High-Energy Calibration of a BGO Detector of the GLAST Burst Monitor (open access)

High-Energy Calibration of a BGO Detector of the GLAST Burst Monitor

The understanding of the instrumental response of the GLAST Burst Monitor BGO detectors at energies above the energy range which is accessible by common laboratory radiation sources (< 4.43 MeV), is important, especially for the later cross-calibration with the LAT response in the overlap region between {approx}20 MeV to 30 MeV. In November 2006 the high-energy calibration of the GBM-BGO spare detector was performed at the small Van-de-Graaff accelerator at SLAC. High-energy gamma-rays from excited {sup 8}Be* (14.6 MeV and 17.5 MeV) and {sup 16}O* (6.1 MeV) were generated through (p, {gamma})-reactions by irradiating a LiF-target. For the calibration at lower energies radioactive sources were used. The results, including spectra, the energy/channel-relation and the dependence of energy resolution are presented.
Date: November 30, 2011
Creator: von Kienlin, Andreas; Fishman, Gerald J.; Briggs, Michael S.; Godfrey, Gary L. & Steinle, Helmut
Object Type: Article
System: The UNT Digital Library
Geomechanical Simulation of Fluid-Driven Fractures (open access)

Geomechanical Simulation of Fluid-Driven Fractures

The project supported graduate students working on experimental and numerical modeling of rock fracture, with the following objectives: (a) perform laboratory testing of fluid-saturated rock; (b) develop predictive models for simulation of fracture; and (c) establish educational frameworks for geologic sequestration issues related to rock fracture. These objectives were achieved through (i) using a novel apparatus to produce faulting in a fluid-saturated rock; (ii) modeling fracture with a boundary element method; and (iii) developing curricula for training geoengineers in experimental mechanics, numerical modeling of fracture, and poroelasticity.
Date: November 30, 2012
Creator: Makhnenko, R.; Nikolskiy, D.; Mogilevskaya, S. & Labuz, J.
Object Type: Report
System: The UNT Digital Library
Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials (open access)

Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials

Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still several key issues that need to be addressed: (1) the cost of OLEDs is very high, largely due to the costly current manufacturing process; (2) the efficiency of OLEDs needs to be improved. This is vital to the success of OLEDs in the FPD and SSL industries; (3) the lifetime of OLEDs, especially blue OLEDs, is the biggest technical challenge. All these issues raise the demand for new organic materials, new device structures, and continued lower-cost fabrication methods. In an attempt to address these issues, we used solution-processing methods to fabricate highly efficient small molecule OLEDs (SMOLEDs); this approach is costeffective in comparison to the more common thermal vacuum evaporation. We also successfully made efficient indium tin oxide (ITO)-free SMOLEDs to further improve the efficiency of …
Date: November 30, 2011
Creator: Cai, Min
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Bottom Production from Fixed-Target to Large Hadron Collider Energies (open access)

Bottom Production from Fixed-Target to Large Hadron Collider Energies

We present a state-of-the-art compilation of the existing bottom production cross sections in elementary collisions, from fixed-target to collider experiments. We then discuss the theoretical uncertainties on the total and differential bottom cross sections in the FONLL approach. In particular, we show total cross sections and kinematical distributions of the bottom hadrons and their decays: B {yields} e/{mu}X, B {yields} D {yields} e/{mu}, and B {yields} J/{psi}X. After seeing that the calculations give a good description of the existing measurements, we present detailed predictions for the LHC experiments in their specific phase space windows. Recent improvements in heavy quark production theory and experimental measurements at colliders, especially for bottom production, have shown that the perturbative QCD framework seems to work rather well, see Refs. [1, 2]. It is important to continue to validate this theoretical framework and its phenomenological inputs, extracted from other measurements, with new data such as that obtained by the CMS collaboration in pp collisions at {radical}s = 7 TeV. We validate the FONLL approach with lower energy data and also compare the results with preliminary LHC data. By showing good agreement between the calculations and the data, we demonstrate we can confidently extrapolate our results to …
Date: November 30, 2010
Creator: Nelson, R. E.; Vogt, R.; Lourenco, C. & Wohri, H. K.
Object Type: Article
System: The UNT Digital Library
Simulating Collisions for Hydrokinetic Turbines. FY2010 Annual Progress Report. (open access)

Simulating Collisions for Hydrokinetic Turbines. FY2010 Annual Progress Report.

Computational fluid dynamics (CFD) simulations of turbulent flow and particle motion are being conducted to evaluate the frequency and severity of collisions between marine and hydrokinetic (MHK) energy devices and debris or aquatic organisms. The work is part of a collaborative research project between Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratories , funded by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Wind and Water Power Program. During FY2010 a reference design for an axial flow MHK turbine was used to develop a computational geometry for inclusion into a CFD model. Unsteady simulations of turbulent flow and the moving MHK turbine blades are being performed and the results used for simulation of particle trajectories. Preliminary results and plans for future work are presented.
Date: November 30, 2010
Creator: Richmond, Marshall C.; Rakowski, Cynthia L.; Perkins, William A. & Serkowski, John A.
Object Type: Report
System: The UNT Digital Library
J/psi production and absorption in p + A and d+Au collisions (open access)

J/psi production and absorption in p + A and d+Au collisions

The level of 'anomalous' charmonium suppression in high-energy heavy-ion collisions and its interpretation as a signal of quark-gluon plasma formation requires a robust understanding of charmonium production and absorption in proton-nucleus collisions. In a previous study we have shown that, contrary to common belief, the so-called J/{psi} 'absorption cross section', {sigma}{sub abs}{sup J/{psi}}, is not a 'universal constant' but, rather, an effective parameter that depends very significantly on the charmonium rapidity and on the collision energy. Here we present ugraded Glauber calculations with the EPS09 parameterization of nuclear modifications of the parton densities. We confirm that the effective 'absorption cross section' depends on the J/{psi} kinematics and the collision energy. We also make further steps towards understanding the physics of the mechanisms behind the observed 'cold nuclear matter' effects.
Date: November 30, 2010
Creator: Vogt, R; Lourenco, C & Woehri, H
Object Type: Article
System: The UNT Digital Library
Recovery Act: 'Carbonsheds' as a Framework for Optimizing United States Carbon Capture and Storage (CCS) Pipeline Transport on a Regional to National Scale (open access)

Recovery Act: 'Carbonsheds' as a Framework for Optimizing United States Carbon Capture and Storage (CCS) Pipeline Transport on a Regional to National Scale

Carbonsheds are regions in which the estimated cost of transporting CO{sub 2} from any (plant) location in the region to the storage site it encompasses is cheaper than piping the CO{sub 2} to a storage site outside the region. We use carbonsheds to analyze the cost of transport and storage of CO{sub 2} in deploying CCS on land and offshore of the continental U.S. We find that onshore the average cost of transport and storage within carbonsheds is roughly $10/t when sources cooperate to reduce transport costs, with the costs increasing as storage options are depleted over time. Offshore transport and storage costs by comparison are found to be roughly twice as expensive but t may still be attractive because of easier access to property rights for sub-seafloor storage as well as a simpler regulatory system, and possibly lower MMV requirements, at least in the deep-ocean where pressures and temperatures would keep the CO{sub 2} negatively buoyant. Agent-based modeling of CCS deployment within carbonsheds under various policy scenarios suggests that the most cost-effective strategy at this point in time is to focus detailed geology characterization of storage potential on only the largest onshore reservoirs where the potential for mitigating emissions …
Date: November 30, 2012
Creator: Pratson, Lincoln
Object Type: Report
System: The UNT Digital Library
Pore-scale mechanisms of gas flow in tight sand reservoirs (open access)

Pore-scale mechanisms of gas flow in tight sand reservoirs

Tight gas sands are unconventional hydrocarbon energy resource storing large volume of natural gas. Microscopy and 3D imaging of reservoir samples at different scales and resolutions provide insights into the coaredo not significantly smaller in size than conventional sandstones, the extremely dense grain packing makes the pore space tortuous, and the porosity is small. In some cases the inter-granular void space is presented by micron-scale slits, whose geometry requires imaging at submicron resolutions. Maximal Inscribed Spheres computations simulate different scenarios of capillary-equilibrium two-phase fluid displacement. For tight sands, the simulations predict an unusually low wetting fluid saturation threshold, at which the non-wetting phase becomes disconnected. Flow simulations in combination with Maximal Inscribed Spheres computations evaluate relative permeability curves. The computations show that at the threshold saturation, when the nonwetting fluid becomes disconnected, the flow of both fluids is practically blocked. The nonwetting phase is immobile due to the disconnectedness, while the permeability to the wetting phase remains essentially equal to zero due to the pore space geometry. This observation explains the Permeability Jail, which was defined earlier by others. The gas is trapped by capillarity, and the brine is immobile due to the dynamic effects. At the same time, in …
Date: November 30, 2010
Creator: Silin, D.; Kneafsey, T.J.; Ajo-Franklin, J.B. & Nico, P.
Object Type: Report
System: The UNT Digital Library
OVERVIEW OF IMPACTS OF TECHNOLOGY DEPLOYMENT ON THE MISSION OF THE DEPARTMENT OF ENERGY OFFICE OF ENVIRONMENTAL MANAGEMENT (open access)

OVERVIEW OF IMPACTS OF TECHNOLOGY DEPLOYMENT ON THE MISSION OF THE DEPARTMENT OF ENERGY OFFICE OF ENVIRONMENTAL MANAGEMENT

The Environmental Management (EM) mission is to complete the safe cleanup of the environmental legacy brought about from five decades of nuclear weapons development and government-sponsored nuclear energy research. The EM program has embraced a mission completion philosophy based on reducing risk and environmental liability over a 40-50 year lifecycle. The Department has made great progress toward safely disposing of its legacy nuclear waste. EM Research and Development (R&D) program management strategies have driven numerous technology and engineering innovations to reduce risk, minimize cleanup costs, and reduce schedules. Engineering and technology investments have provided the engineering foundation, technical assistance, approaches, and technologies that have contributed to moving the cleanup effort forward. These successes include start-up and operation of several waste treatment facilities and processes at the sites.
Date: November 30, 2010
Creator: McCabe, D.; Chamberlain, G.; Looney, B. & Gladden, J.
Object Type: Article
System: The UNT Digital Library
Aggregate Building Simulator (ABS) Methodology Development, Application, and User Manual (open access)

Aggregate Building Simulator (ABS) Methodology Development, Application, and User Manual

As the relationship between the national building stock and various global energy issues becomes a greater concern, it has been deemed necessary to develop a system of predicting the energy consumption of large groups of buildings. Ideally this system is to take advantage of the most advanced energy simulation software available, be able to execute runs quickly, and provide concise and useful results at a level of detail that meets the users needs without inundating them with data. The resulting methodology that was developed allows the user to quickly develop and execute energy simulations of many buildings simultaneously, taking advantage of parallel processing to greatly reduce total simulation times. The result of these simulations can then be rapidly condensed and presented in a useful and intuitive manner.
Date: November 30, 2011
Creator: Dirks, James A. & Gorrissen, Willy J.
Object Type: Report
System: The UNT Digital Library
Carbon Sequestration Monitoring Activities (open access)

Carbon Sequestration Monitoring Activities

In its 'Carbon Sequestration Technology Roadmap and Program Plan 2007' the U.S. Department of Energy (DOE)'s Office of Fossil Energy National Energy Technology Laboratory (NETL) identified as a major objective extended field tests to fully characterize potential carbon dioxide (CO{sub 2}) storage sites and to demonstrate the long-term storage of sequestered carbon (p. 5). Among the challenges in this area are 'improved understanding of CO{sub 2} flow and trapping within the reservoir and the development and deployment of technologies such as simulation models and monitoring systems' (p. 20). The University of Wyoming (UW), following consultations with the NETL, the Wyoming State Geological Survey, and the Governor's office, identified potential for geologic sequestration of impure carbon dioxide (CO{sub 2}) in deep reservoirs of the Moxa Arch. The Moxa Arch is a 120-mile long north-south trending anticline plunging beneath the Wyoming Thrust Belt on the north and bounded on the south by the Uinta Mountains. Several oil and gas fields along the Moxa Arch contain accumulations of natural CO{sub 2}. The largest of these is the La Barge Platform, which encompasses approximately 800 square miles. Several formations may be suitable for storage of impure CO{sub 2} gas, foremost among them the Madison …
Date: November 30, 2010
Creator: Frost, Carol
Object Type: Report
System: The UNT Digital Library
A Germanium Detector with Optimized Compton Veto for High Sensitivity at Low Energy (open access)

A Germanium Detector with Optimized Compton Veto for High Sensitivity at Low Energy

We have built a prototype germanium detector with a Compton veto that is optimized for high sensitivity in the low-energy range around {approx}100 keV. It is specifically designed to address the problem to directly detect plutonium gamma emissions in spent nuclear fuel by non-destructive assay. This is not possible with current detectors due to the large low-energy background of Compton-scattered high-energy radiation from the fission products, whose gamma flux is at least 6 to 7 orders of magnitude higher than the Pu signal. Our instrument is designed to assess the feasibility to selectively suppress the background in the low-energy region around {approx}100 keV with the strongest Pu X-ray and gamma emissions lines. It employs a thin Ge detector with a large Compton veto directly behind it to suppress the background from forward-scattered radiation by anti-coincidence vetoing. This report summarizes the design considerations and the performance of the instrument.
Date: November 30, 2011
Creator: Friedrich, S
Object Type: Report
System: The UNT Digital Library
A new class of accelerated kinetic Monte Carlo algorithms (open access)

A new class of accelerated kinetic Monte Carlo algorithms

Kinetic (aka dynamic) Monte Carlo (KMC) is a powerful method for numerical simulations of time dependent evolution applied in a wide range of contexts including biology, chemistry, physics, nuclear sciences, financial engineering, etc. Generally, in a KMC the time evolution takes place one event at a time, where the sequence of events and the time intervals between them are selected (or sampled) using random numbers. While details of the method implementation vary depending on the model and context, there exist certain common issues that limit KMC applicability in almost all applications. Among such is the notorious 'flicker problem' where the same states of the systems are repeatedly visited but otherwise no essential evolution is observed. In its simplest form the flicker problem arises when two states are connected to each other by transitions whose rates far exceed the rates of all other transitions out of the same two states. In such cases, the model will endlessly hop between the two states otherwise producing no meaningful evolution. In most situation of practical interest, the trapping cluster includes more than two states making the flicker somewhat more difficult to detect and to deal with. Several methods have been proposed to overcome or …
Date: November 30, 2011
Creator: Bulatov, V V; Oppelstrup, T & Athenes, M
Object Type: Report
System: The UNT Digital Library
Building America Industrialized Housing Partnership (BAIHP II) (open access)

Building America Industrialized Housing Partnership (BAIHP II)

This report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the final budget period (BP5) of our contract, January 1, 2010 to November 30, 2010. Highlights from the four previous budget periods are included for context. BAIHP is led by the Florida Solar Energy Center (FSEC) of the University of Central Florida. With over 50 Industry Partners including factory and site builders, work in BP5 was performed in six tasks areas: Building America System Research Management, Documentation and Technical Support; System Performance Evaluations; Prototype House Evaluations; Initial Community Scale Evaluations; Project Closeout, Final Review of BA Communities; and Other Research Activities.
Date: November 30, 2010
Creator: Abernethy, Bob; Chandra, Subrato; Baden, Steven; Cummings, Jim; Cummings, Jamie; Beal, David et al.
Object Type: Report
System: The UNT Digital Library
Development of a Low-Lift Chiller Controller and Simplified Precooling Control Algorithm - Final Report (open access)

Development of a Low-Lift Chiller Controller and Simplified Precooling Control Algorithm - Final Report

KGS Buildings LLC (KGS) and Pacific Northwest National Laboratory (PNNL) have developed a simplified control algorithm and prototype low-lift chiller controller suitable for model-predictive control in a demonstration project of low-lift cooling. Low-lift cooling is a highly efficient cooling strategy conceived to enable low or net-zero energy buildings. A low-lift cooling system consists of a high efficiency low-lift chiller, radiant cooling, thermal storage, and model-predictive control to pre-cool thermal storage overnight on an optimal cooling rate trajectory. We call the properly integrated and controlled combination of these elements a low-lift cooling system (LLCS). This document is the final report for that project.
Date: November 30, 2011
Creator: Gayeski, N.; Armstrong, Peter; Alvira, M.; Gagne, J. & Katipamula, Srinivas
Object Type: Report
System: The UNT Digital Library
TYPE A VERIFICATION REPORT FOR THE HIGH FLUX BEAM REACTOR STACK AND GROUNDS, BROOKHAVEN NATIONAL LABORATORY, UPTON, NEW YORK DCN 5098-SR-08-0 (open access)

TYPE A VERIFICATION REPORT FOR THE HIGH FLUX BEAM REACTOR STACK AND GROUNDS, BROOKHAVEN NATIONAL LABORATORY, UPTON, NEW YORK DCN 5098-SR-08-0

The U.S. Department of Energy (DOE) Order 458.1 requires independent verification (IV) of DOE cleanup projects (DOE 2011). The Oak Ridge Institute for Science and Education (ORISE) has been designated as the responsible organization for IV of the High Flux Beam Reactor (HFBR) Stack and Grounds area at Brookhaven National Laboratory (BNL) in Upton, New York. The IV evaluation may consist of an in-process inspection with document and data reviews (Type A Verification) or a confirmatory survey of the site (Type B Verification). DOE and ORISE determined that a Type A verification of the documents and data for the HFBR Stack and Grounds: Survey Units (SU) 6, 7, and 8 was appropriate based on the initial survey unit classification, the walkover surveys, and the final analytical results provided by the Brookhaven Science Associates (BSA).
Date: November 30, 2011
Creator: Harpenau, Evan
Object Type: Report
System: The UNT Digital Library
Commercial and Industrial Base Intermittent Resource Management Pilot (open access)

Commercial and Industrial Base Intermittent Resource Management Pilot

This scoping study summarizes the challenges with integrating wind and solar generation into the California's electricity grid. These challenges include: Smoothing intra-hour variability; - Absorbing excess renewable energy during over-generation periods; - Addressing morning and evening ramping periods. In addition, there are technical challenges to integrating retail demand response (DR) triggered by the wholesale conditions into the CAISO markets. The study describes the DR programs available to the consumers through the utilities in California and CAISO's ancillary services market because an integration of the wholesale and retail DR requires an understanding of these different offerings and the costs associated with acquiring them. Demand-side active and passive storage systems are proposed as technologies that may be used to mitigate the effects of intermittence due to renewable generation. Commercial building technologies as well as industrial facilities with storage capability are identified as targets for the field tests. Two systems used for ancillary services communications are identified as providing the triggers for DR enablement. Through the field tests, issues related to communication, automation and flexibility of demand-side resources will be explored and the performance of technologies that participate in the field tests will be evaluated. The major outcome of this research is identifying …
Date: November 30, 2010
Creator: Kiliccote, Sila; Sporborg, Pamela; Sheik, Imran; Huffaker, Erich & Piette, Mary Ann
Object Type: Report
System: The UNT Digital Library
TIMELY DELIVERY OF LASER INERTIAL FUSION ENERGY (LIFE) (open access)

TIMELY DELIVERY OF LASER INERTIAL FUSION ENERGY (LIFE)

The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory. A key goal of the NIF is to demonstrate fusion ignition for the first time in the laboratory. Its flexibility allows multiple target designs (both indirect and direct drive) to be fielded, offering substantial scope for optimization of a robust target design. In this paper we discuss an approach to generating gigawatt levels of electrical power from a laser-driven source of fusion neutrons based on these demonstration experiments. This 'LIFE' concept enables rapid time-to-market for a commercial power plant, assuming success with ignition and a technology demonstration program that links directly to a facility design and construction project. The LIFE design makes use of recent advances in diode-pumped, solid-state laser technology. It adopts the paradigm of Line Replaceable Units utilized on the NIF to provide high levels of availability and maintainability and mitigate the need for advanced materials development. A demonstration LIFE plant based on these design principles is described, along with the areas of technology development required prior to plant construction. A goal-oriented, evidence-based approach has been proposed to allow LIFE power plant rollout on a time scale …
Date: November 30, 2010
Creator: Dunne, A M
Object Type: Article
System: The UNT Digital Library
Analysis of NSTX Upgrade OH Magnet and Center Stack (open access)

Analysis of NSTX Upgrade OH Magnet and Center Stack

The new ohmic heating (OH) coil and center stack for the National Spherical Torus Experiment (NSTX) upgrade are required to meet cooling and structural requirements for operation at the enhanced 1 Tesla toroidal field and 2 MA plasma current. The OH coil is designed to be cooled in the time between discharges by water flowing in the center of the coil conductor. We performed resistive heating and thermal hydraulic analyses to optimize coolant channel size to keep the coil temperature below 100 C and meet the required 20 minute cooling time. Coupled electromagnetic, thermal and structural FEA analyses were performed to determine if the OH coil meets the requirements of the structural design criteria. Structural response of the OH coil to its self-field and the field from other coils was analyzed. A model was developed to analyze the thermal and electromagnetic interaction of centerstack components such as the OH coil, TF inner legs and the Bellville washer preload mechanism. Torsional loads from the TF interaction with the OH and poloidal fields are transferred through the TF flag extensions via a torque transfer coupling to the rest of the tokamak structure. A 3D FEA analysis was performed to qualify this design. …
Date: November 30, 2010
Creator: A. Zolfaghari, P. Titus, J. Chrzanowski, A. Salehzadeh, F. Dahlgren
Object Type: Article
System: The UNT Digital Library
Development and Fabrication of Nb3Sn Rutherford Cable for the 11 T DS Dipole Demonstration Model (open access)

Development and Fabrication of Nb3Sn Rutherford Cable for the 11 T DS Dipole Demonstration Model

Fermilab and CERN started the development of 11 T 11-m long Nb{sub 3}Sn dipoles to replace few regular LHC NbTi dipoles and free space for cold collimators in LHC DS areas. An important step in the design of these magnets is the development of the high aspect ratio Nb{sub 3}Sn cable to achieve the nominal field of 11 T at the nominal LHC operating current of 11.85 kA with 20% margin. The keystoned cables 14.7 mm wide with and without a stainless steel core were made out of hard Cu wires and Nb{sub 3}Sn RRP strand 0.7 mm nominal diameter. The cable optimization process was aimed at achieving both mechanical stability and minimal damage to the delicate internal architecture of the Restacked-Rod-Process (RRP) Nb{sub 3}Sn strands with 127 restack design to be used in the magnet short models. Each cable was characterized electrically for transport properties degradation at high field and for low field stability, and metallographically for internal damage.
Date: November 30, 2011
Creator: Barzi, E.; Lombardo, V.; Nobrega, F.; Turrioni, D.; Yamada, R.; Zlobin, A.V. et al.
Object Type: Article
System: The UNT Digital Library
Recovery Act: Molecular Simulation of Dissolved Inorganic Carbons for Underground Brine CO2 Sequestration (open access)

Recovery Act: Molecular Simulation of Dissolved Inorganic Carbons for Underground Brine CO2 Sequestration

To further our understanding and develop the method for measuring the DICs under geological sequestration conditions, we studied the infrared spectra of DICs under high pressure and temperature conditions. First principles simulations of DICs in brine conditions were performed using a highly optimized ReaxFF-DIC forcefield. The thermodynamics stability of each species were determined using the 2PT method, and shown to be consistent with the Reax simulations. More importantly, we have presented the IR spectra of DIC in real brine conditions as a function of temperature and pressure. At near earth conditions, we find a breaking of the O-C-O bending modes into asymmetric and symmetric modes, separated by 100cm{sup -1} at 400K and 5 GPa. These results can now be used to calibrate FTIR laser measurements.
Date: November 30, 2012
Creator: Goddard, William
Object Type: Report
System: The UNT Digital Library
Utilizing Electric Vehicles to Assist Integration of Large Penetrations of Distributed Photovoltaic Generation Capacity (open access)

Utilizing Electric Vehicles to Assist Integration of Large Penetrations of Distributed Photovoltaic Generation Capacity

Executive Summary Introduction and Motivation This analysis provides the first insights into the leveraging potential of distributed photovoltaic (PV) technologies on rooftop and electric vehicle (EV) charging. Either of the two technologies by themselves - at some high penetrations – may cause some voltage control challenges or overloading problems, respectively. But when combined, there – at least intuitively – could be synergistic effects, whereby one technology mitigates the negative impacts of the other. High penetration of EV charging may overload existing distribution system components, most prominently the secondary transformer. If PV technology is installed at residential premises or anywhere downstream of the secondary transformer, it will provide another electricity source thus, relieving the loading on the transformers. Another synergetic or mitigating effect could be envisioned when high PV penetration reverts the power flow upward in the distribution system (from the homes upstream into the distribution system). Protection schemes may then no longer work and voltage violation (exceeding the voltage upper limited of the ANSI voltage range) may occur. In this particular situation, EV charging could absorb the electricity from the PV, such that the reversal of power flow can be reduced or alleviated. Given these potential mutual synergistic behaviors of …
Date: November 30, 2012
Creator: Tuffner, Francis K.; Chassin, Forrest S.; Kintner-Meyer, Michael CW & Gowri, Krishnan
Object Type: Report
System: The UNT Digital Library
Charmless Hadronic B Decays at Belle and BaBar (open access)

Charmless Hadronic B Decays at Belle and BaBar

I report on recent measurements from the Belle and BABAR collaborations on the decay of the B meson to hadronic final states without a charm quark. The study of the branching fractions and angular distributions of B meson decays to hadronic final states without a charm quark probes the dynamics of both the weak and strong interactions, and plays an important role in understanding CP Violation (CPV) in the quark sector. CP Violation at the B factories is described graphically by a triangle with sides formed from the CKM matrix elements V{sub qd}V*{sub qb} (q = u, c, t) and internal angles {alpha}, {beta} {gamma} (or {phi}{sub 2}, {phi}{sub 1}, {phi}{sub 3}). Discrepancies in the measured values of the sides and angles could be an indication of New Physics beyond the Standard Model (SM) due to enhanced branching fractions or modified CP asymmetries. The experimental measurements of branching fractions, CP asymmetries, polarization and phases (both weak and strong) can be compared to theoretical models based on, for example, QCD factorization, SU(3) symmetry and Lattice QCD.
Date: November 30, 2011
Creator: Wilson, F. F.
Object Type: Article
System: The UNT Digital Library
Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate-Scale Hydrodynamic Model (open access)

Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate-Scale Hydrodynamic Model

The Washington State Department of Ecology contracted with Pacific Northwest National Laboratory to develop an intermediate-scale hydrodynamic and water quality model to study dissolved oxygen and nutrient dynamics in Puget Sound and to help define potential Puget Sound-wide nutrient management strategies and decisions. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or dominate human impacts to dissolved oxygen levels in the sensitive areas. In this study, an intermediate-scale hydrodynamic model of Puget Sound was developed to simulate the hydrodynamics of Puget Sound and the Northwest Straits for the year 2006. The model was constructed using the unstructured Finite Volume Coastal Ocean Model. The overall model grid resolution within Puget Sound in its present configuration is about 880 m. The model was driven by tides, river inflows, and meteorological forcing (wind and net heat flux) and simulated tidal circulations, temperature, and salinity distributions in Puget Sound. The model was validated against observed data of water surface elevation, velocity, temperature, and salinity at various stations within the study domain. …
Date: November 30, 2010
Creator: Yang, Zhaoqing; Khangaonkar, Tarang; Labiosa, Rochelle G. & Kim, Taeyun
Object Type: Report
System: The UNT Digital Library