A Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp-bar Collisions at sqrt(s) = 1.96 TeV (open access)

A Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp-bar Collisions at sqrt(s) = 1.96 TeV

None
Date: January 18, 2013
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic (open access)

A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic

Topic models have been used successfully for a variety of problems, often in the form of application-specific extensions of the basic Latent Dirichlet Allocation (LDA) model. Because deriving these new models in order to encode domain knowledge can be difficult and time-consuming, we propose the Fold-all model, which allows the user to specify general domain knowledge in First-Order Logic (FOL). However, combining topic modeling with FOL can result in inference problems beyond the capabilities of existing techniques. We have therefore developed a scalable inference technique using stochastic gradient descent which may also be useful to the Markov Logic Network (MLN) research community. Experiments demonstrate the expressive power of Fold-all, as well as the scalability of our proposed inference method.
Date: January 18, 2011
Creator: Andrzejewski, D.; Zhu, X.; Craven, M. & Recht, B.
Object Type: Article
System: The UNT Digital Library
Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction (open access)

Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction

None
Date: January 18, 2013
Creator: Aznauryan, I. G.; Bashir, A.; Braun, V.; Brodsky, S. J.; Burkert, V. D.; Chang, L. et al.
Object Type: Article
System: The UNT Digital Library
Treated Wood Waste Identification and Characterization (open access)

Treated Wood Waste Identification and Characterization

None
Date: January 18, 2012
Creator: Belue, A
Object Type: Report
System: The UNT Digital Library
NEW MATERIALS DEVELOPED TO MEET REGULATORY AND TECHNICAL REQUIREMENTS ASSOCIATED WITH IN-SITU DECOMMISSIONING OF NUCLEAR REACTORS AND ASSOCIATED FACILITIES (open access)

NEW MATERIALS DEVELOPED TO MEET REGULATORY AND TECHNICAL REQUIREMENTS ASSOCIATED WITH IN-SITU DECOMMISSIONING OF NUCLEAR REACTORS AND ASSOCIATED FACILITIES

For the 2010 ANS Embedded Topical Meeting on Decommissioning, Decontamination and Reutilization and Technology, Savannah River National Laboratory's Mike Serrato reported initial information on the newly developed specialty grout materials necessary to satisfy all requirements associated with in-situ decommissioning of P-Reactor and R-Reactor at the U.S. Department of Energy's Savannah River Site. Since that report, both projects have been successfully completed and extensive test data on both fresh properties and cured properties has been gathered and analyzed for a total of almost 191,150 m{sup 3} (250,000 yd{sup 3}) of new materials placed. The focus of this paper is to describe the (1) special grout mix for filling the P-Reactor vessel (RV) and (2) the new flowable structural fill materials used to fill the below grade portions of the facilities. With a wealth of data now in hand, this paper also captures the test results and reports on the performance of these new materials. Both reactors were constructed and entered service in the early 1950s, producing weapons grade materials for the nation's defense nuclear program. R-Reactor was shut down in 1964 and the P-Reactor in 1991. In-situ decommissioning (ISD) was selected for both facilities and performed as Comprehensive Environmental Response, Compensations …
Date: January 18, 2012
Creator: Blankenship, J.; Langton, C.; Musall, J. & Griffin, W.
Object Type: Article
System: The UNT Digital Library
Measurement of Mixing and CP Violation in the Two-Body D0 decays to KK, pipi and Kpi with the BaBar Experiment (open access)

Measurement of Mixing and CP Violation in the Two-Body D0 decays to KK, pipi and Kpi with the BaBar Experiment

None
Date: January 18, 2013
Creator: Casarosa, Giulia
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Study of Vertical Gas Jets in a Bubbling Fluidized Bed (open access)

A Study of Vertical Gas Jets in a Bubbling Fluidized Bed

A detailed experimental study of a vertical gas jet impinging a fluidized bed of particles has been conducted with the help of Laser Doppler Velocimetry measurements. Mean and fluctuating velocity profiles of the two phases have been presented and analyzed for different fluidization states of the emulsion. The results of this work would be greatly helpful in understanding the complex two-phase mixing phenomenon that occurs in bubbling beds, such as in coal and biomass gasification, and also in building more fundamental gas-solid Eulerian/Lagrangian models which can be incorporated into existing CFD codes. Relevant simulations to supplement the experimental findings have also been conducted using the Department of Energy’s open source code MFIX. The goal of these simulations was two-fold. One was to check the two-dimensional nature of the experimental results. The other was an attempt to improve the existing dense phase Eulerian framework through validation with the experimental results. In particular the sensitivity of existing frictional models in predicting the flow was investigated. The simulation results provide insight on wall-bounded turbulent jets and the effect frictional models have on gas-solid bubbling flows. Additionally, some empirical minimum fluidization correlations were validated for non-spherical particles with the idea of extending the present …
Date: January 18, 2011
Creator: Ceccio, Steven & Curtis, Jennifer
Object Type: Report
System: The UNT Digital Library
Energy Savings Assessment for Digital-to-Analog Converter Boxes (open access)

Energy Savings Assessment for Digital-to-Analog Converter Boxes

The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.
Date: January 18, 2011
Creator: Cheung, Hoi Ying Iris; Meier, Alan & Brown, Richard
Object Type: Article
System: The UNT Digital Library
FOAM FORMATION IN THE SALTSTONE PRODUCTION FACILITY: EVALUATION OF SOURCES AND MITIGATION (open access)

FOAM FORMATION IN THE SALTSTONE PRODUCTION FACILITY: EVALUATION OF SOURCES AND MITIGATION

The Saltstone Production Facility receives waste from Tank 50H for treatment. Influents into Tank 50H include the Effluent Treatment Project waste concentrate, H-Canyon low activity waste and General Purpose Evaporator bottoms, Modular Caustic Side Solvent Extraction Unit decontaminated salt solution, and salt solution from the Deliquification, Dissolution and Adjust campaign. Using the Waste Characterization System (WCS), this study tracks the relative amounts of each influent into Tank 50H, as well as the total content of Tank 50H, in an attempt to identify the source of foaming observed in the Saltstone Production Facility hopper. Saltstone has been using antifoam as part of routine processing with the restart of the facility in December 2006. It was determined that the maximum admix usage in the Saltstone Production Facility, both antifoam and set retarder, corresponded with the maximum concentration of H-Canyon low activity waste in Tank 50H. This paper also evaluates archived salt solutions from Waste Acceptance Criteria analysis for propensity to foam and the antifoam dosage required to mitigate foaming. It was determined that Effluent Treatment Project contributed to the expansion factor (foam formation) and General Purpose Evaporator contributed to foaminess (persistence). It was also determined that undissolved solids contribute to foam persistence. …
Date: January 18, 2011
Creator: Cozzi, A.
Object Type: Report
System: The UNT Digital Library
Imaging nanoscale magnetic structures with polarized soft x-ray photons (open access)

Imaging nanoscale magnetic structures with polarized soft x-ray photons

Imaging nanoscale magnetic structures and their fast dynamics is scientifically interesting and technologically of highest relevance. The combination of circularly polarized soft X-ray photons which provide a strong X-ray magnetic circular dichroism effect at characteristic X-ray absorption edges, with a high resolution soft X-ray microscope utilizing Fresnel zone plate optics allows to study in a unique way the stochastical behavior in the magnetization reversal process of thin films and the ultrafast dynamics of magnetic vortices and domain walls in confined ferromagnetic structures. Future sources of fsec short and high intense soft X-ray photon pulses hold the promise of magnetic imaging down to fundamental magnetic length and time scales.
Date: January 18, 2010
Creator: Fischer, P. & Im, M.-Y.
Object Type: Article
System: The UNT Digital Library
Using fully coupled hydro-geomechanical numerical test bed to study reservoir stimulation with low hydraulic pressure (open access)

Using fully coupled hydro-geomechanical numerical test bed to study reservoir stimulation with low hydraulic pressure

None
Date: January 18, 2012
Creator: Fu, P.; Johnson, S. M. & Carrigan, C. R.
Object Type: Article
System: The UNT Digital Library
Fully Coupled Geomechanics and Discrete Flow Network Modeling of Hydraulic Fracturing for Geothermal Applications (open access)

Fully Coupled Geomechanics and Discrete Flow Network Modeling of Hydraulic Fracturing for Geothermal Applications

The primary objective of our current research is to develop a computational test bed for evaluating borehole techniques to enhance fluid flow and heat transfer in enhanced geothermal systems (EGS). Simulating processes resulting in hydraulic fracturing and/or the remobilization of existing fractures, especially the interaction between propagating fractures and existing fractures, represents a critical goal of our project. To this end, we are continuing to develop a hydraulic fracturing simulation capability within the Livermore Distinct Element Code (LDEC), a combined FEM/DEM analysis code with explicit solid-fluid mechanics coupling. LDEC simulations start from an initial fracture distribution which can be stochastically generated or upscaled from the statistics of an actual fracture distribution. During the hydraulic stimulation process, LDEC tracks the propagation of fractures and other modifications to the fracture system. The output is transferred to the Non-isothermal Unsaturated Flow and Transport (NUFT) code to capture heat transfer and flow at the reservoir scale. This approach is intended to offer flexibility in the types of analyses we can perform, including evaluating the effects of different system heterogeneities on the heat extraction rate as well as seismicity associated with geothermal operations. This paper details the basic methodology of our approach. Two numerical examples …
Date: January 18, 2011
Creator: Fu, P.; Johnson, S. M.; Hao, Y. & Carrigan, C. R.
Object Type: Article
System: The UNT Digital Library
Assessing the Control Systems Capacity for Demand Response in California Industries (open access)

Assessing the Control Systems Capacity for Demand Response in California Industries

California's electricity markets are moving toward dynamic pricing models, such as real-time pricing, within the next few years, which could have a significant impact on an industrial facility's cost of energy use during the times of peak use. Adequate controls and automated systems that provide industrial facility managers real-time energy use and cost information are necessary for successful implementation of a comprehensive electricity strategy; however, little is known about the current control capacity of California industries. To address this gap, Lawrence Berkeley National Laboratory, in close collaboration with California industrial trade associations, conducted a survey to determine the current state of controls technologies in California industries. This,study identifies sectors that have the technical capability to implement Demand Response (DR) and Automated Demand Response (Auto-DR). In an effort to assist policy makers and industry in meeting the challenges of real-time pricing, facility operational and organizational factors were taken into consideration to generate recommendations on which sectors Demand Response efforts should be focused. Analysis of the survey responses showed that while the vast majority of industrial facilities have semi- or fully automated control systems, participation in Demand Response programs is still low due to perceived barriers. The results also showed that the …
Date: January 18, 2012
Creator: Ghatikar, Girish; McKane, Aimee; Goli, Sasank; Therkelsen, Peter & Olsen, Daniel
Object Type: Report
System: The UNT Digital Library
EVALUATION OF SPRING OPERATED RELIEF VALVE MAINTENANCE INTERVALS AND EXTENSION OF MAINTENANCE TIMES USING A WEIBULL ANALYSIS WITH MODIFIED BAYESIAN UPDATING (open access)

EVALUATION OF SPRING OPERATED RELIEF VALVE MAINTENANCE INTERVALS AND EXTENSION OF MAINTENANCE TIMES USING A WEIBULL ANALYSIS WITH MODIFIED BAYESIAN UPDATING

The Savannah River Site (SRS) spring operated pressure relief valve (SORV) maintenance intervals were evaluated using an approach provided by the American Petroleum Institute (API RP 581) for risk-based inspection technology (RBI). In addition, the impact of extending the inspection schedule was evaluated using Monte Carlo Simulation (MCS). The API RP 581 approach is characterized as a Weibull analysis with modified Bayesian updating provided by SRS SORV proof testing experience. Initial Weibull parameter estimates were updated as per SRS's historical proof test records contained in the Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD). The API RP 581 methodology was used to estimate the SORV's probability of failing on demand (PFD), and the annual expected risk. The API RP 581 methodology indicates that the current SRS maintenance plan is conservative. Cost savings may be attained in certain mild service applications that present low PFD and overall risk. Current practices are reviewed and recommendations are made for extending inspection intervals. The paper gives an illustration of the inspection costs versus the associated risks by using API RP 581 Risk Based Inspection (RBI) Technology. A cost effective maintenance frequency balancing both financial risk and inspection cost is demonstrated.
Date: January 18, 2011
Creator: Harris, S.; Gross, R. & Mitchell, E.
Object Type: Article
System: The UNT Digital Library
Room-temperature Formation of Hollow Cu2O Nanoparticles (open access)

Room-temperature Formation of Hollow Cu2O Nanoparticles

Monodisperse Cu and Cu2O nanoparticles (NPs) are synthesized using tetradecylphosphonic acid as a capping agent. Dispersing the NPs in chloroform and hexane at room temperature results in the formation of hollow Cu2O NPs and Cu@Cu2O core/shell NPs, respectively. The monodisperse Cu2O NPs are used to fabricate hybrid solar cells with efficiency of 0.14percent under AM 1.5 and 1 Sun illumination.
Date: January 18, 2010
Creator: Hung, Ling-I; Tsung, Chia-Kuang; Huang, Wenyu & Yang, Peidong
Object Type: Article
System: The UNT Digital Library
Temperature-induced martensite in magnetic shape memory Fe{sub 2}MnGa observed by photoemission electron microscopy (open access)

Temperature-induced martensite in magnetic shape memory Fe{sub 2}MnGa observed by photoemission electron microscopy

The magnetic domain structure in single crystals of a Heusler shape memory compound near the composition Fe{sub 2}MnGa was observed during phase transition by photoelectron emission microscopy at Beamline 11.0.1.1 of the Advanced Light Source. The behavior is comparable with recent observations of an adaptive martensite phase in prototype Ni{sub 2}MnGa, although the pinning in the recent work is an epitaxial interface and in this work the e#11;ective pinning plane is a boundary between martensitic variants that transform in a self-accommodating way from the single crystal austenite phase present at high temperatures. Temperature dependent observations of the twinning structure give information as to the coupling behavior between the magnetism and the structural evolution.
Date: January 18, 2012
Creator: Jenkins, Catherine; Scholl, Andreas; Kainuma, R.; Elmers, Hans-Joachim & Omori, Toshihiro
Object Type: Article
System: The UNT Digital Library
Energetics of Oxygen Adatoms, Hydroxyl Species and Water Dissociation on Pt(111) (open access)

Energetics of Oxygen Adatoms, Hydroxyl Species and Water Dissociation on Pt(111)

None
Date: January 18, 2013
Creator: Karp, Eric M.; Campbell, Charles T.; /Washington U., Dept. Chem.; Studt, Felix; Abild-Pedersen, Frank; Norskov, Jens K. et al.
Object Type: Article
System: The UNT Digital Library
MIXING MODELING ANALYSIS FOR SRS SALT WASTE DISPOSITION (open access)

MIXING MODELING ANALYSIS FOR SRS SALT WASTE DISPOSITION

Nuclear waste at Savannah River Site (SRS) waste tanks consists of three different types of waste forms. They are the lighter salt solutions referred to as supernate, the precipitated salts as salt cake, and heavier fine solids as sludge. The sludge is settled on the tank floor. About half of the residual waste radioactivity is contained in the sludge, which is only about 8 percentage of the total waste volume. Mixing study to be evaluated here for the Salt Disposition Integration (SDI) project focuses on supernate preparations in waste tanks prior to transfer to the Salt Waste Processing Facility (SWPF) feed tank. The methods to mix and blend the contents of the SRS blend tanks were evalutaed to ensure that the contents are properly blended before they are transferred from the blend tank such as Tank 50H to the SWPF feed tank. The work consists of two principal objectives to investigate two different pumps. One objective is to identify a suitable pumping arrangement that will adequately blend/mix two miscible liquids to obtain a uniform composition in the tank with a minimum level of sludge solid particulate in suspension. The other is to estimate the elevation in the tank at which …
Date: January 18, 2011
Creator: Lee, S.
Object Type: Article
System: The UNT Digital Library
Search for a Low-Mass Scalar Higgs Boson Decaying to a Tau Pair in Single-Photon Decays of Upsilon(1S) (open access)

Search for a Low-Mass Scalar Higgs Boson Decaying to a Tau Pair in Single-Photon Decays of Upsilon(1S)

None
Date: January 18, 2013
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A. et al.
Object Type: Article
System: The UNT Digital Library
Advanced Nanostructured Molecular Sieves for Energy Efficient Industrial Separations (open access)

Advanced Nanostructured Molecular Sieves for Energy Efficient Industrial Separations

Due to the very small relative volatility difference between propane and propylene, current propane/propylene separation by distillation requires very tall distillation towers (150-250 theoretical plates) and large reflux ratios (up to 15), which is considered to be the most energy consuming large-scale separation process. Adsorptive separation processes are widely considered to be more energy-efficient alternatives to distillation. However, slow diffusion kinetics/mass transport rate through the adsorbent bed often limits the performance of such processes, so further improvements are possible if intra-particle mass transfer rates can be improved. Rive Technology, Inc. is developing and commercializing its proprietary mesoporous zeolite technology for catalysis and separation. With well-controlled intracrystalline mesoporosity, diffusion kinetics through such mesoporous zeolite based catalysts is much improved relative to conventional zeolites, leading to significantly better product selectivity. This 'proof-of-principle' project (DE-EE0003470) is intended to demonstrate that Rive mesoporous zeolite technology can be extended and applied in adsorptive propane/propylene separation and lead to significant energy saving compared to the current distillation process. In this project, the mesoporous zeolite Y synthesis technology was successfully extended to X and A zeolites that are more relevant to adsorbent applications. Mesoporosity was introduced to zeolite X and A for the first time while maintaining …
Date: January 18, 2012
Creator: Li, Kunhao
Object Type: Report
System: The UNT Digital Library
Final Report on Statistical Debugging for Petascale Environments (open access)

Final Report on Statistical Debugging for Petascale Environments

None
Date: January 18, 2013
Creator: Liblit, B
Object Type: Report
System: The UNT Digital Library
Extracting Scattering Phase-Shifts in Higher Partial-Waves from Lattice QCD Calculations (open access)

Extracting Scattering Phase-Shifts in Higher Partial-Waves from Lattice QCD Calculations

None
Date: January 18, 2011
Creator: Luu, T & Savage, M J
Object Type: Article
System: The UNT Digital Library
Analysis of Combined Hydrogen, Heat, and Power as a Bridge to a Hydrogen Transition. (open access)

Analysis of Combined Hydrogen, Heat, and Power as a Bridge to a Hydrogen Transition.

Combined hydrogen, heat, and power (CHHP) technology is envisioned as a means to providing heat and electricity, generated on-site, to large end users, such as hospitals, hotels, and distribution centers, while simultaneously producing hydrogen as a by-product. The hydrogen can be stored for later conversion to electricity, used on-site (e.g., in forklifts), or dispensed to hydrogen-powered vehicles. Argonne has developed a complex-adaptive-system model, H2CAS, to simulate how vehicles and infrastructure can evolve in a transition to hydrogen. This study applies the H2CAS model to examine how CHHP technology can be used to aid the transition to hydrogen. It does not attempt to predict the future or provide one forecast of system development. Rather, the purpose of the model is to understand how the system works. The model uses a 50- by 100-mile rectangular grid of 1-square-mile cells centered on the Los Angeles metropolitan area. The major expressways are incorporated into the model, and local streets are considered to be ubiquitous, except where there are natural barriers. The model has two types of agents. Driver agents are characterized by a number of parameters: home and job locations, income, various types of 'personalities' reflective of marketing distinctions (e.g., innovators, early adopters), willingness …
Date: January 18, 2011
Creator: Mahalik, M. & Stephan, C. (Decision and Information Sciences)
Object Type: Report
System: The UNT Digital Library
Using Tabular EOS at Low Temperatures (open access)

Using Tabular EOS at Low Temperatures

None
Date: January 18, 2013
Creator: Managan, R. A.
Object Type: Article
System: The UNT Digital Library