub 2} fixed, biocrude production potential, and area required. The cost of producing algal biomass can be estimated using an approximation of the distance to move CO{sub 2} and water to the desired land parcel and an estimation of capital and operating costs for a theoretical open pond facility. Preliminary results suggest that in most cases, the CO{sub …
Date: November 1, 2011
Creator: Passell, Howard David; Roach, Jesse Dillon & Klise, Geoffrey T.
Object Type: Report
System: The UNT Digital Library
Experimental Evaluation of Installed Cooking Exhaust Fan Performance (open access)

Experimental Evaluation of Installed Cooking Exhaust Fan Performance

The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range (MOR) units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one wall-mount chimney), four under-cabinet open hoods, and two open hoods with chimney mounts over islands. Performance assessment included measurement of airflow and sound levels across fan settings and experiments to quantify the contemporaneous capture efficiency for the exhaust generated by natural gas cooking burners.Capture efficiency is defined as the fraction of generated pollutants that are removed through the exhaust and thus not available for inhalation of household occupants. Capture efficiency (CE) was assessed for various configurations of burner use (e.g., single front, single back, combination of one front and one back, oven) and fan speed setting. Measured airflow rates were substantially lower than the levels noted in product literature for many of the units. This shortfall was observed for several units costing in excess of $1000. Capture …
Date: November 1, 2010
Creator: Singer, Brett C.; Delp, William W. & Apte, Michael G.
Object Type: Report
System: The UNT Digital Library
FY2011 Progress Report: Agreement 8697 - NOx Sensor Development (open access)

FY2011 Progress Report: Agreement 8697 - NOx Sensor Development

Objectives are: (1) Develop an inexpensive, rapid-response, high-sensitivity and selective electrochemical sensor for oxides of nitrogen (NO{sub x}) for compression-ignition, direct-injection (CIDI) OBD II systems; (2) Explore and characterize novel, effective sensing methodologies based on impedance measurements and designs and manufacturing methods that are compatible with mass fabrication; and (3) Collaborate with industry in order to (ultimately) transfer the technology to a supplier for commercialization. Approach used is: (1) Use an ionic (O{sup 2-}) conducting ceramic as a solid electrolyte and metal or metal-oxide electrodes; (2) Correlate NO{sub x} concentration with changes in cell impedance; (3) Evaluate sensing mechanisms and aging effects on long-term performance using electrochemical techniques; and (4) Collaborate with Ford Research Center to optimize sensor performance and perform dynamometer and on-vehicle testing. Work in FY2011 focused on using an algorithm developed in FY2010 in a simplified strategy to demonstrate how data from controlled laboratory evaluation could be applied to data from real-world engine testing. The performance of a Au wire prototype sensor was evaluated in the laboratory with controlled gas compositions and in dynamometer testing with diesel exhaust. The laboratory evaluation indicated a nonlinear dependence of the NO{sub x} and O{sub 2} sensitivity with concentration. For both …
Date: November 1, 2011
Creator: Woo, L. Y. & Glass, R. S.
Object Type: Report
System: The UNT Digital Library
A Fisheye Lens for Many Point PDV (open access)

A Fisheye Lens for Many Point PDV

The features of the fisheye lens are illustrated, including a design with reflector prisms. The fisheye fiber map and the beam footprint are shown. Fisheye rough-angle metrology was done and results presented. Next steps are given, including a smaller top fisheye lens element, longer reflector prisms with better mounting, and different fiber arrangements.
Date: November 1, 2011
Creator: Frogget, B.
Object Type: Article
System: The UNT Digital Library
The Importance of Motor Shaft Alignment, Motor Systems Tip Sheet #4 (Fact Sheet) (open access)

The Importance of Motor Shaft Alignment, Motor Systems Tip Sheet #4 (Fact Sheet)

Motor tip sheet for the Advanced Manufacturing Office.
Date: November 1, 2012
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Ecological outcomes and evaluation of success in passively restored southeastern depressional wetlands. (open access)

Ecological outcomes and evaluation of success in passively restored southeastern depressional wetlands.

Abstract: Depressional wetlands may be restored passively by disrupting prior drainage to recover original hydrology and relying on natural revegetation. Restored hydrology selects for wetland vegetation; however, depression geomorphology constrains the achievable hydroperiod, and plant communities are influenced by hydroperiod and available species pools. Such constraints can complicate assessments of restoration success. Sixteen drained depressions in South Carolina, USA, were restored experimentally by forest clearing and ditch plugging for potential crediting to a mitigation bank. Depressions were assigned to alternate revegetation methods representing desired targets of herbaceous and wet-forest communities. After five years, restoration progress and revegetation methods were evaluated. Restored hydroperiods differed among wetlands, but all sites developed diverse vegetation of native wetland species. Vegetation traits were influenced by hydroperiod and the effects of early drought, rather than by revegetation method. For mitigation banking, individual wetlands were assessed for improvement from pre-restoration condition and similarity to assigned reference type. Most wetlands met goals to increase hydroperiod, herb-species dominance, and wetland-plant composition. Fewer wetlands achieved equivalence to reference types because some vegetation targets were incompatible with depression hydroperiods and improbable without intensive management. The results illustrated a paradox in judging success when vegetation goals may be unsuited to system constraints.
Date: November 1, 2010
Creator: De Steven, Diane; Sharitz, Rebecca R. & Barton, Christopher, D.
Object Type: Article
System: The UNT Digital Library
Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems (open access)

Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems

The ability to reliably predict flow and transport in fractured porous rock is an essential condition for performance evaluation of geologic (underground) nuclear waste repositories. In this report, a suite of programs (TRIPOLY code) for calculating and analyzing flow and transport in two-dimensional fracture-matrix systems is used to model single-well injection-withdrawal (SWIW) tracer tests. The SWIW test, a tracer test using one well, is proposed as a useful means of collecting data for site characterization, as well as estimating parameters relevant to tracer diffusion and sorption. After some specific code adaptations, we numerically generated a complex fracture-matrix system for computation of steady-state flow and tracer advection and dispersion in the fracture network, along with solute exchange processes between the fractures and the porous matrix. We then conducted simulations for a hypothetical but workable SWIW test design and completed parameter sensitivity studies on three physical parameters of the rock matrix - namely porosity, diffusion coefficient, and retardation coefficient - in order to investigate their impact on the fracture-matrix solute exchange process. Hydraulic fracturing, or hydrofracking, is also modeled in this study, in two different ways: (1) by increasing the hydraulic aperture for flow in existing fractures and (2) by adding a …
Date: November 1, 2010
Creator: Cotte, F.P.; Doughty, C. & Birkholzer, J.
Object Type: Report
System: The UNT Digital Library
Transgenic Plants Lower the Costs of Cellulosic Biofuels (Fact Sheet) (open access)

Transgenic Plants Lower the Costs of Cellulosic Biofuels (Fact Sheet)

A new transgenic maize was observed to be less recalcitrant than wild-type biomass, as manifested through lower severity requirements to achieve comparable levels of conversion. Expression of a single gene derived from bacteria in plants has resulted in transgenic plants that are easier and cheaper to convert into biofuels. Part of the high production cost of cellulosic biofuels is the relatively poor accessibility of substrates to enzymes due to the strong associations between plant cell wall components. This biomass recalcitrance makes costly thermochemical pretreatment necessary. Scientists at the National Renewable Energy Laboratory (NREL) have created transgenic maize expressing an active glycosyl hydrolase enzyme, E1 endoglucanase, originally isolated from a thermophilic bacterium, Acidothermus cellulolyticus. This engineered feedstock was observed to be less recalcitrant than wild-type biomass when subjected to reduced severity pretreatments and post-pretreatment enzymatic hydrolysis. This reduction in recalcitrance was manifested through lower severity requirements to achieve comparable levels of conversion of wild-type biomass. The improvements observed are significant enough to positively affect the economics of the conversion process through decreased capital construction costs and decreased degradation products and inhibitor formation.
Date: November 1, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Elements of a pragmatic approach for dealing with bias and uncertainty in experiments through predictions : experiment design and data conditioning; %22real space%22 model validation and conditioning; hierarchical modeling and extrapolative prediction. (open access)

Elements of a pragmatic approach for dealing with bias and uncertainty in experiments through predictions : experiment design and data conditioning; %22real space%22 model validation and conditioning; hierarchical modeling and extrapolative prediction.

This report explores some important considerations in devising a practical and consistent framework and methodology for utilizing experiments and experimental data to support modeling and prediction. A pragmatic and versatile 'Real Space' approach is outlined for confronting experimental and modeling bias and uncertainty to mitigate risk in modeling and prediction. The elements of experiment design and data analysis, data conditioning, model conditioning, model validation, hierarchical modeling, and extrapolative prediction under uncertainty are examined. An appreciation can be gained for the constraints and difficulties at play in devising a viable end-to-end methodology. Rationale is given for the various choices underlying the Real Space end-to-end approach. The approach adopts and refines some elements and constructs from the literature and adds pivotal new elements and constructs. Crucially, the approach reflects a pragmatism and versatility derived from working many industrial-scale problems involving complex physics and constitutive models, steady-state and time-varying nonlinear behavior and boundary conditions, and various types of uncertainty in experiments and models. The framework benefits from a broad exposure to integrated experimental and modeling activities in the areas of heat transfer, solid and structural mechanics, irradiated electronics, and combustion in fluids and solids.
Date: November 1, 2011
Creator: Romero, Vicente Jose
Object Type: Report
System: The UNT Digital Library
Transverse modes and instabilities of a bunched beam with space charge and resistive wall impedance (open access)

Transverse modes and instabilities of a bunched beam with space charge and resistive wall impedance

Transverse instability of a bunch in a ring accelerator is considered with space charge and wakefield taken into account. It is assumed that space charge tune shift significantly exceeds the synchrotron tune. Bunch spectrum, instability growth rate, and effects of chromaticity are studied with different bunch and wake forms. Fast instability caused by coupling of transverse modes is studied in detail. It is shown that, for monotonic wakes, the transverse mode coupling instability is possible only with a certain sign of the wake. Its threshold and growth rate are calculated precisely over a wide range of parameters.
Date: November 1, 2011
Creator: Balbekov, V.
Object Type: Article
System: The UNT Digital Library
A general model of resource production and exchange in systems of interdependent specialists. (open access)

A general model of resource production and exchange in systems of interdependent specialists.

Infrastructures are networks of dynamically interacting systems designed for the flow of information, energy, and materials. Under certain circumstances, disturbances from a targeted attack or natural disasters can cause cascading failures within and between infrastructures that result in significant service losses and long recovery times. Reliable interdependency models that can capture such multi-network cascading do not exist. The research reported here has extended Sandia's infrastructure modeling capabilities by: (1) addressing interdependencies among networks, (2) incorporating adaptive behavioral models into the network models, and (3) providing mechanisms for evaluating vulnerability to targeted attack and unforeseen disruptions. We have applied these capabilities to evaluate the robustness of various systems, and to identify factors that control the scale and duration of disruption. This capability lays the foundation for developing advanced system security solutions that encompass both external shocks and internal dynamics.
Date: November 1, 2011
Creator: Conrad, Stephen Hamilton; Finley, Patrick D.; Beyeler, Walter Eugene; Brown, Theresa Jean; Glass, Robert John, Jr.; Breen, Peter et al.
Object Type: Report
System: The UNT Digital Library