43 Matching Results

Search Results

rSUGRA: Putting Nonuniversal Gaugino Masses on the (W)MAP

Description: In this talk, we investigate the relic density and direct detection prospects of rSUGRA, a simple paradigm for supersymmetry breaking that allows for nonuniversal gaugino masses. We present updated plots reflecting the latest cosmological measurements from WMAP.
Date: June 17, 2003
Creator: Birkedal-Hansen, Andreas
Partner: UNT Libraries Government Documents Department

MICROBAROGRAPH INSTRUMENTATION

Description: Microbarographs are used at the Nevada test site to measure acoustic energy at certain locations with respect to blasts. These data are used then to decide if weather conditions are favorable for a nuclear test. The microbarograph and its operation are described in detail. (T.R.H.)
Date: June 1, 1959
Creator: Hansen, H.E.
Partner: UNT Libraries Government Documents Department

From science to compliance: Geomechanics studies of the Waste Isolation Pilot Plant

Description: Mechanical and hydrological properties of salt provide excellent bases for geological isolation of hazardous materials. Regulatory certification of the Waste Isolation Pilot Plant (WIPP) testifies to the nearly ideal characteristics of bedded salt deposits in southeast New Mexico. The WIPP history includes decades of testing and scientific investigations, which have resulted in a comprehensive understanding of salt's mechanical deformational and hydrological properties over an applicable range of stresses and temperatures. Comprehensive evaluation of salt's favorable characteristics helped demonstrate regulatory compliance and ensure isolation of radioactive waste placed in a salt geological setting.
Date: June 5, 2000
Creator: HANSEN,FRANCIS D.
Partner: UNT Libraries Government Documents Department

Performance and Modeling of Amorphous Silicon Photovoltaics for Building-Integrated Applications (Preprint prepared for Solar 99)

Description: Amorphous silicon photovoltaic (PV) modules offer several advantages for building-integrated applications. The material can be deposited on glass or flexible substrates, which allows for products like roofing shingles and integrated PV/building glass. The material also has a uniform surface, which is ideal for many architectural applications. Amorphous silicon modules perform well in warm weather and have a small temperature coefficient for power. Depending on the building load, this may be beneficial when compared to crystalline systems. At the National Renewable Energy Laboratory, we are monitoring the performance of a triple-junction a-Si system. The system consists of 72 roofing shingles mounted directly to simulated roofing structures. This paper examines the performance of the building-integrated amorphous silicon PV system and applicability for covering residential loads. A simple model of system performance is also developed and is presented.
Date: June 7, 1998
Creator: Kroposki, B. & Hansen, R.
Partner: UNT Libraries Government Documents Department

CLOSURE OF HLW TANKS PHASE 2 FULL SCALE COOLING COILS GROUT FILL DEMONSTATIONS

Description: This report documents the Savannah River National Laboratory (SRNL) support for the Tank Closure and Technology Development (TCTD) group's strategy for closing high level radioactive waste (HLW) tanks at the Savannah River Site (SRS). Specifically, this task addresses the ability to successfully fill intact cooling coils, presently within the HLW tanks, with grout that satisfies the fresh and cured grout requirements [1] under simulated field conditions. The overall task was divided into two phases. The first phase was the development of a grout formulation that satisfies the processing requirements for filling the HLW tank cooling coils [5]. The second phase of the task, which is documented in this report, was the filling of full scale cooling coils under simulated field conditions using the grout formulation developed in the first phase. SRS Type I tank cooling coil assembly design drawings and pressure drop calculations were provided by the Liquid Waste (LW) customer to be used as the basis for configuring the test assemblies. The current concept for closing tanks equipped with internal cooling coils is to pump grout into the coils to inhibit pathways for infiltrating water. Access to the cooling coil assemblies is through the existing supply/return manifold headers located on top of the Type I tanks. The objectives for the second phase of the testing, as stated in the Task Technical and Quality Assurance plan (TTQAP) [2], were to: (1) Perform a demonstration test to assess cooling coil grout performance in simulated field conditions, and (2) Measure relevant properties of samples prepared under simulated field conditions. SRNL led the actual work of designing, fabricating and filling two full-scale cooling coil assemblies which were performed at Clemson Engineering Technologies Laboratory (CETL) using the South Carolina University Research and Education Foundation (SCUREF) program. A statement of work (SOW) was issued to ...
Date: June 19, 2008
Creator: Hansen, E & Alex Cozzi, A
Partner: UNT Libraries Government Documents Department

Finite element method for neutron diffusion problems in hexagonal geometry

Description: The use of the finite element method for solving two-dimensional static neutron diffusion problems in hexagonal reactor configurations is considered. It is investigated as a possible alternative to the low-order finite difference method. Various piecewise polynomial spaces are examined for their use in hexagonal problems. The central questions which arise in the design of these spaces are the degree of incompleteness permissible and the advantages of using a low-order space fine-mesh approach over that of a high-order space coarse-mesh one. There is also the question of the degree of smoothness required. Two schemes for the construction of spaces are described and a number of specific spaces, constructed with the questions outlined above in mind, are presented. They range from a complete non-Lagrangian, non-Hermite quadratic space to an incomplete ninth order space. Results are presented for two-dimensional problems typical of a small high temperature gas-cooled reactor. From the results it is concluded that the space used should at least include the complete linear one. Complete spaces are to be preferred to totally incomplete ones. Once function continuity is imposed any additional degree of smoothness is of secondary importance. For flux shapes typical of the small high temperature gas-cooled reactor the linear space fine-mesh alternative is to be preferred to the perturbation quadratic space coarse-mesh one and the low-order finite difference method is to be preferred over both finite element schemes. (auth)
Date: June 1, 1975
Creator: Wei, T.Y.C. & Hansen, K.F.
Partner: UNT Libraries Government Documents Department

Tissue architecture and breast cancer: the role of extracellular matrix and steroid hormones

Description: The changes in tissue architecture that accompany the development of breast cancer have been the focus of investigations aimed at developing new cancer therapeutics. As we learn more about the normal mammary gland, we have begun to understand the complex signaling pathways underlying the dramatic shifts in the structure and function of breast tissue. Integrin-, growth factor-, and steroid hormone-signaling pathways all play an important part in maintaining tissue architecture; disruption of the delicate balance of signaling results in dramatic changes in the way cells interact with each other and with the extracellular matrix, leading to breast cancer. The extracellular matrix itself plays a central role in coordinating these signaling processes. In this review, we consider the interrelationships between the extracellular matrix, integrins, growth factors, and steroid hormones in mammary gland development and function.
Date: June 1, 2000
Creator: Hansen, R K & Bissell, M J
Partner: UNT Libraries Government Documents Department

A numerical procedure for designing cascade blades with prescribed velocity distribution in incompressible potential flow

Description: Report presenting a step-by-step numerical procedure based on conformal-mapping theory for the design of a cascade of airfoils with a prescribed dimensionless-velocity distribution in incompressible potential flow. It includes a set of tables to serve as a guide in computation. A comparison of several different types of airfoil design are included to examine the reliability of the procedure.
Date: June 1950
Creator: Hansen, Arthur G. & Yohner, Peggy L.
Partner: UNT Libraries Government Documents Department

NREL photovoltaic program FY 1997 annual report

Description: This report summarizes the in-house and subcontracted research and development (R and D) activities under the NREL PV Program from October 1, 1996, through September 30, 1997 (FY 1997). The NREL PV Program is part of the US Department of Energy`s (DOE`s) National Photovoltaics Program, as described in the DOE National Photovoltaics Program Plan for 1996--2000. The FY 1997 budget authority for carrying out the NREL PV Program was $39.3 million in operating funds and $0.4 million in capital equipment funds. Subcontract activities represent a major part of the NREL PV Program, with $21.8 million (55% of PV funds) going to some 84 subcontractors. Cost sharing by industry added almost $8.8 million to the subcontract R and D activities with industry.
Date: June 1, 1998
Creator: McConnell, R.D.; Hansen, A. & Smoller, S.
Partner: UNT Libraries Government Documents Department

Biodiversity analysis of vegetation on the Nevada Test Site

Description: The Nevada Test Site (NTS), located in south-central Nevada, encompasses approximately 3,500 square kilometers and straddles two major North American deserts, Mojave and Great Basin. Transitional areas between the two desert types have been created by gradients in elevation, precipitation, temperature, and soils. From 1996 to 1998, more than 1,500 ecological landform units were sampled at the NTS for numerous biotic and abiotic parameters. The data provide a basis for spatial evaluations of biodiversity over landscape scales at the NTS. Biodiversity maps (species richness vs. species abundance) have been produced. Differences in biodiversity among ecoregions and vegetation alliances are presented. Spatial distribution maps of species' presence and abundance provide evidence of where transition zones occur and the resulting impact on biodiversity. The influences of abiotic factors, such as elevation, soil, and precipitation, on biodiversity are assessed.
Date: June 30, 2000
Creator: Ostler, W. K. & Hansen, D. J.
Partner: UNT Libraries Government Documents Department

Computer imaging of EBR-II fuel handling equipment

Description: This paper describes a three-dimensional graphics application used to visualize the positions of remotely operated fuel handling equipment in the EBR-II reactor. A three-dimensional (3D) visualization technique is necessary to simulate direct visual observation of the transfers of fuel and experiments into and out of the reactor because the fuel handling equipment is submerged in liquid sodium and therefore is not visible to the operator. The system described in this paper uses actual signals to drive a three-dimensional computer-generated model in real-time in response to movements of equipment in the plant This paper will present details on how the 3D model of the intank equipment was created and how real-time dynamic behavior was added to each of the moving components.
Date: June 1, 1995
Creator: Peters, G.G. & Hansen, L.H.
Partner: UNT Libraries Government Documents Department

Biodiversity Analysis of Vegetation on the Nevada Test Site

Description: The Nevada Test Site (NTS) located in south central Nevada encompasses approximately 3,561 square kilometers and straddles two major North American deserts, Mojave and Great Basin. Transitional areas between the two desert types have been created by gradients in elevation, precipitation, temperature, and soils. From 1996-1998, more than 1,500 ecological landform units were sampled at the NTS for numerous biotic and abiotic parameters. These data provide a basis for spatial evaluations of biodiversity over landscape scales at the NTS. Species diversity maps (species richness vs. species abundance) have been produced. Differences in ecosystem diversity at the ecoregion, alliance, association, and ecological landform unit levels are presented. Spatial distribution maps of species presence and abundance provide evidence of where transition zones occur and the resulting impact on biodiversity. The influences of abiotic factors (elevation, soil, precipitation) and anthropogenic disturbance on biodiversity are assessed.
Date: June 1, 2001
Creator: Ostler, W. K. & Hansen, D. J.
Partner: UNT Libraries Government Documents Department

Radiological survey and evaluation of the fallout area from the Trinity test: Chupadera Mesa and White Sands Missile Range, New Mexico

Description: Current radiological conditions were evaluated for the site of the first nuclear weapons test, the Trinity test, and the associated fallout zone. The test, located on White Sands Missile Range, was conducted as part of the research with nuclear materials for the World War II Manhattan Engineer District atomic bomb project. Some residual radioactivity attributable to the test was found in the soils of Ground Zero on White Sands Missile Range and the areas that received fallout from the test. The study considered relevant information including historical records, environmental data extending back to the 1940s, and new data acquired by field sampling and measurements. Potential exposures to radiation were evaluated for current land uses. Maximum estimated doses on Chupadera Mesa and other uncontrolled areas are less than 3% of the DOE Radiation Protection Standards (RPSs). Radiation exposures during visits to the US Army-controlled Ground Zero area are less than 1 mrem per annual visit or less than 0.2% of the RPS for a member of the public. Detailed data and interpretations are provided in appendixes. 14 figs., 45 tabs.
Date: June 1, 1985
Creator: Hansen, W.R. & Rodgers, J.C.
Partner: UNT Libraries Government Documents Department

Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

Description: This report contains the technical basis in support of the DOE?s derivation of Authorized Limits (ALs) for the DOE Paducah C-746-U Landfill. A complete description of the methodology, including an assessment of the input parameters, model inputs, and results is provided in this report. This report also provides initial recommendations on applying the derived soil guidelines. The ORISE-derived soil guidelines are specifically applicable to the Landfill at the end of its operational life. A suggested 'upper bound' multiple of the derived soil guidelines for individual shipments is provided.
Date: June 1, 2012
Creator: Boerner, A. J.; Maldonado, D. G. & Hansen, Tom
Partner: UNT Libraries Government Documents Department

Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties

Description: Future superconducting radio frequency (SRF) cavities, as part of Project X at Fermilab, will be cooled to superfluid helium temperatures by a cryogenic distribution system supplying cold supercritical helium. To reduce vapor fraction during the final Joule-Thomson (J-T) expansion into the superfluid helium cooling bath, counter-flow, plate-fin heat exchangers will be utilized. Due to their compact size and ease of fabrication, plate-fin heat exchangers are an effective option. However, the design of compact and high-effectiveness cryogenic heat exchangers operating at liquid helium temperatures requires consideration of axial heat conduction along the direction of flow, in addition to variable fluid properties. Here we present a numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger. The model is used to guide design decisions on heat exchanger material choice and geometry. In addition, the J-T expansion process is modeled with the heat exchanger to analyze the effect of heat load and cryogenic supply parameters. A numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger was developed and the effect of various design parameters on overall heat exchanger size was investigated. It was found that highly conductive metals should be avoided in the design of compact JT heat exchangers. For the geometry considered, the optimal conductivity is around 3.5 W/m-K and can range from 0.3-10 W/m-K without a large loss in performance. The model was implemented with an isenthalpic expansion process. Increasing the cold side inlet temperature from 2K to 2.2 K decreased the liquid fraction from 0.856 to 0.839 which corresponds to a 0.12 g/s increase in supercritical helium supply needed to maintain liquid level in the cooling bath. Lastly, it was found that the effectiveness increased when the heat load was below the design ...
Date: June 10, 2011
Creator: Hansen, B.J.; White, M.J.; Klebaner, A. & /Fermilab
Partner: UNT Libraries Government Documents Department

A study of shock mitigating materials in a split Hopkinson bar configuration. Phase 1

Description: Sandia National Laboratories (SNL) designs mechanical systems with electronics that must survive high shock environments. These mechanical systems include penetrators that must survive soil, rock, and ice penetration, nuclear transportation casks that must survive transportation environments, and laydown weapons that must survive delivery impact of 125 fps. These mechanical systems contain electronics that may operate during and after the high shock environment and that must be protected from the high shock environments. A study has been started to improve the packaging techniques for the advanced electronics utilized in these mechanical systems because current packaging techniques are inadequate for these more sensitive electronics. In many cases, it has been found that the packaging techniques currently used not only do not mitigate the shock environment but actually amplify the shock environment. An ambitious goal for this packaging study is to avoid amplification and possibly attenuate the shock environment before it reaches the electronics contained in the various mechanical systems. As part of the investigation of packaging techniques, a two phase study of shock mitigating materials is being conducted. The purpose of the first phase reported here is to examine the performance of a joint that consists of shock mitigating material sandwiched in between steel and to compare the performance of the shock mitigating materials. A split Hopkinson bar experimental configuration simulates this joint and has been used to study the shock mitigating characteristics of seventeen, unconfined materials. The nominal input for these tests is an incident compressive wave with 50 fps peak (1,500 {micro}{var_epsilon} peak) amplitude and a 100 {micro}s duration (measured at 10% amplitude).
Date: June 1, 1998
Creator: Bateman, V.I.; Brown, F.A. & Hansen, N.R.
Partner: UNT Libraries Government Documents Department

SERF photovoltaic systems. Technical report on system performance for the period, August 1, 1994--July 31, 1995

Description: This report presents an analysis of performance data on the two identical, 6 kW{sub ac}, grid-connected photovoltaic systems located on the roof of the Solar Energy Research Facility building at the National Renewable Energy Laboratory in Golden, Colorado. The data cover the monitoring period August 1, 1994, to July 31, 1995, and the performance parameters analyzed include direct current and alternating current power, aperture-area efficiency, energy, capacity factor, and performance index. These parameters are compared to plane-of-array irradiance, ambient temperature, and back-of-module temperature as a function of time, either daily or monthly. We also obtained power ratings of the systems for data corresponding to different test conditions. This study has shown, in addition to expected seasonal trends, that system monitoring is a valuable tool in assessing performance and detecting faulty equipment. Furthermore, methods applied for this analysis may be used to evaluate and compare systems using cells of different technologies. The systems were both found to be operating at approximately 7% below their estimated rating, which was based on Photovoltaics for Utility-Scale Applications test conditions. This may be attributed to the design inverter efficiency being estimated at 95% compared to measured values of approximately 88%, as well as the fact that aperture-area efficiency that was overestimated at 12.8% compared to a measured value of 11.0%. The continuous monitoring also revealed faulty peak-power point tracking equipment.
Date: June 1, 1996
Creator: Dyk, E.E. van; Strand, T.R. & Hansen, R.
Partner: UNT Libraries Government Documents Department

Pre-treating Seed to Enhance Germination of Desert Shrubs

Description: Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.
Date: June 1, 2002
Creator: Ostler, W. K.; Anderson, D. C. & Hansen, D. J.
Partner: UNT Libraries Government Documents Department

Process feasibility study in support of silicon material. Task I. Quarterly technical progress report (XV), April-June 1979

Description: Analyses of process system properties were continued for materials involved in the alternate processes under consideration for semiconductor silicon. Primary efforts centered on physical and thermodynamic property data for dichlorosilane. The following property data are reported for dichlorosilane which is involved in processing operations for solar cell grade silicon: critical temperature, critical pressure, critical volume, critical density, acentric factor, vapor pressure, heat of vaporization, gas heat capacity, liquid heat capacity and density. Work was initiated on the assembly of a system to prepare binary gas mixtures of known proportions and to measure the thermal conductivity of these mixtures between 30/sup 0/ and 350/sup 0/C. The binary gas mixtures will include silicon source material such as silanes and halogenated silanes which are used in the production of semiconductor silicon. Chemical engineering analysis of the BCL process was continued with major efforts being concentrated to the preliminary process design. Primary activities in the preliminary design were devoted to determining production labor requirements for operating the major process equipment. The plant was divided into the following sections for determining labor: Purification (I), Deposition (II), Electrolysis (III), Waste Treatment (IV) and Product Handling (V). The results indicated the production labor requirements were 0.06309 man-hr/kg silicon production for the plant size of 1,000 metric tons/year.
Date: June 1, 1979
Creator: Li, K.; Hansen, K.C. & Yaws, C.L.
Partner: UNT Libraries Government Documents Department

Ecological Monitoring and Compliance Program 2011 Report

Description: The Ecological Monitoring and Compliance (EMAC) Program, funded through the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, monitors the ecosystem of the Nevada National Security Site and ensures compliance with laws and regulations pertaining to NNSS biota. This report summarizes the program's activities conducted by National Security Technologies, LLC, during calendar year 2011. Program activities included (a) biological surveys at proposed construction sites, (b) desert tortoise compliance, (c) ecosystem monitoring, (d) sensitive plant species monitoring, (e) sensitive and protected/regulated animal monitoring, (f) habitat restoration monitoring, and (g) monitoring of the Nonproliferation Test and Evaluation Complex. During 2011, all applicable laws, regulations, and permit requirements were met, enabling EMAC to achieve its intended goals and objectives.
Date: June 13, 2012
Creator: Hansen, D. J., Anderson, D. C., Hall, D. B., Greger, P. D., Ostler, W. K.
Partner: UNT Libraries Government Documents Department