Degree Department

States

23 Matching Results

Results open in a new window/tab.

Status report : guard containment CFD analysis. (open access)

Status report : guard containment CFD analysis.

Under the auspices of the CEA Cadarache/ANL-US I-NERI project a comprehensive investigation has been made of improvements to the Gen-IV GFR safety case over that of the GCFR safety case twenty five years ago. In particular, it has been concluded and agreed upon [1] that the GFR safety approach for the passive removal of decay heat in a protected depressurization accident with total loss of electric power needs to be different from that taken for the HTRs. The HTR conduction cooldown to the vessel wall boundary mode for an economically attractive core is not feasible in the case of the GFR because the high power densities (100kW/1 compared to 5 kW/1 for pebble bed thermal reactor) require decay heat fluxes well beyond those achievable by the heat conduction and radiation heat transfer mode. A set of alternative novel design options has been evaluated for potential passive safety mechanisms unique to the GFR. In summary, from a technological risk viewpoint and R&D planning, the option which has been identified is the block/plate-based or a pin-based reactor with a secondary guard containment/vessel around the primary vessel to maintain the primary system pressure at a high enough level which would allow primary system …
Date: March 3, 2006
Creator: Tzanos, C. P.
Object Type: Report
System: The UNT Digital Library
Physics division annual report 2005. (open access)

Physics division annual report 2005.

This report highlights the research performed in 2005 in the Physics Division of Argonne National Laboratory. The Division's programs include operation of ATLAS as a national user facility, nuclear structure and reaction research, nuclear theory, medium energy nuclear research and accelerator research and development. The mission of Nuclear Physics is to understand the origin, evolution and structure of baryonic matter in the universe--the matter that makes up stars, planets and human life itself. The Division's research focuses on innovative new ways to address this mission and 2005 was a year of great progress. One of the most exciting developments is the initiation of the Californium Rare Ion Breeder Upgrade, CARIBU. By combining a Cf-252 fission source, the gas catcher technology developed for rare isotope beams, a high-resolution isobar separator, and charge breeding ECR technology, CARIBU will make hundreds of new neutron-rich isotope beams available for research. The cover illustration shows the anticipated intensities of low-energy beams that become available for low-energy experiments and for injection into ATLAS for reacceleration. CARIBU will be completed in early 2009 and provide us with considerable experience in many of the technologies developed for a future high intensity exotic beam facility. Notable results in research …
Date: March 12, 2007
Creator: Glover, J. & Physics
Object Type: Report
System: The UNT Digital Library
Surveillance of site A and plot M, report for 2007. (open access)

Surveillance of site A and plot M, report for 2007.

The results of the environmental surveillance program conducted at Site A/Plot M in the Palos Forest Preserve area for Calendar Year 2007 are presented. Based on the results of the 1976-1978 radiological characterization of the site, a determination was made that a surveillance program be established. The characterization study determined that very low levels of hydrogen-3 (as tritiated water) had migrated from the burial ground and were present in two nearby hand pumped picnic wells. The current surveillance program began in 1980 and consists of sample collection and analysis of surface and subsurface water. The results of the analyses are used to: (1) monitor the migration pathway of water from the burial ground (Plot M) to the hand-pumped picnic wells, (2) establish if other buried radionuclides have migrated, and (3) monitor the presence of radioactive materials in the environment of the area. Hydrogen-3 in the Red Gate Woods picnic wells was still detected this year, but the average and maximum concentrations were significantly less than found earlier. Hydrogen-3 continues to be detected in a number of wells, boreholes, dolomite holes, and a surface stream. Analyses since 1984 have indicated the presence of low levels of strontium-90 in water from a …
Date: March 25, 2008
Creator: Golchert, N. W. & Oversight, ESH /QA
Object Type: Report
System: The UNT Digital Library
Measurement of the Branching Ratio Lambda_C+ -> P Pi+ Pi- (open access)

Measurement of the Branching Ratio Lambda_C+ -> P Pi+ Pi-

The confirmation of the Cabibbo-suppressed charm baryon decay mode {Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -} is reported. All data analyzed are from SELEX, a fixed target experiment at Fermilab that took data during 1996 and 1997, mainly with a 600 GeV/c {Sigma}{sup -} beam. The branching ratio of the Cabibbo-suppressed decay mode {Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -} relative to the Cabibbo-favored mode {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} is measured to be: {Gamma}({Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -})/{Gamma}({Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}) = 0.103 {+-} 0.022.
Date: March 1, 2008
Creator: Lopez-Hinojosa, Guillermo & U., /San Luis Potosi
Object Type: Report
System: The UNT Digital Library
Implementation of nodal equivalence parameters in DIF3D-VARIANT for core analysis of prismatic Very High Temperature Reactor (VHTR). (open access)

Implementation of nodal equivalence parameters in DIF3D-VARIANT for core analysis of prismatic Very High Temperature Reactor (VHTR).

The VARIANT module of the DIF3D code has been upgraded to utilize surface-dependent discontinuity factors. The performance of the new capability is verified using two-dimensional core cases with control rods in reflector and fuel blocks. Cross sections for VHTR components were generated using the DRAGON and HELIOS codes. For rodded block cross sections, the DRAGON calculations used a single-block model or the multi-block models combined with MCNP4C flux solutions, whereas the HELIOS calculations utilized multi-block models. Results from core calculations indicate that multiplication factor, block power, and control rod worth are significantly improved by using surface-dependent discontinuity factors.
Date: March 15, 2007
Creator: Lee, C. H.; Joo, H. K.; Yang, W. S. & Taiwo, T. A.
Object Type: Report
System: The UNT Digital Library
Well-to-wheels energy use and greenhouse gas emissions analysis of plug-in hybrid electric vehicles. (open access)

Well-to-wheels energy use and greenhouse gas emissions analysis of plug-in hybrid electric vehicles.

Researchers at Argonne National Laboratory expanded the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model and incorporated the fuel economy and electricity use of alternative fuel/vehicle systems simulated by the Powertrain System Analysis Toolkit (PSAT) to conduct a well-to-wheels (WTW) analysis of energy use and greenhouse gas (GHG) emissions of plug-in hybrid electric vehicles (PHEVs). The WTW results were separately calculated for the blended charge-depleting (CD) and charge-sustaining (CS) modes of PHEV operation and then combined by using a weighting factor that represented the CD vehicle-miles-traveled (VMT) share. As indicated by PSAT simulations of the CD operation, grid electricity accounted for a share of the vehicle's total energy use, ranging from 6% for a PHEV 10 to 24% for a PHEV 40, based on CD VMT shares of 23% and 63%, respectively. In addition to the PHEV's fuel economy and type of on-board fuel, the marginal electricity generation mix used to charge the vehicle impacted the WTW results, especially GHG emissions. Three North American Electric Reliability Corporation regions (4, 6, and 13) were selected for this analysis, because they encompassed large metropolitan areas (Illinois, New York, and California, respectively) and provided a significant variation of marginal generation …
Date: March 31, 2009
Creator: Elgowainy, A.; Burnham, A.; Wang, M.; Molburg, J.; Rousseau, A. & Systems, Energy
Object Type: Report
System: The UNT Digital Library
Weather forecast-based optimization of integrated energy systems. (open access)

Weather forecast-based optimization of integrated energy systems.

In this work, we establish an on-line optimization framework to exploit detailed weather forecast information in the operation of integrated energy systems, such as buildings and photovoltaic/wind hybrid systems. We first discuss how the use of traditional reactive operation strategies that neglect the future evolution of the ambient conditions can translate in high operating costs. To overcome this problem, we propose the use of a supervisory dynamic optimization strategy that can lead to more proactive and cost-effective operations. The strategy is based on the solution of a receding-horizon stochastic dynamic optimization problem. This permits the direct incorporation of economic objectives, statistical forecast information, and operational constraints. To obtain the weather forecast information, we employ a state-of-the-art forecasting model initialized with real meteorological data. The statistical ambient information is obtained from a set of realizations generated by the weather model executed in an operational setting. We present proof-of-concept simulation studies to demonstrate that the proposed framework can lead to significant savings (more than 18% reduction) in operating costs.
Date: March 1, 2009
Creator: Zavala, V. M.; Constantinescu, E. M.; Krause, T. & Anitescu, M.
Object Type: Report
System: The UNT Digital Library
Optimal explicit strong-stability-preserving general linear methods : complete results. (open access)

Optimal explicit strong-stability-preserving general linear methods : complete results.

This paper constructs strong-stability-preserving general linear time-stepping methods that are well suited for hyperbolic PDEs discretized by the method of lines. These methods generalize both Runge-Kutta (RK) and linear multistep schemes. They have high stage orders and hence are less susceptible than RK methods to order reduction from source terms or nonhomogeneous boundary conditions. A global optimization strategy is used to find the most efficient schemes that have low storage requirements. Numerical results illustrate the theoretical findings.
Date: March 3, 2009
Creator: Constantinescu, E. M.; Sandu, A.; Science, Mathematics and Computer & Univ., Virginia Polytechnic Inst. and State
Object Type: Report
System: The UNT Digital Library
Structured hints : extracting and abstracting domain expertise. (open access)

Structured hints : extracting and abstracting domain expertise.

We propose a new framework for providing information to help optimize domain-specific application codes. Its design addresses problems that derive from the widening gap between the domain problem statement by domain experts and the architectural details of new and future high-end computing systems. The design is particularly well suited to program execution models that incorporate dynamic adaptive methodologies for live tuning of program performance and resource utilization. This new framework, which we call 'structured hints', couples a vocabulary of annotations to a suite of performance metrics. The immediate target is development of a process by which a domain expert describes characteristics of objects and methods in the application code that would not be readily apparent to the compiler; the domain expert provides further information about what quantities might provide the best indications of desirable effect; and the interactive preprocessor identifies potential opportunities for the domain expert to evaluate. Our development of these ideas is progressing in stages from case study, through manual implementation, to automatic or semi-automatic implementation. In this paper we discuss results from our case study, an examination of a large simulation of a neural network modeled after the neocortex.
Date: March 16, 2009
Creator: Hereld, M.; Stevens, R.; Sterling, T.; Gao, G. R.; Science, Mathematics and Computer; Tech., California Inst. of et al.
Object Type: Report
System: The UNT Digital Library
Validation of the G-PASS code : status report. (open access)

Validation of the G-PASS code : status report.

Validation is the process of determining whether the models in a computer code can describe the important phenomena in applications of interest. This report describes past work and proposed future work for validating the Gas Plant Analyzer and System Simulator (G-PASS) code. The G-PASS code was developed for simulating gas reactor and chemical plant system behavior during operational transients and upset events. Results are presented comparing code properties, individual component models, and integrated system behavior against results from four other computer codes. Also identified are two experiment facilities nearing completion that will provide additional data for individual component and integrated system model validation. The main goal of the validation exercise is to ready a version of G-PASS for use as a tool in evaluating vendor designs and providing guidance to vendors on design directions in nuclear-hydrogen applications.
Date: March 12, 2009
Creator: Vilim, R. B.
Object Type: Report
System: The UNT Digital Library
Research proposal for development of an electron stripper using a thin liquid lithium film for rare isotope accelerator. (open access)

Research proposal for development of an electron stripper using a thin liquid lithium film for rare isotope accelerator.

Hydrodynamic instability phenomena in a thin liquid lithium film, which has been proposed for the first stripper in the driver linac of Rare Isotope Accelerator (RIA), were discussed. Since it was considered that film instability could significantly impair the feasibility of the liquid lithium film stripper concept, potential issues and research tasks in the RIA project due to these instability phenomena were raised. In order to investigate these instability phenomena, a research proposal plan was developed. In the theoretical part of this research proposal, a use of the linear stability theory was suggested. In the experimental part, it was pointed out that the concept of Reynolds number and Weber number scaling may allow conducting a preliminary experiment using inert simulants, hence reducing technical difficulty, complexity, and cost of the experiments. After confirming the thin film formation in the preliminary experiment using simulants, demonstration experiments using liquid lithium were proposed.
Date: March 6, 2006
Creator: Momozaki, Y.
Object Type: Report
System: The UNT Digital Library
Validation on the thermal effect of roof with the spraying and green plants in an insulated building (open access)

Validation on the thermal effect of roof with the spraying and green plants in an insulated building

In recent years, roof-spraying and rooftop lawns has proved effective on roofs with poor thermal insulation. However, roofs of most buildings have insulating material to provide thermal insulation during the winter. The effects of such a practice have not previously been quantified. In this study, the authors conducted measurements of an insulated building to quantify the thermal effects of roof-spraying and rooftop lawns. Roof-spraying did not significantly reduce cooling loads, and required significant amounts of water. The conclusion is that roof spraying is not suitable for buildings with well-insulated roofs. Rooftop lawns, however, significantly stabilized the indoor temperature while additionally helping to mitigate the heat island phenomenon.
Date: March 20, 2004
Creator: Zhou, Nan; Gao, Weijun; Nishida, Masaru & Ojima, Toshio
Object Type: Article
System: The UNT Digital Library
Fast neutrons incident on rotors : - tantalum. (open access)

Fast neutrons incident on rotors : - tantalum.

Reports in the Argonne National Laboratory Nuclear Data and Measurement Series present results of studies in the field of microscopic nuclear data. The primary objective of the series is the dissemination of information in the comprehensive form required for nuclear technology applications. This series is devoted to: (a) measured microscopic nuclear parameters, (b) experimental techniques and facilities employed in measurements, (c) the analysis, correlation and interpretation of nuclear data, and (d) the compilation and evaluation of nuclear data.
Date: March 21, 2005
Creator: Smith, A. B.
Object Type: Report
System: The UNT Digital Library

Ensemble: 2006-03-09 – A Cappella Choir

Access: Use of this item is restricted to the UNT Community
A Cappella Choir performance at the UNT College of Music Winspear Performance Hall.
Date: March 9, 2006
Creator: University of North Texas. A Cappella Choir.
Object Type: Sound
System: The UNT Digital Library

Ensemble: 2007-03-28 – Collegium Singers & Instrumentalists

Collegium concert performed at the UNT College of Music Winspear Hall.
Date: March 28, 2007
Creator: University of North Texas. Collegium Singers.
Object Type: Sound
System: The UNT Digital Library

Ensemble: 2009-03-02 – Spectrum

Access: Use of this item is restricted to the UNT Community
New Music concert performed at the UNT College of Music Recital Hall.
Date: March 2, 2009
Creator: University of North Texas. Composers' Forum.
Object Type: Sound
System: The UNT Digital Library
Study of the CP Symmetry Violation in Partially Reconstructed B0 ---> D* Pi Decays With the BABAR Detector (open access)

Study of the CP Symmetry Violation in Partially Reconstructed B0 ---> D* Pi Decays With the BABAR Detector

None
Date: March 27, 2006
Creator: Legendre, Marie
Object Type: Report
System: The UNT Digital Library

Master's Recital: 2009-03-26 - Bryce Myerhoff, tenor

Access: Use of this item is restricted to the UNT Community
Recital presented at the UNT College of Music Concert Hall is partial fulfillment of the Master of Music (MM) degree.
Date: March 26, 2009
Creator: Myerhoff, Bryce
Object Type: Sound
System: The UNT Digital Library

Guest Artist Recital: 2007-03-06 - Emanuel Borok, violin & Andrey Ponochevny, piano

Access: Use of this item is restricted to the UNT Community
Guest artist recital performed at the UNT College of Music Concert Hall.
Date: March 6, 2007
Creator: Borok, Emanuel & Ponochevny, Andrey
Object Type: Sound
System: The UNT Digital Library

Ensemble: 2003-03-29 – 6th Annual African Cultural Festival

Access: Use of this item is restricted to the UNT Community
Concert presented at Winspear Hall at the Murchison Performing Arts Center
Date: March 29, 2003
Creator: Afrikania Cultural Troupe of Denton
Object Type: Sound
System: The UNT Digital Library

Ensemble: 2004-03-09 – Canticum Novum, Concert Choir, and A Cappella Choir

Access: Use of this item is restricted to the UNT Community
Concert performed at UNT Murchison Performing Arts Center, Winspear Performance Hall on March 9, 2004 at 8:00 pm.
Date: March 9, 2004
Creator: University of North Texas. Canticum Novum.
Object Type: Sound
System: The UNT Digital Library

Doctoral Recital: 2009-03-05 - Conroy Cupido, tenor

Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date: March 5, 2009
Creator: Cupido, Conroy
Object Type: Sound
System: The UNT Digital Library

Ensemble: 2008-03-04 – Concert Choir and A Cappella Choir

Access: Use of this item is restricted to the UNT Community
Concert presented at the UNT College of Music Winspear Performance Hall.
Date: March 4, 2008
Creator: University of North Texas. Concert Choir.
Object Type: Sound
System: The UNT Digital Library