Sample records for shield building stage

  1. WASTE HANDLING BUILDING SHIELD WALL ANALYSIS

    SciTech Connect

    D. Padula

    2000-01-13

    The scope of this analysis is to estimate the shielding wall, ceiling or equivalent door thicknesses that will be required in the Waste Handling Building to maintain the radiation doses to personnel within acceptable limits. The shielding thickness calculated is the minimum required to meet administrative limits, and not necessarily what will be recommended for the final design. The preliminary evaluations will identify the areas which have the greatest impact on mechanical and facility design concepts. The objective is to provide the design teams with the necessary information to assure an efficient and effective design.

  2. Shield Through Rejuvenated Stage Volcanism On Kauai and Niihau, Hawaii

    NASA Astrophysics Data System (ADS)

    Cousens, B.; Clague, D. A.

    2013-12-01

    Kauai and Niihau are the northwesternmost large islands in the Hawaiian chain and consist of shield, rare postshield, and abundant rejuvenated stage lavas. We present new geochronological, geochemical and isotopic data for all phases of volcanic activity on the adjacent islands. K-Ar ages show Niihau shield volcanism occurred from 6.3-4.4 Ma, and K-Ar and new Ar-Ar ages for postshield volcanism range from 5.4-4.7 Ma. Kauai shield volcanism (K-Ar) overlaps with shield volcanism on Niihau. A new Ar-Ar age for a Kauai postshield dike is 4.4 Ma, older than previously-dated postshield lavas (3.95-3.58 Ma). New Ar-Ar ages show that Kauai rejuvenated stage volcanism began prior to 3.42 Ma (Izuka & Sherrod, 2011), compared to ~2.3 Ma on Niihau. Tholeiitic shield lavas from Kauai vary only slightly in trace element chemistry but have variable isotopic compositions. Subtle trends in some trace element and isotopic ratios between Napali Member shield lavas from the east and west side of Kauai support the two-shield hypothesis of Holcomb et al. (1997). Shield lavas from Niihau are chemically similar to those on Kauai, although Niihau tholeiites extend to higher 143Nd/144Nd ratios. Onland and submarine postshield rocks from Niihau are slightly more alkaline and LREE-enriched compared to shield lavas, but postshield rocks from Kauai are more chemically evolved, more LREE-enriched, and have more depleted Sr and Nd isotopic signatures than Kauai tholeiites. Postshield rocks on Kauai overlap in apparent age with lavas that are chemically like later rejuvenated stage lavas, suggesting either interfingering of the chemically distinct lavas or problems with the K-Ar ages. Rejuvenated stage lavas from the two islands differ dramatically; Kauai lavas are alkaline, LREE-enriched, and have even more depleted Sr and Nd isotopic compositions than postshield lavas, whereas Niihau lavas are only mildly alkaline, have lower REE abundances than postshield basalts, but isotopically are like Kauai rejuvenated rocks. Niihau rejuvenated lavas are shifted to slightly higher 87Sr/86Sr at a given 143Nd/144Nd than Kauai rejuvenated lavas, consistent with an enhanced carbonate component in their source (Dixon et al., 2008). Rejuvenated stage lavas have a diagnostic Sr and Nd isotopic signature on both Kauai and Niihau, but on Kauai the isotopic shift begins during the postshield stage. For Kauai, age and geochemical data suggest that volcanic activity was near-continuous from shield to postshield to rejuvenated stage, with a change in mantle source at the postshield to rejuvenated transition. On Niihau, a prominent erosional and age gap separates onland shield and postshield rocks from the rejuvenated stage lavas, with the change in mantle sources at the beginning of the rejuvenated stage. ROV dives on six vents off the NW coast of Niihau recovered a suite of highly alkaline basanites with REE patterns similar to Kauai rejuvenated lavas but with isotopic ratios spanning the range of Niihau shield and postshield lavas. These alkaline lavas are highly vesicular and more altered than rejuvenated stage Niihau rocks, are undated, but may straddle the postshield to rejuvenated stage transition. No equivalents exist at other Hawaiian volcanoes.

  3. Geochemistry of Kauai shield-stage lavas: Implications for the chemical evolution

    E-print Network

    Mukhopadhyay, Sujoy

    Geochemistry of Kauai shield-stage lavas: Implications for the chemical evolution of the Hawaiian and paleomagnetically controlled shield-stage lavas from Kauai, Hawaii. The range of 3 He/4 He ratios (17­28 RA) from for Hawaiian shield lavas, does not adequately explain the isotopic data in Kauai shield lavas. The addition

  4. Shielding effectiveness of original and modified building materials

    NASA Astrophysics Data System (ADS)

    Frenzel, T.; Stumpf, J.; Koch, M.

    2007-06-01

    This contribution deals with the determination of the shielding effectiveness of building materials used for office, factory and government buildings. Besides the examination of standard materials, measurements were also performed on modified materials, e.g. ferro concrete with enhanced shielding effectiveness due to a changed mixture or structure of the reinforcement. The measurements of original and modified materials were carried out in a fully anechoic room (FAR) according to IEEE 299-1997 from 80 MHz up to 10 GHz.

  5. Slipforming of reinforced concrete shield building

    Microsoft Academic Search

    M. C. Hsieh; J. R. King

    1982-01-01

    The unique design and construction features of slipforming the heavily reinforced concrete cylindrical shield walls at the Satsop nuclear plant in Washington, D.C. site are presented. The shield walls were designed in compliance with seismic requirements which resulted in the need for reinforcing steel averaging 326 kg\\/m³. A 7.6 m high, three-deck moving platform was designed to permit easy installation

  6. Slipforming of reinforced concrete shield building

    SciTech Connect

    Hsieh, M.C.; King, J.R.

    1982-03-01

    The unique design and construction features of slipforming the heavily reinforced concrete cylindrical shield walls at the Satsop nuclear plant in Washington, D.C. site are presented. The shield walls were designed in compliance with seismic requirements which resulted in the need for reinforcing steel averaging 326 kg/m/sup 3/. A 7.6 m high, three-deck moving platform was designed to permit easy installation of the reinforcing steel, embedments, and blockouts, and to facilitate concrete placement and finishing. Two circular box trusses, one on each side of the shield wall, were used in combination with a spider truss to meet both the tolerance and strength requirements for the slipform assembly.

  7. Contaminant deposition building shielding factors for US residential structures.

    PubMed

    Dickson, E D; Hamby, D M; Eckerman, K F

    2015-06-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit. PMID:25859888

  8. Cloud immersion building shielding factors for US residential structures.

    PubMed

    Dickson, E D; Hamby, D M

    2014-12-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units. PMID:25340542

  9. Investigations of some building materials for ?-rays shielding effectiveness

    NASA Astrophysics Data System (ADS)

    Mann, Kulwinder Singh; Kaur, Baljit; Sidhu, Gurdeep Singh; Kumar, Ajay

    2013-06-01

    For construction of residential and non-residential buildings bricks are used as building blocks. Bricks are made from mixtures of sand, clay, cement, fly ash, gypsum, red mud and lime. Shielding effectiveness of five soil samples and two fly ash samples have been investigated using some energy absorption parameters (Mass attenuation coefficients, mass energy absorption coefficients, KERMA (kinetic energy released per unit mass), HVL, equivalent atomic number and electron densities) firstly at 14 different energies from 81-1332 keV then extended to wide energy range 0.015-15 MeV. The soil sample with maximum shielding effectiveness has been used for making eight fly ash bricks [(Lime)0.15 (Gypsum)0.05 (Fly Ash)x (Soil)0.8-x, where values of x are from 0.4-0.7]. High Purity Germanium (HPGe) detector has been used for gamma-ray spectroscopy. The elemental compositions of samples were analysed using an energy dispersive X-ray fluorescence (EDXRF) spectrometer. The agreements of theoretical and experimental values of mass attenuation coefficient have been found to be quite satisfactory. It has been verified that common brick possess the maximum shielding effectiveness for wide energy range 0.015-15 MeV. The results have been shown graphically with some useful conclusions for making radiation safe buildings.

  10. Shielding study for fast-burst reactor building

    SciTech Connect

    Rees, B. G. (Brian G.); Malenfant, R. E. (Richard E.)

    2002-01-01

    A study was conducted to evaluate the radiation levels and the response of various diagnostic components in and around the building that houses the Godiva IV fast-burst reactor assembly. In a typical operation of 1 MW-s (3.6{approx}10f'is{approx}s ions) in a 50 ps fwhm burst the peak power approaches 100,000 MW. The unshielded dose at 3 m is about 500 Rem. The results will be used to evaluate the radiation levels and shielding requirements for a new facility, and to anticipate problems with new safety, security, and diagnostic instrumentation. The study was required because of the difficulty of making accurate calculations, the intensity of the radiation, the mixed neutron and gamnta-ray source terms, and the complex nature of the structure. In addition to detailed dosimetry, attention was paid to the evaluation of spurious electromagnetic and radiofrequency signals produced in detectors, cables, and conduits.

  11. North Kona slump: Submarine flank failure during the early(?) tholeiitic shield stage of Hualalai Volcano

    USGS Publications Warehouse

    Lipman, P.W.; Coombs, M.L.

    2006-01-01

    The North Kona slump is an elliptical region, about 20 by 60 km (1000-km2 area), of multiple, geometrically intricate benches and scarps, mostly at water depths of 2000-4500 m, on the west flank of Hualalai Volcano. Two dives up steep scarps in the slump area were made in September 2001, using the ROV Kaiko of the Japan Marine Science and Technology Center (JAMSTEC), as part of a collaborative Japan-USA project to improve understanding of the submarine flanks of Hawaiian volcanoes. Both dives, at water depths of 2700-4000 m, encountered pillow lavas draping the scarp-and-bench slopes. Intact to only slightly broken pillow lobes and cylinders that are downward elongate dominate on the steepest mid-sections of scarps, while more equant and spherical pillow shapes are common near the tops and bases of scarps and locally protrude through cover of muddy sediment on bench flats. Notably absent are subaerially erupted Hualalai lava flows, interbedded hyaloclastite pillow breccia, and/or coastal sandy sediment that might have accumulated downslope from an active coastline. The general structure of the North Kona flank is interpreted as an intricate assemblage of downdropped lenticular blocks, bounded by steeply dipping normal faults. The undisturbed pillow-lava drape indicates that slumping occurred during shield-stage tholeiitic volcanism. All analyzed samples of the pillow-lava drape are tholeiite, similar to published analyses from the submarine northwest rift zone of Hualalai. Relatively low sulfur (330-600 ppm) and water (0.18-0.47 wt.%) contents of glass rinds suggest that the eruptive sources were in shallow water, perhaps 500-1000-m depth. In contrast, saturation pressures calculated from carbon dioxide concentrations (100-190 ppm) indicate deeper equilibration, at or near sample sites at water depths of -3900 to -2800 m. Either vents close to the sample sites erupted mixtures of undegassed and degassed magmas, or volatiles were resorbed from vesicles during flowage downslope after eruption in shallow water. The glass volatile compositions suggest that the tholeiitic lavas that drape the slump blocks were erupted either (1) early during shield-stage tholeiitic volcanism prior to emergence of a large subaerial edifice, or alternatively (2) from submarine radial vents during subaerial shield-building. Because no radial vents have been documented on land or underwater for the unbuttressed flanks of any Hawaii volcano, alternative (1) is favored. In comparison to other well-documented Hawaiian slumps and landslides, North Kona structures suggest a more incipient slump event, with smaller down-slope motions and lateral displacements.

  12. HOT CELL BUILDING, TRA632. SHIELDED WINDOWS HAVE BEEN INSTALLED. MANIPULATORS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HOT CELL BUILDING, TRA-632. SHIELDED WINDOWS HAVE BEEN INSTALLED. MANIPULATORS AWAIT ATTACHMENT TO HAND CONTROLS. INL NEGATIVE NO. 9001. Unknown Photographer, photo is identified as taken 10/28/1953, but it may be an error as it shows progress since ID-33-G-266 of same date. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. LOFT. Reactor apparatus leaves A&M building (TAN607). Shielded locomotive has ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOFT. Reactor apparatus leaves A&M building (TAN-607). Shielded locomotive has aerojet logo, which replaced old general electric logo, pulls reactor from assembly shop on dolly. Camera facing easterly. Date: 1973. INEEL negative no. 73-3700 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  14. LPT. Shield test control building (TAN645), north facade. Camera facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LPT. Shield test control building (TAN-645), north facade. Camera facing south. Obsolete sign dating from post-1970 program says "Energy and Systems Technology Experimental Facility, INEL." INEEL negative no. HD-40-5-4 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  15. HOT CELL BUILDING, TRA632. HOT CELL AWAITS INSTALLATION OF SHIELDED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HOT CELL BUILDING, TRA-632. HOT CELL AWAITS INSTALLATION OF SHIELDED WINDOWS. OVERHEAD MASTER/SLAVE MANIPULATORS (LEFT, ABOVE WORKING WINDOWS) WILL MOVE ACROSS GUIDE RAILS IN SLOT ABOVE THE WINDOWS. CAMERA FACING SOUTHEAST. INL NEGATIVE NO. 8996. Unknown Photographer, 10/28/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  16. HOT CELL BUILDING, TRA632. SHIELDING DOOR TO HOT CELL IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HOT CELL BUILDING, TRA-632. SHIELDING DOOR TO HOT CELL IS IN OPEN POSITION. DOOR SLIDES SHUT WITH HELP OF MANUALLY OPERATED CHAIN. STAIRWAY TO MEZZANINE IN VIEW AT LEFT. CAMERA FACES NORTHWEST. INL NEGATIVE NO. 9000. Unknown Photographer, 10/28/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. LPT. Shield test facility test building interior (TAN646). Camera points ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LPT. Shield test facility test building interior (TAN-646). Camera points down into interior of north pool. Equipment on wall is electronical bus used for post-1970 experiment. Personnel ladder at right. INEEL negative no. HD-40-9-1 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  18. SPERTI Reactor Pit Building (PER605). Earth shielding protect adjacent Instrument ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SPERT-I Reactor Pit Building (PER-605). Earth shielding protect adjacent Instrument Cell (PER-606). Security fencing surrounds complex, to which gate entry is provided next to Guard House (PER-607). Note gravel road leading to control area. Earth-covered conduit leads from instrument cell to terminal building out of view. Photographer: R.G. Larsen. Date: June 22, 1955. INEEL negative no. 55-1701 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  19. Three-dimensional analysis of AP600 standard plant shield building roof

    SciTech Connect

    Greimann, L.; Fanous, F.; Safar, S.; Khalil, A.; Bluhm, D.

    1999-06-01

    The AP600 passive containment vessel is surrounded by a concrete cylindrical shell covered with a truncated conical roof. This roof supports the passive containment cooling system (PCS) annular tank, shield plate and other nonstructural attachments. When the shield building is subjected to different loading combinations as defined in the Standard Review Plan (SRP), some of the sections in the shield building could experience forces in excess of their design values. This report summarized the three-dimensional finite element analysis that was conducted to review the adequacy of the proposed Westinghouse shield building design. The ANSYS finite element software was utilized to analyze the Shield Building Roof (SBR) under dead, snow, wind, thermal and seismic loadings. A three-dimensional model that included a portion of the shield building cylindrical shell, the conical roof and its attachments, the eccentricities at the cone-cylinder connection and at the compression ring and the PCS tank was developed. Mesh sensitivity studies were conducted to select appropriate element size in the cylinder, cone, near air intakes and in the vicinity of the eccentricities. Also, a study was carried out to correctly idealize the water-structure interaction in the PCS tank. Response spectrum analysis was used to calculate the internal forces at different sections in the SBR under Safe Shutdown Earthquake (SSE). Forty-nine structural modes and twenty sloshing modes were used. Two horizontal components of the SSE together with a vertical component were used. Modal stress resultants were combined taking into account the effects of closely spaced modes. The three earthquake directions were combined by the Square Root of the Sum Squares method. Two load combinations were studied. The load combination that included dead, snow, fluid, thermal and seismic loads was selected to be the most critical. Interaction diagrams for critical sections were developed and used to check the design adequacy. The results demonstrated that provided area of steal on each face of several sections of the AP600 SBR was inadequate. This was also noticed when comparing the total provided area of steel per section, i.e., the area of steel on both faces. The discrepancy between Westinghouse results and these reported herein could have resulted from the different finite element mesh sizes and the assumption used in Westinghouse design.

  20. Designing Shelter in New Buildings. A Manual for Architects on the Preliminary Designing of Shielding from Fallout Gamma Radiation in Normally Functioning Spaces in New Buildings.

    ERIC Educational Resources Information Center

    Knott, Albert

    Analysis of radiation fallout prevention factors in new construction is presented with emphasis on architectural shielding principles. Numerous diagrams and charts illustrate--(1) radiation and fallout properties, (2) building protection principles, (3) details and planning suggestions, and (4) tabular data interpretation. A series of charts is…

  1. Building A New Kind of Graded-Z Shield for Swift's Burst Alert Telescope

    NASA Technical Reports Server (NTRS)

    Robinson, David W.

    2002-01-01

    The Burst Alert Telescope (BAT) on Swift has a graded-Z Shield that closes out the volume between the coded aperture mask and the Cadmium-Zinc-Telluride (CZT) detector array. The purpose of the 37 kilogram shield is to attenuate gamma rays that have not penetrated the coded aperture mask of the BAT instrument and are therefore a major source of noise on the detector array. Unlike previous shields made from plates and panels, this shield consists of multiple layers of thin metal foils (lead, tantalum, tin, and copper) that are stitched together much like standard multi-layer insulation blankets. The shield sections are fastened around BAT, forming a curtain around the instrument aperture. Strength tests were performed to validate and improve the design, and the shield will be vibration tested along with BAT in late 2002. Practical aspects such as the layup design, methods of manufacture, and testing of this new kind of graded-Z Shield are presented.

  2. Magma supply, storage, and transport at shield-stage Hawaiian volcanoes: Chapter 5 in Characteristics of Hawaiian volcanoes

    USGS Publications Warehouse

    Poland, Michael P.; Miklius, Asta; Montgomery-Brown, Emily K.

    2014-01-01

    Magma supply to Hawaiian volcanoes has varied over millions of years but is presently at a high level. Supply to K?lauea’s shallow magmatic system averages about 0.1 km3/yr and fluctuates on timescales of months to years due to changes in pressure within the summit reservoir system, as well as in the volume of melt supplied by the source hot spot. Magma plumbing systems beneath K?lauea and Mauna Loa are complex and are best constrained at K?lauea. Multiple regions of magma storage characterize K?lauea’s summit, and two pairs of rift zones, one providing a shallow magma pathway and the other forming a structural boundary within the volcano, radiate from the summit to carry magma to intrusion/eruption sites located nearby or tens of kilometers from the caldera. Whether or not magma is present within the deep rift zone, which extends beneath the structural rift zones at ~3-km depth to the base of the volcano at ~9-km depth, remains an open question, but we suggest that most magma entering K?lauea must pass through the summit reservoir system before entering the rift zones. Mauna Loa’s summit magma storage system includes at least two interconnected reservoirs, with one centered beneath the south margin of the caldera and the other elongated along the axis of the caldera. Transport of magma within shield-stage Hawaiian volcanoes occurs through dikes that can evolve into long-lived pipe-like pathways. The ratio of eruptive to noneruptive dikes is large in Hawai‘i, compared to other basaltic volcanoes (in Iceland, for example), because Hawaiian dikes tend to be intruded with high driving pressures. Passive dike intrusions also occur, motivated at K?lauea by rift opening in response to seaward slip of the volcano’s south flank.

  3. Improvements to building energy usage modeling during early design stages and retrofits

    E-print Network

    Mandelbaum, Andrew (Andrew Joseph)

    2014-01-01

    A variety of improvements to the MIT Design Advisor, a whole-building energy usage modeling tool intended for use during early design stages, are investigated. These include changes to the thermal mass temperature distribution ...

  4. The Initial Stage of a School's Capacity Building

    ERIC Educational Resources Information Center

    Stocklin, Sacha

    2010-01-01

    The rationale of this article is that schools and their leaders need to establish and formalize a system which focuses on integrating staff effectively into the organization's community and instituting esteem and competency. Competent educators in a professional community constitute two of the three dimensions that build the capacity to create…

  5. Final environmental assessment: TRU waste drum staging building, Technical Area 55, Los Alamos National Laboratory

    SciTech Connect

    NONE

    1996-02-09

    Much of the US Department of Energy`s (DOE`s) research on plutonium metallurgy and plutonium processing is performed at Los Alamos National Laboratory (LANL), in Los Alamos, New Mexico. LANL`s main facility for plutonium research is the Plutonium Facility, also referred to as Technical Area 55 (TA-55). The main laboratory building for plutonium work within the Plutonium Facility (TA-55) is the Plutonium Facility Building 4, or PF-4. This Environmental Assessment (EA) analyzes the potential environmental effects that would be expected to occur if DOE were to stage sealed containers of transuranic (TRU) and TRU mixed waste in a support building at the Plutonium Facility (TA-55) that is adjacent to PF-4. At present, the waste containers are staged in the basement of PF-4. The proposed project is to convert an existing support structure (Building 185), a prefabricated metal building on a concrete foundation, and operate it as a temporary staging facility for sealed containers of solid TRU and TRU mixed waste. The TRU and TRU mixed wastes would be contained in sealed 55-gallon drums and standard waste boxes as they await approval to be transported to TA-54. The containers would then be transported to a longer term TRU waste storage area at TA-54. The TRU wastes are generated from plutonium operations carried out in PF-4. The drum staging building would also be used to store and prepare for use new, empty TRU waste containers.

  6. Lithospheric Expressions of the Precambrian Shield, Mesozoic Rifting, and Cenozoic Subduction and Mountain Building in Venezuela

    NASA Astrophysics Data System (ADS)

    Levander, A.; Masy, J.; Niu, F.

    2013-05-01

    The Caribbean (CAR)-South American (SA) plate boundary in Venezuela is a broad zone of faulting and diffuse deformation. GPS measurements show the CAR moving approximately 2 cm/yr relative to SA, parallel to the strike slip fault system in the east, with more oblique convergence in the west (Weber et al., 2001) causing the southern edge of the Caribbean to subduct beneath northwestern South America. The west is further complicated by the motion of the triangular Maracaibo block, which is escaping northeastward relative to SA along the Bocono and Santa Marta Faults. In central and eastern Venezuela, plate motion is accommodated by transpression and transtension along the right lateral San Sebastian- El Pilar strike-slip fault system. The strike-slip system marks the northern edge of coastal thrust belts and their associated foreland basins. The Archean-Proterozoic Guayana Shield, part of the Amazonian Craton, underlies southeastern and south-central Venezuela. We used the 87 station Venezuela-U.S. BOLIVAR array (Levander et al., 2006) to investigate lithospheric structure in northern South America. We combined finite-frequency Rayleigh wave tomography with Ps and Sp receiver functions to determine lithosphere-asthenosphere boundary (LAB) depth. We measured Rayleigh phase velocities from 45 earthquakes in the period band 20-100s. The phase velocities were inverted for 1D shear velocity structure on a 0.5 by 0.5 degree grid. Crustal thickness for the starting model was determined from active seismic experiments and receiver function analysis. The resulting 3D shear velocity model was then used to determine the depth of the LAB, and to CCP stack Ps and Sp receiver functions from ~45 earthquakes. The receiver functions were calculated in several frequency bands using iterative deconvolution and inverse filtering. Lithospheric thickness varies by more a factor of 2.5 across Venezuela. We can divide the lithosphere into several distinct provinces, with LAB depth reflecting the signatures of the Precambrian craton in the south, Mesozoic rifting in central Venezuela, and Neogene subduction and orogenesis in both the northeast and northwest. Specifically, LAB depth varies from 110-130 km beneath the Guayana Shield, in agreement with finite-frequency body wave tomography (Bezada et al., 2010b). To the north beneath the Serrania del Interior and Maturin Basin the Rayleigh waves image two high velocity features to depths of 200 km. The northernmost, beneath the Serrania, corresponds to the top of the subducting Atlantic plate, in agreement with P-wave tomography that images the Atlantic plate to transition zone depths. Another localized high velocity feature extending to ~200 km depth lies to the south. We speculate that this is a lithospheric drip caused by destabilization of the SA lithospheric caused by Atlantic subduction. Immediately to the west beneath the Cariaco basin the LAB is at ~50 km, marking the top of a pronounced low velocity zone. The thin lithosphere extends southwestward from the Cariaco Basin beneath the Mesozoic Espino Graben to the craton. To the west the LAB deepens to ~80 km beneath the Barinas Apure Basin and then to ~90 km beneath the Neogene Merida Andes and Maracaibo block.

  7. Computational Specification of Building Requirements in theEarly Stages of Design

    Microsoft Academic Search

    Omer Akin; Zeyno Aygen; Michael Cumming; Magd Donia; Rana Sen; Ye Zhang

    1998-01-01

    We have been exploring computational techniques to help building designers to specify design requirements during the early stages of design. In the past, little has been accomplished in this area either in terms of innovative computational technologies or the improvement of design performance. The prospect of improving design productivity and creating a seamless process between requirements specification and formal design

  8. Optimization of the preform shape in the three-stage forming process of the shielded slot plate in fuel cell manufacturing

    NASA Astrophysics Data System (ADS)

    Yang, Dong-Yol; Lee, Chang-Whan; Kang, Dong-Woo; Chang, In-Gab; Lee, Tae-Won

    2013-05-01

    The shielded slot plate, a repeated structure of high sheared protrusions, is a major component of metallic bipolar plates for the molten carbonate fuel cell (MCFC). In order to increase the efficiency of the MCFC and long-term operation capability, the sheared protrusion should have a relatively large flat contact area. In addition, defects from the forming process such as local thinning should be minimized. In this work, the preform shape in the three-stage forming process that integrates the slitting process, the preforming process, and the final forming process was optimized to minimize the effective plastic strain. In the simulation of the forming process, the ductile fracture criterion was employed to the user material subroutine VUMAT in ABAQUS/Explicit. Steepest descent method was utilized in the design of the forming process to minimize equivalent plastic strain. High sheared protrusions were manufactured without defects from the three-stage forming process using the optimized preform shape. The minimum thickness of one sheared protrusion was increased by 25% over that of the two-stage forming process. The three-stage forming process using the optimized preform shape enables more uniformly distributed deformation and reduces localized deformation.

  9. Structural response of nuclear containment shield buildings with unanticipated construction openings

    NASA Astrophysics Data System (ADS)

    Mac Namara, Sinead Caitriona

    As Nuclear Power Plants age many require steam generator replacement. There is a nickel alloy in the steam generator tubes that is susceptible to stress cracking and although these cracks can be sealed the generator becomes uneconomical without 10%-15% of the tubes. The steam generator in a typical nuclear power plant is housed in the containment structure next to the reactor. The equipment hatch is not big enough to facilitate steam generator replacement, thus construction openings in the dome of the containment structure are required. To date the structural consequences of construction openings in the dome have not been examined. This thesis examines the effects of such openings. The prototype concrete dome is made up of a 2 ft thick dome atop 3 ft thick and 170 ft high cylindrical walls (radius 65.5 ft) with a tension ring 15 ft high and 8 ft thick in between. The dome of the building is cast in two layers; a lower 9 inch layer that serves as the formwork for an upper 15 inch layer. The weight of the dome is carried in axial compression along the hoops and meridians of the dome. The first finite element model uses shell elements and considers two limiting load cases; where the two layers act as one, and where the lower layer carries the weight of both. The openings interrupt the hoops and meridians and the weight of the dome must be redistributed around the openings. Without openings, the stresses due to dead load in the structure are very low when compared to the material strength. The impact of the openings is increased compression stresses near the opening. The maximum stresses are approximately four times larger than in the original structure. These results are confirmed by the second model which is made from layers of solid elements. This model shows a significant difference between the compression on the top surface of the dome, in the affected areas, and that on the bottom surface, leading to shear stresses. These shear stresses are largest around the opening but are not large enough to cause delamination.

  10. A Gradual Compositional Change from Samoan Shield to Rejuvenated Lavas?

    NASA Astrophysics Data System (ADS)

    Konter, J. G.; Jackson, M. G.; Koppers, A. A.

    2013-12-01

    The geochemical evolution of intraplate volcanoes is often compared to the archetypal model derived from Hawaiian volcanoes that involves a mantle plume source with multiple components. In Samoa, a range in rock types, ages, and isotopic compositions have been obtained across a number of volcanic seamounts and islands. However, due to dense vegetation on the islands, stratigraphic relations are not well known, and therefore a sequence for the construction of Samoan volcanoes is not as well-defined as in Hawaii. On the three largest islands, a shield and a rejuvenated stage have been defined, whereas the existence of a post-shield stage has been suggested and questioned (Natland and Turner, 1985). Moreover, the existing shield isotopic compositions (particularly Sr) are distinct, spanning a larger range than in Hawaii. Tutuila only hosts a small amount of rejuvenated lavas, but they are similar to those of Upolu, and there is an isotopic and compositional overlap between Tutuila shield volcanics and the Upolu lavas. On the island of Upolu, roughly half the surface area is covered in rejuvenated lavas, while the other half consists of shield stage lavas. The shield lavas around Fagaloa Bay are compositionally similar to some of the Tutuila lavas. On the island of Savaii, rejuvenated volcanism covers nearly the entire island, showing similar compositions to Upolu rejuvenated volcanism. We here present new data for samples from a deep canyon in the interior of Savaii, which form the missing link in understanding the geochemical sequence of Samoan volcanic construction. In this canyon, an isotopically distinct composition is found that resembles the composition of Fagaloa lavas on Upolu, instead of the extremely radiogenic Sr isotope compositions dredged from the submarine base of Savaii that represent the early shield stage. In Fagaloa Bay, a slope break on the mountainside has been suggested to form the outline of a crater along which late-stage evolved lavas such as trachytes erupted. A similar slope break is found in the canyon sampled on Savaii, and trachytes have previously been reported as cobbles in the draining river. Therefore, we infer that early shield volcanism in Savaii erupted extremely radiogenic Sr isotope compositions, and that by the end of shield building, compositions had changed to a composition similar to Upolu's Fagaloa. Some of the samples have Pb-Sr isotope compositions between Upolu and rejuvenated lavas, while their trace element compositions correspond to those of rejuvenated lavas. Thus, it appears that during the final stages of shield building, a shift to rejuvenated composition takes place. This contrasts with the definition of rejuvenated volcanism in Samoa, based on erosional contacts, and suggests rejuvenated source material may be sampled before the volcanic rejuvenation really occurs.

  11. Using multi-stage data mining technique to build forecast model for Taiwan stocks

    Microsoft Academic Search

    Chien-Jen Huang; Peng-Wen Chen; Wen-Tsao Pan

    Taiwan stock market trend is fast changing. It is affected by not only the individual investors and the three major institutional\\u000a investors, but also impacted by domestic political and economic situations. Therefore, to precisely grasp the stock market\\u000a movement, one must build a perfect stock forecast model. In this article, we used a multi-stage optimized stock forecast model\\u000a to grasp

  12. Design and performances of a shielded liquid helium insert with an optically heated variable temperature stage for the study of low frequency magnetic noise in HT_c superconductors

    Microsoft Academic Search

    X. Ridereau; M. Lam Chok Sing; D. Bloyet

    2001-01-01

    We have designed and built a liquid helium immersion insert which is magnetically shielded from the ambient magnetic field fluctuations by the use of a superconducting lead can. The insert has a variable temperature stage made of sapphire which is optically heated by the light guided from an external lamp via a glass rod. The temperature regulation is achieved by

  13. Spent Nuclear Fuel project stage and store K basin SNF in canister storage building functions and requirements. Revision 1

    Microsoft Academic Search

    1995-01-01

    This document establishes the functions and requirements baseline for the implementation of the Canister Storage Building Subproject. The mission allocated to the Canister Storage Building Subproject is to provide safe, environmentally sound staging and storage of K Basin SNF until a decision on the final disposition is reached and implemented

  14. Early Stage Design Decisions: The Way to Achieve Sustainable Buildings at Lower Costs

    PubMed Central

    Bragança, Luís; Vieira, Susana M.; Andrade, Joana B.

    2014-01-01

    The construction industry attempts to produce buildings with as lower environmental impact as possible. However, construction activities still greatly affect environment; therefore, it is necessary to consider a sustainable project approach based on its performance. Sustainability is an important issue to consider in design, not only due to environmental concerns but also due to economic and social matters, promoting architectural quality and economic advantages. This paper aims to identify the phases through which a design project should be developed, emphasising the importance and ability of earlier stages to influence sustainability, performance, and life cycle cost. Then, a selection of sustainability key indicators, able to be used at the design conceptual phase and able to start predicting environmental sustainability performance of buildings is presented. The output of this paper aimed to enable designers to compare and evaluate the consequences of different design solutions, based on preliminary data, and facilitate the collaboration between stakeholders and clients and eventually yield a sustainable and high performance building throughout its life cycle. PMID:24578630

  15. Characterization of organic air emissions from the Certification and Segregation Building and Air Support Weather Shield II at the Radioactive Waste Management Complex

    SciTech Connect

    Shoop, D.S.; Jackson, J.M.; Jolley, J.G.; Izbicki, K.J.

    1994-12-01

    During the latter part of Fiscal Year (FY-92), a task was initiated to characterize the organic air emissions from the Certification and Segregation (C and S) Building [Waste Management Facility (WMF) 612] and the Air Support Weather Shield II (ASWS II or ASB II) (WMF 711) at the Radioactive Waste Management Complex (RWMC). The purpose of this task, titled the RWMC Organic Air Emissions Evaluation Task, was to identify and quantify the volatile organic compounds (VOCS) present in the ambient air in these two facilities and to estimate the organic air emissions. The VOCs were identified and quantified by implementing a dual method approach using two dissimilar analytical methodologies, Open-Path Fourier Transform Infrared Spectroscopy (OP-FTIR) and SUMMA canister sampling, following the US Environmental Protection Agency (EPA) analytical method TO-14. The data gathered were used in conjunction with the building`s ventilation rate to calculate an estimated organic air emissions rate. This report presents the data gathered during the performance of this task and relates the data to the relevant regulatory requirements.

  16. Analysis of shield tunnel

    NASA Astrophysics Data System (ADS)

    Ding, W. Q.; Yue, Z. Q.; Tham, L. G.; Zhu, H. H.; Lee, C. F.; Hashimoto, T.

    2004-01-01

    This paper proposes a two-dimensional finite element model for the analysis of shield tunnels by taking into account the construction process which is divided into four stages. The soil is assumed to behave as an elasto-plastic medium whereas the shield is simulated by beam-joint discontinuous model in which curved beam elements and joint elements are used to model the segments and joints, respectively. As grout is usually injected to fill the gap between the lining and the soil, the property parameters of the grout are chosen in such a way that they can reflect the state of the grout at each stage. Furthermore, the contact condition between the soil and lining will change with the construction stage, and therefore, different stress-releasing coefficients are used to account for the changes. To assess the accuracy that can be attained by the method in solving practical problems, the shield tunnelling in the No. 7 Subway Line Project in Osaka, Japan, is used as a case history for our study. The numerical results are compared with those measured in the field. The results presented in the paper show that the proposed numerical procedure can be used to effectively estimate the deformation, stresses and moments experienced by the surrounding soils and the concrete lining segments. The analysis and method presented in this paper can be considered to be useful for other subway construction projects involving shield tunnelling in soft soils. Copyright

  17. Modular shield

    DOEpatents

    Snyder, Keith W. (Sandia Park, NM)

    2002-01-01

    A modular system for containing projectiles has a sheet of material including at least a polycarbonate layer held by a metal frame having a straight frame member corresponding to each straight edge of the sheet. Each frame member has a U-shaped shield channel covering and holding a straight edge of the sheet and an adjacent U-shaped clamp channel rigidly held against the shield channel. A flexible gasket separates each sheet edge from its respective shield channel; and each frame member is fastened to each adjacent frame member only by clamps extending between adjacent clamp channels.

  18. Assigning Robust Default Values in Building Performance Simulation Software for Improved Decision-Making in the Initial Stages of Building Design

    PubMed Central

    2015-01-01

    Applying data mining techniques on a database of BIM models could provide valuable insights in key design patterns implicitly present in these BIM models. The architectural designer would then be able to use previous data from existing building projects as default values in building performance simulation software for the early phases of building design. The author has proposed the method to minimize the magnitude of the variation in these default values in subsequent design stages. This approach maintains the accuracy of the simulation results in the initial stages of building design. In this study, a more convincing argument is presented to demonstrate the significance of the new method. The variation in the ideal default values for different building design conditions is assessed first. Next, the influence of each condition on these variations is investigated. The space depth is found to have a large impact on the ideal default value of the window to wall ratio. In addition, the presence or absence of lighting control and natural ventilation has a significant influence on the ideal default value. These effects can be used to identify the types of building conditions that should be considered to determine the ideal default values. PMID:26090512

  19. Plasma Shield

    NASA Astrophysics Data System (ADS)

    Hershcovitch, Ady

    2005-10-01

    The Plasma Shield is a vortex-stabilized arc that is employed to shield beams and workpiece area of interaction from atmospheric or liquid environment. A vortex-stabilized arc is established between a beam generating device (laser, ion or electron gun) and the target object. The arc, which is composed of a pure noble gas (chemically inert), engulfs the interaction region and generates an outward flow, thus, shielding it from any surrounding liquids (water) or atmospheric gases. The vortex is composed of a sacrificial gas or liquid that swirls around and stabilizes the arc. In current art, many industrial processes that involve ion and electron beams like, dry etching, micro-fabrication, machining, welding and melting are performed exclusively in vacuum, since guns, and accelerators must be kept at a reasonably high vacuum, and since chemical interactions with atmospheric gases adversely affect various processes. Various processes involving electron ion and laser beams can, with the Plasma Shield be performed in practically any environment (under water). It should allow for in situ repair of ship and nuclear reactor components, as well as in-air ion implantation of semiconductors. The plasma shield results in both thermal (since the plasma is hotter than the environment) and chemical shielding. The latter feature brings about in-vacuum process purity out of vacuum, and the thermal shielding aspect results in higher production rates. Experimental results will be presented. *Plasma Shield/Work supported by Acceleron, Inc., Connecticut Light & Power Co., US DOE funding under a NICE3 grant DE-FG41-01R110925, and Connecticut DEP.

  20. Development of a methodology for defining whole-building energy design targets for commercial buildings: Phase 2, Development concept stage report

    SciTech Connect

    Jones, J.W. (American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (USA)); Deringer, J.J. (American Inst. of Architects, Washington, DC (USA)); McKay, H.N. (Illuminating Engineering Society of North America, New York, NY (USA))

    1990-09-01

    Since 1985, the Pacific Northwest Laboratory (PNL) has managed the Whole-Building Energy Design Targets project for the US Department of Energy (DOE) Office of Building Technologies (formerly the Office of Buildings and Community Systems). The primary focus of the Targets project is to develop a flexible methodology for buildings industry use in setting energy performance guidelines for commercial buildings and for determining compliance with those guidelines. The project is being conducted as a two-phase effort. In Phase 1, Planning, the project team determined the research that was necessary for developing the Targets methodology. In the concept stage of Phase 2, Development, the team sought to define the technical and software development concepts upon which the overall Targets methodology will be based. The concept stage work is documented in four volumes, of which this summary volume is the first. The three other volumes are Volume 2: Technical Concept Development Task Reports, Volume 3: Workshop Summaries, and Volume 4: Software Concept Development Task Reports. 8 refs., 14 figs.

  1. New dose-mortality data based on 3-D radiation shielding calculation for concrete buildings at Nagasaki

    SciTech Connect

    Rhoades, W.A.; Childs, R.L.; Ingersoll, D.T.

    1988-01-01

    The analysis of radiation doses received during the World War II attack on Nagasaki provides an important source of biochemical information. More than 40 years after the war, it has been possible to make a satisfactory calculation of the doses to personnel inside reinforced concrete buildings by use of a 3-dimensional discrete ordinates code, TORT. The results were used to deduce a new value of the LD50 parameter that is in good agreement with traditional values. The new discrete ordinates software appears to have potential application to conventional radiation transport calculations as well. 9 refs., 3 figs., 2 tabs.

  2. Source components of the Gran Canaria (Canary Islands) shield stage magmas: evidence from olivine composition and Sr-Nd-Pb isotopes

    NASA Astrophysics Data System (ADS)

    Gurenko, Andrey A.; Hoernle, Kaj A.; Sobolev, Alexander V.; Hauff, Folkmar; Schmincke, Hans-Ulrich

    2010-05-01

    The Canary Island primitive basaltic magmas are thought to be derived from an HIMU-type upwelling mantle containing isotopically depleted (NMORB)-type component having interacted with an enriched (EM)-type component, the origin of which is still a subject of debate. We studied the relationships between Ni, Mn and Ca concentrations in olivine phenocrysts (85.6-90.0 mol.% Fo, 1,722-3,915 ppm Ni, 1,085-1,552 ppm Mn, 1,222-3,002 ppm Ca) from the most primitive subaerial and ODP Leg 157 high-silica (picritic to olivine basaltic) lavas with their bulk rock Sr-Nd-Pb isotope compositions (87Sr/86Sr = 0.70315-0.70331, 143Nd/144Nd = 0.51288-0.51292, 206Pb/204Pb = 19.55-19.93, 207Pb/204Pb = 15.60-15.63, 208Pb/204Pb = 39.31-39.69). Our data point toward the presence of both a peridotitic and a pyroxenitic component in the magma source. Using the model (Sobolev et al. in: Science 316:412-417, 2007) in which the reaction of Si-rich melts originated during partial melting of eclogite (a high pressure product of subducted oceanic crust) with ambient peridotitic mantle forms olivine-free reaction pyroxenite, we obtain an end member composition for peridotite with 87Sr/86Sr = 0.70337, 143Nd/144Nd = 0.51291, 206Pb/204Pb = 19.36, 207Pb/204Pb = 15.61 and 208Pb/204Pb = 39.07 (EM-type end member), and pyroxenite with 87Sr/86Sr = 0.70309, 143Nd/144Nd = 0.51289, 206Pb/204Pb = 20.03, 207Pb/204Pb = 15.62 and 208Pb/204Pb = 39.84 (HIMU-type end member). Mixing of melts from these end members in proportions ranging from 70% peridotite and 30% pyroxenite to 28% peridotite and 72% pyroxenite derived melt fractions can generate the compositions of the most primitive Gran Canaria shield stage lavas. Combining our results with those from the low-silica rocks from the western Canary Islands (Gurenko et al. EPSL 277:514-524, 2009), at least four distinct components are required. We propose that they are (1) HIMU-type pyroxenitic component (representing recycled ocean crust of intermediate age) from the plume center, (2) HIMU-type peridotitic component (ancient recycled ocean crust stirred into the ambient mantle) from the plume margin, (3) depleted, MORB-type pyroxenitic component (young recycled oceanic crust) in the upper mantle entrained by the plume, and (4) EM-type peridotitic component from the asthenosphere or lithosphere above the plume center.

  3. Recycled Component in the Canary Plume: Constraints From Olivine Phenocryst Composition and Radiogenic Isotopes in the Shield Stage Lavas From the Canary Islands

    NASA Astrophysics Data System (ADS)

    Gurenko, A.; Sobolev, A.; Hoernle, K.; Schmincke, H.

    2005-12-01

    One of the major geochemical challenges in understanding the dynamics of mantle melting is to identify the components involved in magma genesis. A contribution from recycled lithosphere is commonly proposed but still the subject of considerable debate. The Canary plume is one of the few plumes that can be traced all the way to the core-mantle boundary with seismic tomography [1], making it an excellent location for studying the deep crustal recycling. Trace element and isotopic signatures of the mafic magmas erupted on the Canary Islands require partial melting of a time-integrated high U/Pb (HIMU)-type mantle source, whose origin is attributed to the recycling of less than 2 Ga old oceanic crust [1,2]. We studied the most primitive picritic through alkali basaltic to basanitic subaerial lavas from Gran Canaria, Tenerife, La Gomera and La Palma shield stages, as well as submarine basaltic hyaloclastites drilled during ODP Leg 157 in the submarine clastic apron of Gran Canaria. In accordance with the experimental results [3], these volcanic rocks could be formed by the greatest degree of partial melting of the source rocks. The lavas are moderately enriched in light rare earth elements, Nb, Ta, and depleted in K and Pb, resembling HIMU-type magmas from ocean islands such as Mangaia and St. Helena. The Sr-Nd-Pb isotope data (87Sr/86Sr = 0.7030-0.7033, 143Nd/144Nd = 0.51288-0.51293, 206Pb/204Pb = 19.49-20.27, 207Pb/204Pb = 15.59-15.66, 208Pb/204Pb = 39.21-39.81) and the relationship between Sr isotopes in whole rocks and O isotopes in olivine phenocrysts (delta-18O = 4.3-5.8+/-0.3 permil) rule out extensive magma contamination within the crust [4]. Variations of Ni concentrations in early crystallized olivine phenocrysts and coexisting melts [5] were used to quantify the amount of recycled material involved in the Canary plume. The observed large, systematic inter- and intra-island variations of Ni in Ol phenocrysts exceeding the obtained 2-sigma analytical error of +/-0.01 wt.% NiO cannot be explained by olivine fractionation. Furthermore, strong positive correlation of Ni/MgO with 87Sr/86Sr (R = 0.86) and negative correlation with 206Pb/204Pb isotopic ratios (R = 0.61) suggest that significant amounts of a recycled component appear to be involved in partial melting of the Canary plume increasing from Tenerife through La Gomera and La Palma to Gran Canaria. The largest amount of the recycled component was found in the ODP Leg 157 hyaloclastites. References: [1] Montelli et al. (2004) Science 303, 338-343; [2] Hoernle et al. (1991) EPSL 106, 44-63; [3] Wyllie (1988) JGR 93, 4171-4181; [4] Gurenko et al. (2005) GCA, submitted manuscript; [5] Sobolev et al. (2005) Nature 434, 590-597.

  4. Ray Shielding

    NSDL National Science Digital Library

    In this activity, students will gather data on space radiation shielding by observing a flashlight beam as it shines through different material, and by measuring, predicting, counting, and weighing the proposed materials. They will then analyze their data, select the most protective and lightweight material for radiation shielding in a spacecraft, and develop a conclusion based on their results. The activity is designed to accompany the Kids' Science News Network (KSNN) 21st Century Exlporer 30-second news break entitled 'What Would You Hear in a Weather Report From Mars?' The activity includes a teacher's guide and instructions for students, and a Spanish translation is available.

  5. Thermocouple shield

    DOEpatents

    Ripley, Edward B. (Knoxville, TN)

    2009-11-24

    A thermocouple shield for use in radio frequency fields. In some embodiments the shield includes an electrically conductive tube that houses a standard thermocouple having a thermocouple junction. The electrically conductive tube protects the thermocouple from damage by an RF (including microwave) field and mitigates erroneous temperature readings due to the microwave or RF field. The thermocouple may be surrounded by a ceramic sheath to further protect the thermocouple. The ceramic sheath is generally formed from a material that is transparent to the wavelength of the microwave or RF energy. The microwave transparency property precludes heating of the ceramic sheath due to microwave coupling, which could affect the accuracy of temperature measurements. The ceramic sheath material is typically an electrically insulating material. The electrically insulative properties of the ceramic sheath help avert electrical arcing, which could damage the thermocouple junction. The electrically conductive tube is generally disposed around the thermocouple junction and disposed around at least a portion of the ceramic sheath. The concepts of the thermocouple shield may be incorporated into an integrated shielded thermocouple assembly.

  6. Drip Shield Emplacement Gantry Concept

    SciTech Connect

    Silva, R.A.; Cron, J.

    2000-03-29

    This design analysis has shown that, on a conceptual level, the emplacement of drip shields is feasible with current technology and equipment. A plan for drip shield emplacement was presented using a Drip Shield Transporter, a Drip Shield Emplacement Gantry, a locomotive, and a Drip Shield Gantry Carrier. The use of a Drip Shield Emplacement Gantry as an emplacement concept results in a system that is simple, reliable, and interfaces with the numerous other exising repository systems. Using the Waste Emplacement/Retrieval System design as a basis for the drip shield emplacement concept proved to simplify the system by using existing equipment, such as the gantry carrier, locomotive, Electrical and Control systems, and many other systems, structures, and components. Restricted working envelopes for the Drip Shield Emplacement System require further consideration and must be addressed to show that the emplacement operations can be performed as the repository design evolves. Section 6.1 describes how the Drip Shield Emplacement System may use existing equipment. Depending on the length of time between the conclusion of waste emplacement and the commencement of drip shield emplacement, this equipment could include the locomotives, the gantry carrier, and the electrical, control, and rail systems. If the exisiting equipment is selected for use in the Drip Shield Emplacement System, then the length of time after the final stages of waste emplacement and start of drip shield emplacement may pose a concern for the life cycle of the system (e.g., reliability, maintainability, availability, etc.). Further investigation should be performed to consider the use of existing equipment for drip shield emplacement operations. Further investigation will also be needed regarding the interfaces and heat transfer and thermal effects aspects. The conceptual design also requires further design development. Although the findings of this analysis are accurate for the assumptions made, further refinements of this analysis are needed as the project parameters change. The designs of the drip shield, the Emplacement Drift, and the other drip shield emplacement equipment all have a direct effect on the overall design feasibility.

  7. Performance of solar shields. [Skylab 1 micrometeoroid shield difficulties

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.

    1974-01-01

    The loss of the micrometeoroid shield from the Orbital Workshop section of Skylab 1 about 63 seconds after lift-off, was the catalyst for a prodigious effort to develop a substitute for the passive portion of the thermal control system. An intensive effort is described in which numerous potential thermal shield materials were assessed, and during which period ten specific shield designs were developed and carried through various stages of development and test. Thermal shield materials data are discussed, including optical, strength, fatigue, outgassing, tackiness, ultraviolet radiation, and material memory properties. Specifically addressed are thermal shield materials selection criteria and the design, development, and test requirements associated with the successful development of Skylab thermal shields, and specifically the two thermal shields subsequently deployed over the exposed gold foil skin of the Orbital Workshop. Also considered are the general performance and thermal improvements provided by both the parasol design deployed by the Skylab 1 crew, and the sail design deployed by the Skylab 2 crew.

  8. Visualizing the Shields Parameter

    NSDL National Science Digital Library

    Tom Hickson

    This is not so much an activity as it is a useful tool to build an activity around. I created an Excel spreadsheet that calculates the Shields parameter and the grain Reynolds number for a given set of conditions, then plots the resultant values on the Shields diagram. Thus, students can tweak the boundary shear stress value to calculate the stress required to move a given grain size in any fluid, under any gravitational conditions. It is a great way for them to understand how changes in fluid density and viscosity (water vs. air) affect initiation of motion, as well as the effects of grain size. I might use this in a lecture on initiation of motion, asking them to answer some basic questions (see attached example).

  9. Sound shield

    NASA Technical Reports Server (NTRS)

    Creel, T. R., Jr.; Beckwith, I. E. (inventors)

    1982-01-01

    An improved test section for a supersonic or hypersonic wind tunnel is disclosed wherein the model tested is shielded from the noise normally radiated by the turbulent tunnel wall boundary layer. A vacuum plenum surrounds spaced rod elements making up the test chamber to extract some of the boundary layer as formed along the rod elements during a test to thereby delay the tendency of the rod boundary layers to become turbulent. Novel rod construction involves bending each rod slightly prior to machining the bent area to provide a flat segment on each rod for connection with the flat entrance fairing. Rods and fairing are secured to provide a test chamber incline on the order of 1 deg outward from the noise shield centerline to produce up to 65% reduction of the root mean square (rms) pressure over previously employed wind tunnel test sections at equivalent Reynolds numbers.

  10. SNF shipping cask shielding analysis

    SciTech Connect

    Johnson, J.O.; Pace, J.V. III

    1996-01-01

    The Waste Management and Remedial Action Division has planned a modification sequence for storage facility 7827 in the Solid Waste Storage Area (SWSA). The modification cycle is: (1) modify an empty caisson, (2) transfer the spent nuclear fuel (SNF) of an occupied caisson to a hot cell in building 3525 for inspection and possible repackaging, and (3) return the package to the modified caisson in the SWSA. Although the SNF to be moved is in the solid form, it has different levels of activity. Thus, the following 5 shipping casks will be available for the task: the Loop Transport Carrier, the In- Pile Loop LITR HB-2 Carrier, the 6.5-inch HRLEL Carrier, the HFIR Hot Scrap Carrier, and the 10-inch ORR Experiment Removal Shield Cask. This report describes the shielding tasks for the 5 casks: determination of shielding characteristics, any streaming avenues, estimation of thermal limits, and shielding calculational uncertainty for use in the transportation plan.

  11. 71. Joe Moore, Photographer. September, 1996. BEVATRON ROOF SHIELDING AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    71. Joe Moore, Photographer. September, 1996. BEVATRON ROOF SHIELDING AND BUILDING TRUSS STRUCTURE - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

  12. E-beam-Cure Fabrication of Polymer Fiber\\/Matrix Composites for Multifunctional Radiation Shielding

    Microsoft Academic Search

    J. W. Wilson; B. J. Jensen; S. A. Thibeault; Tan-Hung Hou; E. Saether; E. H. Glaessgen; D. H. Humes; C. K. Chang; F. F. Badavi; R. Kiefer; D. O. Adams

    Aliphatic polymers were identified as optimum radiation polymeric shielding materials for building multifunctional structural elements. Conceptual damage-tolerant configurations of polyolefins have been proposed but many issues on the manufacture remain. In the present paper, we will investigate fabrication technologies with e-beam curing for inclusion of high-strength aliphatic polymer fibers into a highly cross-linked polyolefin matrix. A second stage of development

  13. Shielding Benchmark Computational Analysis

    SciTech Connect

    Hunter, H.T.; Slater, C.O.; Holland, L.B.; Tracz, G.; Marshall, W.J.; Parsons, J.L.

    2000-09-17

    Over the past several decades, nuclear science has relied on experimental research to verify and validate information about shielding nuclear radiation for a variety of applications. These benchmarks are compared with results from computer code models and are useful for the development of more accurate cross-section libraries, computer code development of radiation transport modeling, and building accurate tests for miniature shielding mockups of new nuclear facilities. When documenting measurements, one must describe many parts of the experimental results to allow a complete computational analysis. Both old and new benchmark experiments, by any definition, must provide a sound basis for modeling more complex geometries required for quality assurance and cost savings in nuclear project development. Benchmarks may involve one or many materials and thicknesses, types of sources, and measurement techniques. In this paper the benchmark experiments of varying complexity are chosen to study the transport properties of some popular materials and thicknesses. These were analyzed using three-dimensional (3-D) models and continuous energy libraries of MCNP4B2, a Monte Carlo code developed at Los Alamos National Laboratory, New Mexico. A shielding benchmark library provided the experimental data and allowed a wide range of choices for source, geometry, and measurement data. The experimental data had often been used in previous analyses by reputable groups such as the Cross Section Evaluation Working Group (CSEWG) and the Organization for Economic Cooperation and Development/Nuclear Energy Agency Nuclear Science Committee (OECD/NEANSC).

  14. High performance building blocks for wireless receiver: multi-stage amplifiers and low noise amplifiers 

    E-print Network

    Fan, Xiaohua

    2009-05-15

    -stage amplifier typologies are proposed to improve the bandwidth and reduce the silicon area for the application where a large capacitive load exists. They were designed using AMI 0.5 m µ CMOS technology. The simulation and measurement results show they have...

  15. Shielded Canister Transporter

    SciTech Connect

    Eidem, G.G. Jr.; Fages, R.

    1993-08-01

    The Hanford Waste Vitrification Plant (HWVP) will produce canisters filled with high-level radioactive waste immobilized in borosilicate glass. This report discusses a Shielded Canister Transporter (SCT) which will provide the means for safe transportation and handling of the canisters from the Vitrification Building to the Canister Storage Building (CSB). The stainless steel canisters are 0.61 meters in diameter, 3.0 meters tall, and weigh approximately 2,135 kilograms, with a maximum exterior surface dose rate of 90,000 R/hr. The canisters are placed into storage tubes to a maximum of three tall (two for overpack canisters) with an impact limiter placed at the tube bottom and between each canister. A floor plug seals the top of the storage tube at the operating floor level of the CSB.

  16. Rootless Shield -- Lava Flow

    USGS Multimedia Gallery

    Rootless shields grow both in breadth and height through the accumulation of repeated overflows from the summits of the shields. In this photo, a stream of lava is flowing southward down the flank of this emergent shield....

  17. Magnetic shielding

    DOEpatents

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1985-02-12

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  18. Magnetic shielding

    DOEpatents

    Kerns, John A. (Livermore, CA); Stone, Roger R. (Walnut Creek, CA); Fabyan, Joseph (Livermore, CA)

    1987-01-01

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  19. Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

    NASA Technical Reports Server (NTRS)

    Rojdev, Kristina; Christiansen, Eric

    2011-01-01

    As NASA is looking to explore further into deep space, multifunctional materials are a necessity for decreasing complexity and mass. One area where multifunctional materials could be extremely beneficial is in the micrometeoroid orbital debris (MMOD) shield. A typical MMOD shield on the International Space Station (ISS) is a stuffed whipple shield consisting of multiple layers. One of those layers is the thermal blanket, or multi-layer insulation (MLI). By increasing the MMOD effectiveness of MLI blankets, while still preserving their thermal capabilities, could allow for a less massive MMOD shield. Thus, a study was conducted to evaluate concept MLI blankets for MMOD shields. In conjunction, these MLI blankets and the subsequent MMOD shields were also evaluated for their radiation shielding effectiveness towards protecting crew. These concepts were evaluated against the ISS MLI blankets and the ISS MMOD shield, which acted as the baseline. These radiation shielding assessments were performed using the high charge and energy transport software (HZETRN). This software is based on a one-dimensional formula of the Boltzmann transport equation with a straight-ahead approximation. Each configuration was evaluated against the following environments to provide a diverse view of radiation shielding effectiveness in most space environments within the heliosphere: August 1972 solar particle event, October 1989 solar particle event, 1982 galactic cosmic ray environment (during solar maximum), 1987 galactic cosmic ray environment (during solar minimum), and a low earth orbit environment in 1970 that corresponded to an altitude of 400 km and inclination of 51.6 . Both the absorbed dose and the dose equivalent were analyzed, but the focus of the discussion was on the dose equivalent since the data is most concerned with radiation shielding of the crew. The following paper outlines the evaluations performed and discusses the results and conclusions of this evaluation for radiation shielding effectiveness. Future work will focus on optimizing the radiation shielding properties for the MMOD shield. Submission

  20. Shield Module Design Considerations

    E-print Network

    McDonald, Kirk

    Shield Module Design Considerations Adam Carroll Van Graves July 3, 2014 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Shield Module Design Considerations 3 July 2014 Overview · Capability to remotely remove and reinstall the shield modules is required · Shield module concept is He-cooled tungsten

  1. Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

    NASA Technical Reports Server (NTRS)

    Rojdev, Kristina; Christiansen, Eric

    2013-01-01

    As NASA is looking to explore further into deep space, multifunctional materials are a necessity for decreasing complexity and mass. One area where multifunctional materials could be extremely beneficial is in the micrometeoroid orbital debris (MMOD) shield. A typical MMOD shield on the International Space Station (ISS) is a stuffed whipple shield consisting of multiple layers. One of those layers is the thermal blanket, or multi-layer insulation (MLI). Increasing the MMOD effectiveness of MLI blankets, while still preserving their thermal capabilities, could allow for a less massive MMOD shield. Thus, a study was conducted to evaluate a concept MLI blanket for an MMOD shield. In conjunction, this MLI blanket and the subsequent MMOD shield was also evaluated for its radiation shielding effectiveness towards protecting crew. The overall MMOD shielding system using the concept MLI blanket proved to only have a marginal increase in the radiation mitigating properties. Therefore, subsequent analysis was performed on various conceptual MMOD shields to determine the combination of materials that may prove superior for radiation mitigating purposes. The following paper outlines the evaluations performed and discusses the results and conclusions of this evaluation for radiation shielding effectiveness.

  2. Principles of quasistatic magnetic shielding with cylindrical and spherical shields

    Microsoft Academic Search

    J. F. Hoburg; J. F. Hobug

    1995-01-01

    The basic principles that underlie materials-based quasistatic magnetic shielding are described. Shielding mechanisms are identified and shown in specific examples that involve long cylindrical and spherical shield geometries. Analytic results are given both for shields that enclose the shielded region and for shields that enclose the source. The two configurations are reciprocal in the sense that identical shields have identical

  3. Setting the stage - building and working in an ancient DNA laboratory.

    PubMed

    Knapp, Michael; Clarke, Andrew C; Horsburgh, K Ann; Matisoo-Smith, Elizabeth A

    2012-01-20

    With the introduction of next generation high throughput sequencing in 2005 and the resulting revolution in genetics, ancient DNA research has rapidly developed from an interesting but marginal field within evolutionary biology into one that can contribute significantly to our understanding of evolution in general and the development of our own species in particular. While the amount of sequence data available from ancient human, other animal and plant remains has increased dramatically over the past five years, some key limitations of ancient DNA research remain. Most notably, reduction of contamination and the authentication of results are of utmost importance. A number of studies have addressed different aspects of sampling, DNA extraction and DNA manipulation in order to establish protocols that most efficiently generate reproducible and authentic results. As increasing numbers of researchers from different backgrounds become interested in using ancient DNA technology to address key questions, the need for practical guidelines on how to construct and use an ancient DNA facility arises. The aim of this article is therefore to provide practical tips for building a state-of-the-art ancient DNA facility. It is intended to help researchers new to the field of ancient DNA research generally, and those considering the application of next generation sequencing, in their planning process. PMID:21514120

  4. Modeling and Simulation of the ARES UPPER STAGE Transportation, Lifting, Stacking and Mating Operations Within the Vehicle Assembly Building at KSC

    NASA Technical Reports Server (NTRS)

    Kromis, Phillip A.

    2010-01-01

    This viewgraph presentation describes the modeling and simulation of the Ares Upper Stage Transportation, lifting, stacking, and mating operations within the Vehicle Assembly Building (VAB) at Kennedy Space Center (KSC). An aerial view of KSC Launch Shuttle Complex, two views of the Delmia process control layout, and an upper stage move subroutine and breakdown are shown. An overhead image of the VAB and the turning basin along with the Pegasus barge at the turning basin are also shown. This viewgraph presentation also shows the actual design and the removal of the mid-section spring tensioners, the removal of the AFT rear and forward tensioners tie downs, and removing the AFT hold down post and mount. US leaving the Pegasus Barge, the upper stage arriving at transfer aisle, upper stage receiving/inspection in transfer aisle, and an overhead view of upper stage receiving/inspection in transfer aisle are depicted. Five views of the actual connection of the cabling to the upper stage aft lifting hardware are shown. The upper stage transporter forward connector, two views of the rotation horizontal to vertical, the disconnection of the rear bolt ring cabling, the lowering of the upper stage to the inspection stand, disconnection of the rear bolt ring from the upper stage, the lifting of the upper stage and inspection of AFT fange, and the transfer of upper stage in an integrated stack are shown. Six views of the mating of the upper stage to the first stage are depicted. The preparation, inspection, and removal of the forward dome are shown. The upper stage mated on the integrated stack and crawler is also shown. This presentation concludes with A Rapid Upper Limb Assessment (RULA) utilizing male and female models for assessing risk factors to the upper extremities of human beings in an actual physical environment.

  5. Energy Performance Evaluation and Development of Control Strategies for the Air-conditioning System of a Building at Construction Stage 

    E-print Network

    Wang, S.; Xu, X.; Ma, Z.

    2006-01-01

    Energy consumption of HVAC systems in commercial buildings takes a great part of the total building energy consumption. Energy performance evaluation plays an important role in building energy efficiency improvement for ...

  6. Comparison of DOE-2.1E with Energyplus and TRNSYS for Ground Coupled Residential Buildings in Hot anf Humid Climates Stage 2

    E-print Network

    Andolsun, S.; Culp, C.

    2011-01-01

    ESL-TR-11-12-09 COMPARISON OF DOE-2.1E WITH ENERGYPLUS AND TRNSYS FOR GROUND COUPLED RESIDENTIAL BUILDINGS IN HOT AND HUMID CLIMATES STAGE 2 “Literature Survey on Comparative Studies on Slab-on-grade and Basement Models of DOE-2, EnergyPlus... ............................................................................................................................. 4 Introduction ................................................................................................................................................... 4 1. Studies that compared DOE-2 with EnergyPlus...

  7. Energy Performance Evaluation and Development of Control Strategies for the Air-conditioning System of a Building at Construction Stage

    E-print Network

    Wang, S.; Xu, X.; Ma, Z.

    2006-01-01

    Shengwei Wang Xinhua Xu Zhenjun Ma Professor & Associate Head Post Doctoral Fellow PhD student Department of Building Services Engineering, The Hong Kong Polytechnic University... Kowloon, Hong Kong SAR, China beswwang@polyu.edu.hk Abstract: Energy consumption of HVAC systems in commercial buildings takes a great part of the total building energy consumption. Energy performance evaluation plays an important role in building...

  8. Rotating shielded crane system

    DOEpatents

    Commander, John C. (Idaho Falls, ID)

    1988-01-01

    A rotating, radiation shielded crane system for use in a high radiation test cell, comprises a radiation shielding wall, a cylindrical ceiling made of radiation shielding material and a rotatable crane disposed above the ceiling. The ceiling rests on an annular ledge intergrally attached to the inner surface of the shielding wall. Removable plugs in the ceiling provide access for the crane from the top of the ceiling into the test cell. A seal is provided at the interface between the inner surface of the shielding wall and the ceiling.

  9. Late Cryogenian-Ediacaran history of the Arabian-Nubian Shield: A review of depositional, plutonic, structural, and tectonic events in the closing stages of the northern East African Orogen

    NASA Astrophysics Data System (ADS)

    Johnson, P. R.; Andresen, A.; Collins, A. S.; Fowler, A. R.; Fritz, H.; Ghebreab, W.; Kusky, T.; Stern, R. J.

    2011-10-01

    During the late Cryogenian-Ediacaran (650-542 Ma), the Arabian-Nubian Shield (ANS) underwent final assembly and accretion to the Saharan Metacraton concurrent with the assembly of eastern and western Gondwana. At the end of the Precambrian it lay at one end of the East African Orogen, with its northern margin (present coordinates) forming a low-relief stable shelf facing an open ocean; to the south the ANS transitioned into the Mozambique Belt. The geologic history of the ANS during this period provides insight into the closing developmental stages of one of the world's largest accretionary orogens. Following a 680-640 Ma orogenic event reflecting amalgamation of a core grouping of island-arc terranes (the proto-Arabian-Nubian Shield; pANS), the region underwent extensive exhumation, erosion, and subsidence. Depositional basins formed in the northern and eastern pANS, with those in the east below sea level and connected to an ocean. Periodic basin closure and formation of new basins in other parts of the ANS followed. Many basins were filled by terrestrial, molasse-type sediments interfingering with subordinate to predominant amounts of volcanic rocks. Magmatism was extensive throughout the period, initially characterized by tonalite-trondhjemite-granodiorite (TTG) and granite (monzogranite, syenogranite), but also characterized, from ˜610 Ma on, by increasing amounts of alkali-feldspar granite and alkali granite. The plutons are largely undeformed, except where cut by brittle-ductile shear zones. The magma sources of the late Cryogenian-Ediacaran granitoids were dominated by juvenile crust and(or) depleted mantle and magmas mostly originated in anorogenic, post-collisional, commonly extensional, settings. They were derived by melting and fractionation of anhydrous high-grade metamorphosed lower crust, mafic- to intermediate calc-alkaline crust, and(or) subduction-modified mantle wedges associated with slab break-off or delamination. By ˜630 Ma, the region was affected by oblique (transpressional) convergence of continental blocks that formed eastern and western Gondwana—the pANS was approaching the Saharan Metacraton; north-trending shear and shortening zones developed in the southern ANS; and northwest-trending strike-slip shear zones of the Najd fault system dominated farther north. In the northwestern ANS, convergence and Najd transpression buckled the crust causing structural highs with domes of gneissic infracrust overlain by supracrust composed of ophiolitic and volcanosedimentary assemblages dating from the Tonian-middle Cryogenian period of island-arc activity. The supracrust was extensively translated to the northwest above a high-strain zone. Extension and tectonic escape augmented exhumation of the gneissic infracrust particularly between ˜620-580 Ma. In the northeastern ANS, linear belts of gneiss formed from reworked older intrusive bodies or syntectonic intrusions that were emplaced along Najd faults. By ˜620 Ma a marine basin on the eastern margin of the pANS (present coordinates) was beginning to close. A thick sedimentary assemblage (Abt formation) in this basin underwent metamorphism and folding, and subduction-related magmatism and volcanism farther into this basin (Al Amar arc; >690-615 Ma) was coming to an end. Amalgamation of the Abt formation, Al Amar arc, and the pANS occurred between ˜620 and ˜605 Ma, and terminal collision between the pANS and the Saharan Metacraton was complete by ˜580 Ma. At this time, the ANS was fully assembled. Granite magmatism continued until ˜565-560 Ma and orogeny ceased by ˜550 Ma. During these terminal events, the region underwent strong chemical weathering and became a vast low-relief surface on which Lower Paleozoic sandstone was eventually deposited.

  10. Shielding Development for Nuclear Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Caffrey, Jarvis A.; Gomez, Carlos F.; Scharber, Luke L.

    2015-01-01

    Radiation shielding analysis and development for the Nuclear Cryogenic Propulsion Stage (NCPS) effort is currently in progress and preliminary results have enabled consideration for critical interfaces in the reactor and propulsion stage systems. Early analyses have highlighted a number of engineering constraints, challenges, and possible mitigating solutions. Performance constraints include permissible crew dose rates (shared with expected cosmic ray dose), radiation heating flux into cryogenic propellant, and material radiation damage in critical components. Design strategies in staging can serve to reduce radiation scatter and enhance the effectiveness of inherent shielding within the spacecraft while minimizing the required mass of shielding in the reactor system. Within the reactor system, shield design is further constrained by the need for active cooling with minimal radiation streaming through flow channels. Material selection and thermal design must maximize the reliability of the shield to survive the extreme environment through a long duration mission with multiple engine restarts. A discussion of these challenges and relevant design strategies are provided for the mitigation of radiation in nuclear thermal propulsion.

  11. Comparison of DOE-2.1E with Energyplus and TRNSYS for Ground Coupled Residential Buildings in Hot anf Humid Climates Stage 1

    E-print Network

    Andolsun, S.; Culp, C.

    2011-01-01

    ESL-TR-11-12-08 COMPARISON OF DOE-2.1E WITH ENERGYPLUS AND TRNSYS FOR GROUND COUPLED RESIDENTIAL BUILDINGS IN HOT AND HUMID CLIMATES STAGE 1 “Literature Survey on Slab-on-grade Heat Transfer Models of DOE-2, EnergyPlus and TRNSYS... .................................................................................................................... 4 2. Introduction ........................................................................................................................................... 4 3. Literature Survey on Slab-on-grade Models of DOE-2, EnergyPlus and TRNSYS...

  12. SOUTHWEST REAR AND SOUTHEAST SIDE. Protective berm at left shields ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SOUTHWEST REAR AND SOUTHEAST SIDE. Protective berm at left shields Air Supply building from launch pad - Edwards Air Force Base, South Base Sled Track, Air Supply Building for Building No. 0545, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  13. 7. DETAIL SHOWING BLAST SHIELDED WINDOWS, WEST SIDE. Edwards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL SHOWING BLAST SHIELDED WINDOWS, WEST SIDE. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  14. 4. DETAIL SHOWING PERISCOPE AND SHIELDED WINDOWS ON EAST SIDE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL SHOWING PERISCOPE AND SHIELDED WINDOWS ON EAST SIDE, NORTH PART. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  15. Low-Cost Shielding to Minimize Radiation Errors of Temperature Sensors in the Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of shielding temperature sensors from solar radiation is understood, but there is a lack of prescriptive advice for plant scientists to build inexpensive, effective shields for replicated field experiments. Using general physical principles that govern radiation shielding, a number of...

  16. Development of a methodology for defining whole-building energy design targets for commercial buildings: Phase 2, Development Concept Stage Report

    SciTech Connect

    McKay, H.N. (Illuminating Engineering Society of North America, New York, NY (USA)); Deringer, J.J. (American Inst. of Architects, Washington, DC (USA)); Jones, J.W. (American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (USA)); Hall, J.D. (Deringer Group, Riva, MD (USA))

    1990-09-01

    This report documents eight tasks performed as part of the Whole-Building Energy Design Targets project, in which detailed conceptual approaches were produced for each element of the proposed Targets model. The eight task reports together describe the important modules proposed for inclusion in the Targets model: input module, energy module, characteristic development moduel, building cost module, analysis control module, energy cost module, search routines module, and economic analysis module. 16 refs., 16 figs., 5 tabs.

  17. Gamma ray detector shield

    DOEpatents

    Ohlinger, R.D.; Humphrey, H.W.

    1985-08-26

    A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

  18. Shielding calculations at dismantled synchrocyclotron

    SciTech Connect

    Yalcintas, M.G.

    1987-01-01

    The Space Radiation Effects Laboratory located in Newport News, Virginia, was operated by the College of William and Mary for the National Aeronautics and Space Administration. A synchrocyclotron which was formerly in operation in this building was removed in 1980. At several locations, the scattered radiation caused an induced radioactivity within the walls of the cyclotron room. A radiological survey has been performed to determine the amount of residual radioactivity on the walls. Calculations were performed to determine the thickness of the concrete walls and floor for shielding the residual radiation in the cyclotron room. Recommendations are made to minimize exposures from the residual radioactivity on the walls and floor of the cyclotron room to potential occupants working in the building. 19 refs., 1 fig., 2 tabs.

  19. Radiation Shielding Materials

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    NASA has relied on the materials to provide radiation shielding for astronauts since the first manned flights. Until very recently existing materials in the structure of manned spacecraft as well as the equipment and consumables onboard have been taken advantage of for radiation shielding. With the advent of the International Space Station and the prospect of extended missions to the Moon or Mars, it has been found that the materials, which were included in the spacecraft for other reasons, do not provide adequate shielding. For the first time materials are being added to manned missions solely to improve the radiation shielding. It is now recognized that dual use materials must be identified/developed. These materials must serve a purpose as part of the spacecraft or its cargo and at the same time be good shielding. This paper will review methods for evaluating the radiation shielding effectiveness of materials and describe the character of materials that have high radiation shielding effectiveness. Some candidate materials will also be discussed.

  20. Heat Shield in Pieces

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity shows the remains of the rover's heat shield, broken into two key pieces, the main piece on the left side and a broken-off flank piece near the middle of the image. The heat shield impact site is identified by the circle of red dust on the right side of the picture. In this view, Opportunity is approximately 20 meters (66 feet) away from the heat shield, which protected it while hurtling through the martian atmosphere.

    In the far left of the image, a meteorite called 'Heat Shield Rock,' sits nearby, The Sun is reflecting off the silver-colored underside of the internal thermal blankets of the heat shield.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact.

    This is an approximately true-color rendering of the scene acquired around 1:22 p.m. local solar time on Opportunity sol 324 (Dec. 21, 2004) in an image mosaic using panoramic filters at wavelengths of 750, 530, and 430 nanometers.

  1. iSHIELD - A Line Source Application of SHIELD11

    SciTech Connect

    Nelson, W.R.; Rokni, S.H.; /SLAC

    2006-04-27

    iSHIELD11 performs a line-source numerical integration of radiation source terms that are defined by the iSHIELD11 computer code[1] . An example is provided to demonstrate how one can use iSHIELD11 to perform a shielding analysis for a 250 GeV electron linear accelerator.

  2. Late Cryogenian–Ediacaran history of the Arabian–Nubian Shield: A review of depositional, plutonic, structural, and tectonic events in the closing stages of the northern East African Orogen

    Microsoft Academic Search

    P. R. Johnson; A. Andresen; A. S. Collins; A. R. Fowler; H. Fritz; W. Ghebreab; T. Kusky; R. J. Stern

    2011-01-01

    During the late Cryogenian–Ediacaran (650–542Ma), the Arabian–Nubian Shield (ANS) underwent final assembly and accretion to the Saharan Metacraton concurrent with the assembly of eastern and western Gondwana. At the end of the Precambrian it lay at one end of the East African Orogen, with its northern margin (present coordinates) forming a low-relief stable shelf facing an open ocean; to the

  3. Adhesive particle shielding

    DOEpatents

    Klebanoff, Leonard Elliott (Dublin, CA); Rader, Daniel John (Albuquerque, NM); Walton, Christopher (Berkeley, CA); Folta, James (Livermore, CA)

    2009-01-06

    An efficient device for capturing fast moving particles has an adhesive particle shield that includes (i) a mounting panel and (ii) a film that is attached to the mounting panel wherein the outer surface of the film has an adhesive coating disposed thereon to capture particles contacting the outer surface. The shield can be employed to maintain a substantially particle free environment such as in photolithographic systems having critical surfaces, such as wafers, masks, and optics and in the tools used to make these components, that are sensitive to particle contamination. The shield can be portable to be positioned in hard-to-reach areas of a photolithography machine. The adhesive particle shield can incorporate cooling means to attract particles via the thermophoresis effect.

  4. Shielded RF Lattice Chris Rogers,

    E-print Network

    McDonald, Kirk

    Shielded RF Lattice Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12;Shielded RF Status Shielded RF Lattice was developed until ~ April 2010 April make the same decision for RDR Time to dust the design off #12;Shielded RF - Reminder Increase cell

  5. Space Station MMOD Shielding

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric

    2006-01-01

    This paper describes International Space Station (ISS) shielding for micrometeoroid orbital debris (MMOD) protection, requirements for protection, and the technical approach to meeting requirements. Current activities in MMOD protection for ISS will be described, including efforts to augment MMOD protection by adding shields on-orbit. Observed MMOD impacts on ISS elements such as radiators, modules and returned hardware will be described. Comparisons of the observed damage with predicted damage using risk assessment software will be made.

  6. Shielded cells transfer automation

    SciTech Connect

    Fisher, J J

    1984-01-01

    Nuclear waste from shielded cells is removed, packaged, and transferred manually in many nuclear facilities. Radiation exposure is absorbed by operators during these operations and limited only through procedural controls. Technological advances in automation using robotics have allowed a production waste removal operation to be automated to reduce radiation exposure. The robotic system bags waste containers out of glove box and transfers them to a shielded container. Operators control the system outside the system work area via television cameras. 9 figures.

  7. Setting the Stage with Geometry: Lessons & Worksheets to Build Skills in Measuring Perimeter, Area, Surface Area, and Volume. Poster/Teaching Guide. Expect the Unexpected with Math[R

    ERIC Educational Resources Information Center

    Actuarial Foundation, 2013

    2013-01-01

    "Setting the Stage with Geometry" is a new math program aligned with the National Council of Teachers of Mathematics (NCTM) standards that is designed to help students in grades 6-8 build and reinforce basic geometry skills for measuring 2D and 3D shapes. Developed by The Actuarial Foundation, this program seeks to provide skill-building math…

  8. Shielding effectiveness of reinforced concrete structures in cellular communication bands

    Microsoft Academic Search

    H. M. Elkamchouchi; A. T. Abdelkader

    2002-01-01

    The proliferation of cellular communication systems in and around man-made structures has resulted in a growing need to determine the shielding properties of various materials commonly used in buildings. This will be useful in two major branches of applications, namely radio base station planning and the effect of exposure to very near radiation sources inside buildings, especially those carrying radio

  9. Development of a methodology for defining whole-building energy design targets for commercial buildings: Phase 2, Development Concept Stage Report

    SciTech Connect

    Deringer, J.J. (American Inst. of Architects, Washington, DC (USA)); Hall, J.D. (Deringer Group, Riva, MD (USA)); Jones, J.W. (American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., New York, NY (USA)); McKay, H.N. (Illuminating Engineering Society of North America, New York, NY (USA)); Alley, P.K. (Pacific Northwest Lab., Richland, WA (USA))

    1990-09-01

    The primary focus of the Whole-Building Energy Design Targets project is to develop a flexible methodology for setting target guidelines with which to assess energy efficiency in commercial building design. The proposed methodology has several innovative features. In this report, the authors document their work to define the software development concepts upon which the overall Targets methodology will be based. Three task reports are included here. Development of the user interface--that critical connection through which the human end-user (architect, engineer, planner, owner) will apply the methodology--is described in Section 2. In Section 3, the use of the software engineering process in Targets model development efforts is described. Section 4 provides details on the data and system integration task, in which interactions between and among all the major components, termed modules, of the Targets model were examined to determine how to put them together to create a methodology that is effective and easy to use. 4 refs., 26 figs.

  10. Methods of Making Z-Shielding

    NASA Technical Reports Server (NTRS)

    Thomsen, III, Donald Laurence (Inventor); Cano, Roberto J. (Inventor); Jensen, Brian J. (Inventor); Hales, Stephen J. (Inventor); Alexa, Joel A. (Inventor)

    2014-01-01

    Methods of building Z-graded radiation shielding and covers. In one aspect, the method includes: providing a substrate surface having about medium Z-grade; plasma spraying a first metal having higher Z-grade than the substrate surface; and infusing a polymer layer to form a laminate. In another aspect, the method includes electro/electroless plating a first metal having higher Z-grade than the substrate surface. In other aspects, the methods include improving an existing electronics enclosure to build a Z-graded radiation shield by applying a temperature controller to at least part of the enclosure and affixing at least one layer of a first metal having higher Z-grade from the enclosure.

  11. Grounding and shielding in the accelerator environment

    SciTech Connect

    Kerns, Q.

    1991-12-31

    Everyday features of the accelerator environment include long cable runs, high power and low level equipment sharing building space, stray electromagnetic fields and ground voltage differences between the sending and receiving ends of an installation. This paper pictures some Fermilab installations chosen to highlight significant features and presents practices, test methods and equipment that have been helpful in achieving successful shielding. Throughout the report are numbered statements aimed at summarizing good practices and avoiding pitfalls.

  12. Grounding and shielding in the accelerator environment

    SciTech Connect

    Kerns, Q.

    1991-01-01

    Everyday features of the accelerator environment include long cable runs, high power and low level equipment sharing building space, stray electromagnetic fields and ground voltage differences between the sending and receiving ends of an installation. This paper pictures some Fermilab installations chosen to highlight significant features and presents practices, test methods and equipment that have been helpful in achieving successful shielding. Throughout the report are numbered statements aimed at summarizing good practices and avoiding pitfalls.

  13. Damaged Skylab Micrometeoroid Shield

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Saturn V vehicle, carrying the unmarned orbital workshop for the Skylab-1 mission, lifted off successfully and all systems performed normally. Sixty-three seconds into flight, engineers in the operation support and control center saw an unexpected telemetry indication that signalled that damages occurred on one solar array and the micrometeoroid shield during the launch. The micrometeoroid shield, a thin protective cylinder surrounding the workshop protecting it from tiny space particles and the sun's scorching heat, ripped loose from its position around the workshop. This caused the loss of one solar wing and jammed the other. Still unoccupied, the Skylab was stricken with the loss of the heat shield and sunlight beat mercilessly on the lab's sensitive skin. Internal temperatures soared, rendering the station uninhabitable, threatening foods, medicines, films, and experiments. This image, taken during a fly-around inspection by the Skylab-2 crew, shows the damaged meteoroid shield being held by a thin aluminum strap entangled with green-hued remnants of the lost heat shield. The Marshall Space Flight Center (MSFC) developed, tested, rehearsed, and approved three repair options. These options included a parasol sunshade and a twin-pole sunshade to restore the temperature inside the workshop, and a set of metal cutting tools to free the jammed solar panel.

  14. Dynamic rotating-shield brachytherapy

    SciTech Connect

    Liu, Yunlong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States)] [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)] [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Yang, Wenjun [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Wu, Xiaodong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)] [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2013-12-15

    Purpose: To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process.Methods: A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D{sub 90} for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and {sup 192}Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D{sub 2cc} of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with ?/?= 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively.Results: For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes/fraction (min/fx) assuming a 10 Ci{sup 192}Ir source, and the average HR-CTV D{sub 90} was 78.9 Gy. In order to match the HR-CTV D{sub 90} of IS + ICBT, D-RSBT required an average of 10.1 min/fx more delivery time, and S-RSBT required 6.7 min/fx more. If an additional 20 min/fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D{sub 90} above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively.Conclusions: For cervical cancer patients, D-RSBT can boost HR-CTV D{sub 90} over IS + ICBT and S-RSBT without violating the tolerance doses to the bladder, rectum, or sigmoid. The D{sub 90} improvements from D-RSBT depend on the patient, the delivery time budget, and the applicator structure.

  15. Shield sizing and response equations

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric L.

    1991-01-01

    A consolidated list is presented of meteoroid debris shield equations which have been given in the referenced memorandums. In some cases, equations have been updated; thus, this memorandum supersedes reference 1. The equations are presented in two parts: (1) shield sizing equations which are used to produce preliminary estimates of shielding weights; and (2) response equations to describe the impact conditions (projectile size as a function of velocity, density, and impact angle) causing failure of a given shield that are to be used for probability analyses (such as in the modified BUMPER program). Specific equations are given that are applicable for the following types of shields: aluminum Whipple shields; Nextel multishock (MS) shields; and mesh double bumper (MDB) shields. These equations will be updated in the future as warranted by the results of additional HVI tests, analyses, and shield modeling.

  16. Radiation shielding composition

    DOEpatents

    Quapp, W.J.; Lessing, P.A.

    1998-07-28

    A composition is disclosed for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm{sup 3} and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile. 5 figs.

  17. Radiation shielding composition

    DOEpatents

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    2000-12-26

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  18. Radiation shielding composition

    DOEpatents

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    1998-01-01

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  19. Opportunity's Heat Shield Scene

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity reveals the scene of the rover's heat shield impact. In this view, Opportunity is approximately 130 meters (427 feet) away from the device that protected it while hurtling through the martian atmosphere.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact.

    This is the panoramic camera team's best current attempt at generating a true-color view of what this scene would look like if viewed by a human on Mars. It was generated from a mathematical combination of six calibrated, left-eye panoramic camera images acquired around 1:50 p.m. local solar time on Opportunity's sol 322 (Dec. 19, 2004) using filters ranging in wavelengths from 430 to 750 nanometers.

  20. Space Radiation Superconducting Shields

    NASA Astrophysics Data System (ADS)

    R-Musenich; Calvelli, V.; Farinon, S.; Burger, W. J.; Battiston, R.

    2014-05-01

    The interest on shields to protect astronauts I long term missions against GCR has recently grown and several projects have been funded. Due to their large mass, passive shields for large volume habitable modules are no longer an option and the attention is focused on the more complex, technologically challenging active systems. Among the possible solutions, the most promising is based on huge superconducting coils having a bending power sufficient to deflect out of the habitat charged particles with kinetic energy in the order of 1 GeV. Toroidal magnet systems based wound with Ti clad MgB2 conductor is proposed and described.

  1. ARIES-CS Radial Builds and Compositions

    E-print Network

    everywhere (no shield-only zones). · 1% nuclear heating in LT shield and/or VV. · Shield, VV, and magnet Configuration R = 8.25 m a = 1.85 m #12;08/30/2004 10 Internal VV #12;08/30/2004 11 Flibe/FS Radial Build (Water

  2. Enhancing network robustness via shielding

    E-print Network

    Zhang, Jianan, S.M. Massachusetts Institute of Technology

    2014-01-01

    Shielding critical links enhances network robustness and provides a new way of designing robust networks. We first consider shielding critical links to guarantee network connectivity after any failure under geographical ...

  3. Lightweight blast shield

    DOEpatents

    Mixon, Larry C. (Madison, AL); Snyder, George W. (Huntsville, AL); Hill, Scott D. (Toney, AL); Johnson, Gregory L. (Decatur, AL); Wlodarski, J. Frank (Huntsville, AL); von Spakovsky, Alexis P. (Huntsville, AL); Emerson, John D. (Arab, AL); Cole, James M. (Huntsville, AL); Tipton, John P. (Huntsville, AL)

    1991-01-01

    A tandem warhead missile arrangement that has a composite material housing structure with a first warhead mounted at one end and a second warhead mounted near another end of the composite structure with a dome shaped composite material blast shield mounted between the warheads to protect the second warhead from the blast of the first warhead.

  4. PHOTON TRANSPORT AND SHIELDING

    E-print Network

    Lin, Zi-wei

    PHOTON TRANSPORT AND SHIELDING (DETERMINISTIC OR MC) KEYWORDS: lunar albedo, space radiation, radiation transport ANISOTROPY OF THE ALBEDO RADIATION ENVIRONMENT ON THE LUNAR SURFACE FROM GEANT4 radiation particles on the lunar surface in the 1977 solar minimum galactic- cosmic-ray environment when

  5. Hydrocode modeling of advanced debris shield designs

    NASA Astrophysics Data System (ADS)

    Kerr, J. H.; Christiansen, E. L.; Crews, J. L.

    1996-05-01

    The NASA Johnson Space Center (JSC) Hypervelocity Impact Test Facility (HIT-F) has developed several low mass, high performance shielding concepts to protect spacecraft from orbital debris and meteoroid impact. Development testing requires shield concept validation in the impact velocity regime from <1 km/s to ˜14.5 km/s. Current two-stage light gas gun testing limits maximum impact velocities to 8 km/s; therefore, Sandia National Laboratories and Southwest Research Institute have developed advanced launchers capable of accelerating non-spherical shaped masses to ˜15 km/s. Since the shape of the impactor influences final rear wall damage, hydrocodes are employed to evaluate the so called shape effect at velocities greater than 8 km/s. A series of 14 hypervelocity impact simulations were conducted using the CTH hydrocode. Simulations modeled spherical aluminum (Al) and Al flat plate projectiles of various masses impacting double bumper all Al Whipple shields (DB). Experimental results at ˜7 km/s are compared with simulation and ballistic limit curves are constructed for the DB Whipple shield in the velocity regime greater than 7 km/s. Comments are also made on the shape effect mass ratio for spherical and flat plate projectiles.

  6. SUPERCONDUCTING SHIELDING By W. O. HAMILTON,

    E-print Network

    Paris-Sud XI, Université de

    41. SUPERCONDUCTING SHIELDING By W. O. HAMILTON, Stanford University, Department of Physics, Stanford, California (U.S.A.). Abstract. 2014 Superconducting shields offer the possibility of obtaining shielding from external time varying fields. Various techniques of superconducting shielding

  7. Review Article RADIATION SHIELDING TECHNOLOGY

    E-print Network

    Shultis, J. Kenneth

    Review Article RADIATION SHIELDING TECHNOLOGY J. Kenneth Shultis and Richard E. Faw* Abstract--An historical review of the development of shielding techniques for indirectly ionizing radiation is presented and analysis. Health Phys. 88(4):297­322; 2005 Key words: reviews; shielding; historical profiles; Health

  8. Early stages of building a rare disease registry, methods and 2010 data from the Belgian Neuromuscular Disease Registry (BNMDR).

    PubMed

    Roy, Anna J; Van den Bergh, Peter; Van Damme, Philip; Doggen, Kris; Van Casteren, Viviane

    2015-06-01

    The Belgian Neuromuscular Disease Registry, commissioned in 2008, aims to collect data to improve knowledge on neuromuscular diseases and enhance quality health services for neuromuscular disease patients. This paper presents a clear outline of the strategy to launch a global national registry. All patients diagnosed with one of the predefined 62 neuromuscular disease groups and living in Belgium may be included in the yearly updated Registry. Basic core data is harvested through a newly designed web application by the six accredited neuromuscular reference centres. In 2010, 3,424 patients with a neuromuscular disorder were registered. The most prevalent disease group in the Registry is Hereditary Motor and Sensory Neuropathy, as similarly stated by other studies, albeit the prevalence in Belgium is five times lower: 6.5 per 100,000 in the north of Belgium, versus 17.0-41.0 per 100,000 in other areas of Europe. Very few patients were captured in the south of the country. With the aim to collect valuable epidemiological data, the registry targets to gather high quality data, that the sample to be representative of the population and that it be complete. The past 5 years of building the registry have improved its quality, albeit the consistent gap in data from the south of the country prevails, influencing the estimated prevalence of these diseases. To this day, the true burden of neuromuscular diseases in Belgium is not known but actions have been undertaken to address these issues. PMID:24957677

  9. Roof Shield for Advance and Retreat Mining

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1985-01-01

    Shield sections change their configuration to suit mining mode. Articulation cylinders raise rear shield to advance position, and locking cylinders hold it there. To change to retreat position articulation cylinders lower shield. Locking pins at edge of outermost shield plate latch shield to chock base. Shield accommodates roof heights ranging from 36 to 60 inches (0.9 to 1.52 meters).

  10. Gas shielding apparatus

    DOEpatents

    Brandt, D.

    1984-06-05

    An apparatus for preventing oxidation by uniformly distributing inert shielding gas over the weld area of workpieces such as pipes being welded together. The apparatus comprises a chamber and a gas introduction element. The chamber has an annular top wall, an annular bottom wall, an inner side wall and an outer side wall connecting the top and bottom walls. One side wall is a screen and the other has a portion defining an orifice. The gas introduction element has a portion which encloses the orifice and can be one or more pipes. The gas introduction element is in fluid communication with the chamber and introduces inert shielding gas into the chamber. The inert gas leaves the chamber through the screen side wall and is dispersed evenly over the weld area.

  11. VLHC Thermal Shield Cooling

    Microsoft Academic Search

    C. Darve; P. Bauer; T. Nicol; T. Peterson

    The Very Large Hadron Collider (VLHC) - stage 2 cooling system has been optimized regarding the ability to minimize the total refrigeration power. The stage 2 VLHC synchrotron radiation dictates a high optimal beam screen temperature. LHC dipole cryostat thermal model results provide data to characterize the behavior of the stage 2 VLHC cooling system. In the cryogenic concept pursued

  12. Crumpled Heat Shield

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Phoenix Mars Lander's Surface Stereo Imager took this image of the spacecraft's crumpled heat shield on Sept. 16, 2008, the 111th Martian day of the mission.

    The 2-1/2 meter (about 8-1/2 feet) heat shield landed southeast of Phoenix, about halfway between the spacecraft and its backshell/parachute. The backshell/parachute touched ground 300 meters (1,000 ft) to the south of the lander.

    The dark area to the right of the heat shield is the 'bounce mark' it made on impact with the Red Planet. This image is the highest-resolution image that will likely be taken by the lander, and is part of the 1,500-image 'Happily Ever After' panorama.

    The Phoenix mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. Magnetic shielding of the cold atom space clock PHARAO

    NASA Astrophysics Data System (ADS)

    Moric, Igor; Laurent, Philippe; Chatard, Philippe; de Graeve, Charles-Marie; Thomin, Stephane; Christophe, Vincent; Grosjean, Olivier

    2014-09-01

    The space clock PHARAO is an atomic clock based on laser cooled cesium atoms. In order to attenuate magnetic field fluctuation in orbit, PHARAO clock uses three concentric Mumetal magnetic shields combined with several coils to improve the field homogeneity. We have characterized the attenuation and magnetic field homogeneity of the shields used to build the flight model. The average value of attenuation inside the three shields is around 18,000 when the external field is similar to the orbit field (30 ?T) and the field homogeneity is lower than 10 nT. These values have not changed after vibrations and thermal tests for the space qualification. Permeability variation of the shields as a function of the intercepted flux has been analyzed.

  14. WASTE TREATMENT BUILDING SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    F. Habashi

    2000-06-22

    The Waste Treatment Building System provides the space, layout, structures, and embedded subsystems that support the processing of low-level liquid and solid radioactive waste generated within the Monitored Geologic Repository (MGR). The activities conducted in the Waste Treatment Building include sorting, volume reduction, and packaging of dry waste, and collecting, processing, solidification, and packaging of liquid waste. The Waste Treatment Building System is located on the surface within the protected area of the MGR. The Waste Treatment Building System helps maintain a suitable environment for the waste processing and protects the systems within the Waste Treatment Building (WTB) from most of the natural and induced environments. The WTB also confines contaminants and provides radiological protection to personnel. In addition to the waste processing operations, the Waste Treatment Building System provides space and layout for staging of packaged waste for shipment, industrial and radiological safety systems, control and monitoring of operations, safeguards and security systems, and fire protection, ventilation and utilities systems. The Waste Treatment Building System also provides the required space and layout for maintenance activities, tool storage, and administrative facilities. The Waste Treatment Building System integrates waste processing systems within its protective structure to support the throughput rates established for the MGR. The Waste Treatment Building System also provides shielding, layout, and other design features to help limit personnel radiation exposures to levels which are as low as is reasonably achievable (ALARA). The Waste Treatment Building System interfaces with the Site Generated Radiological Waste Handling System, and with other MGR systems that support the waste processing operations. The Waste Treatment Building System interfaces with the General Site Transportation System, Site Communications System, Site Water System, MGR Site Layout, Safeguards and Security System, Site Radiological Monitoring System, Site Electrical Power System, Site Compressed Air System, and Waste Treatment Building Ventilation System.

  15. Experimental Shielding Evaluation of the Radiation Protection Provided by Residential Structures

    NASA Astrophysics Data System (ADS)

    Dickson, Elijah D.

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment has been a public and regulatory concern since the early development of nuclear technology and researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to research and develop the technical basis for contemporary building shielding factors for the U.S. housing stock. Building shielding factors quantify the protection a certain building-type provides from ionizing radiation. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950's era suburbia and is no longer applicable to the densely populated urban environments seen today. To analyze a building's radiation shielding properties, the ideal approach would be to subject a variety of building-types to various radioactive materials and measure the radiation levels in and around the building. While this is not entirely practicable, this research uniquely analyzes the shielding effectiveness of a variety of likely U.S. residential buildings from a realistic source term in a laboratory setting. Results produced in the investigation provide a comparison between theory and experiment behind building shielding factor methodology by applying laboratory measurements to detailed computational models. These models are used to develop a series of validated building shielding factors for generic residential housing units using the computational code MCNP5. For these building shielding factors to be useful in radiologic consequence assessments and emergency response planning, two types of shielding factors have been developed for; (1) the shielding effectiveness of each structure within a semi-infinite cloud of radioactive material, and (2) the shielding effectiveness of each structure from contaminant deposition on the roof and surrounding surfaces. For example, results from this investigation estimate the building shielding factors from a semi-infinite plume between comparable two-story models with a basement constructed with either brick-and-mortar or vinyl siding composing the exterior wall weather and a typical single-wide manufactured home with vinyl siding to be 0.36, 0.65, and 0.82 respectively.

  16. 3. EAST SIDE FROM ATOP TUNNEL, SHOWING BLAST SHIELDED WINDOWS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. EAST SIDE FROM ATOP TUNNEL, SHOWING BLAST SHIELDED WINDOWS AND PERISCOPE FACING TO TEST STAND 1-3. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  17. 76. View of copper screen shielded and grounded test area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    76. View of copper screen shielded and grounded test area in transmitter building no. 102, room 115. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  18. RIS-M-2474 CALCULATED SHIELDING FACTORS FOR SELECTED EUROPEAN HOUSES

    E-print Network

    -describtors: APARTMENT BUILDINGS; COMPUTER CALCULATIONS; DOSE RATES; EXTERNAL IRRADIATION; FALLOUT DEPOSITS; GAMMA RADIA- TION; RADIATION DOSES; SHIELDING; SURFACE CONTAMINATION; SUR- FACES; HOUSES December 1984 Risø National In studies of the potential radiological consequences from hypo- thetical nuclear reactor accidents where

  19. Heat Shields for Aerobrakes

    NASA Technical Reports Server (NTRS)

    Pitts, W. C.; Murbach, M. S.

    1987-01-01

    Performances of three types of heat protectors predicted. Estimates of expected performances of heat shields for conical drag brake presented in paper. Drag brakes, or aerobrakes, being considered as devices for slowing space vehicles when they return to Space Shuttle altitudes from higher satellite altitudes after supply missions. Aerobrakes add less weight than do retro-rockets for same purpose and consume no fuel. Paper provides general information on sensitivity of performance to thermal and physical properties of materials used in aerobrakes. Information useful to both designers of brakes and developers of materials for brake fabrication on aerospace structures.

  20. Spacecraft ceramic protective shield

    NASA Technical Reports Server (NTRS)

    Larriva, Rene F. (Inventor); Nelson, Anne (M.); Czechanski, James G. (Inventor); Poff, Ray E. (Inventor)

    1995-01-01

    A low areal density protective shield apparatus, and method for making same, for protecting spacecraft structures from impact with hypervelocity objects, including a bumper member comprising a bumper ceramic layer, a bumper shock attenuator layer, and a bumper confining layer. The bumper ceramic layer can be SiC or B.sub.4 C; the bumper shock attenuator layer can be zirconia felt; and the bumper confining layer can be aluminum. A base armor member can be spaced from the bumper member and a ceramic fiber-based curtain can be positioned between the bumper and base armor members.

  1. The axion shield

    E-print Network

    A. Andrianov; D. Espriu; F. Mescia; A. Renau

    2009-12-16

    We investigate the propagation of a charged particle in a spatially constant, but time dependent, pseudoscalar background. Physically this pseudoscalar background could be provided by a relic axion density. The background leads to an explicit breaking of Lorentz invariance; as a consequence the process p-> p gamma is possible and the background acts as a shield against extremely energetic cosmic rays, an effect somewhat similar to the GZK cut-off effect. The effect is model independent and can be computed exactly. The hypothetical detection of the photons radiated via this mechanism would provide an indirect way of verifying the cosmological relevance of axions.

  2. Actively driven thermal radiation shield

    DOEpatents

    Madden, Norman W. (Livermore, CA); Cork, Christopher P. (Pleasant Hill, CA); Becker, John A. (Alameda, CA); Knapp, David A. (Livermore, CA)

    2002-01-01

    A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

  3. SHIELD verification and validation report

    SciTech Connect

    Boman, C.

    1992-02-01

    This document outlines the verification and validation effort for the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system code. Along with its predecessors, SHIELD has been in use at the Savannah River Site (SRS) for more than ten years. During this time the code has been extensively tested and a variety of validation documents have been issued. The primary function of this report is to specify the features and capabilities for which SHIELD is to be considered validated, and to reference the documents that establish the validation.

  4. EXAMPLES OF RADIATION SHIELDING MODELS

    SciTech Connect

    Willison, J

    2006-07-27

    The attached pictures are examples of shielding models used by WSMS. The models were used in shielding evaluations for Tank 50 pump replacement. They show the relative location of shielding to radiation sources for pumps and pipes. None of the calculations that were associated with these models involved UCNI. The last page contains two pictures from a shielding calculation for the saltstone area. The upper picture is a conceptual drawing. The lower picture is an image copied from the website of a supplier for the project.

  5. Enhanced meteoroid and orbital debris shielding

    Microsoft Academic Search

    E. L. Christiansen; J. L. Crews; J. E. Williamsen; J. H. Robinson; A. M. Nolen

    1995-01-01

    An innovative, low-weight shield system has been developed by NASA Johnson Space Center (JSC) and Marshall Space Flight Center (MSFC) engineers to enhance the protection of conventional Whipple shields. This shield, the “Stuffed Whipple” shield, includes a flexible blanket combining Nextel™ ceramic fabric and Kevlar™ fabric (or “stuffing”) between the aluminum bumper and rear wall of a Whipple shield. The

  6. GCFR grid plate shield design confirmation experiment

    Microsoft Academic Search

    F. J. Muckenthaler; J. L. Hull; J. J. Manning

    1979-01-01

    This report presents measurements of neutron fluxes and energy spectra made in the Grid Plate Shield Design Confirmation Experiment at the ORNL Tower Shielding Facility (TSF) for the Gas Cooled Fast Breeder Reactor (GCFR) shielding program. The experimental configuration consisted of four basic segments: a concrete shadow shield placed directly in the Tower Shielding Reactor II (TSR-II) reactor beam; a

  7. PBF Cubicle 13. Shield wall details illustrate shielding technique of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cubicle 13. Shield wall details illustrate shielding technique of stepped penetrations and brick layout scheme for valve stem extension sleeve. Aerojet Nuclear Company. Date: May 1976. INEEL index no. 761-0620-00-400-195280 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  8. Estimation of perforation thickness for concrete shield against high-speed impact

    Microsoft Academic Search

    G. Ben-Dor; A. Dubinsky; T. Elperin

    2010-01-01

    We extended the existing engineering two-stage models for high-speed penetration of projectiles into concrete shields and suggested a semi-empirical model that is applicable for truncated bodies of revolution penetrating into shields having a finite thickness. In this model at the first stage of penetration (cratering), the resistance force is a linear function of the distance between the nose of the

  9. Design experience: CRBRP radiation shielding

    Microsoft Academic Search

    R. K. Disney; T. C. Chan; F. G. Gallo; L. R. Hedgecock; C. A. McGinnis; G. N. Wrights

    1978-01-01

    The Clinch River Breeder Reactor Plant (CRBRP) is being designed as a fast breeder demonstration project in the U.S. Liquid Metal Fast Breeder Reactor (LMFBR) program. Radiation shielding design of the facility consists of a comprehensive design approach to assure compliance with design and government regulatory requirements. Studies conducted during the CRBRP design process involved the aspects of radiation shielding

  10. Spacecraft heat shield testing method

    Microsoft Academic Search

    Delacy

    1973-01-01

    A process for measuring the service life of heat shields on reentry ; spacecraft after each flight is disclosed. A low electronenergy level, beta ; emitting, isotope, having a reasonably long halflife, preferably promethium-147, ; is uniformly dispersed throughout a refractory heat shield coating. The beta ; particle emission level at the coating surface is measured to provide a base

  11. EMP Coupling Through Cable Shields

    Microsoft Academic Search

    Kendali Casey; Edward Vance

    1978-01-01

    Recent research in electromagnetic coupling between the interior and exterior of coaxial cables is described. Both tubular shields and shields with apertures are discussed with reference to the physical coupling mechanisms and their mathematical representations in terms of transmission-line models.

  12. Radiation Shielding for Fusion Reactors

    SciTech Connect

    Santoro, R.T.

    1999-10-01

    Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel.

  13. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2010-10-26

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  14. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2007-05-22

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  15. Turbine heat shield and bolt retainer assembly

    SciTech Connect

    Fledderjohn, S.R.

    1993-07-13

    A bolt retention and shield apparatus for thermal protection and axial retention of bolts in gas turbine engine rotor bolt holes is described, the bolt retention and shield apparatus comprising: an annular heat shield, a retention means for axial retaining the bolts in the bolt holes at one end of the shield, and a means to mount the heat shield to the rotor at another station of the heat shield.

  16. Shielded enclosures for experimental studies of shielding topology

    NASA Astrophysics Data System (ADS)

    Yang, F. C.; Lee, K. S. H.; Kokorowski, S. A.; Baum, C. E.; Hamm, J.; Graf, W.; Vance, E. F.

    1984-11-01

    The report discusses the effort to provide shielded enclosures for EMP experimental studies of shielding topology. Section 1 discusses the theoretical modeling for which scattering matrices of subshields and their norms are used to relate the internal signals to the electromagnetic source environment. Both the line and aperture penetrations are included in the scattering matrix formulation. Experimental and analytical methods are proposed for estimating parameters of the scattering matrices. It is pointed out in the discussion that these methods can, in turn, be employed to analyze the overall shielding performance and to synthesize the subshield requirements of a system. The discussion in Section 1 includes an illustrative example. Section 2 describes experiments to characterize and quantify the shielding performance of a rectangular metal enclosure containing various line and aperture penetrations. Experimental techniques and procedures are given for obtaining certain parameters involved in the theoretical model for bounding the shielding performance of an enclosure. Techniques for evaluation of the accuracy of the theoretical calculation and its comparison to measured data are also discussed. Section 3 describes specifications that were developed to construct two shielded enclosures, one with a single layer topology and one with a double layer topology. Details are given on the mechanical design of the two enclosures, and on the design of various replaceable panels that can be used to test the accuracy of the theoretical model. Section 4 describes the experimental results of the shielding performance of the two enclosures constructed by SRI International.

  17. Informatica Stages Informatica Stages

    E-print Network

    Steels, Luc

    gewerkt worden op een Sharepoint portal met behulp van de build-in mogelijkheden, custom webparts management), Sales cijfers enz. Gebruikte Technologie: c#, Sharepoint, SQL BI Aantal Stagiairs: 2 Kinect Game

  18. Static Aerodynamic Performance Investigation of a Fluid Shield Nozzle

    NASA Technical Reports Server (NTRS)

    Balan, C.; Askew, J. W.

    2005-01-01

    In pursuit of an acoustically acceptable, high performance exhaust system capable of meeting Federal Aviation Regulation 36 Stage 3 noise goals for the High Speed Civil Transport application, General Electric Aircraft Engines conducted a design study to incorporate a fluid shield into a 36-chute suppressor exhaust-nozzle system. After a full scale preliminary mechanical design of the resulting fluid shield exhaust system, scale model aerodynamic performance tests and acoustic tests were conducted to establish both aerodynamic performance and acoustic characteristics. Data are presented as thrust coefficients, discharge coefficients, chute-base pressure drags, and plug static pressure distributions.

  19. Modified shielding jet model for twin-jet shielding analysis 

    E-print Network

    Gilbride, Jennifer Frances

    1983-01-01

    aircraft noise level, but also indicates the possibility of jet engine installation as a means of The format of this paper follows the style of the "Journal of Heat Transfer" aircraft noise control. For instance, an ovezwing, underwing configuration... August 1983 Major Subject: Mechanical Engineering MODIFIED SHIELDING JET MODEL FOR TWIN-JET SHIELDING ANALYSIS A Thesis by JENNIFER FRANCES GILBRIDE Approved as to stvle and content by: 'Carl H. Gerhold (Chairman of Committee) J. Craag Dutton...

  20. Radiation Shielding Properties of Some Marbles in Turkey

    SciTech Connect

    Guenoglu, K.; Akkurt, I. [Sueleyman Demirel University, Faculty of Arts and Sciences, Dept. of Physics, Isparta (Turkey)

    2011-12-26

    Especially after development of technology, radiation started to be used in a large fields such as medicine, industry and energy. Using radiation in those fields bring hazardous effect of radiation into humancell. Thus radiation protection becomes important in physics. Although there are three ways for radiation protection, shielding of the radiation is the most commonly used method. Natural Stones such as marble is used as construction material especially in critical building and thus its radiation shielding capability should be determined.In this study, gamma ray shielding properties of some different types of marble mined in Turkey, have been measured using a NaI(Tl) scintillator detector. The measured results were also compared with the theoretical calculations XCOM.

  1. PELSHIE2; point kernel integration shielding. [IBM360,303x; FORTRAN IV (99%) and BAL (1%)

    Microsoft Academic Search

    T. B. Fowler; M. L. Tobias; J. N. Fox; B. E. Lawler; J. U. Koppel; J. R. Triplett; L. L. Lynn; L. A. Waldman; I. Goldberg; P. Greebler; M. D. Kelley; R. A. Davis; C. E. Keck; J. A. Redfield; J. I. Thompson

    2008-01-01

    PELSHIE2 calculates dose rates from gamma-emitting sources with different source geometries and shielding configurations. Eight source geometries are provided and are called by means of geometry index numbers. Gamma-emmission characteristics of 133 isotopes, attenuation coefficients for 57 elements and other shielding materials, and Berger build-up parameters for 17 shielding materials can be obtained from two associated direct-access libraries. For extended

  2. Structural/Radiation-Shielding Epoxies

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Smith, Joseph G.; Hinkley, Jeffrey; Blattnig, Steve; Delozier, Donavon M.; Watson, Kent A.; Ghose, Sayata

    2009-01-01

    A development effort was directed toward formulating epoxy resins that are useful both as structural materials and as shielding against heavy-ion radiation. Hydrogen is recognized as the best element for absorbing heavy-ion radiation, and high-hydrogen-content polymers are now in use as shielding materials. However, high-hydrogen-content polymers (e.g. polyethylene) are typically not good structural materials. In contrast, aromatic polymers, which contain smaller amounts of hydrogen, often have the strength necessary for structural materials. Accordingly, the present development effort is based on the concept that an ideal structural/ heavy-ion-radiation-shielding material would be a polymer that contains sufficient hydrogen (e.g., in the form of aliphatic molecular groups) for radiation shielding and has sufficient aromatic content for structural integrity.

  3. Shielding of moving line charges

    NASA Astrophysics Data System (ADS)

    Wang, Youmei; He, Bingyu; Yu, Wei; Yu, M. Y.

    2015-07-01

    A charged object moving in plasma can excite plasma waves that inevitably modify its Debye shielding characteristics. When the excited waves propagate sufficiently fast, the shielding can even break down. Here the properties of finite amplitude plasma waves excited by a moving line charge are investigated. It is found that when the speed of the latter is close to but less than the thermal speed of the background plasma electrons, only a localized disturbance in the form of a soliton that moves together with the line charge is excited. That is, the line charge is well shielded even though it is moving at a high speed and has generated a large local electrostatic field. However, for a pair of line charges moving together, such complete shielding behavior could not be found.

  4. Heat Shield Flank Close Up

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity features an up-close view of the flank piece of the rover's broken heat shield.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact. Overall, engineers were interested in evaluating the performance of the heat shield's thermal protection system.

    This is the the panormamic camera team's best current attempt at generating a 'true color' view of what this scene would look like if viewed by a human on Mars. It was generated from a mathematical combination of six calibrated, left-eye panoramic camera images acquired around 3:07 p.m. local solar time on Opportunity's sol 331 (Dec. 28, 2004) using filters ranging in wavelengths from 430 to 750 nanometers.

  5. Radiation shielding for neutron guides

    NASA Astrophysics Data System (ADS)

    Ersez, T.; Braoudakis, G.; Osborn, J. C.

    2006-11-01

    Models of the neutron guide shielding for the out of bunker guides on the thermal and cold neutron beam lines of the OPAL Reactor (ANSTO) were constructed using the Monte Carlo code MCNP 4B. The neutrons that were not reflected inside the guides but were absorbed by the supermirror (SM) layers were noted to be a significant source of gammas. Gammas also arise from neutrons absorbed by the B, Si, Na and K contained in the glass. The proposed shielding design has produced compact shielding assemblies. These arrangements are consistent with safety requirements, floor load limits, and cost constraints. To verify the design a prototype was assembled consisting of 120 mm thick Pb(96%)Sb(4%) walls resting on a concrete block. There was good agreement between experimental measurements and calculated dose rates for bulk shield regions.

  6. Age and petrology of alkalic postshield and rejuvenated-stage lava from Kauai, Hawaii

    Microsoft Academic Search

    David A. Clague; G. Brent Dalrymple

    1988-01-01

    At the top of the Waimea Canyon Basalt on the island of Kauai, rare flows of alkalic postshield-stage hawaiite and mugearite overlie tholeiitic flows of the shield stage. These postshield-stage flows are 3.92 Ma and provide a younger limit for the age of the tholeiitic shield stage. The younger Koloa Volcanics consist of widespread alkalic rejuvenated-stage flows and vents of

  7. Magnetic Shield for Adiabatic Demagnetization Refrigerators (ADR)

    NASA Technical Reports Server (NTRS)

    Chui, Talso C.; Haddad, Nicolas E.

    2013-01-01

    A new method was developed for creating a less expensive shield for ADRs using 1018 carbon steel. This shield has been designed to have similar performance to the expensive vanadium permendur shields, but the cost is 30 to 50% less. Also, these shields can be stocked in a variety of sizes, eliminating the need for special forgings, which also greatly reduces cost.

  8. Shielding Strategies for Human Space Exploration

    Microsoft Academic Search

    J. W. Wilson; J. Miller; A. Konradi; F. A. Cucinotta

    1997-01-01

    The shield effectiveness of lunar regolith is compared with possible prefabricated shield materials from Earth,including commercially used shield materials in nuclear facilities. Several of the fabricated materials categorized asneutron absorbers and moderators exhibit favorable characteristics for space radiation protection. Although thiseffort is not intended to be a definitive trade study for specific shielding recommendations, attention is given toseveral factors that

  9. Integral Face Shield Concept for Firefighter's Helmet

    NASA Technical Reports Server (NTRS)

    Abeles, F.; Hansberry, E.; Himel, V.

    1982-01-01

    Stowable face shield could be made integral part of helmet worn by firefighters. Shield, made from same tough clear plastic as removable face shields presently used, would be pivoted at temples to slide up inside helmet when not needed. Stowable face shield, being stored in helmet, is always available, ready for use, and is protected when not being used.

  10. SHIELDING THE ENRICO FERMI FAST BREEDER REACTOR

    Microsoft Academic Search

    H. E. Hungerford; R. F. Mantey

    1958-01-01

    The solution of the shielding problems encountered in the Enrico Fermi ; Reactor are given. The shield has been designed from common materials whose ; durability over the expected life of the plant is known and whose cost is low. ; These are graphite, steel, and concrete, all used in the primary, secondary, and ; biological shields. Special shields are

  11. The Radiation Shielding Competition Sponsored by

    E-print Network

    Wang, Xiaorui "Ray"

    The Radiation Shielding Competition Sponsored by: The American Nuclear Society (MNS) Introduction: A radiation shield, simply put, is anything that blocks radiation from an intended target. It can do. But what happens when they are shielded from our detectors? To understand how to detect shielded materials

  12. Enhancement of EMP Shielding by Ferromagnetic Saturation

    Microsoft Academic Search

    R. R. Ferber; F. J. Young

    1970-01-01

    Although the subject of shielding by means of ferromagnetic materials has been investigated for almost four centuries, 1 it is not as well understood as the subject of shielding by means of nonferromagnetic materials. Many publications have dealt with magnetic shielding in both steady and time varying situations. Most of these papers are concerned with the calculations of shielding effectiveness

  13. Shields to Reduce Spray Drift

    Microsoft Academic Search

    HE Ozkan; A Miralles; C Sinfort; H Zhu

    1997-01-01

    The effects of several spray-boom shield designs and ‘‘low-drift ’’ nozzles on spray drift are presented. Results are based on experiments conducted in a wind tunnel. Performances of all experimental shields were evaluated under two spray pressures (0·15 and 0·3MPa), and two air velocities (2·75 and 4·80m\\/s) in the wind tunnel. The distance to the centre of mass of the

  14. Structural Design and Thermal Analysis for Thermal Shields of the MICE Coupling Magnets

    SciTech Connect

    Green, Michael A.; Pan, Heng; Liu, X. K.; Wang, Li; Wu, Hong; Chen, A. B.; Guo, X.L.

    2009-07-01

    A superconducting coupling magnet made from copper matrix NbTi conductors operating at 4 K will be used in the Muon Ionization Cooling Experiment (MICE) to produce up to 2.6 T on the magnet centerline to keep the muon beam within the thin RF cavity indows. The coupling magnet is to be cooled by two cryocoolers with a total cooling capacity of 3 W at 4.2 K. In order to keep a certain operating temperature margin, the most important is to reduce the heat leakage imposed on cold surfaces of coil cold mass assembly. An ntermediate temperature shield system placed between the coupling coil and warm vacuum chamber is adopted. The shield system consists of upper neck shield, main shields, flexible connections and eight supports, which is to be cooled by the first stage cold heads of two ryocoolers with cooling capacity of 55 W at 60 K each. The maximum temperature difference on the shields should be less than 20 K, so the thermal analyses for the shields with different thicknesses, materials, flexible connections for shields' cooling and structure design for heir supports were carried out. 1100 Al is finally adopted and the maximum temperature difference is around 15 K with 4 mm shield thickness. The paper is to present detailed analyses on the shield system design.

  15. Jet Noise Shielding Provided by a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Doty, Michael J.; Brooks, Thomas F.; Burley, Casey L.; Bahr, Christopher J.; Pope, Dennis S.

    2014-01-01

    One approach toward achieving NASA's aggressive N+2 noise goal of 42 EPNdB cumulative margin below Stage 4 is through the use of novel vehicle configurations like the Hybrid Wing Body (HWB). Jet noise measurements from an HWB acoustic test in NASA Langley's 14- by 22-Foot Subsonic Tunnel are described. Two dual-stream, heated Compact Jet Engine Simulator (CJES) units are mounted underneath the inverted HWB model on a traversable support to permit measurement of varying levels of shielding provided by the fuselage. Both an axisymmetric and low noise chevron nozzle set are investigated in the context of shielding. The unshielded chevron nozzle set shows 1 to 2 dB of source noise reduction (relative to the unshielded axisymmetric nozzle set) with some penalties at higher frequencies. Shielding of the axisymmetric nozzles shows up to 6.5 dB of reduction at high frequency. The combination of shielding and low noise chevrons shows benefits beyond the expected additive benefits of the two, up to 10 dB, due to the effective migration of the jet source peak noise location upstream for increased shielding effectiveness. Jet noise source maps from phased array results processed with the Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) algorithm reinforce these observations.

  16. Finite-element modeling of magnetic shielding for SCUBA-2

    NASA Astrophysics Data System (ADS)

    Hollister, Matthew I.; Audley, Michael D.; Duncan, William D.; Holland, Wayne S.

    2006-06-01

    SCUBA-2 is a new wide-field submillimeter camera under construction for the James Clerk Maxwell Telescope on Mauna Kea in Hawaii. SCUBA-2 images simultaneously at 450 and 850 ?m using large-scale arrays of superconducting bolometers, with over five thousand pixels at each wavelength. Time division multiplexed readouts and cryogenic amplifiers, both based on superconducting quantum interference devices (SQUIDs), are also used in the design. The SCUBA-2 detector arrays must be well shielded against magnetic fields, since the performance of the bolometers can be seriously affected by the presence of a strong field, and the SQUIDs are themselves sensitive magnetometers. This shielding is to be provided by a combination of high-permeability and superconducting layers on both the ambient temperature and cryogenic stages of the instrument. To optimise and demonstrate the effectiveness of the shielding design, a finite-element modelling method was employed, using the Ansoft (R) Maxwell 3D TM package. Although a number of approximations had to be made in the modelling, the finite-element results allow a good estimation of the effectiveness of the shielding at attenuating external magnetic fields to be made. This paper describes the modelling process, outlines the key results and summarises the final shielding design.

  17. New K-Ar ages for calculating end-of-shield extrusion rates at West Maui volcano, Hawaiian island chain

    USGS Publications Warehouse

    Sherrod, D.R.; Murai, T.; Tagami, Takahiro

    2007-01-01

    Thirty-seven new K-Ar ages from West Maui volcano, Hawai'i, are used to define the waning stages of shield growth and a brief episode of postshield volcanism. All but two samples from shield-stage strata have reversed polarity magnetization, so conceivably the exposed shield is not much older than the Olduvai Normal-Polarity subchron, or about 1.8 Ma. The oldest ages obtained are in the range 1.9-2.1 Ma but have large analytical error. Shield volcanism ended about 1.35 Ma, and postshield volcanism followed soon thereafter, persisting until about 1.2 Ma. Exposed shield-stage strata were emplaced at a rate of about 0.001 km3 per year, a rate smaller than historic Hawaiian magmatic rates by a factor of 100. Stratigraphic accumulation rates are similar to those measured previously at Wai'anae volcano (O'ahu) or the upper part of the Mauna Kea shield sequence (Hilo drill core, Hawai'i). These rates diminish sharply during the final 0.3-0.5 m.y. of the shield stage. Hawaiian shield volcanoes begin waning well before their last 0.5 m.y. of life, then end quickly, geologically speaking, if West Maui is representative. ?? Springer-Verlag 2006.

  18. Electrodynamic Dust Shield Demonstrator

    NASA Technical Reports Server (NTRS)

    Stankie, Charles G.

    2013-01-01

    The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid running a multiphase low frequency AC signal. Electrostatically charged particles, such as those encountered on the moon, Mars, or an asteroid, are carried along by the traveling field due to the action of Coulomb and dielectrophoretic forces."2 The technical details have been described in a separate article. This document details the design and construction process of a small demonstration unit. Once finished, this device will go to the Office of the ChiefTechnologist at NASA headquarters, where it will be used to familiarize the public with the technology. 1 NASA KSC FO Intern, Prototype Development Laboratory, Kennedy Space Center, University of Central Florida Kennedy Space

  19. Shielding of a 3600 curie AmBe source 

    E-print Network

    Grimes, Mary Jeanine

    1989-01-01

    and Community Health and the Department of Radiology of the University of Texas Medical Branch have initiated planning for the construction of a state-of-the-art, lov background, vhole body counter facility. A integral part of this facility vill be a vhole... body, neutron activation analysis irzadiator employing 3600 cuties of AmBe. The proposed shielding material foz 241 construction of the irradiator is a high density concrete. The izzadiatoz vill be located in an already existing building vhich limits...

  20. Staging Airliner Service

    NASA Technical Reports Server (NTRS)

    Hahn, Andrew S.

    2007-01-01

    There is a general consensus building that historically high fuel prices and greater public awareness of the emissions that result from burning fuel are going to be long-term concerns for those who design, build, and operate airliners. The possibility of saving both fuel and reducing emissions has rekindled interest in breaking very long-range airline flights into multiple stages or even adopting in-flight refueling. It is likely that staging will result in lower fuel burn, and recent published reports have suggested that the savings are substantial, particularly if the airliner is designed from the outset for this kind of operation. Given that staging runs against the design and operation historical trend, this result begs for further attention. This paper will examine the staging question, examining both analytic and numeric performance estimation methodologies to quantify the likely amount of fuel savings that can be expected and the resulting design impacts on the airliner.

  1. Radiation Shielding Materials and Containers Incorporating Same

    DOEpatents

    Mirsky, Steven M.; Krill, Stephen J.; and Murray, Alexander P.

    2005-11-01

    An improved radiation shielding material and storage systems for radioactive materials incorporating the same. The PYRolytic Uranium Compound (''PYRUC'') shielding material is preferably formed by heat and/or pressure treatment of a precursor material comprising microspheres of a uranium compound, such as uranium dioxide or uranium carbide, and a suitable binder. The PYRUC shielding material provides improved radiation shielding, thermal characteristic, cost and ease of use in comparison with other shielding materials. The shielding material can be used to form containment systems, container vessels, shielding structures, and containment storage areas, all of which can be used to house radioactive waste. The preferred shielding system is in the form of a container for storage, transportation, and disposal of radioactive waste. In addition, improved methods for preparing uranium dioxide and uranium carbide microspheres for use in the radiation shielding materials are also provided.

  2. Trailer shield assembly for a welding torch

    NASA Technical Reports Server (NTRS)

    Dyer, Gerald E. (inventor)

    1989-01-01

    This invention relates generally to trailer shields for gas shielded arc welding torches, and more particularly to a trailer shield assembly provided with a shield gas manifold for providing an even dispersion of shield gas to the interior of the shield assembly, which generally encloses a joint being welded and a welding trailing portion of hot welded metal. The novelty of the invention lies in providing trailer shield with a manifold tube having a plurality of openings from which shield gas is distributed. A gas manifold region ahead of the torch is also provided with shield gas from a tube to protect metal preheated by the torch. Further novelty lies in constructing portions of sides and housing and portions of side walls of the guide of stainless steel screen having a tight mesh.

  3. Cancer Staging

    MedlinePLUS

    ... over time. They continue to change as scientists learn more about cancer. Some staging systems cover many ... cancer treatment summaries that describe the staging of adult and childhood cancers. Information about cancer staging can ...

  4. Acoustic and Aero-Mixing Experimental Results for Fluid Shield Scale Model Nozzles

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Mengle, V. G.; Shin, H. W.; Majjigi, R. K.

    2005-01-01

    The principle objectives of this investigation are to evaluate the acoustic and aerodynamic characteristics of fluid shield nozzle concept and to assess Far 36, Stage 3 potential for fluid shield nozzle with Flade Cycle. Acoustic data for nine scale model nozzle configurations are obtained. The effects of simulated flight and geometric and aerothermodynamic flow variables on the acoustic behavior of the fluid shield are determined. The acoustic tests are aimed at studying the effect of: (1) shield thickness, (2) wrap angle, (3) mass flow and velocity ratios between shield and core streams at constant cycle specific thrust (i.e., mixed velocity), (4) porous plug, and (5) subsonic shield. Shadowgraphs of six nozzle configurations are obtained to understand the plume flowfield features. Static pressure data on suppressor chutes in the core stream (shielded and unshielded) sides and on plug surface are acquired to determine the impact of fluid shield on base drag of the 36-chute suppressor nozzle and the thrust augmentation due to the plug, respectively.

  5. Thermal Degradation of Lead Monoxide Filled Polymer Composite Radiation Shields

    SciTech Connect

    Harish, V. [Department of Physics, Government First Grade College, Shivamogga-577201 (India); Nagaiah, N. [Department of Physics, Bangalore University, Jnanabharati, Bangalore-560056 (India)

    2011-07-15

    Lead monoxide filled Isophthalate resin particulate polymer composites were prepared with different filler concentrations and investigated for physical, thermal, mechanical and gamma radiation shielding characteristics. This paper discusses about the thermo gravimetric analysis of the composites done to understand their thermal properties especially the effect of filler concentration on the thermal stability and degradation rate of composites. Pristine polymer exhibits single stage degradation whereas filled composites exhibit two stage degradation processes. Further, the IDT values as well as degradation rates decrease with the increased filler content in the composite.

  6. Rotary stripper for shielded and unshielded FCC

    NASA Technical Reports Server (NTRS)

    Angele, W.; Chambers, C. M.

    1971-01-01

    Rotary stripper removes narrow strips of insulation and shielding to any desired depth. Unshielded cables are stripped on both sides with one stroke, shielded cables are stripped in steps of different depths.

  7. Improved Connector Shell for Cable Shields

    NASA Technical Reports Server (NTRS)

    Prisk, A. L.; Rotta, J. W., Jr.

    1983-01-01

    Cable connector shell improves electrostatic and electromagnetic shielding by electrically connecting cable braid around entire circumference. Connector cable braid is slipped over ferrule and sleeve is slipped over braid, clamping it tightly to shell. Connector shell completely shields cable conductors.

  8. 10 CFR 36.25 - Shielding.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Shielding. 36.25 Section 36...REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS...for Irradiators § 36.25 Shielding. (a) The radiation dose rate in...

  9. Improved space radiation shielding methods

    NASA Technical Reports Server (NTRS)

    Davis, H. S.; Jordan, T. M.

    1976-01-01

    The computing software that was used to perform the charged particle radiation transport analysis and shielding design for the Mariner Jupiter/Saturn 1977 spacecraft is described. Electron fluences, energy spectra and dose rates obtained with this software are presented and compared with independent computer calculations.

  10. Shielded RF Lattice Chris Rogers,

    E-print Network

    McDonald, Kirk

    H, fields Cooling channel cost ~ same (New!) #12;12 Require The modified1 Shielded RF Lattice Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford at cooling section This is where the RF is most limited This is where optics are most demanding How well

  11. Material Effectiveness for Radiation Shielding

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Materials with a smaller mean atomic mass, such as lithium (Li) hydride and polyethylene, make the best radiation shields for astronauts. The materials have a higher density of nuclei and are better able to block incoming radiation. Also, they tend to produce fewer and less dangerous secondary particles after impact with incoming radiation.

  12. Concerning superconducting inertial guidance gyroscopes inside superconducting magnetic shields

    SciTech Connect

    Satterthwaite, J.C.; Gawlinski, E.T. [Department of Physics, Temple University, Philadelphia, Pennsylvania (United States)] [Department of Physics, Temple University, Philadelphia, Pennsylvania (United States)

    1997-12-01

    Superconductors can in theory be used to detect rotation by Josephson interference or by detection of the London field, a magnetic induction that fills the interior of any rotating bulk superconductor. One might hope to use these properties of superconductors to build a practical inertial guidance gyroscope. A problem arises from the necessity of surrounding the device with superconducting magnetic shielding: the London field generated by a co-rotating shield eliminates the response of the superconducting device within the shield. The present article demonstrates this point more rigorously than has been done before, discussing solutions of Ampere`s law for rotating and nonrotating superconductors and paying careful attention to boundary conditions. Beginning with a supercurrent density derivable from either the Ginzburg-Landau or the London theory of superconductivity, the article shows: (1) that a superconducting device cannot distinguish between rotation and an applied magnetic field; (2) that a superconducting device surrounded by a co-rotating superconducting shield cannot detect rotation. The term `superconducting gyroscope` in this article refers only to a device whose working principle is the response of the superconductor itself to rotation, not to any device in which superconducting electronic components are used to detect some other effect. {copyright} {ital 1997 American Institute of Physics.}

  13. Predictions for Radiation Shielding Materials

    NASA Technical Reports Server (NTRS)

    Kiefer, Richard L.

    2002-01-01

    Radiation from galactic cosmic rays (GCR) and solar particle events (SPE) is a serious hazard to humans and electronic instruments during space travel, particularly on prolonged missions outside the Earth s magnetic fields. Galactic cosmic radiation (GCR) is composed of approx. 98% nucleons and approx. 2% electrons and positrons. Although cosmic ray heavy ions are 1-2% of the fluence, these energetic heavy nuclei (HZE) contribute 50% of the long-term dose. These unusually high specific ionizations pose a significant health hazard acting as carcinogens and also causing microelectronics damage inside spacecraft and high-flying aircraft. These HZE ions are of concern for radiation protection and radiation shielding technology, because gross rearrangements and mutations and deletions in DNA are expected. Calculations have shown that HZE particles have a strong preference for interaction with light nuclei. The best shield for this radiation would be liquid hydrogen, which is totally impractical. For this reason, hydrogen-containing polymers make the most effective practical shields. Shielding is required during missions in Earth orbit and possibly for frequent flying at high altitude because of the broad GCR spectrum and during a passage into deep space and LunarMars habitation because of the protracted exposure encountered on a long space mission. An additional hazard comes from solar particle events (SPEs) which are mostly energetic protons that can produce heavy ion secondaries as well as neutrons in materials. These events occur at unpredictable times and can deliver a potentially lethal dose within several hours to an unshielded human. Radiation protection for humans requires safety in short-term missions and maintaining career exposure limits within acceptable levels on future long-term exploration missions. The selection of shield materials can alter the protection of humans by an order of magnitude. If improperly selected, shielding materials can actually increase radiation damage due to penetration properties and nuclear fragmentation. Protecting space-borne microelectronics from single event upsets (SEUs) by transmitted radiation will benefit system reliability and system design cost by using optimal shield materials. Long-term missions on the surface of the Moon or Mars will require the construction of habitats to protect humans during their stay. One approach to the construction is to make structural materials from lunar or Martian regolith using a polymeric material as a binder. The hydrogen-containing polymers are considerably more effective for radiation protection than the regolith, but the combination minimizes the amount of polymer to be transported. We have made composites of simulated lunar regolith with two different polymers, LaRC-SI, a high-performance polyimide thermoset, and polyethylene, a thermoplastic.

  14. UWB: Success in AircraftUWB: Success in Aircraft Shielding MetrologyShielding Metrology

    E-print Network

    Southern California, University of

    -way - wave TEM vpol Optical rx Single-Mode Optical Fibers rx port tx port Airframe #12;UWBUWB: Success in AircraftUWB: Success in Aircraft Shielding MetrologyShielding Metrology Dr. Robert;Aircraft Shielding MeasurementsAircraft Shielding Measurements · Aircraft systems integration engineers

  15. Some observations about shielding extremely low-frequency magnetic fields by finite width shields

    Microsoft Academic Search

    Robert G. Olsen; Pablo Moreno

    1996-01-01

    Shielding of extremely low-frequency magnetic fields is limited by fields penetrating through imperfect material and leakage around the edges of shields which do not completely enclose the shielded region. The latter effect, more specifically the effect of source geometry and shield type on leakage, is the subject of this work. Particular attention is paid to elementary cylindrical dipole sources since

  16. A new estimation of the axial shielding factors for multishell cylindrical shields

    E-print Network

    Paperno, Eugene

    A new estimation of the axial shielding factors for multishell cylindrical shields Eugene Paperno double and multiple-shell axial magnetic shielding is obtained as a result of numerical verification of the new algorithm, a new formula describing multishell axial magnetic shielding is suggested. © 2000

  17. Heat pipe thermionic reactor shield optimization studies

    Microsoft Academic Search

    Vahé Keshishan; Terry E. Dix

    1992-01-01

    Shield optimization studies were conducted for a thermionic reactor, that uses heat pipes for both reactor heat removal and radiator. The radiator was placed on the opposite side of the payload to more efficiency reject the heat without affecting the LiH shadow shield. Neutron scattering off the radiator was an important consideration. The shield that was added to reduce the

  18. Research Article Conflict-Triggered Goal Shielding

    E-print Network

    Schubart, Christoph

    Research Article Conflict-Triggered Goal Shielding Response Conflicts Attenuate Background ABSTRACT--Action control in a changing environment re- quires that one shield current goals from distracting in- formation (goal shielding) and at the same time monitor the environment for potentially

  19. Random Active Shield Sebastien BRIAIS1

    E-print Network

    Paris-Sud XI, Université de

    Random Active Shield S´ebastien BRIAIS1 , Jean-Michel CIORANESCO2,3 , Jean-Luc DANGER1,4 , Sylvain, France. david.naccache@ens.fr Abstract--Recently, some active shielding techniques have been broken (e of shielding, which is seldom found in publicly available sources. Notably, we precise the expected

  20. Special concrete shield selection using the analytic hierarchy process

    SciTech Connect

    Abulfaraj, W.H. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Nuclear Engineering Dept.)

    1994-08-01

    Special types of concrete radiation shields that depend on locally available materials and have improved properties for both neutron and gamma-ray attenuation were developed by using plastic materials and heavy ores. The analytic hierarchy process (AHP) is implemented to evaluate these types for selecting the best biological radiation shield for nuclear reactors. Factors affecting the selection decision are degree of protection against neutrons, degree of protection against gamma rays, suitability of the concrete as building material, and economic considerations. The seven concrete alternatives are barite-polyethylene concrete, barite-polyvinyl chloride (PVC) concrete, barite-portland cement concrete, pyrite-polyethylene concrete, pyrite-PVC concrete, pyrite-portland cement concrete, and ordinary concrete. The AHP analysis shows the superiority of pyrite-polyethylene concrete over the others.

  1. Shielding techniques for communication cable - An update

    NASA Astrophysics Data System (ADS)

    Scott, T. R.; Russell, T. R.

    Techniques of shielding against electronic interference (EI) in the frequency range 1-100 MHz are reviewed. The various sources of EI are discussed, including electrostatic induction; electromagnetic induction; magnetic induction; and electromagnetic pulse (EMP). The effectiveness of different shielding constructions is examined with respect to new FCC regulations for electromagnetic compatibility. Among the shielding constructions examined are: braids; tape shield; and foil designs. The relative transfer impedance of the shielded cable was measured following exposure to EI from the different sources, and the results were compared. The ideal shield for use at frequencies of 1 MHz was a solid copper tube. For frequencies greater than 10 MHz, however, a composite foil/braid was found the most effective shield construction.

  2. Thermally isolated deployable shield for spacecraft

    NASA Technical Reports Server (NTRS)

    Redmon, John W., Jr. (inventor); Miller, Andre E. (inventor); Lawson, Bobby E. (inventor); Cobb, William E. (inventor)

    1991-01-01

    A thermally isolated deployable shield for spacecraft is provided utilizing a plurality of lattice panels stowable generally against the craft and deployable to some fixed distance from the craft. The lattice panels are formed from replaceable shield panels affixed to lattice structures. The lattice panels generally encircle the craft providing 360 degree coverage therearound. Actuation means are provided from translating the shield radially outward from the craft and thermally isolating the shield from the craft. The lattice panels are relatively flexible, allowing the shield to deploy to variable diameters while retaining uniform curvature thereof. Restraining means are provided for holding the shield relatively tight in its stowed configuration. Close-out assemblies provide light sealing and protection of the annular spaces between the deployed shield and the crafts end structure.

  3. Comparison of DOE-2.1E with Energyplus and TRNSYS for Ground Coupled Residential Buildings in Hot anf Humid Climates Stage 4

    E-print Network

    Andolsun, S.; Culp, C.

    2012-01-01

    sealed boxes in four U.S. climates. 2. INTRODUCTION Ground coupled heat transfer (GCHT) through concrete floor slabs can be a significant component of the total load for heating or cooling in low-rise residential buildings. For a contemporary code... sensible heat losses in temperate and cold climates (Figure 5), which became an important factor that explained the 3% higher heating loads in EnergyPlus than in DOE-2 in these climates (Figure 2). The different air changes obtained from DOE-2...

  4. S8DR shield examination

    NASA Technical Reports Server (NTRS)

    Mason, D. G.; Mccurnin, W. R.

    1973-01-01

    The SNAP 8 developmental reactor lithium hydride shield was examined after being irradiated for over 7000 hours at relatively low temperature. A crack was located in the seam weld of the containment vessel, probably the result of hot short cracking under thermal stress. The LiH was visually examined at two locations and its appearance was typical of low temperature irradiated LiH. The adherence of the chrome oxide emittance coating was found to be excellent.

  5. Steam generator hand hole shielding.

    PubMed

    Cox, W E

    2000-05-01

    Seabrook Station is an 1198 MWE Pressurized Water Reactor (PWR) that began commercial operation in 1990. Expensive and dose intensive Steam Generator Replacement Projects among PWR operators have led to an increase in steam generator preventative maintenance. Most of this preventative maintenance is performed through access ports in the shell of the steam generator just above the tube sheet known as secondary side hand holes. Secondary side work activities performed through the hand holes are typically performed without the shielding benefit of water in the secondary side of the steam generator. An increase in cleaning and inspection work scope has led to an increase in dose attributed to steam generator secondary side maintenance. This increased work scope and the station goal of maintaining personnel radiation dose ALARA led to the development of the shielding concept described in this article. This shield design saved an estimated 2.5 person-rem (25 person-Smv) the first time it was deployed and is expected to save an additional 50 person-rem (500 person-mSv) over the remaining life of the plant. PMID:10770158

  6. Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors

    SciTech Connect

    Aguayo Navarrete, Estanislao; Orrell, John L.; Ankney, Austin S.; Berguson, Timothy J.

    2011-09-21

    This document provides a detailed study of cost and materials that could be used to shield the detector material of the international Tonne-scale germanium neutrinoless double-beta decay experiment from hadronic particles from cosmic ray showers at the Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during storage; in particular, when the detector material is being worked on at the detector manufacturer's facility. This work considers two options for shielding the detector material from cosmic ray particles. One option is to use a pre-existing structure already located near the detector manufacturer, such as Canberra Industries in Meriden, Connecticut. The other option is to build a shield onsite at a detector manufacturer's site. This paper presents a cost and efficiency analysis of such construction.

  7. Heat-shield design for glovebox applications.

    SciTech Connect

    Frigo, A. A.

    1998-07-10

    Heat shields can often be used in place of insulation materials as an effective means of insulating glovebox furnace vessels. If used properly, shields can accomplish two important objectives: thermal insulation of the vessel to maintain a desired process temperature and protection of the glovebox, equipment, and user. A heat-shield assembly can be described as an arrangement of thin, properly-spaced, metal sheets that reduce radiation heat transfer. The main problem encountered in the design of a heat shield assembly is choosing the number of shields. In determining the heat transfer characteristics of a heat-shield assembly, a number of factors must be taken into consideration. The glovebox or outside environment, material properties, geometry, and operating temperature all have varying effects on the expected results. A simple method, for planar-horizontal and cylindrical-vertical shields, allowing the approximation of the outermost shield temperature, the practical number of shields, and the net heat-transfer rate will be presented. Methods used in the fabrication of heat-shield assemblies will also be discussed.

  8. The Feasibility of Multipole Electrostatic Radiation Shielding

    NASA Technical Reports Server (NTRS)

    Metzger, Philip T.; Lane, John E.; Youngquist, Robert C.

    2004-01-01

    Although passive shielding appears to be the only workable solution for galactic cosmic radiation (GCR), active shielding may play an important augmenting role to control the dose from solar particle events (SPEs). It has been noted that, to meet the guidelines of NCRP Report No. 98 through the six SPEs of 1989, a crew member would need roughly double the passive shielding that is necessary to control the GCR dose . This would dramatically increase spacecraft mass, and so it has been proposed that a small but more heavily shielded storm shelter may be used to protect the crew during SPEs. Since a gradual SPE may last 5 or more days, staying in a storm shelter may be psychologically and physiologically distressing to the crew. Storm shelters do not provide shielding for the spacecraft itself against the SPE radiation, and radiation damage to critical electronics may result in loss of mission and life. Single-event effects during the radiation storm may require quick crew response to maintain the integrity of the spacecraft, and confining the crew to a storm shelter prohibits their attending to the spacecraft at the precise time when that attention is needed the most. Active shielding cannot protect against GCR because the particle energies are too high. Although lower energy particles are easier to stop in a passive shield, such shielding is more satisfactory against GCR than against SPE radiation because of the tremendous difference in their initial fluences. Even a small fraction of the SPE fluence penetrating the passive shielding may result in an unacceptably high dose. Active shielding is more effective than passive shielding against SPE radiation because it offers 100% shielding effectiveness up to the cutoff energy, and significant shielding effectiveness beyond the cutoff as well.

  9. Heat flow from the West African shield

    SciTech Connect

    Brigaud, F.; Lucazeau, F.; Ly, S.; Sauvage, J.F.

    1985-09-01

    The heat flow over Precambrian shields is generally lower than over other continental provinces. Previous observations at 9 sites of the West African shield have shown that heat flow ranges from 20 mW m/sup -2/ in Niger to 38-42 mW m/sup -2/ in Liberia, Ghana and Nigeria. Since some of these values are lower than expected for Precambrian shields, it is important to find out whether or not they are representative of the entire shield before trying to derive its thermal structure. In this paper, we present new heat flow determinations from seven sites of the West African shield. These indicate that the surface heat flow is comparable with that of other Precambrian shields in the world.

  10. Vortex-type elastic structured media and dynamic shielding

    E-print Network

    Michele Brun; Ian S. Jones; Alexander B. Movchan

    2012-01-27

    The paper addresses a novel model of metamaterial structure. A system of spinners has been embedded into a two-dimensional periodic lattice system. The equations of motion of spinners are used to derive the expression for the chiral term in the equations describing the dynamics of the lattice. Dispersion of elastic waves is shown to possess innovative filtering and polarization properties induced by the vortextype nature of the structured media. The related homogenised effective behavior is obtained analytically and it has been implemented to build a shielding cloak around an obstacle. Analytical work is accompanied by numerical illustrations.

  11. Continuous Energy, Multi-Dimensional Transport Calculations for Problem Dependent Resonance Self-Shielding

    SciTech Connect

    T. Downar

    2009-03-31

    The overall objective of the work here has been to eliminate the approximations used in current resonance treatments by developing continuous energy multi-dimensional transport calculations for problem dependent self-shielding calculations. The work here builds on the existing resonance treatment capabilities in the ORNL SCALE code system.

  12. Shielding of the electromagnetic field of a coplanar waveguide by a Matthieu Bailleul

    E-print Network

    Paris-Sud XI, Université de

    spin wave modes) which could not be excited in the absence of shielding. In this letter, we build upon are usually strongly conducting [typically 30 /square for a 10 nm thick permalloy (Py = Ni80Fe20) film], which flowing along the conducting film:9 calculations in simplified plane wave propagation geometries indicate

  13. Repulsive shield between polar molecules

    E-print Network

    A. V. Gorshkov; P. Rabl; G. Pupillo; A. Micheli; P. Zoller; M. D. Lukin; H. P. Büchler

    2008-05-05

    We propose and analyze a technique that allows to suppress inelastic collisions and simultaneously enhance elastic interactions between cold polar molecules. The main idea is to cancel the leading dipole-dipole interaction with a suitable combination of static electric and microwave fields in such a way that the remaining van-der-Waals-type potential forms a three-dimensional repulsive shield. We analyze the elastic and inelastic scattering cross sections relevant for evaporative cooling of polar molecules and discuss the prospect for the creation of crystalline structures.

  14. Studying the Heat Shield's Seal

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity highlights the seal on the rover's protective heat shield. Engineers evaluated the performance of the protective shell's seal during a 36-sol investigation.

    After viewing these images, engineers were pleased with how the seal performed.

    This is an approximately true-color rendering of the scene acquired around 1:07 p.m. local solar time on Opportunity's sol 339 (Jan. 6, 2005) in an image mosaic using panoramic camera filters at wavelengths of 750, 530, and 430 nanometers.

  15. EMC effects of the lightning protection system: shielding properties of the roof-grid

    Microsoft Academic Search

    S. Cristina; A. Orlandi

    1991-01-01

    A suitable set of parameters is used to evaluate the shielding performance of the roof-grid constituted by a mesh of conductors, electrically interconnected, laying on top of buildings with a large-area roof. The influence of the roof-grid on the electromagnetic field inside the building due to a direct lightning strike is shown. The values of the electromotive force induced in

  16. The ORNL-SNAP shielding program

    NASA Technical Reports Server (NTRS)

    Mynatt, F. R.; Clifford, C. E.; Muckenthaler, F. J.; Gritzner, M. L.

    1972-01-01

    The effort in the ORNL-SNAP shielding program is directed toward the development and verification of computer codes using numerical solutions to the transport equation for the design of optimized radiation shields for SNAP power systems. A brief discussion is given for the major areas of the SNAP shielding program, which are cross-section development, transport code development, and integral experiments. Detailed results are presented for the integral experiments utilizing the TSF-SNAP reactor. Calculated results are compared with experiments for neutron and gamma-ray spectra from the bare reactor and as transmitted through slab shields.

  17. Accelerator magnet designs using superconducting magnetic shields

    SciTech Connect

    Brown, B.C.

    1990-10-01

    Superconducting dipoles and quadrupoles for existing accelerators have a coil surrounded by an iron shield. The shield limits the fringe field of the magnet while having minimal effect on the field shape and providing a small enhancement of the field strength. Shields using superconducting materials can be thinner and lighter and will not experience the potential of a large de-centering force. Boundary conditions for these materials, material properties, mechanical force considerations, cryostat considerations and some possible geometrical configurations for superconducting shields will be described. 7 refs., 3 figs., 3 tabs.

  18. Nuclear data relevant to shield design of FMIT facility

    SciTech Connect

    Carter, L.L.; Morford, R.J.; Wilcox, A.D.

    1980-04-01

    Nuclear data requirements are reviewed for the design of the Fusion Materials Irradiation Test (FMIT) facility. This accelerator-based facility, now in the early stages of construction at Hanford, will provide high fluences in a fusion-like radiation environment for the testing of materials. The nuclear data base required encompasses the entire range of neutron energies from thermal to 50 MeV. In this review, we consider neutron source terms, cross sections for thermal and bulk shield design, and neutron activation for the facility.

  19. Nuclear data relevant to shield design of FMIT facility

    SciTech Connect

    Carter, L.L.; Morford, R.J.; Wilcox, A.D.

    1980-01-01

    Nuclear data requirements are reviewed for the design of the Fusion Materials Irradiation Test (FMIT) facility. This accelerator-based facility, now in the early stages of construction at Hanford, will provide high fluences in a fusion-like radiation environment for the testing of materials. The nuclear data base required encompasses the entire range of neutron energies from thermal to 50 MeV. In this review, we consider neutron source terms, cross sections for thermal and bulk shield design, and neutron activation for the facility.

  20. Fan broadband noise shielding for over-wing engines

    NASA Astrophysics Data System (ADS)

    Powell, Stephen; Sóbester, András; Joseph, Phillip

    2012-11-01

    Increasingly demanding community noise targets are promoting noise performance ever higher on the list of airliner design drivers. In response, significant noise reductions are being made, though at a declining rate—it appears that a whole airframe approach is now needed to achieve significant further gains. As a possible step in this direction, over-wing engine installations are considered here, which use the airframe itself as a noise shield. The paper is the account of an experimental investigation of the comparative shielding performances of a range of relative engine positions on such a layout. Using the statistical modelling technique Kriging, we build an approximation of the noise shielding metric as a function of the position of the engines above the wing—this can serve as the input to multi-disciplinary design trade-off studies. We then compare the results found with the results of applying simple half-barrier diffraction theory to the same problem. We conclude that the latter could be considered as a first order, conceptual design tool, though it misses certain features of the design merit landscape identified by the experiment presented here.

  1. Intercalated graphite fiber composites as EMI shields in aerospace structures

    Microsoft Academic Search

    James R. Gaier

    1992-01-01

    The requirements for electromagnetic interference (EMI) shielding in aerospace structures are more complicated than those for ground structures because of their weight limitations. As a result, the best EMI shielding materials must combine low density, high strength, and high elastic modulus with high shielding ability. EMI shielding characteristics were calculated for shields formed from pristine and intercalated graphite fiber\\/epoxy composites

  2. Atlas SCT/Pixel Grounding and Shielding ATLAS SCT/Pixel Grounding and Shielding Note

    E-print Network

    California at Santa Cruz, University of

    mostly connects existing mechanical electrical conductive #12; Atlas SCT/Pixel Grounding and Shielding 2 cryostat outer heat shield. The commoning power conductors the heat spreader plate. PPB1 board, Schematic. The spreader plate needs a seam the barrel outer heat shield. The spreader plate needs electrical isolation

  3. THE NIOSH SHIELD HYDRAULICS INSPECTION AND EVALUATION OF LEG DATA (SHIELD) COMPUTER PROGRAM

    Microsoft Academic Search

    David P. Conover; Senior Mine Engineer

    Longwall shields provide essential ground control in longwall mining, yet a high percentage of shields are operating at less than peak capacity and many at well below the rated support capacity due to defective hydraulic cylinders or malfunctions in other hydraulic components. Leg pressure data are currently collected on state-of- the-art longwall shields, but typically are not analyzed to evaluate

  4. Biological Diversity of the Guiana Shield: Georeferencing Plants of the Guiana Shield

    E-print Network

    Mathis, Wayne N.

    Biological Diversity of the Guiana Shield: Georeferencing Plants of the Guiana Shield Eduardo To document, understand, and conserve the biological diversity of the shield area. #12;#12;What does · Expeditions (collect) · Preserve · Process · Identify · Inventory · Barcode · File in collection (At home

  5. High-Speed Penetration Modeling and Shape Optimization of the Projectile Penetrating into Concrete Shields

    Microsoft Academic Search

    G. Ben-Dor; A. Dubinsky; T. Elperin

    2009-01-01

    We generalize the existing engineering approaches to modeling of high-speed penetration of projectiles into semi-infinite concrete shields and suggest a modified semi-empirical two-stage model that is applicable for bodies of revolution with a flat bluntness. At the first stage of penetration (cratering), the resistance force is described as a linear function of the instantaneous distance between the nose of the

  6. Multi-stage mountain building vs. relative plate motions in the Betic Cordillera deduced from integrated microstructural and petrological analysis of porphyroblast inclusion trails

    NASA Astrophysics Data System (ADS)

    Aerden, D. G. A. M.; Bell, T. H.; Puga, E.; Sayab, M.; Lozano, J. A.; Diaz de Federico, A.

    2013-03-01

    The tectonic evolution of the Betic Cordillera has been investigated through integrated microstructural and petrological analysis of 93 samples of garnetiferous Grt ± Cld ± Plg ± Ky ± St phengite schists from its lowermost allochthon, the Nevado-Filabride Domain. Porphyroblast inclusion trails in these samples exhibit well-developed preferred vertical and horizontal orientations and truncational relationships. These features indicate a complex history of multiple crenulation cleavage development during alternating contractional and gravity-induced deformations. Associated Foliation-Intersection Axes preserved in porphyroblasts (FIA) were determined separately for 2 groups of samples using the "asymmetry technique" (Bell et al., 1995) and the "FitPitch" method (Aerden, 2003), respectively. Broadly consistent results establish a succession of 4 FIA sets with specific trends, which from the oldest to the youngest FIA set are: NE-SW (FIA set 1), NW-SE (FIA set 2), W-E (FIA set 3) and NNW-SSE (FIA set 4). This trend sequence is also reflected in the orientations of successive fold generations and associated lineations. More remarkably, the FIA-trend sequence mimics known changes in the plate motions of Africa and Adria relative to Iberia in the 50-10 Ma interval. This is also the time span indicated by published radiometric ages. Garnet-isopleth thermobarometry applied to selected samples and compositional zoning of garnets indicate that the earliest 3 FIA sets formed along a prograde metamorphic path from ca. 5 kb/500 °C to 10 kb/550 °C, whereas the latest stages of FIA set 3 and FIA set 4 developed during exhumation. Exhumation involved a period of heterogeneous reheating that was spatially and temporally linked to emplacement of the overlying Alpujarride Complex.

  7. Decontaminating lead bricks and shielding

    SciTech Connect

    Lussiez, G.

    1994-02-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially of planned decommissioning operations. Thus lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for contaminated lead is removing the superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a scaled-off area. The slurry of abrasive and particles of lead falls through a floor and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling.

  8. Studies on the neutron field behind shielding of proton accelerators Part I: Concrete shielding

    NASA Astrophysics Data System (ADS)

    Dinter, H.; Tesch, K.; Dworak, D.

    1996-01-01

    Energy- and angular distributions of neutrons behind concrete side shielding of proton accelerators were calculated. Simple arguments are given to understand the characteristic shape of the neutron spectrum. Calculations were repeated to receive data for simple shielding estimations. The dose equivalent attenuation coefficient of concrete for monoenergetic neutrons with energies between 1 and 400 MeV were determined and compared with the coefficient for neutrons leaving an accelerator shield at angles around 90°. Data for shielding gaps in accelerator shielding walls are given as an application. The calculations were performed by using the Monte Carlo codes FLUKA92 and MORSE.

  9. Flexible shielding system for radiation protection

    NASA Technical Reports Server (NTRS)

    Babin, A.

    1972-01-01

    Modular construction of low cost flexible radiation shielding panels consists of water filled steels cans, zinc bromide windows, turntable unit, master-slave manipulators, and interlocking lead bricks. Easy modifications of shielding wall thicknesses are obtained by rearranging overall geometry of portable components.

  10. Preliminary radiation shielding design for BOOMERANG

    SciTech Connect

    Donahue, Richard J.

    2002-10-23

    Preliminary radiation shielding specifications are presented here for the 3 GeV BOOMERANG Australian synchrotron light source project. At this time the bulk shield walls for the storage ring and injection system (100 MeV Linac and 3 GeV Booster) are considered for siting purposes.

  11. Simultaneous Shield and Repeater Insertion Renatas Jakushokas

    E-print Network

    Friedman, Eby G.

    Simultaneous Shield and Repeater Insertion Renatas Jakushokas jakushok@ece.rochester.edu Eby G- cuits is presented. The methodology is applied to simultaneous shield and repeater insertion, resulting in minimum coupling noise under power, delay, and area constraints. Design expressions ex- hibiting parabolic

  12. On the effectiveness of the metamorphic shield

    Microsoft Academic Search

    Anh Nguyen-Tuong; Andrew Wang; Jason D. Hiser; John C. Knight; Jack W. Davidson

    2010-01-01

    In this paper we determine analytically the effectiveness of dynamic artificial diversity, i.e., artificial diversity in which the subject of the diversity is re-randomized periodically and mechanically. We refer to a mechanism that implements dynamic diversity as a Metamorphic Shield since this mechanism applies metamorphosis to the system's attack surface to try to shield the system from certain attacks. Contrary

  13. Reliability Methods for Shield Design Process

    Microsoft Academic Search

    R. K. Tripathi; J. W. Wilson

    Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and

  14. Reliability Methods for Shield Design Process

    Microsoft Academic Search

    R. K. Tripathi; J. W. Wilson

    2003-01-01

    Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and

  15. Working through the Maze of Liability Shields.

    ERIC Educational Resources Information Center

    King, Jeff; Schmiesing, Ryan

    1998-01-01

    Liability shields that can be incorporated into an Extension risk management program include permission slips, informed consent forms, waivers and releases, and indemnification agreements. Risk identification should be part of youth program planning; communication with parents is essential; the best shields are most specific; and legal counsel…

  16. EMP coupling to coaxial shielded cables

    Microsoft Academic Search

    M. D'Amore; M. Feliziani

    1988-01-01

    A method for determining the effects induced within shielded cables by a high-altitude nuclear electromagnetic pulse (EMP), represented as a plane wave, is presented. The cable is regarded as a multiconductor line in which the EMP sources are impressed on the shield. An efficient matrix procedure permits simultaneous calculation of transient voltages and currents at any point on each conductor.

  17. Postshield stage transitional volcanism on Mahukona Volcano, Hawaii

    USGS Publications Warehouse

    Clague, D.A.; Calvert, A.T.

    2009-01-01

    Age spectra from 40Ar/39Ar incremental heating experiments yield ages of 298??25 ka and 310??31 ka for transitional composition lavas from two cones on submarine Mahukona Volcano, Hawaii. These ages are younger than the inferred end of the tholeiitic shield stage and indicate that the volcano had entered the postshield alkalic stage before going extinct. Previously reported elevated helium isotopic ratios of lavas from one of these cones were incorrectly interpreted to indicate eruption during a preshield alkalic stage. Consequently, high helium isotopic ratios are a poor indicator of eruptive stage, as they occur in preshield, shield, and postshield stage lavas. Loihi Seamount and Kilauea are the only known Hawaiian volcanoes where the volume of preshield alkalic stage lavas can be estimated. ?? Springer-Verlag 2008.

  18. Underground barrier construction apparatus with soil-retaining shield

    DOEpatents

    Gardner, Bradley M. (Idaho Falls, ID); Smith, Ann Marie (Pocatello, ID); Hanson, Richard W. (Spokane, WA); Hodges, Richard T. (Deer Park, WA)

    1998-01-01

    An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

  19. Engineering of Composite Media for Shields at Microwave Frequencies

    E-print Network

    Koledintseva, Marina Y.

    Engineering of Composite Media for Shields at Microwave Frequencies Marina Koledintseva, Poorna of wideband microwave shields is considered. The model uses Maxwell Garnett formalism for multiphase mixtures- Maxwell Garnett formalism; shielding; conducting inclusions; dielectric base material I. INTRODUCTION

  20. Building No. 918, detail of skirt board and concrete post ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building No. 918, detail of skirt board and concrete post foundation with termite shield - Presidio of San Francisco, Enlisted Men's Barracks Type, West end of Crissy Field, between Pearce & Maudlin Streets, San Francisco, San Francisco County, CA

  1. 3. BUILDING 901, EXTERIOR DETAILING ON NORTH SIDE SHOWING CONCRETE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. BUILDING 901, EXTERIOR DETAILING ON NORTH SIDE SHOWING CONCRETE FOUNDATION AND METAL TERMITE SHIELD. - Presidio of San Francisco, Warehouse, West End of Crissy Field, Livingston Street, San Francisco, San Francisco County, CA

  2. 23. Historic American Buildings Survey E. W. Russell, Photographer, September ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Historic American Buildings Survey E. W. Russell, Photographer, September 29, 1936 GATE TO LOT OF EDWIN F. SHIELDS, MAGNOLIA CEMETERY - Magnolia Cemetery (Ironwork), Virginia Street, Mobile, Mobile County, AL

  3. GFR Sub-Assembly Shielding Design Studies

    SciTech Connect

    J. R. Parry

    2006-01-01

    This report presents the methodology and results for a preliminary study for Gas-Cooled Fast Reactor (GFR) subassembly fast neutron shielding configurations. The purpose of the shielding in the subassembly is to protect reactor components from fast (E>0.1 MeV) neutrons. The subassembly is modeled in MCNP version 5 release 1.30. Parametric studies were performed varying the thickness of the shielding and calculating the fast neutron flux at the vessel head and the core grid plate. This data was used to determine the minimum thickness needed to protect the vessel head and the core grid plate. These thicknesses were used to analyze different shielding configurations incorporating coolant passages and also to estimate the neutron and photon energy deposition in the shielding material.

  4. Mars Exploration Rover Heat Shield Recontact Analysis

    NASA Technical Reports Server (NTRS)

    Raiszadeh, Behzad; Desai, Prasun N.; Michelltree, Robert

    2011-01-01

    The twin Mars Exploration Rover missions landed successfully on Mars surface in January of 2004. Both missions used a parachute system to slow the rover s descent rate from supersonic to subsonic speeds. Shortly after parachute deployment, the heat shield, which protected the rover during the hypersonic entry phase of the mission, was jettisoned using push-off springs. Mission designers were concerned about the heat shield recontacting the lander after separation, so a separation analysis was conducted to quantify risks. This analysis was used to choose a proper heat shield ballast mass to ensure successful separation with low probability of recontact. This paper presents the details of such an analysis, its assumptions, and the results. During both landings, the radar was able to lock on to the heat shield, measuring its distance, as it descended away from the lander. This data is presented and is used to validate the heat shield separation/recontact analysis.

  5. SINEX: SCALE shielding analysis GUI for X-Windows

    SciTech Connect

    Browman, S.M.; Barnett, D.L.

    1997-12-01

    SINEX (SCALE Interface Environment for X-windows) is an X-Windows graphical user interface (GUI), that is being developed for performing SCALE radiation shielding analyses. SINEX enables the user to generate input for the SAS4/MORSE and QADS/QAD-CGGP shielding analysis sequences in SCALE. The code features will facilitate the use of both analytical sequences with a minimum of additional user input. Included in SINEX is the capability to check the geometry model by generating two-dimensional (2-D) color plots of the geometry model using a new version of the SCALE module, PICTURE. The most sophisticated feature, however, is the 2-D visualization display that provides a graphical representation on screen as the user builds a geometry model. This capability to interactively build a model will significantly increase user productivity and reduce user errors. SINEX will perform extensive error checking and will allow users to execute SCALE directly from the GUI. The interface will also provide direct on-line access to the SCALE manual.

  6. Spacesuit Radiation Shield Design Methods

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Anderson, Brooke M.; Cucinotta, Francis A.; Ware, J.; Zeitlin, Cary J.

    2006-01-01

    Meeting radiation protection requirements during EVA is predominantly an operational issue with some potential considerations for temporary shelter. The issue of spacesuit shielding is mainly guided by the potential of accidental exposure when operational and temporary shelter considerations fail to maintain exposures within operational limits. In this case, very high exposure levels are possible which could result in observable health effects and even be life threatening. Under these assumptions, potential spacesuit radiation exposures have been studied using known historical solar particle events to gain insight on the usefulness of modification of spacesuit design in which the control of skin exposure is a critical design issue and reduction of blood forming organ exposure is desirable. Transition to a new spacesuit design including soft upper-torso and reconfigured life support hardware gives an opportunity to optimize the next generation spacesuit for reduced potential health effects during an accidental exposure.

  7. Demagnetization of magnetically shielded rooms

    NASA Astrophysics Data System (ADS)

    Thiel, F.; Schnabel, A.; Knappe-Grüneberg, S.; Stollfuß, D.; Burghoff, M.

    2007-03-01

    Magnetically shielded rooms for specific high resolution physiological measurements exploiting the magnetic field, e.g., of the brain (dc-magnetoencephalograpy), low-field NMR, or magnetic marker monitoring, need to be reproducibly demagnetized to achieve reliable measurement conditions. We propose a theoretical, experimental, and instrumental base whereupon the parameters which affect the quality of the demagnetization process are described and how they have to be handled. It is demonstrated how conventional demagnetization equipment could be improved to achieve reproducible conditions. The interrelations between the residual field and the variability at the end of the demagnetization process are explained on the basis of the physics of ferromagnetism and our theoretical predictions are evaluated experimentally.

  8. Hypervelocity impact on shielded plates

    NASA Technical Reports Server (NTRS)

    Smith, James P.

    1993-01-01

    A ballistic limit equation for hypervelocity impact on thin plates is derived analytically. This equation applies to cases of impulsive impact on a plate that is protected by a multi-shock shield, and it is valid in the range of velocity above 6 km/s. Experimental tests were conducted at the NASA Johnson Space Center on square aluminum plates. Comparing the center deflections of these plates with the theoretical deflections of a rigid-plastic plate subjected to a blast load, one determines the dynamic yield strength of the plate material. The analysis is based on a theory for the expansion of the fragmented projectile and on a simple failure criterion. Curves are presented for the critical projectile radius versus the projectile velocity, and for the critical plate thickness versus the velocity. These curves are in good agreement with curves that have been generated empirically.

  9. ISABELLE shielding criteria and design.

    PubMed

    Gollon, P J; Casey, W R

    1984-01-01

    ISABELLE is a high-intensity 400-GeV proton-storage ring under construction at Brookhaven National Laboratory (BNL). The radiation-protection problems encountered in its design are in many ways similar to those at high-energy fixed-target facilities: both the laboratory personnel nearby and the public several kilometers away must be appropriately protected from high-energy neutron and muon radiation. These radiations will result from the routine operation of the accelerators, as well as from unplanned and possibly large losses of the stored beam. The radiation exposures resulting from the loss of beam already in the accelerator could be more severe than those resulting from a full year's normal operation. The design goals (mrem/yr) which have been adopted for different populations, exposure scenarios and radiation sources are outlined. We also describe the methods (hardware, shielding, access control) which will be used to achieve these goals. PMID:6319330

  10. Shielding superconductors with thin films

    E-print Network

    Posen, Sam; Catelani, Gianluigi; Liepe, Matthias U; Sethna, James P

    2015-01-01

    Determining the optimal arrangement of superconducting layers to withstand large amplitude AC magnetic fields is important for certain applications such as superconducting radiofrequency cavities. In this paper, we evaluate the shielding potential of the superconducting film/insulating film/superconductor (SIS') structure, a configuration that could provide benefits in screening large AC magnetic fields. After establishing that for high frequency magnetic fields, flux penetration must be avoided, the superheating field of the structure is calculated in the London limit both numerically and, for thin films, analytically. For intermediate film thicknesses and realistic material parameters we also solve numerically the Ginzburg-Landau equations. It is shown that a small enhancement of the superheating field is possible, on the order of a few percent, for the SIS' structure relative to a bulk superconductor of the film material, if the materials and thicknesses are chosen appropriately.

  11. Electromagnetic shielding in quantum metrology

    E-print Network

    Yao Jin; Hongwei Yu

    2015-04-21

    The dynamics of the quantum Fisher information of the parameters of the initial atomic state and atomic transition frequency is studied, in the framework of open quantum systems, for a static polarizable two-level atom coupled in the multipolar scheme to a bath of fluctuating vacuum electromagnetic fields without and with the presence of a reflecting boundary. Our results show that in the case without a boundary, the electromagnetic vacuum fluctuations always cause the quantum Fisher information of the initial parameters and thus the precision limit of parameter estimation to decrease. Remarkably, however, with the presence of a boundary, the quantum Fisher information becomes position and atomic polarization dependent, and as a result, it may be enhanced as compared to that in the case without a boundary and may even be shielded from the influence of the vacuum fluctuations in certain circumstances as if it were a closed system.

  12. Radiation Shielding Systems Using Nanotechnology

    NASA Technical Reports Server (NTRS)

    Chen, Bin (Inventor); McKay, Christoper P. (Inventor)

    2011-01-01

    A system for shielding personnel and/or equipment from radiation particles. In one embodiment, a first substrate is connected to a first array or perpendicularly oriented metal-like fingers, and a second, electrically conducting substrate has an array of carbon nanostructure (CNS) fingers, coated with an electro-active polymer extending toward, but spaced apart from, the first substrate fingers. An electric current and electric charge discharge and dissipation system, connected to the second substrate, receives a current and/or voltage pulse initially generated when the first substrate receives incident radiation. In another embodiment, an array of CNSs is immersed in a first layer of hydrogen-rich polymers and in a second layer of metal-like material. In another embodiment, a one- or two-dimensional assembly of fibers containing CNSs embedded in a metal-like matrix serves as a radiation-protective fabric or body covering.

  13. Foam Core Shielding for Spacecraft

    NASA Technical Reports Server (NTRS)

    Adams, Marc

    2007-01-01

    A foam core shield (FCS) system is now being developed to supplant multilayer insulation (MLI) systems heretofore installed on spacecraft for thermal management and protection against meteoroid impacts. A typical FCS system consists of a core sandwiched between a face sheet and a back sheet. The core can consist of any of a variety of low-to-medium-density polymeric or inorganic foams chosen to satisfy application-specific requirements regarding heat transfer and temperature. The face sheet serves to shock and thereby shatter incident meteoroids, and is coated on its outer surface to optimize its absorptance and emittance for regulation of temperature. The back sheet can be dimpled to minimize undesired thermal contact with the underlying spacecraft component and can be metallized on the surface facing the component to optimize its absorptance and emittance. The FCS systems can perform better than do MLI systems, at lower mass and lower cost and with greater volumetric efficiency.

  14. E-Beam Processing of Polymer Matrix Composites for Multifunctional Radiation Shielding

    NASA Technical Reports Server (NTRS)

    Hou, Tan-Hung; Wilson, John W.; Jensen, Brian J.; Thibeault, Sheila A.; Chang, Chie K.; Kiefer, Richard L.

    2005-01-01

    Aliphatic polymers were identified as optimum radiation shielding polymeric materials for building multifunctional structural elements for in-space habitats. Conceptual damage tolerant configurations of polyolefins have been proposed, but many manufacturing issues relied on methods and materials which have sub-optimal radiation shielding characteristics (for example, epoxy matrix and adhesives). In the present approach, we shall investigate e-beam processing technologies for inclusion of high-strength aliphatic polymer reinforcement structures into a highly cross-linked polyolefin matrix. This paper reports the baseline thermo-mechanical properties of low density polyethylene and highly crystallized polyethylene.

  15. Radiation shielding calculations for MuCool test area at Fermilab

    SciTech Connect

    Igor Rakhno; Carol Johnstone

    2004-05-26

    The MuCool Test Area (MTA) is an intense primary beam facility derived directly from the Fermilab Linac to test heat deposition and other technical concerns associated with the liquid hydrogen targets being developed for cooling intense muon beams. In this shielding study the results of Monte Carlo radiation shielding calculations performed using the MARS14 code for the MuCool Test Area and including the downstream portion of the target hall and berm around it, access pit, service building, and parking lot are presented and discussed within the context of the proposed MTA experimental configuration.

  16. Preliminary design of a meteoroid/orbital debris shield system for a Mars mission spacecraft

    NASA Technical Reports Server (NTRS)

    Robinson, J. H.; Mog, R. A.

    1992-01-01

    A preliminary design of a spacecraft shield system to defeat meteoroids and orbital debris during a Mars mission is presented. The mission scenario is first defined in terms of stage times which include LEO, transit, low-Mars orbit, and Mars surface periods. The environment definitions for earth-orbital space debris, planetary meteoroids, and interplanetary meteoroids are next introduced. Shield system design approaches incorporate stochastic simulation, hydrocode analyses, hypervelocity impact testing, and optimization techniques. Structural design trades presented include spacecraft configuration, mission schedule, penetration risk, and total standoff distance between the bumper and wall.

  17. Integrated shielding systems for manned interplanetary spaceflight

    NASA Astrophysics Data System (ADS)

    George, Jeffrey A.

    1992-01-01

    The radiation environment encountered by manned interplanetary missions can have a severe impact on both vehicle design and mission performance. This study investigates the potential impact of radiation protection on interplanetary vehicle design for a manned Mars mission. A systems approach was used to investigate the radiation protection requirements of the sum interplanetary environment. Radiation budgets were developed which result in minimum integrated shielding system masses for both nuclear and non-nuclear powered missions. A variety of system configurations and geometries were assessed over a range of dose constraints. For an annual dose equivalent rate limit of 50 rem/yr, an environmental shielding system composed of a habitat shield and storm shelter was found to result in the lowest total mass. For a limit of 65 rem/yr, a system composed of a sleeping quarters shield was least massive, and resulted in significantly reduced system mass. At a limit of 75 rem/yr, a storm shelter alone was found to be sufficient, and exhibited a further mass reduction. Optimal shielding system results for 10 MWe nuclear powered missions were found to follow along similar lines, with the addition of a reactor shadow shield. A solar minimum galactic cosmic ray spectrum and one anomalously large solar particle event during the course of a two year mission were assumed. Water was assumed for environmental radiation shielding.

  18. International Space Station Radiation Shielding Model Development

    NASA Technical Reports Server (NTRS)

    Qualls, G. D.; Wilson, J. W.; Sandridge, C.; Cucinotta, F. A.; Nealy, J. E.; Heinbockel, J. H.; Hugger, C. P.; Verhage, J.; Anderson, B. M.; Atwell, W.

    2001-01-01

    The projected radiation levels within the International Space Station (ISS) have been criticized by the Aerospace Safety Advisory Panel in their report to the NASA Administrator. Methods for optimal reconfiguration and augmentation of the ISS shielding are now being developed. The initial steps are to develop reconfigurable and realistic radiation shield models of the ISS modules, develop computational procedures for the highly anisotropic radiation environment, and implement parametric and organizational optimization procedures. The targets of the redesign process are the crew quarters where the astronauts sleep and determining the effects of ISS shadow shielding of an astronaut in a spacesuit. The ISS model as developed will be reconfigurable to follow the ISS. Swapping internal equipment rack assemblies via location mapping tables will be one option for shield optimization. Lightweight shield augmentation materials will be optimally fit to crew quarter areas using parametric optimization procedures to minimize the augmentation shield mass. The optimization process is being integrated into the Intelligence Synthesis Environment s (ISE s) immersive simulation facility at the Langley Research Center and will rely on High Performance Computing and Communication (HPCC) for rapid evaluation of shield parameter gradients.

  19. Radiation shielding concrete made of Basalt aggregates.

    PubMed

    Alhajali, S; Yousef, S; Kanbour, M; Naoum, B

    2013-04-01

    In spite of the fact that Basalt is a widespread type of rock, there is very little available information on using it as aggregates for concrete radiation shielding. This paper investigates the possibility of using Basalt for the aforementioned purpose. The results have shown that Basalt could be used successfully for preparing radiation shielding concrete, but some attention should be paid to the choice of the suitable types of Basalt and for the neutron activation problem that could arise in the concrete shield. PMID:22933408

  20. Tank evaluation system shielded annular tank application

    SciTech Connect

    Freier, D.A.

    1988-10-04

    TEST (Tank Evaluation SysTem) is a research project utilizing neutron interrogation techniques to analyze the content of nuclear poisons and moderators in tank shielding. TEST experiments were performed on an experimental SAT (Shielded Annular Tank) at the Rocky Flats Plant. The purpose of these experiments was threefold: (1) to assess TEST application to SATs, (2) to determine if Nuclear Safety inspection criteria could be met, and (3) to perform a preliminary calibration of TEST for SATs. Several experiments were performed, including measurements of 11 tank shielding configurations, source-simulated holdup experiments, analysis of three detector modes, resolution studies, and TEST scanner geometry experiments. 1 ref., 21 figs., 4 tabs.

  1. Exterior of Opportunity Heat Shield, Sol 344

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA's Mars Exploration Rover Opportunity took a detailed look at what was once the exterior of its heat shield. Hitting the martian surface inverted the heat shield, making it difficult to photograph the outside where evidence of any atmospheric effects may be found.

    Engineers sought this image to help determine how the heat shield weathered the intense frictional heat created as it passed through the martian atmosphere.

    This is an approximately true-color rendering of the scene acquired around 12:47 p.m. local solar time on Opportunity's sol 344 (Jan. 11, 2005) using panoramic camera filters at wavelengths of 750, 530, and 430 nanometers.

  2. Fabrication of transparent and ultraviolet shielding composite films based on graphene oxide and cellulose acetate.

    PubMed

    de Moraes, Ana Carolina Mazarin; Andrade, Patricia Fernanda; de Faria, Andreia Fonseca; Simões, Mateus Batista; Salomão, Francisco Carlos Carneiro Soares; Barros, Eduardo Bedê; Gonçalves, Maria do Carmo; Alves, Oswaldo Luiz

    2015-06-01

    Graphene oxide (GO) has been considered a promising filler material for building polymeric nanocomposites because of its excellent dispersibility and high surface area. In this work, we present the fabrication and characterization of transparent and ultraviolet (UV) shielding composite films based on GO and cellulose acetate (CA). GO sheets were found to be well-dispersed throughout the CA matrix, providing smooth and homogeneous composite films. Moreover, the GO sheets were completely embedded within the CA matrix and no presence of this nanomaterial was found at the surface. Nevertheless, CAGO composite films offered an improved high energy light-shielding capacity when compared to pristine CA films. Particularly for UVC irradiation, the CAGO film containing 0.50wt% GO displayed a UV-shielding capacity of 57%, combined with 79% optical transparency under visible light. These CAGO composite films can be potentially applied as transparent UV-protective coatings for packing biomedical, pharmaceutical, and food products. PMID:25843853

  3. Effects of fluctuating magnetic fields on a superconducting bulk rotor shielded with superconducting rings

    NASA Astrophysics Data System (ADS)

    Yamagishi, K.; Ogawa, J.; Tsukamoto, O.

    2014-05-01

    We study the effect of a fluctuating magnetic field, which is one of the technical problems for trapped magnetic fields in a bulk superconductor, to realize a practical bulk superconductor rotating machine. Previous research and other's research has shown that fluctuating magnetic fields reduce the strength of trapped magnetic fields in superconducting bulk modules [1, 2]. This deters development of applications of AC rotating machines because superconducting bulk modules are always exposed to a fluctuating magnetic field. Therefore, it is necessary to develop a method to control decrease of the trapped magnetic field. We propose a method to use the shielding ring of a superconducting wire to achieve this goal and the effects are confirmed experimentally [3]. We are now building test equipment for examining the performance of a shielding ring in a bulk rotating machine. This paper reports the test result for the shielding ring applied to the bulk superconducting rotor that is a part of the test equipment.

  4. Ablative shielding for hypervelocity projectiles

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A. (inventor)

    1993-01-01

    A hypervelocity projectile shield which includes a hollow semi-flexible housing fabricated from a plastic like, or otherwise transparent membrane which is filled with a fluid (gas or liquid) is presented. The housing has a inlet valve, similar to that on a tire or basketball, to introduce an ablating fluid into the housing. The housing is attached by a Velcro mount or double-sided adhesive tape to the outside surface of a structure to be protected. The housings are arrayed in a side-by-side relationship for complete coverage of the surface to be protected. In use, when a hypervelocity projectile penetrates the outer wall of a housing it is broken up and then the projectile is ablated as it travels through the fluid, much like a meteorite 'burns up' as it enters the earth's atmosphere, and the housing is deflated. The deflated housing can be easily spotted for replacement, even from a distance. Replacement is then accomplished by simply pulling a deflated housing off the structure and installing a new housing.

  5. Shield Design for Lunar Surface Applications

    NASA Astrophysics Data System (ADS)

    Johnson, Gregory A.

    2006-01-01

    A shielding concept for lunar surface applications of nuclear power is presented herein. The reactor, primary shield, reactor equipment and power generation module are placed in a cavity in the lunar surface. Support structure and heat rejection radiator panels are on the surface, outside the cavity. The reactor power of 1,320 kWt was sized to deliver 50 kWe from a thermoelectric power conversion subsystem. The dose rate on the surface is less than 0.6 mRem/hr at 100 meters from the reactor. Unoptimized shield mass is 1,020 kg which is much lighter than a comparable 4? shield weighing in at 17,000 kg.

  6. Analytical study of twin-jet shielding

    NASA Technical Reports Server (NTRS)

    Gerhold, C. H.

    1980-01-01

    An analytical model a three-dimensional model, of twin-jet shielding, consisting of a point noise source impinging on a cylinder of heated flow in which the temperature and flow velocity are uniform across the cross-section is discussed. Wave equations are given for the regions outside the flow and within the flow cylinder and solutions are matched at the jet boundary under the conditions of continuity of pressure and continuity of the vortex sheet. The model was analyzed to identify mechanisms of transmission and diffraction which control sheilding in the shadow of the shielding jet. It was found that in the zone of the shadow region dominates, shielding is relatively insensitive to variations of such parameters as Mach Number and spacing ratio, but in the zone in which diffraction dominates; shielding is more sensitive to variations in Mach Number, jet temperature and spacing ratio.

  7. Passive Magnetic Shielding in Gradient Fields

    E-print Network

    Bidinosti, C P

    2013-01-01

    The effect of passive magnetic shielding on dc magnetic field gradients imposed by both external and internal sources is studied. It is found that for concentric cylindrical or spherical shells of high permeability material, higher order multipoles in the magnetic field are shielded progressively better, by a factor related to the order of the multipole. In regard to the design of internal coil systems for the generation of uniform internal fields, we show how one can take advantage of the coupling of the coils to the innermost magnetic shield to further optimize the uniformity of the field. These results demonstrate quantitatively a phenomenon that was previously well-known qualitatively: that the resultant magnetic field within a passively magnetically shielded region can be much more uniform than the applied magnetic field itself. Furthermore we provide formulae relevant to active magnetic compensation systems which attempt to stabilize the interior fields by sensing and cancelling the exterior fields clos...

  8. Shield Design for Lunar Surface Applications

    SciTech Connect

    Johnson, Gregory A. [Pratt and Whitney -- Rocketdyne, Inc., 6633 Canoga Avenue, P.O. Box 7922 MC LA-13, Canoga Park, California 91309-7922 (United States)

    2006-01-20

    A shielding concept for lunar surface applications of nuclear power is presented herein. The reactor, primary shield, reactor equipment and power generation module are placed in a cavity in the lunar surface. Support structure and heat rejection radiator panels are on the surface, outside the cavity. The reactor power of 1,320 kWt was sized to deliver 50 kWe from a thermoelectric power conversion subsystem. The dose rate on the surface is less than 0.6 mRem/hr at 100 meters from the reactor. Unoptimized shield mass is 1,020 kg which is much lighter than a comparable 4{pi} shield weighing in at 17,000 kg.

  9. Thermal Shield and Reactor Structure Temperatures

    SciTech Connect

    Collier, A.R.

    2001-07-31

    The purpose of this report is to present reactor structure and thermal shield temperature data taken during P-3 and P-5 cycles and compare them with design calculations in order to predict temperatures at higher power levels.

  10. Resonance self-shielding methodology in MPACT

    SciTech Connect

    Liu, Y.; Collins, B.; Kochunas, B.; Martin, W. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI, 48109 (United States); Kim, K. S.; Williams, M. [Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN 37831-6172 (United States)

    2013-07-01

    The resonance self-shielding methods of the neutron transport code Michigan Parallel Characteristics based Transport (MPACT) are described in this paper. Two resonance-integral table based methods are utilized to resolve the resonance self-shielding effect. The subgroup method is a mature approach used in MPACT as the basic functionality for the resonance calculation. Another new iterative method, named the embedded self-shielding method is also implemented in MPACT. Comparisons of the two methods as well as their numerical verifications are presented. The results show that MPACT is capable of modeling the resonance self-shielding in a variety of PWR benchmarking cases, including difficult fuel lattice cases with poison, control rods or mixed gadolinia fuel rods. (authors)

  11. Potential of building-scale alternative energy to alleviate risk from the future price of energy

    Microsoft Academic Search

    David Bristow; Christopher A. Kennedy

    2010-01-01

    The energy used for building operations, the associated greenhouse gas emissions, and the uncertainties in future price of natural gas and electricity can be a cause of concern for building owners and policy makers. In this work we explore the potential of building-scale alternative energy technologies to reduce demand and emissions while also shielding building owners from the risks associated

  12. Comparison of graphite, aluminum, and TransHab shielding material characteristics in a high-energy neutron field

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Huff, H.; Wilkins, R.; Thibeault, Sheila

    2002-01-01

    Space radiation transport models clearly show that low atomic weight materials provide a better shielding protection for interplanetary human missions than high atomic weight materials. These model studies have concentrated on shielding properties against charged particles. A light-weight, inflatable habitat module called TransHab was built and shown to provide adequate protection against micrometeoroid impacts and good shielding properties against charged particle radiation in the International Space Station orbits. An experiment using a tissue equivalent proportional counter, to study the changes in dose and lineal energy spectra with graphite, aluminum, and a TransHab build-up as shielding, was carried out at the Los Alamos Nuclear Science Center neutron facility. It is a continuation of a previous study using regolith and doped polyethylene materials. This paper describes the results and their comparison with the previous study. Published by Elsevier Science Ltd.

  13. Magnetic shielding by soft magnetic materials in alternating magnetic field

    Microsoft Academic Search

    Yasuo Okazaki; Kiyoshi Ueno

    1992-01-01

    The magnetic shielding effect of an alternating field up to 20 kHz was examined in 3% Si steel sheets and amorphous ribbons. Not only the permeability but also the domain configuration was found to affect the shielding effects. The annealed Fe-based amorphous shield without field showed exceedingly high shielding effectiveness for higher frequencies.

  14. Effectiveness of IC shielded packages against space radiation

    Microsoft Academic Search

    J. P. Spratt; B. C. Passenheim; R. E. Leadon; S. Clark; D. J. Strobel

    1997-01-01

    This paper discusses research undertaken to evaluate and improve the effectiveness of shielded packages for protecting commercial microelectronics against ionizing dose from electrons and protons in space. The IC shielded package design data base was extended to include all important shield parameters (thickness, atomic number (Z), and edge effects). The shielding effectiveness of these packages was calculated using both forward

  15. Shielded beam delivery apparatus and method

    DOEpatents

    Hershcovitch, Ady; Montano, Rory Dominick

    2006-07-11

    An apparatus includes a plasma generator aligned with a beam generator for producing a plasma to shield an energized beam. An electrode is coaxially aligned with the plasma generator and followed in turn by a vortex generator coaxially aligned with the electrode. A target is spaced from the vortex generator inside a fluid environment. The electrode is electrically biased relative to the electrically grounded target for driving the plasma toward the target inside a vortex shield.

  16. Nuclear reactor shield including magnesium oxide

    DOEpatents

    Rouse, Carl A. (Del Mar, CA); Simnad, Massoud T. (La Jolla, CA)

    1981-01-01

    An improvement in nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux, the reactor shielding including means providing structural support, neutron moderator material, neutron absorber material and other components as described below, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron.

  17. Space shuttle holddown post blast shield

    NASA Technical Reports Server (NTRS)

    Larracas, F. B.

    1991-01-01

    The original and subsequent designs of the Solid Rocket Booster/Holddown Post blast shield assemblies and their associated hardware are described. It presents the major problems encountered during their early use in the Space Shuttle Program, during the Return-to-Flight Modification Phase, and during their fabrication and validation testing phases. The actions taken to correct the problems are discussed, along with the various concepts now being considered to increase the useful life of the blast shield.

  18. Reliability Methods for Shield Design Process

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, J. W.

    2002-01-01

    Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and duty phase of space missions. The total shield mass over all pieces of equipment and habitats is optimized subject to career dose and dose rate constraints. An important component of this technology is the estimation of two most commonly identified uncertainties in radiation shield design, the shielding properties of materials used and the understanding of the biological response of the astronaut to the radiation leaking through the materials into the living space. The largest uncertainty, of course, is in the biological response to especially high charge and energy (HZE) ions of the galactic cosmic rays. These uncertainties are blended with the optimization design procedure to formulate reliability-based methods for shield design processes. The details of the methods will be discussed.

  19. Atlas SCT/Pixel Grounding and Shielding Note 1 ATLAS SCT/Pixel Grounding and Shielding Note

    E-print Network

    California at Santa Cruz, University of

    Atlas SCT/Pixel Grounding and Shielding Note 1 ATLAS SCT/Pixel Grounding and Shielding Note November 22, 1999, Ned Spencer, UCSC The objective of a grounding and shielding configuration/Pixel Grounding and Shielding Note 2 elements in a manner to provide this noise current minimization by design

  20. Shielding of manned space vehicles against protons and alpha particles

    NASA Technical Reports Server (NTRS)

    Alsmiller, R. G., Jr.; Santoro, R. T.; Barish, J.; Claiborne, H. C.

    1972-01-01

    The available information on the shielding of manned space vehicles against protons and alpha particles is summarized. The emphasis is placed on shielding against Van Allen belt protons and against solar-flare protons and alpha particles, but information on shielding against galactic cosmic rays is also presented. The approximation methods for use by nonexperts in the space shielding field are those that are standard in the space shielding literature.

  1. Space Shielding Materials for Prometheus Application

    SciTech Connect

    R. Lewis

    2006-01-20

    At the time of Prometheus program restructuring, shield material and design screening efforts had progressed to the point where a down-selection from approximately eighty-eight materials to a set of five ''primary'' materials was in process. The primary materials were beryllium (Be), boron carbide (B{sub 4}C), tungsten (W), lithium hydride (LiH), and water (H{sub 2}O). The primary materials were judged to be sufficient to design a Prometheus shield--excluding structural and insulating materials, that had not been studied in detail. The foremost preconceptual shield concepts included: (1) a Be/B{sub 4}C/W/LiH shield; (2) a Be/B{sub 4}C/W shield; (3) and a Be/B{sub 4}C/H{sub 2}O shield. Since the shield design and materials studies were still preliminary, alternative materials (e.g., {sup nal}B or {sup 10}B metal) were still being screened, but at a low level of effort. Two competing low mass neutron shielding materials are included in the primary materials due to significant materials uncertainties in both. For LiH, irradiation-induced swelling was the key issue, whereas for H{sub 2}O, containment corrosion without active chemistry control was key, Although detailed design studies are required to accurately estimate the mass of shields based on either hydrogenous material, both are expected to be similar in mass, and lower mass than virtually any alternative. Unlike Be, W, and B{sub 4}C, which are not expected to have restrictive temperature limits, shield temperature limits and design accommodations are likely to be needed for either LiH or H{sub 2}O. The NRPCT focused efforts on understanding swelting of LiH, and observed, from approximately fifty prior irradiation tests, that either casting ar thorough out-gassing should reduce swelling. A potential contributor to LiH swelling appears to be LiOH contamination due to exposure to humid air, that can be eliminated by careful processing. To better understand LiH irradiation performance and mitigate the risks in LiH development for a project with an aggressive schedule like JIMO, some background or advanced development effort for LiH should be considered for future space reactor projects.

  2. 118. Stage basement. View, facing south, of the south hydraulic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    118. Stage basement. View, facing south, of the south hydraulic ram (type D) in the middle row. Photo was taken before the stage flooring was removed. - Auditorium Building, 430 South Michigan Avenue, Chicago, Cook County, IL

  3. 40. SOUTHWEST CORNER OF STAGE SHOWING RIGGING FOR FLYING SETS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. SOUTHWEST CORNER OF STAGE SHOWING RIGGING FOR FLYING SETS, LOCATION OF ORIGINAL DOORS IN PROSCENIUM WALL, AND COUNTERWEIGHTS FOR STAGE CURTAIN. - Auditorium Building, 430 South Michigan Avenue, Chicago, Cook County, IL

  4. 25. DETAIL OF TIE ROD REINFORCING BELOW WESTERNMOST MOVABLE STAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. DETAIL OF TIE ROD REINFORCING BELOW WESTERNMOST MOVABLE STAGE SECTION, LOWER LEVEL OF STAGE, LOOKING SOUTH. TAKEN FROM A POINT JUST SOUTH OF RAM IN IL-1007-24. - Auditorium Building, 430 South Michigan Avenue, Chicago, Cook County, IL

  5. Magnetic shielding of interplanetary spacecraft against solar flare radiation

    NASA Astrophysics Data System (ADS)

    Cocks, Franklin H.; Watkins, Seth

    1993-07-01

    The ultimate objective of this work is to design, build, and fly a dual-purpose, piggyback payload whose function is to produce a large volume, low intensity magnetic field and to test the concept of using such a magnetic field (1) to protect spacecraft against solar flare protons, (2) to produce a thrust of sufficient magnitude to stabilize low satellite orbits against orbital decay from atmospheric drag, and (3) to test the magsail concept. These all appear to be capable of being tested using the same deployed high temperature superconducting coil. In certain orbits, high temperature superconducting wire, which has now been developed to the point where silver-sheathed high T sub c wires one mm in diameter are commercially available, can be used to produce the magnetic moments required for shielding without requiring any mechanical cooling system. The potential benefits of this concept apply directly to both earth-orbital and interplanetary missions. The usefulness of a protective shield for manned missions needs scarcely to be emphasized. Similarly, the usefulness of increasing orbit perigee without expenditure of propellant is obvious. This payload would be a first step in assessing the true potential of large volume magnetic fields in the US space program. The objective of this design research is to develop an innovative, prototype deployed high temperature superconducting coil (DHTSC) system.

  6. Mountain Stage

    NSDL National Science Digital Library

    Mountain Stage, a famous Charleston, West Virginia, venue where folk musicians play, is broadcast on National Public Radio, and can be heard on the NPR website, simply by clicking on "Listen", next to the artist's picture and brief bio. Visitors wishing to read more about the artist's musical history can click on the name of the artist next to their picture. Included in the history is their set list for the broadcast show. Visitors can comment on each artist's show, or recommend it to other visitors, by clicking on the icons at the bottom of each brief bio on the homepage.

  7. J STAGE

    NSDL National Science Digital Library

    Developed by the Japan Science and Technology Corporation (JST), J-STAGE (The Japan Science and Technology Aggregator, Electronic) is a recently launched electronic journal center that publishes and disseminates Japanese electronic scientific journals. At present, the site hosts four journals (one of which is Japanese only), but expects to add over a hundred in the near future. The three available English-language journals include the Japanese Journal of Applied Physics, the Journal of the Physical Society of Japan, and SHIGEN-TO-SOZAI, a journal of the Mining and Materials Processing Institute of Japan. The full-text articles are available free of charge with searchable back issues also available.

  8. DURABILITY OF DEPLETED URANIUM AGGREGATES (DUAGG) IN DUCRETE SHIELDING APPLICATIONS

    SciTech Connect

    Mattus, Catherine H.; Dole, Leslie R.

    2003-02-27

    The depleted uranium (DU) inventory in the United States exceeds 500,000 metric tonnes. To evaluate the possibilities for reuse of this stockpile of DU, the U.S. Department of Energy (DOE) has created a research and development program to address the disposition of its DU(1). One potential use for this stockpile material is in the fabrication of nuclear shielding casks for the storage, transport, and disposal of spent nuclear fuels. The use of the DU-based shielding would reduce the size and weight of the casks while allowing a level of protection from neutrons and gamma rays comparable to that afforded by steel and concrete. DUAGG (depleted uranium aggregate) is formed of depleted uranium dioxide (DUO2) sintered with a synthetic-basalt-based binder. This study was designed to investigate possible deleterious reactions that could occur between the cement paste and the DUAGG. After 13 months of exposure to a cement pore solution, no deleterious expansive mineral phases were observed to form either with the DUO2 or with the simulated-basalt sintering phases. In the early stages of these exposure tests, Oak Ridge National Laboratory preliminary results confirm that the surface reactions of this aggregate proceed more slowly than expected. This finding may indicate that DUAGG/DUCRETE (depleted uranium concrete) casks could have service lives sufficient to meet the projected needs of DOE and the commercial nuclear power industry.

  9. Finite Element Analysis of Tunnel and Building Settlements

    E-print Network

    Houlsby, Guy T.

    (m) Stage 1 Stage 2 Stage 3 Stage 4 -0.030 -0.025 -0.020 -0.015 -0.010 -0.005 0.000 -40 -20 0 20 40 60 x (m) w(m) Stage 1 Stage 2 Stage 3 Stage 4 1. In a preliminary analysis the settlements are calculated Frontfacade 60 50 100 45o building base outline 30 30 tunnel excavation stages 3541 nodes 2243 solid

  10. Shielding of Tevatron Meson Laboratory target piles - M-west, M-center, M-polarized

    SciTech Connect

    Cossairt, J.D.

    1983-12-01

    This note reports on shielding calculations pertinent to the new target piles planned for the Meson Detector Building. The primary emphasis here is upon the external dose equivalent rates and groundwater activation. A previous TM describes the activation of the target, sweeping magnet cooling water, and beam sweeping magnets. A separate note summarizes the radiation protection aspects of the muon radiation due to all four meson target piles and is attached.

  11. Effects of shield impedance, connector resistance, and coaxial inductors on ground noise interference in nuclear reactor instrumentation systems

    Microsoft Academic Search

    1976-01-01

    Electrical noise interference in low-level (approximately 50 ..mu..V), wide band (approximately 15 MHz) flux monitoring systems applied to nuclear reactor control causes safety and reliability problems. Others have shown that one predominant source of noise interference is conduction of currents in instrument cable shields and building conduits. Since these currents produce noise that is similar to signals produced by nuclear

  12. Radiation shield ring assembly and method of disassembling components of a nuclear steam generator using such assembly

    Microsoft Academic Search

    R. E. Meuschke; D. L. Wolfe

    1981-01-01

    This invention provides shielded access to the irradiated heat exchanger tube bundle of a nuclear steam generator contained within a cask after removal from the generator. This tube bundle must be reduced in size and confined for removal from the containment building through hatchways of generally limited size. Access to the enclosed bundle is at the flanged joints of adjacent

  13. A Novel Target Field Method for Designing Uniplanar Self-shield Gradient Coils of Fully Open MRI Device

    Microsoft Academic Search

    X. Li; D. Xie; J. Wang

    2007-01-01

    A new approach to the design of uniplanar self-shield gradient coils for fully open magnetic resonance imaging system is proposed to build a specified gradient magnetic field in a target region. In this new design methodology, the surface current density of the coils is represented by a two-dimensional Fourier series expansion. A cost function is constructed in terms of the

  14. Archaean TTG of Vodlozero Terrain, Fennoscandian Shield

    NASA Astrophysics Data System (ADS)

    Chekulaev, Valery; Arestova, Natalia

    2014-05-01

    The Vodlozero terrain is the largest (about 270*240 km) early Archaean fragment of Fennoscandian Shield and composes its eastern part. The granitoids of TTG suite are predominant component of the terrain. The greenstone belts are placed along the margins of the terrain. Several stages of TTG formation can be distinguished in Achaean crust history. (1) The oldest TTG are trondhjemites and tonalities with age of 3240 Ma. They contain rare and small amphibolite inclusions of the same age. These TTG are characterized by high Sr (av. 412 ppm), Sr/Y (70), (La/Yb)n (54) and low Y (av. 7 ppm), Yb (0.32 ppm) and Nb (4 ppm). It was shown (Lobach-Zhuchenko et al., 2000), that the source of these TTG could be basic rocks, having composition similar with TH1 by K.Condie. (2) The tonalities and granodiorites with age of 3150 Ma are disposed near greenstone belts and contain compared to TTG of the first group less Sr (av. 250 ppm), Sr/Y (22), (La/Yb)n (18) and more K, Rb (av. 70 ppm), Ba (470 ppm), Y (11 ppm),Yb (1.16 ppm). TTG of both groups have identical T(DM)Nd (3250-3400 Ma) and differences in composition is evidently connected with lower level of source melting of the second group and also with K-metasomatism. The volcanics of the greenstone belts have age 3020 - 2940 Ma. Dykes of gabbro-amphibolites and andesites with the same age and composition cut TTG of the first and the second groups. The age of the third TTG group is about 2900 Ma ago. These rocks form leucosoma of migmatites within TTG of the second group. The composition of the third TTG and Nd isotope data suppose their origin by the melting of ancient TTG crust simultaneously with greenstone belt emplacement. The fourth TTG group with age 2780-2850 Ma forms a small intrusions, cutting older TTG and greenstone rocks. Their composition is similar to 3150 Ma TTG. Nd isotope data indicate that these TTG have younger (about 2850 Ma) source. Thus there are four TTG groups formed into interval more 400 Ma. The age and composition of the rocks indicate on the absence of connection in origin of TTG and volcanics. References Lobach-Zhuchenko S.B., Kovalenko A.V., Krylov I.N., Levsky L.K., Bogomolov E.S. Geochemistry and petrology of the ancient Vygozero Granitoids, Southeastern Karelia // Geochemistry International. 2000. V. 38. S. 1. P. 584-599.

  15. Shielding Structures for Interplanetary Human Mission

    NASA Astrophysics Data System (ADS)

    Tracino, Emanuele; Lobascio, Cesare

    2012-07-01

    Since the end of Apollo missions, human spaceflight has been limited to the Low Earth Orbit (LEO), inside the protective magnetic field of the Earth, because astronauts are, to the largest degree, protected from the harsh radiation environment of the interplanetary space. However, this situation will change when space exploration missions beyond LEO will become the real challenge of the human exploration program. The feasibility of these missions in the solar system is thus strongly connected to the capability to mitigate the radiation-induced biological effects on the crew during the journey and the permanence on the intended planet surface. Inside the International Space Station (ISS), the volumes in which the crew spends most of the time, namely the crew quarters are the only parts that implement dedicated additional radiation shielding made of polyethylene tiles designed for mitigating SPE effects. Furthermore, specific radiation shielding materials are often added to the described configuration to shield crew quarters or the entire habitat example of these materials are polyethylene, liquid hydrogen, etc. but, increasing the size of the exploration vehicles to bring humans beyond LEO, and without the magnetosphere protection, such approach is unsustainable because the mass involved is a huge limiting factor with the actual launcher engine technology. Moreover, shielding against GCR with materials that have a low probability of nuclear interactions and in parallel a high ionizing energy loss is not always the best solution. In particular there is the risk to increase the LET of ions arriving at the spacecraft shell, increasing their Radio-Biological Effectiveness. Besides, the production of secondary nuclei by projectile and target fragmentation is an important issue when performing an engineering assessment of materials to be used for radiation shielding. The goal of this work is to analyze different shielding solutions to increase as much as possible the radiation shielding power of the interplanetary habitat structures, like the spacecraft shell, minimizing the amount of mass used. From the radiation protection point of view the spacecraft shell is an interesting spacecraft system because it surrounds almost homogeneously all the habitat and it is typically composed by the Micrometeorites and Debris Protection Systems (MDPS), the Multilayer Insulation (MLI) for thermal control purposes, and the primary structure that offers the pressure containment functionality. Nevertheless, the spacecraft internal outfitting is important to evaluate the different shielded areas in the habitat. Using Geant4 Monte Carlo simulations toolkit through GRAS (Geant4 Radiation Analysis for Space) tool, different spacecraft structures will be analyzed for their shielding behavior in terms of fluxes, dose reduction and radiation quality, and for their implementation in a real pressurized module. Effects on astronauts and electronic equipments will be also assessed with respect to the standard aluminum structures.

  16. Cosmic Ray Interactions in Shielding Materials

    SciTech Connect

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.; Orrell, John L.; Berguson, Timothy J.; Troy, Meredith D.

    2011-09-08

    This document provides a detailed study of materials used to shield against the hadronic particles from cosmic ray showers at Earth’s surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during transport for the MAJORANA collaboration. The materials suitable for cosmic-ray shield design are materials such as lead and iron that will stop the primary protons, and materials like polyethylene, borated polyethylene, concrete and water that will stop the induced neutrons. The interaction of the different cosmic-ray components at ground level (protons, neutrons, muons) with their wide energy range (from kilo-electron volts to giga-electron volts) is a complex calculation. Monte Carlo calculations have proven to be a suitable tool for the simulation of nucleon transport, including hadron interactions and radioactive isotope production. The industry standard Monte Carlo simulation tool, Geant4, was used for this study. The result of this study is the assertion that activation at Earth’s surface is a result of the neutronic and protonic components of the cosmic-ray shower. The best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.

  17. Advances in space radiation shielding codes

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Tripathi, Ram K.; Qualls, Garry D.; Cucinotta, Francis A.; Prael, Richard E.; Norbury, John W.; Heinbockel, John H.; Tweed, John; De Angelis, Giovanni

    2002-01-01

    Early space radiation shield code development relied on Monte Carlo methods and made important contributions to the space program. Monte Carlo methods have resorted to restricted one-dimensional problems leading to imperfect representation of appropriate boundary conditions. Even so, intensive computational requirements resulted and shield evaluation was made near the end of the design process. Resolving shielding issues usually had a negative impact on the design. Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary concept to the final design. For the last few decades, we have pursued deterministic solutions of the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard Finite Element Method (FEM) geometry common to engineering design methods. A single ray trace in such geometry requires 14 milliseconds and limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given.

  18. Experimental evaluation of resistojet thruster plume shields

    NASA Technical Reports Server (NTRS)

    Carney, Lynnette M.; Bailey, Allan B.

    1988-01-01

    The exhaust of an engineering model resistojet has been investigated using rotary pitot probes and a rotary quartz crystal microbalance. The resistojet operated on CO2 propellant at a mass flow rate of 0.29 g/sec in both heated and unheated flows. Measurements of local flow angles in the near field of a conical plume shield indicated that the shield was not wholly effective in confining the flow to the region upstream of its exit plane. However, the absolute levels of the measured mass flux into the backflow region were very low, on the order of 7 x 10 to the -7 power g/sqcm/sec or less. The use of a circualr disk at the exit plane of the existing conical shield showed some benefit in decreasing the amount of backflow by a factor of two. Lastly, a detached shield placed upstream of the resistojet exit plane demonstrated a small degree of local shielding for the region directly behind it.

  19. Analytic Ballistic Performance Model of Whipple Shields

    NASA Technical Reports Server (NTRS)

    Miller, J. E.; Bjorkman, M. D.; Christiansen, E. L.; Ryan, S. J.

    2015-01-01

    The dual-wall, Whipple shield is the shield of choice for lightweight, long-duration flight. The shield uses an initial sacrificial wall to initiate fragmentation and melt an impacting threat that expands over a void before hitting a subsequent shield wall of a critical component. The key parameters to this type of shield are the rear wall and its mass which stops the debris, as well as the minimum shock wave strength generated by the threat particle impact of the sacrificial wall and the amount of room that is available for expansion. Ensuring the shock wave strength is sufficiently high to achieve large scale fragmentation/melt of the threat particle enables the expansion of the threat and reduces the momentum flux of the debris on the rear wall. Three key factors in the shock wave strength achieved are the thickness of the sacrificial wall relative to the characteristic dimension of the impacting particle, the density and material cohesion contrast of the sacrificial wall relative to the threat particle and the impact speed. The mass of the rear wall and the sacrificial wall are desirable to minimize for launch costs making it important to have an understanding of the effects of density contrast and impact speed. An analytic model is developed here, to describe the influence of these three key factors. In addition this paper develops a description of a fourth key parameter related to fragmentation and its role in establishing the onset of projectile expansion.

  20. Reactor and shielding design implications of clustering nuclear thermal rockets

    NASA Astrophysics Data System (ADS)

    Buksa, John J.; Houts, Michael G.

    1992-07-01

    This paper examines design considerations in the context of engine-out accidents in clustered nuclear-thermal rocket stages, and an accident-management protocol is devised. Safety and performance issues are considered in the light of designs for the reactor and shielding elements of ROVER/NERVA-type engines. The engine-out management process involves: phase one, in which sufficient propulsive power is guaranteed for mission completion; and phase two, in which engine failure is isolated and not allowed to propagate to other engines or to the spacecraft. Phase-one designs can employ spare engines, throttled engines, and/or long-burning engines. Phase-two safety concepts can include techniques for cooling or jettisoning the failed engines. Engine-out management philosophies are shown to be shaped by a combination of safety and mission-trajectory requirements.

  1. Reactor and shielding design implications of clustering nuclear thermal rockets

    SciTech Connect

    Buksa, J.J.; Houts, M.G. (Los Alamos National Laboratory, NM (United States))

    1992-07-01

    This paper examines design considerations in the context of engine-out accidents in clustered nuclear-thermal rocket stages, and an accident-management protocol is devised. Safety and performance issues are considered in the light of designs for the reactor and shielding elements of ROVER/NERVA-type engines. The engine-out management process involves: phase one, in which sufficient propulsive power is guaranteed for mission completion; and phase two, in which engine failure is isolated and not allowed to propagate to other engines or to the spacecraft. Phase-one designs can employ spare engines, throttled engines, and/or long-burning engines. Phase-two safety concepts can include techniques for cooling or jettisoning the failed engines. Engine-out management philosophies are shown to be shaped by a combination of safety and mission-trajectory requirements. 6 refs.

  2. Intercalated graphite fiber composites as EMI shields in aerospace structures

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    1992-01-01

    The requirements for electromagnetic interference (EMI) shielding in aerospace structures are more complicated than those for ground structures because of their weight limitations. As a result, the best EMI shielding materials must combine low density, high strength, and high elastic modulus with high shielding ability. EMI shielding characteristics were calculated for shields formed from pristine and intercalated graphite fiber/epoxy composites and compare to preliminary experimental results for these materials and to the characteristics of shields made from aluminum. Calculations indicate that effective EMI shields could be fabricated from intercalated graphite composites which would have less than 12 percent of the mass of conventional aluminum shields, based on mechanical properties and shielding characteristics alone.

  3. BUILDING SIMULATION AS AN ASSISTING TOOL IN DESIGNING AN ENERGY EFFICIENT BUILDING: A CASE STUDY

    Microsoft Academic Search

    Michael Pollock; Ya Roderick; David McEwan; Craig Wheatley

    Decisions made in the very first stages of a building's design often have a significant impact on energy efficiency and internal environment of the building. Although many buildings have energy efficiency strategies embedded in their conceptual design, it is seldom that these concepts would be fully analysed at the initial design stages. In this paper, a case study based on

  4. Magnetic shielding for MRI superconducting magnets

    SciTech Connect

    Ishiyama, A.; Hirooka, H. (Dept. of Electrical Engineering, Waseda Univ., Tokyo (JP))

    1991-03-01

    This paper describes an optimal design of a highly homogeneous superconducting coil system with magnetic shielding for Magnetic Resonance Imaging (MRI). The presented optimal design method; which is originally proposed in our earlier papers, is a combination of the hybrid finite element and boundary element method for analysis of an axially symmetric nonlinear open boundary magnetic field problem, and the mathematical programming method for solving the corresponding optimization problem. In this paper, the multi-objective goal programming method and the nonlinear least squares method have been adopted. The optimal design results of 1.5- and 4.7-Tesla-magnet systems with different types of magnetic shielding for whole-body imaging are compared and the advantages of a combination of active and yoke shields are shown.

  5. Phenomenological calculations of shielding spallation neutron sources

    NASA Astrophysics Data System (ADS)

    Fragopoulou, M.; Zamani, M.

    2013-06-01

    The high level of radiation generated by a spallation source requires the design of an appropriate shielding to surround the source in order to fulfill radiation protection standards. A calculation of the spallation neutron attenuation is presented for various shielding materials, using a phenomenological model, based on the Moyer model. In the first step of the calculation, the interaction length of neutrons for each neutron energy and shielding material was estimated using inelastic cross-sections. In the second step the calculation deals with the attenuation of the neutron flux applying the Moyer model, for each material and neutron energy region. The transmission factors were calculated and compared with experimental data collected from the "Gamma-2" and the "E+T" projects running in JINR (Dubna, Russia). The results of the present work were also compared to the data obtained by different Monte Carlo codes such as MORSE, MCNPX, MARS14 and LAHET.

  6. Vehicle drive module having improved EMI shielding

    SciTech Connect

    Beihoff, Bruce C.; Kehl, Dennis L.; Gettelfinger, Lee A.; Kaishian, Steven C.; Phillips, Mark G.; Radosevich, Lawrence D.

    2006-11-28

    EMI shielding in an electric vehicle drive is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  7. Power converter having improved EMI shielding

    DOEpatents

    Beihoff, Bruce C.; Kehl, Dennis L.; Gettelfinger, Lee A.; Kaishian, Steven C.; Phillips, Mark G.; Radosevich, Lawrence D.

    2006-06-13

    EMI shielding is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  8. Shielding quantum discord through continuous dynamical decoupling

    E-print Network

    Felipe F. Fanchini; Emanuel F. de Lima; Leonardo K. Castelano

    2012-11-06

    This work investigates the use of dynamical decoupling to shield quantum discord from errors introduced by the environment. Specifically, a two-qubits system interacting with independent baths of bosons is considered. The initial conditions of the system were chosen as pure and mixed states, while the dynamical decoupling has been achieved by means of continuous fields. The effects of the temperature on the shielding of quantum discord is also studied. It is shown that although the quantum discord for particular initial states may be perfectly preserved over some finite time window in the absence of any protective field, the effectiveness of the dynamical decoupling with continuous fields depends essentially on the timescale required to preserve quantum discord. It is also shown that for these particular initial states the time for which the shielding of the quantum discord becomes effective decreases as the temperature increases.

  9. High purity silica reflective heat shield development

    NASA Technical Reports Server (NTRS)

    Nachtscheim, P. R.; Blome, J. C.

    1976-01-01

    A hyperpure vitreous silica material is being developed for use as a reflective and ablative heat shield for planetary entry. Various purity grades and forms of raw materials were evaluated along with various processing methods. Slip casting of high purity grain was selected as the best processing method, resulting in a highly reflective material in the wavelength bands of interest (the visible and ultraviolet regions). The selected material was characterized with respect to optical, mechanical and physical properties using a limited number of specimens. The process has been scaled up to produce a one-half scale heat shield (18 in. dia.) (45.72 cm) for a Jupiter entry vehicle. This work is now being extended to improve the structural safety factor of the heat shield by making hyperpure silica material tougher through the addition of silica fibers.

  10. Radiation shielding effectiveness of newly developed superconductors

    NASA Astrophysics Data System (ADS)

    Singh, Vishwanath P.; Medhat, M. E.; Badiger, N. M.; Saliqur Rahman, Abu Zayed Mohammad

    2015-01-01

    Gamma ray shielding effectiveness of superconductors with a high mass density has been investigated. We calculated the mass attenuation coefficients, the mean free path (mfp) and the exposure buildup factor (EBF). The gamma ray EBF was computed using the Geometric Progression (G-P) fitting method at energies 0.015-15 MeV, and for penetration depths up to 40 mfp. The fast-neutron shielding effectiveness has been characterized by the effective neutron removal cross-section of the superconductors. It is shown that CaPtSi3, CaIrSi3, and Bi2Sr2Ca1Cu2O8.2 are superior shielding materials for gamma rays and Tl0.6Rb0.4Fe1.67Se2 for fast neutrons. The present work should be useful in various applications of superconductors in fusion engineering and design.

  11. Carbohydrate based materials for gamma radiation shielding

    NASA Astrophysics Data System (ADS)

    Tabbakh, F.; Babaee, V.; Naghsh-Nezhad, Z.

    2015-05-01

    Due to the limitation in using lead as a shielding material for its toxic properties and limitation in abundance, price or non-flexibility of other commonly used materials, finding new shielding materials and compounds is strongly required. In this conceptual study carbohydrate based compounds were considered as new shielding materials. The simulation of radiation attenuation is performed using MCNP and Geant4 with a good agreement in the results. It is found that, the thickness of 2 mm of the proposed compound may reduce up to 5% and 50% of 1 MeV and 35 keV gamma-rays respectively in comparison with 15% and 100% for the same thickness of lead.

  12. Hepatic phase of malaria: a crucial role as "go-between" with other stages.

    PubMed Central

    Mazier, D.; Goma, J.; Pied, S.; Renia, L.; Nussler, A.; Miltgen, F.; Mattei, D.; Grau, G.

    1990-01-01

    Besides potential interest in itself, the hepatic stage of malaria might play a crucial role as "go-between" with other stages. When present in the parasitophorous vacuole, antibodies induced by both sporozoite and erythrocytic stages efficiently disturb hepatic development of the parasite. Likewise previous and ensuing erythrocytic stages can modulate the "shielded" phase by cytokines, directly or as a result of a cascade of events, and by MHC-restricted or antibody-dependent cytotoxic mechanisms. PMID:2151269

  13. Vehicle Shield Optimization and Risk Assessment for Future Human Space Missions

    NASA Technical Reports Server (NTRS)

    Nounu, Hatem N.; Kim, Myung-Hee; Cucinotta, Francis A.

    2011-01-01

    As the focus of future human space missions shifts to destinations beyond low Earth orbit such as Near Earth Objects (NEO), the moon, or Mars, risks associated with extended stay in hostile radiation environment need to be well understood and assessed. Since future spacecrafts designs and shapes are evolving continuous assessments of shielding and radiation risks are needed. In this study, we use a predictive software capability that calculates risks to humans inside a spacecraft prototype that builds on previous designs. The software uses CAD software Pro/Engineer and Fishbowl tool kit to quantify radiation shielding provided by the spacecraft geometry by calculating the areal density seen at a certain point, dose point, inside the spacecraft. Shielding results are used by NASA-developed software, BRYNTRN, to quantify organ doses received in a human body located in the vehicle in case of solar particle event (SPE) during such prolonged space missions. Organ doses are used to quantify risks on astronauts health and life using NASA Space Cancer Model. The software can also locate shielding weak points-hotspots-on the spacecraft s outer surface. This capability is used to reinforce weak areas in the design. Results of shielding optimization and risk calculation on an exploration vehicle design for missions of 6 months and 30 months are provided in this study. Vehicle capsule is made of aluminum shell that includes main cabin and airlock. The capsule contains 5 sets of racks that surround working and living areas. Water shelter is provided in the main cabin of the vehicle to enhance shielding in case of SPE.

  14. Shielding in ungated field emitter arrays

    NASA Astrophysics Data System (ADS)

    Harris, J. R.; Jensen, K. L.; Shiffler, D. A.; Petillo, J. J.

    2015-05-01

    Cathodes consisting of arrays of high aspect ratio field emitters are of great interest as sources of electron beams for vacuum electronic devices. The desire for high currents and current densities drives the cathode designer towards a denser array, but for ungated emitters, denser arrays also lead to increased shielding, in which the field enhancement factor ? of each emitter is reduced due to the presence of the other emitters in the array. To facilitate the study of these arrays, we have developed a method for modeling high aspect ratio emitters using tapered dipole line charges. This method can be used to investigate proximity effects from similar emitters an arbitrary distance away and is much less computationally demanding than competing simulation approaches. Here, we introduce this method and use it to study shielding as a function of array geometry. Emitters with aspect ratios of 102-104 are modeled, and the shielding-induced reduction in ? is considered as a function of tip-to-tip spacing for emitter pairs and for large arrays with triangular and square unit cells. Shielding is found to be negligible when the emitter spacing is greater than the emitter height for the two-emitter array, or about 2.5 times the emitter height in the large arrays, in agreement with previously published results. Because the onset of shielding occurs at virtually the same emitter spacing in the square and triangular arrays, the triangular array is preferred for its higher emitter density at a given emitter spacing. The primary contribution to shielding in large arrays is found to come from emitters within a distance of three times the unit cell spacing for both square and triangular arrays.

  15. A model of shield-strata interaction and its implications for active shield setting requirements

    SciTech Connect

    Barczak, T.M.; Oyler, D.C.

    1991-12-01

    This book reports that this U.S. Bureau of Mines study evaluates factors that influence longwall support and strata interaction. The longwall system is composed of an immediate and main roof structure and three supporting foundations: longwall structure that is generally supported by all three foundations, while the immediate roof acts as a beam that cantilevers from the coal face to the powered support. In most cases, shield loading involves a complex interaction of both main roof and immediate roof behavior and is a combination of loads produced from convergence of the main roof and displacements of the immediate roof caused by deformations of the cantilevered roof beam. Since the shield stiffness remains constant for all leg pressures and main roof convergence is irresistible in terms of shield capacity, the shield must be able to control the behavior of the immediate roof or floor structure for shield loading to be sensitive to setting pressures. If the goal is to minimize total shield loading, any active setting force must be offset by reduced passive shield loading to justify the active setting loads. Field data suggest that the typical reductions in passive loading do not justify the required increases in setting pressure in some applications.

  16. Blue Shield of California outpatient payment program.

    PubMed

    Roughan, J F

    1994-01-01

    Faced with major increases in the cost of outpatient medical care, Blue Shield of California initiated an effort to develop and implement a prospective payment system that could be used for contracting with hospitals and freestanding facilities. Utilizing an outpatient classification system designed to categorize outpatient visits with similar clinical characteristics as well as similar resource consumption, Blue Shield introduced a negotiated case rate system of payment for outpatient surgical care. This article will review the background of the project, the methodology used to implement the system, and the results achieved from its implementation. PMID:10136812

  17. Scale-PC shielding analysis sequences

    SciTech Connect

    Bowman, S.M.

    1996-05-01

    The SCALE computational system is a modular code system for analyses of nuclear fuel facility and package designs. With the release of SCALE-PC Version 4.3, the radiation shielding analysis community now has the capability to execute the SCALE shielding analysis sequences contained in the control modules SAS1, SAS2, SAS3, and SAS4 on a MS- DOS personal computer (PC). In addition, SCALE-PC includes two new sequences, QADS and ORIGEN-ARP. The capabilities of each sequence are presented, along with example applications.

  18. Hysteresis prediction inside magnetic shields and application

    NASA Astrophysics Data System (ADS)

    Mori?, Igor; De Graeve, Charles-Marie; Grosjean, Olivier; Laurent, Philippe

    2014-07-01

    We have developed a simple model that is able to describe and predict hysteresis behavior inside Mumetal magnetic shields, when the shields are submitted to ultra-low frequency (<0.01 Hz) magnetic perturbations with amplitudes lower than 60 ?T. This predictive model has been implemented in a software to perform an active compensation system. With this compensation the attenuation of longitudinal magnetic fields is increased by two orders of magnitude. The system is now integrated in the cold atom space clock called PHARAO. The clock will fly onboard the International Space Station in the frame of the ACES space mission.

  19. Hysteresis prediction inside magnetic shields and application.

    PubMed

    Mori?, Igor; De Graeve, Charles-Marie; Grosjean, Olivier; Laurent, Philippe

    2014-07-01

    We have developed a simple model that is able to describe and predict hysteresis behavior inside Mumetal magnetic shields, when the shields are submitted to ultra-low frequency (<0.01 Hz) magnetic perturbations with amplitudes lower than 60??T. This predictive model has been implemented in a software to perform an active compensation system. With this compensation the attenuation of longitudinal magnetic fields is increased by two orders of magnitude. The system is now integrated in the cold atom space clock called PHARAO. The clock will fly onboard the International Space Station in the frame of the ACES space mission. PMID:25085183

  20. Blue Cross and Blue Shield of Alabama

    NSDL National Science Digital Library

    The Alabama BlueCross and BlueShield Medical Information Server, located and developed by the University of Alabama at Birmingham Department of Computer and Information Sciences, through a grant from Blue Cross and Blue Shield of Alabama for the express purpose of providing Internet access to medical information for all physicians and other health care providers in the state of Alabama. It provides links to a broad range of medical information resources located throughout the Internet. Menus provide information on diseases and disorders, patient care and medical practice, medical specialties, journals and newsletters, health care reform, and other medical information.

  1. [Electromagnetic Shielding Alters Behaviour of Rats].

    PubMed

    Temuryants, N A; Kostyuk, A S; Tumanyants, K N

    2015-01-01

    It has been found that long-term electromagnetic shielding (19 hours per day for 10 days) leads to an increase in the duration of passive swimming time in male rats, decrease the duration of active swimming in the "forced swim" test as well as decrease of libido. On the other hand animals kept under the "open field" conditions do not show significant deviations from their normal behavior. Therefore, one could conclude that moderate electromagnetic shielding causes a depression-like state in rats. PMID:26080600

  2. Thermophysical Properties of Heat Resistant Shielding Material

    SciTech Connect

    Porter, W.D.

    2004-12-15

    This project was aimed at determining thermal conductivity, specific heat and thermal expansion of a heat resistant shielding material for neutron absorption applications. These data are critical in predicting the structural integrity of the shielding under thermal cycling and mechanical load. The measurements of thermal conductivity and specific heat were conducted in air at five different temperatures (-31 F, 73.4 F, 140 F, 212 F and 302 F). The transient plane source (TPS) method was used in the tests. Thermal expansion tests were conducted using push rod dilatometry over the continuous range from -40 F (-40 C) to 302 F (150 C).

  3. A Slice of the Heat Shield

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity features a cross section through the structure and thermal protection system of the rover's heat shield. Shown is one of six separation fittings used to join and separate the heat shield from the backshell during atmospheric entry, descent, and landing. Upon impact, this separation fitting punched through the structure.

    This is an approximately true-color rendering of the scene acquired around 1:21 p.m. local solar time on Opportunity's sol 340 (Jan. 7, 2005) using panoramic camera filters at wavelengths of 750, 530, and 430 nanometers.

  4. Commercial Building Partners Catalyze High Performance Buildings Across the Nation

    SciTech Connect

    Baechler, Michael C.; Dillon, Heather E.; Bartlett, Rosemarie

    2012-08-01

    In 2008 the US Department of Energy (DOE) launched the Commercial Buildings Partnership (CBP) project to accelerate market adoption of commercially available energy saving technologies into the design process for new and upgraded commercial buildings. The CBP represents a unique collaboration between industry leaders and DOE to develop high performance buildings as a model for future construction and renovation. CBP was implemented in two stages. This paper focuses on lessons learned at Pacific Northwest National Laboratory (PNNL) in the first stage and discusses some partner insights from the second stage. In the first stage, PNNL and the National Renewable Energy Laboratory recruited CBP partners that own large portfolios of buildings. The labs provide assistance to the partners' design teams and make a business case for energy investments.

  5. Two-stage free electron laser research

    NASA Astrophysics Data System (ADS)

    Segall, S. B.

    1984-10-01

    KMS Fusion, Inc. began studying the feasibility of two-stage free electron lasers for the Office of Naval Research in June, 1980. At that time, the two-stage FEL was only a concept that had been proposed by Luis Elias. The range of parameters over which such a laser could be successfully operated, attainable power output, and constraints on laser operation were not known. The primary reason for supporting this research at that time was that it had the potential for producing short-wavelength radiation using a relatively low voltage electron beam. One advantage of a low-voltage two-stage FEL would be that shielding requirements would be greatly reduced compared with single-stage short-wavelength FEL's. If the electron energy were kept below about 10 MeV, X-rays, generated by electrons striking the beam line wall, would not excite neutron resonance in atomic nuclei. These resonances cause the emission of neutrons with subsequent induced radioactivity. Therefore, above about 10 MeV, a meter or more of concrete shielding is required for the system, whereas below 10 MeV, a few millimeters of lead would be adequate.

  6. FORESTRY BUILDING: BUILDING EMERGENCY PLAN

    E-print Network

    FORESTRY BUILDING: BUILDING EMERGENCY PLAN Date Adopted: August 18, 2009 Date Revised June 17, 2013 Prepared By: Diana Evans and Jennifer Meyer #12;PURDUE UNIVERSITY BUILDING EMERGENCY PLAN VERSION 3 2 Table Suspension or Campus Closure SECTION 3: BUILDING INFORMATION 3.1 Building Deputy/Alternate Building Deputy

  7. Logic circuitry used to automatically test shielded cables

    NASA Technical Reports Server (NTRS)

    Dibb, G.

    1966-01-01

    Automatic cable tester checks multiple shielded conductors assembly cable connections. The tester uses logic circuitry to sequentially test all conductors and their shields to reveal any connection error in a GO-NO GO test.

  8. Light shield and cooling apparatus. [high intensity ultraviolet lamp

    NASA Technical Reports Server (NTRS)

    Meador, T. G., Jr. (inventor)

    1974-01-01

    A light shield and cooling apparatus was developed for a high intensity ultraviolet lamp including water and high pressure air for cooling and additional apparatus for shielding the light and suppressing the high pressure air noise.

  9. Antibodies expose multiple weaknesses in the glycan shield of HIV.

    PubMed

    Crispin, Max; Bowden, Thomas A

    2013-07-01

    A shield of glycans coats the viral-envelope proteins of HIV. Recent work shows how broadly neutralizing antibodies can recognize this shield despite structural variation in these ‘self’ carbohydrate structures. PMID:23984441

  10. Shielding analysis of the long length contaminated equipment transportation package

    SciTech Connect

    Nelson, J.V., Westinghouse Hanford

    1996-05-10

    A shielding analysis of a potential long length contaminated equipment transportation package was completed. The analysis was performed to support the design of the transportation package and external shielding.

  11. Safety shield for vacuum/pressure-chamber windows

    NASA Technical Reports Server (NTRS)

    Shimansky, R. A.; Spencer, R.

    1980-01-01

    Optically-clear shatter-resistant safety shield protects workers from implosion and explosion of vacuum and pressure windows. Plastic shield is inexpensive and may be added to vacuum chambers, pressure chambers, and gas-filling systems.

  12. Early test facilities and analytic methods for radiation shielding: Proceedings

    SciTech Connect

    Ingersoll, D.T. (comp.) (Oak Ridge National Lab., TN (United States)); Ingersoll, J.K. (comp.) (Tec-Com, Knoxville, TN (United States))

    1992-11-01

    This report represents a compilation of eight papers presented at the 1992 American Nuclear Society/European Nuclear Society International Meeting. The meeting is of special significance since it commemorates the fiftieth anniversary of the first controlled nuclear chain reaction. The papers contained in this report were presented in a special session organized by the Radiation Protection and Shielding Division in keeping with the historical theme of the meeting. The paper titles are good indicators of their content and are: (1) The origin of radiation shielding research: The Oak Ridge experience, (2) Shielding research at the hanford site, (3) Aircraft shielding experiments at General Dynamics Fort Worth, 1950-1962, (4) Where have the neutrons gone , a history of the tower shielding facility, (5) History and evolution of buildup factors, (6) Early shielding research at Bettis atomic power laboratory, (7) UK reactor shielding: then and now, (8) A very personal view of the development of radiation shielding theory.

  13. Rod-Wall Sound Shield for Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Creel, T. R. J.; Beckwith, I. E.

    1983-01-01

    Test model is shielded from turbulence radiated from wind tunnel walls. Shield overcomes problems caused by leading-edge configuration and leading edge angle of inclination of previous designs. Has successfully maintained a laminar rather than turbulent boundary layer.

  14. 6. View shows Shield 11, looking west. Typical concrete debris ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. View shows Shield 11, looking west. Typical concrete debris shield. - Lake Hodges Flume, Along San Dieguito River between Lake Hodges & San Dieguito Reservoir, Rancho Santa Fe, San Diego County, CA

  15. Beer and Economic Growth Dr. Martin Shields

    E-print Network

    Beer and Economic Growth Dr. Martin Shields Regional Economics Institute Colorado State University #12;The Idea · Regional economic growth depends, in part, on the ability to sell goods and services) ­ Industry employment is 35 times more concentrated in Larimer County than the US average! #12;Economic

  16. Theoretical and Physical Aspects of Nuclear Shielding

    Microsoft Academic Search

    Cynthia J. Jameson; Angel C. De Dios

    1991-01-01

    G General Theory - The relativistic analog of Ramsey's theory of nuclear magnetic shielding has been derived by Pyper' and Pyykko2 but no computed results based on these expressions have been published until re~ently.~ In the latter paper the relativistic corrections are determined by finding the nonrelativisitic limits of various matrix elements of the operators in the relativistic theory. The

  17. Seismic Properties of the Central Indian Shield

    Microsoft Academic Search

    Limei Zhou; Wang-Ping Chen; Serdar Ozalaybey

    2000-01-01

    We use broadband seismic data at Hyderabad to investigate average crustal properties of the central Indian shield. Crustal receiver-functions (P to SV conversions) based on data of excellent quality and azimuthal coverage show essen- tially no signal on the transverse component, indicating laterally homogeneous struc- tures near this station. A joint analysis of receiver-functions and the dispersion of fundamental mode

  18. Fusion reactor blanket\\/shield design study

    Microsoft Academic Search

    D. L. Smith; R. G. Clemmer; S. D. Harkness; J. Jung; J. L. Krazinski; R. F. Mattas; H. C. Stevens; C. K. Youngdahl; C. Trachsel; D. Bowers

    1979-01-01

    A joint study of Tokamak reactor first wall\\/blanket\\/shield technology was conducted to identify key technological limitations for various tritium breeding blanket design concepts, establishment of a basis for assessment and comparison of the design features of each concept, and development of optimized blanket designs. The approach used involved a review of previously proposed blanket designs, analysis of critical technological problems

  19. Understanding space weather to shield society

    E-print Network

    Schrijver, Karel

    Understanding space weather to shield society Improving understanding and forecasts of space weather requires addressing scientific challenges within the network of physical processes that connect the Sun to society. The roadmap team identified the highest-priority areas within the Sun-Earth space-weather

  20. The Tower Shielding Facility: Its glorious past

    SciTech Connect

    Muckenthaler, F.J.

    1997-05-07

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.

  1. Planned Change Request for Shielded Containers

    E-print Network

    of Transportation (DOT) 7A Type A and the Nuclear Regulatory Commission (NRC) Type B drop tests and are awaiting demonstrate that emplacing RH waste in the WIPP using shielded containers will not have a significant impact. The lid and the bottom of the container are made of carbon steel and are 3-in thick. The empty weight

  2. Passive magnetic shielding in static gradient fields

    NASA Astrophysics Data System (ADS)

    Bidinosti, C. P.; Martin, J. W.

    2014-04-01

    The effect of passive magnetic shielding on dc magnetic field gradients imposed by both external and internal sources is studied for two idealized shield models: concentric spherical and infinitely-long cylindrical shells of linear material. It is found that higher-order multipoles of an externally applied magnetic field are always shielded progressively better for either geometry by a factor related to the order of the multipole. In regard to the design of internal coil systems, we determine reaction factors for the general multipole field and provide examples of how one can take advantage of the coupling of the coils to the innermost shell to optimize the uniformity of the field. Furthermore, we provide formulae relevant to active magnetic compensation systems which attempt to stabilize the interior fields by sensing and cancelling the exterior fields close to the outermost shell. Overall this work provides a comprehensive framework that is useful for the analysis and optimization of dc magnetic shields, serving as a theoretical and conceptual design guide as well as a starting point and benchmark for finite-element analysis.

  3. Radiation Shielding Analysis for Deep Space Missions

    Microsoft Academic Search

    Giovanni de Angelis; Martha S. Clowdsley; John E. Nealy; Robert C. Singleterry; Ram K. Tripathi; John W. Wilson

    2003-01-01

    An environment for radiation shielding analysis for manned deep space mission scenarios has been developed. The analysis is performed by dividing a mission scenario into three possible different phases, namely the interplanetary cruise phase, the final planetary approach and orbit insertion, and the surface phase. In the first phase only Galactic Cosmic Rays and Solar Events particles are used, in

  4. Minimizing noise via shield and repeater insertion

    Microsoft Academic Search

    Renatas Jakushokas; Eby G. Friedman

    2009-01-01

    Two techniques, shield and repeater insertion, are simultaneously investigated. Based on resource optimization, the relationship among noise, power, and delay is investigated. Coupling noise as a function of power dissipation is shown to behave parabolically. Due to this parabolic behavior, the minimum noise can be established. The resulting design expressions are compared with SPICE simulations, exhibiting good agreement. A design

  5. PET/CT shielding design comparisons 

    E-print Network

    Coker, Audra Lee

    2007-09-17

    The objective of this project was to compare two different methods of calculating dose through lead-shielded walls in the PET/CT suite at Scott & White Hospital in Temple, Texas. The ultimate goal was to see which of the ...

  6. Radiation Shielding for Manned Deep Space Missions

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    2003-01-01

    The arrival of the Expedition 1 Crew at the International Space Station represents the beginning of the continuous presence of man in space. Already we are deploying astronauts and cosmonauts for missions of approx. 6 months onboard the ISS. In the future we can anticipate that more people will be in space and they will be there for longer periods. Even with 6-months deployments to the ISS, the radiation exposure that crew members receive is approaching the exposure limits imposed by the governments of the space- faring nations. In the future we can expect radiation protection to be a dominant consideration for long manned missions. Recognizing this, NASA has expanded their research program on radiation health. This program has three components, bioastronautics, fundamental biology and radiation shielding materials. Bioastronautics is concerned with the investigating the effects of radiation on humans. Fundamental biology investigates the basic mechanisms of radiation damage to tissue. Radiation shielding materials research focuses on developing accurate computational tools to predict the radiation shielding effectiveness of materials. It also investigates new materials that can be used for spacecraft. The radiation shielding materials program will be described and examples of results from the ongoing research will be shown.

  7. Neutron monitors : self-indication of shielding

    SciTech Connect

    Menlove, Howard O.; Swinhoe, M. T. (Martyn T.)

    2004-01-01

    Neutron monitoring is extensively used in safeguards to detect the passage of nuclear material. In many of these applications neutron monitors are coupled with camera surveillance systems. In addition to recording movement of items of interest, the camera system has also been traditionally used to confirm that no neutron shielding has been placed around the monitors and that therefore they are still effectively monitoring the area. Using cameras for this purpose means that the neutron monitoring system cannot be considered a single layer of containment and surveillance by itself because it needs the camera system to ensure that it is still operational. However, the potential diverter would need to apply a significant amount of shielding to mask the movement of a typical item. This shelding would affect the 'background' counting rate of each neutron monitor, due to cosmic rays or nuclear material in the vicinity. This change in counting rate can be used to determine if shielding has been applied to the monitor. Thus, the neutron monitor provides a self-indication that shielding has been applied and the dependence on the camera data is removed. This paper gives numerical examples for the case of a nuclear material storage area and proposes that neutron monitors can be used as a stand-alone layer for containment and surveillance purposes.

  8. PATH. Gamma Dose Calculations and Shielding Analysis

    SciTech Connect

    Su, S.D.; Baylor, K.J.; Engholm, B.A. [CEGA Corporation, San Diego, CA (United States)

    1988-02-01

    PATH is a highly flexible shielding code utilizing the common point-kernel integration technique primarily for treating gamma radiation from reactors, radioactive components and from complex piping systems. Major features of the code include complex geometry capability, various source options, extensive data library, simple but flexible input and well-organized output format.

  9. DWPF Recycle Evaporator Shielded Cells Testing

    Microsoft Academic Search

    T. L. Fellinger; D. T. Herman; M. E Stone

    2005-01-01

    Testing was performed to determine the feasibility and processing characteristics of evaporation of actual Defense Waste Processing Facility (DWPF) recycle material. Samples of the Off Gas Condensate Tank (OGCT) and Slurry Mix Evaporator Condensate Tank (SMECT) were transferred from DWPF to the Savannah River National Lab (SRNL) Shielded Cells and blended with De-Ionized (DI) water and a small amount of

  10. Radiation shielding calculations for the vista spacecraft

    Microsoft Academic Search

    Sümer ?ahin; Hac? Mehmet ?ahin; Adem Ac?r

    2005-01-01

    The VISTA spacecraft design concept has been proposed for manned or heavy cargo deep space missions beyond earth orbit with inertial fusion energy propulsion. Rocket propulsion is provided by fusion power deposited in the inertial confined fuel pellet debris and with the help of a magnetic nozzle.The calculations for the radiation shielding have been revised under the fact that the

  11. Corrosion protection and EMP/EMI shielding

    SciTech Connect

    Brahney, J.H.

    1990-06-01

    The high-voltage electrical surges which are released from nuclear explosions are called electromagnetic pulses (EMP). Because they can have adverse effects on aircraft and other weapon system electrical circuits, the DOD has evaluated a variety of approaches to providing protection against EMP and electromagnetic interference (EMI). Researchers are now working to develop conductive sealants which can provide corrosion protection while meeting the EMP/EMI shielding requirements of military aircraft and missiles. Test results indicate that shielding effectiveness increases as dc resistance decreases, and shielding effectiveness does not appear to be a strong function of frequency above the 500-1000 MHz test frequency range. The correlations of resistance and shielding effectiveness necessitates that a low resistance exists across a joint or bond. Thus the researchers recommended that the conductive sealants successfully tested be used on existing and future aircraft and missiles where sealants can be liquid-applied. In addition to the test findings and their applications to the operational arena, a primary outcome of these tests is a set of recommended changes to selected military standards, specifications, and handbooks. These recommendations will be used as inputs to any proceedings conducted for the purpose of modifying those documents.

  12. Composite Structures Materials Testing for the Orion Crew Vehicle Heat Shield

    NASA Technical Reports Server (NTRS)

    Khemani, Farah N.

    2011-01-01

    As research is being performed for the new heat shield for the Orion capsule, National Aeronautics and Space Administration (NASA) is developing the first composite heat shield. As an intern of the Structures Branch in the Engineering Directorate (ES 2), my main task was to set up a test plan to determine the material properties of the honeycomb that will be used on the Orion Crew Module heat shield to verify that the composite is suitable for the capsule. Before conducting composite shell tests, which are performed to simulate the crush performance of the heat shield on the capsule, it is necessary to determine the compression and shear properties of the composite used on the shell. During this internship, I was responsible for developing a test plan, designing parts for the test fixtures as well as getting them fabricated for the honeycomb shear and compression testing. This involved work in Pro/Engineer as well as coordinating with Fab Express, the Building 9 Composite Shop and the Structures Test Laboratory (STL). The research and work executed for this project will be used for composite sandwich panel testing in the future as well. As a part of the Structures Branch, my main focus was to research composite structures. This involves system engineering and integration (SE&I) integration, manufacturing, and preliminary testing. The procedures for these projects that were executed during this internship included design work, conducting tests and performing analysis.

  13. BUILDING NAME HEYDON-LAURENCE BUILDING

    E-print Network

    Viglas, Anastasios

    BUILDING NAME HEYDON-LAURENCE BUILDING PHARMACY AND BANK BUILDING JOHN WOOLEY BUILDING OLD TEARCHER'S BUILDING PHYSICS BUILDING BAXTER'S LODGE INSTITUTE BUILDING CONSERVATION WORKS R.D.WATT BUILDING MACLEAY BUILDING THE QUARANGLE BADHAM BUILDING J.D. STEWART BUILDING BLACKBURN BUILDING MADSEN BUILDING STORE

  14. Shielding aspects of D- sup 3 He fusion power reactors

    Microsoft Academic Search

    El-Guebaly

    1992-01-01

    In this paper the implications of the D-³He fuel cycle on shielding design are investigated for tokamak power reactors of the ARIES\\/Apollo class. The prime function of the shield is to protect the superconducting magnets against radiation. A variety of shield options is examined, and the various shields are optimized for the D-³He neutron spectrum. The results demonstrate the relative

  15. Effective shielding to measure beam current from an ion source

    SciTech Connect

    Bayle, H., E-mail: bayle@bergoz.com [Bergoz Instrumentation, Saint-Genis-Pouilly (France); Delferrière, O.; Gobin, R.; Harrault, F.; Marroncle, J.; Senée, F.; Simon, C.; Tuske, O. [CEA, Saclay (France)] [CEA, Saclay (France)

    2014-02-15

    To avoid saturation, beam current transformers must be shielded from solenoid, quad, and RFQ high stray fields. Good understanding of field distribution, shielding materials, and techniques is required. Space availability imposes compact shields along the beam pipe. This paper describes compact effective concatenated magnetic shields for IFMIF-EVEDA LIPAc LEBT and MEBT and for FAIR Proton Linac injector. They protect the ACCT Current Transformers beyond 37 mT radial external fields. Measurements made at Saclay on the SILHI source are presented.

  16. Electromagnetic interference shielding mechanisms of CNT\\/polymer composites

    Microsoft Academic Search

    Mohammed H. Al-Saleh; Uttandaraman Sundararaj

    2009-01-01

    The electromagnetic interference (EMI) shielding mechanisms of multi-walled carbon nanotube (MWCNT)\\/polymer composites were analyzed experimentally and theoretically. For the experimental analysis, EMI shielding effectiveness (SE) of MWCNT\\/polypropylene (PP) composite plates made in three different thicknesses and at four different concentrations were studied. A model based on the shielding of electromagnetic plane wave was used to theoretically study the EMI shielding

  17. Designing dual-plate meteoroid shields: A new analysis

    NASA Technical Reports Server (NTRS)

    Swift, H. F.; Bamford, R.; Chen, R.

    1982-01-01

    Physics governing ultrahigh velocity impacts onto dual-plate meteor armor is discussed. Meteoroid shield design methodologies are considered: failure mechanisms, qualitative features of effective meteoroid shield designs, evaluating/processing meteoroid threat models, and quantitative techniques for optimizing effective meteoroid shield designs. Related investigations are included: use of Kevlar cloth/epoxy panels in meteoroid shields for the Halley's Comet intercept vehicle, mirror exposure dynamics, and evaluation of ion fields produced around the Halley Intercept Mission vehicle by meteoroid impacts.

  18. High-Flux, High-Temperature Thermal Vacuum Qualification Testing of a Solar Receiver Aperture Shield

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.; Mason, Lee S.; Strumpf, Hal J.

    1997-01-01

    As part of the International Space Station (ISS) Phase 1 program, NASA Lewis Research Center (LERC) and the Russian Space Agency (RSA) teamed together to design, build and flight test the world's first orbital Solar Dynamic Power System (SDPS) on the Russian space station Mir. The Solar Dynamic Flight Demonstration (SDFD) program was to operate a nominal 2 kWe SDPS on Mir for a period up to 1-year starting in late 1997. Unfortunately, the SDFD mission was demanifested from the ISS phase 1 shuttle program in early 1996. However, substantial flight hardware and prototypical flight hardware was built including a heat receiver and aperture shield. The aperture shield comprises the front face of the cylindrical cavity heat receiver and is located at the focal plane of the solar concentrator. It is constructed of a stainless steel plate with a 1-m outside diameter, a 0.24-m inside diameter and covered with high-temperature, refractory metal Multi-Foil Insulation (MFI). The aperture shield must minimize heat loss from the receiver cavity, provide a stiff, high strength structure to accommodate shuttle launch loads and protect receiver structures from highly concentrated solar fluxes during concentrator off-pointing events. To satisfy Mir operational safety protocols, the aperture shield was required to accommodate direct impingement of the intensely concentrated solar image for a 1-hour period. To verify thermal-structural durability under the anticipated high-flux, high-temperature loading, an aperture shield test article was constructed and underwent a series of two tests in a large thermal vacuum chamber configured with a reflective, point-focus solar concentrator and a solar simulator. The test article was positioned near the focal plane and exposed to concentrated solar flux for a period of 1-hour. In the first test, a near equilibrium temperature of 1862 K was attained in the center of the shield hot spot. In the second test, with increased incident flux, a near equilibrium temperature of 2072 K was achieved. The aperture shield sustained no visible damage as a result of the exposures. This paper describes the aperture shield thermal-vacuum qualification test program including the test article, test facility, procedures, data collection, test success criteria, results and conclusions.

  19. High-flux, high-temperature thermal vacuum qualification testing of a solar receiver aperture shield

    SciTech Connect

    Kerslake, T.W.; Mason, L.S. [NASA Lewis Research Center, Cleveland, OH (United States); Strumpf, H.J. [AlliedSignal Aerospace Equipment Systems, Torrance, CA (United States)

    1997-12-31

    As part of the International Space Station (ISS) Phase 1 program, NASA Lewis Research Center (LeRC) and the Russian Space Agency (RSA) teamed together to design, build and flight test the world`s first orbital Solar Dynamic Power System (SDPS) on the Russian space station Mir. The Solar Dynamic Flight Demonstration (SDFD) program was to operate a nominal 2 kWe SDPS on Mir for a period up to 1-year starting in late 1997. Unfortunately, the SDFD mission was demanifested from the ISS Phase 1 shuttle program in early 1996. However, substantial flight hardware and prototypical flight hardware was built including a heat receiver and aperture shield. The aperture shield comprises the front face of the cylindrical cavity heat receiver and is located at the focal plane of the solar concentrator. It is constructed of a stainless steel plate with a 1-m outside diameter, a 0.24-m inside diameter and covered with high-temperature, refractory metal multi-foil insulation (MFI). The aperture shield must minimize heat loss from the receiver cavity, provide a stiff, high strength structure to accommodate shuttle launch loads and protect receiver structures from highly concentrated solar fluxes during concentrator off-pointing events. To satisfy Mir operational safety protocols, the aperture shield was required to accommodate direct impingement of the intensely concentrated solar image for a 1-hour period. To verify thermal-structural durability under the anticipated high-flux, high-temperature loading, an aperture shield test article was constructed and underwent a series of two tests in a large thermal vacuum chamber configured with a reflective, point-focus solar concentrator and a solar simulator. The test article was positioned near the focal plane and exposed to concentrated solar flux for a period of 1-hour. In the first test, a near equilibrium temperature of 1862 K was attained in the center of the shield hot spot. In the second test, with increased incident flux, a near equilibrium temperature of 2072 K was achieved. The aperture shield sustained no visible damage as a result of the exposures. This paper describes the aperture shield thermal-vacuum qualification test program including the test article, test facility, procedures, data collection, test success criteria, results and conclusions.

  20. Influence of whole body irradiation and local shielding on matrix-induced endochondral bone differentiation

    SciTech Connect

    Wientroub, S.; Weiss, J.F.; Catravas, G.N.; Reddi, A.H. (National Institute of Dental Research, Bethesda, MD (USA))

    1990-01-01

    Subcutaneous implantation of demineralized bone matrix into allogeneic rats induces endochondral bone formation. We have investigated the effects of irradiation on the sequelae of the interaction of collagenous matrix and mesenchymal cells and on cartilage and bone differentiation. Rats were irradiated in a vertical direction with a midline dose of 850 rad. Radiation entered the rats ventrally while a small area of the upper thorax was locally shielded. After irradiation, bone matrix was implanted in shielded and nonshielded sites, and the implants were studied at various stages. On day 3, (3H)thymidine incorporation, an index of cell proliferation, was inhibited by 70% in the nonshielded sites compared to nonirradiated control rats. The degree of inhibition (35%) was less pronounced in shielded sites. Furthermore, there was recovery of cell proliferation in the shielded sites as opposed to the nonshielded contralateral site. A similar pattern was observed on day 7 as assessed by 35SO4 incorporation into proteoglycans during chondrogenesis. Bone formation and mineralization were quantified on day 11 by alkaline phosphatase activity and 45Ca incorporation. In nonshielded sites, there was a 73% inhibition of alkaline phosphatase activity. In conclusion, radiation impaired progenitor cell proliferation which resulted in decreased cartilage and bone differentiation. These findings imply that local mesenchymal cells proliferate and differentiate into bone in response to implanted collagenous matrix.

  1. (TWST = Tri-Cities West Building) West Building

    E-print Network

    Collins, Gary S.

    Elevator (TWST = Tri-Cities West Building) West Building 1st Floor Stage to parking lot Nursing TV Receiving Engineering Lab Viticulture & Enology/Sciences Elevator Facilities Shower Eyewash Station Fire Extinguisher First Aid Kit Automatic External Defibrillator 127 125 110 140 #12;Atrium Conference Room Main

  2. SURFACE FLUXES AND CURRENTS FOR VARIOUS SHIELDED RADIATION SOURCES

    Microsoft Academic Search

    E. R. Cohen; F. B. Estabrook

    1957-01-01

    The flux and current of radiation at the surface of shielded sources are ; calculated as a function of source radius and shield thickness. Curves are ; presented for source radius (or half-thickness) from 0 to 20 mean-freepaths and ; for shield thickness from 0 to 20 mean-free-paths for plane, cylindrical, and ; slab geometries. The curves are particularly useful

  3. Analytical formulation for the shielding effectiveness of enclosures with apertures

    Microsoft Academic Search

    Martin Paul Robinson; Trevor M. Benson; Christos Christopoulos; John F. Dawson; M. D. Ganley; A. C. Marvin; S. J. Porter; David W. P. Thomas

    1998-01-01

    An analytical formulation has been developed for the shielding effectiveness of a rectangular enclosure with an aperture. Both the magnetic and electric shielding may be calculated as a function of frequency, enclosure dimensions, aperture dimensions and position within the enclosure. Theoretical values of shielding effectiveness are in good agreement with measurements. The theory has been extended to account for circular

  4. Prediction of effective atomic number (Z) for laminated shielding material 

    E-print Network

    Sarder, Md. Maksudur Rahaman

    1999-01-01

    material followed by low Z material using the Monte Carlo code, MCNP. In this study, the shielding materials water, iron, and lead were used in various combinations as multi-layer shielding for buildup factor calculation. For the multi-layered shields...

  5. SHIELDING STUDIES FOR THE MUON COLLIDER TARGET NICHOLAS SOUCHLAS

    E-print Network

    McDonald, Kirk

    SHIELDING STUDIES FOR THE MUON COLLIDER TARGET NICHOLAS SOUCHLAS BNL Nov 30, 2010 1 #12;MUON. SHIELDING CONFIGURATIONS (WC BEADS+H2O). 2 #12;REQUIREMENTS/LIMITATIONS PROTON BEAM AND MERCURY JET. :SPACE FOR SHIELDING MATERIAL IS LIMITED. CHOOSE A CONFIGURATION/GEOMETRY THAT HAS THE RIGHT BALANCE

  6. 16 CFR 1511.3 - Guard or shield requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Guard or shield requirements. 1511.3 Section 1511...FOR PACIFIERS § 1511.3 Guard or shield requirements. (a) Performance requirements...pacifiers with non-circular guards or shields, align the major axis of the guard...

  7. An update on the middle levels problem Ian Shields

    E-print Network

    Savage, Carla D.

    An update on the middle levels problem Ian Shields IBM, P.O. Box 12195, Research Triangle Park, North Carolina 27709, USA Brendan J. Shields Department of Physics, Massachusetts Institute- Corresponding author. Email addresses: ishields@us.ibm.com (Ian Shields), bshields@fas.harvard.edu (Brendan J

  8. Effects of Dynamics and Environment on 15 N Chemical Shielding

    E-print Network

    Skrynnikov, Nikolai

    Effects of Dynamics and Environment on 15 N Chemical Shielding Anisotropy in Proteins of nuclear spin relaxation data of biomolecules often requires the accurate knowledge of chemical shielding of chemical shielding anisotropy (CSA) tensors is important in the context of biomolecular applications

  9. SHIELD: A Fault-Tolerant MPI for an Infiniband Cluster

    E-print Network

    Yeom, Heon Young

    SHIELD: A Fault-Tolerant MPI for an Infiniband Cluster Hyuck Han, Hyungsoo Jung, Jai Wug Kim, a successful solution has yet to be delivered to commercial vendors. This paper presents SHIELD, a prac- tical and easily-deployable fault-tolerant MPI and management system of MPI for an Infiniband cluster. SHIELD

  10. LARGE-VOLUME CONVENTIONAL MAGNETIC SHIELDS By D. COHEN,

    E-print Network

    Boyer, Edmond

    53. LARGE-VOLUME CONVENTIONAL MAGNETIC SHIELDS By D. COHEN, Massachusetts Institute of Technology resulted in the construction of many magnetically-shielded walk-in rooms. Most have been of the cubic, two of the magnetic sheets. The shielding characteristics and performance of this room were measured in some detail

  11. Chicane shielding and energy deposition (IPAC'13 followup)

    E-print Network

    McDonald, Kirk

    Chicane shielding and energy deposition (IPAC'13 followup) Pavel Snopok IDSNF phone meetingIDS NF. Radius = 4353 cm, length of 18 cm, onaxis field 1.5 T throughout the channel. · Cyan: W shielding (pure W need to change the density to 60%) 4 cm thickness @· Cyan: W shielding (pure W, need to change

  12. 16 CFR 1511.3 - Guard or shield requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Guard or shield requirements. 1511.3 Section 1511...FOR PACIFIERS § 1511.3 Guard or shield requirements. (a) Performance requirements...pacifiers with non-circular guards or shields, align the major axis of the guard...

  13. OPTIMAL MAGNETIC SHIELD DESIGN WITH SECOND-ORDER CONE PROGRAMMING

    E-print Network

    Tsuchiya, Takashi

    OPTIMAL MAGNETIC SHIELD DESIGN WITH SECOND-ORDER CONE PROGRAMMING TAKASHI SASAKAWA AND TAKASHI-dual interior-point algorithms have been developed recently. An optimal magnetic shielding design problem efficiency and stability, we further apply the algorithm to robust design of the magnetic shielding. Key

  14. 16 CFR 1511.3 - Guard or shield requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Guard or shield requirements. 1511.3 Section 1511...FOR PACIFIERS § 1511.3 Guard or shield requirements. (a) Performance requirements...pacifiers with non-circular guards or shields, align the major axis of the guard...

  15. Simultaneous Shield Insertion and Net Ordering for Capacitive and Inductive

    E-print Network

    He, Lei

    Simultaneous Shield Insertion and Net Ordering for Capacitive and Inductive Coupling Minimization of inductive noise, and shield insertion is needed to minimize inductive noise. Using a Keff model as the figure of merit for inductive coupling, we then formulate two simultaneous shield insertion and net

  16. Simultaneous Shield Insertion and Net Ordering for Capacitive and

    E-print Network

    He, Lei

    Simultaneous Shield Insertion and Net Ordering for Capacitive and Inductive Coupling Minimization Outline 1. Previous net ordering and shielding work 2. SINO problem formulations 3. SINO problem. Lepak, University of Wisconsin n Noise avoidance techniques: n Net ordering n Shield insertion

  17. Argumentation Logic to Assist in Security Administration One Shields Ave

    E-print Network

    California at Davis, University of

    Argumentation Logic to Assist in Security Administration Jeff Rowe UC Davis One Shields Ave Davis, CA 95616 rowe@cs.ucdavis.edu Karl Levitt UC Davis One Shields Ave Davis, CA 95616 levitt@sci.brooklyn.cuny.edu Andrew Applebaum UC Davis One Shields Ave Davis, CA 95616 applebau@ucdavis.edu Sharmin Jalal UC Davis One

  18. SHIELDING AREA OPTIMIZATION UNDER THE SOLUTION OF INTERCONNECT CROSSTALK1

    E-print Network

    He, Lei

    SHIELDING AREA OPTIMIZATION UNDER THE SOLUTION OF INTERCONNECT CROSSTALK1 1 This paper is supported integrity. Simultaneous shield insertion and net ordering (SINO) has been shown to be effective to reduce both capacitive and inductive coupling. Although shield insertion could reduce crosstalk efficiently

  19. BABAR SVT Data Transmission System Grounding and Shielding Implementation

    E-print Network

    California at Santa Cruz, University of

    , and ABORT modules). a) Assembly_com Within one Mux module, the DAQ Link Card and HDI Link ground planes boards is called ``Assembly_com''. Without jumpers, it does not extend beyond the module. b) Power and Signal cable shields All cable shields within a module are tied to Assembly_com. Cable shields

  20. Three dimensional hypervelocity impact simulation for orbital debris shield design

    Microsoft Academic Search

    Justin H. Kerr; Eric P. Fahrenthold

    1997-01-01

    This paper assesses a Whipple shield impact simulation method which is both accurate and computationally efficient. The paper documents the simulation methodology and results of Whipple shield simulations at an oblique impact angle of 30°. These results are compared with HVI experiments to demonstrate the accuracy of the simulation technique. In addition, simulations of Whipple shields in the velocity regime

  1. VIEW OF BUILDING 440 LOOKING WEST, NORTHWEST. BUILDING 440, THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF BUILDING 440 LOOKING WEST, NORTHWEST. BUILDING 440, THE TRANSPORT MODIFICATION CENTER, CONSISTS OF FOUR HIGH-BAY CORRUGATED METAL STRUCTURES. BUILDING 440 WAS USED FOR PACKAGING AND STAGING SPECIAL NUCLEAR MATERIALS AND DEPLETED URANIUM FOR SHIPMENT AND TO MODIFY VEHICLES TO MEET SPECIFIC UNITED STATES DEPARTMENT OF ENERGY REQUIREMENTS. (2/8/84) - Rocky Flats Plant, Transport Modification Center, North of Cactus Avenue, approximately 400 feet east of Third Street, Golden, Jefferson County, CO

  2. Building the Best Auditorium

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2008-01-01

    Building a quality auditorium has never come at a cheap price. In today's economy, a $750,000 minimum price tag just for sound, lighting, stage rigging and seats can be exorbitant. However, schools that have built new auditoriums or upgraded existing ones in the past decade say the investment is worth every penny. This article discusses the…

  3. Computational Building Requirements Specification 1

    Microsoft Academic Search

    Ömer Akin; Michael Cumming; Magd Donia; Rana Sen; Ye Zhang

    We have been exploring appropriate computational techniques to help building designers specify design requirements during the early stages of design. SEED-Pro (the architectural programming module of SEED -- Software Environment to Support Early Phases in Building Design), is a working prototype for building design requirements specification. The core functionalities of SEED-Pro operate in an interactive mode relying on a case-based

  4. Simultaneous Shield Insertion and Net Ordering for Capacitive and Inductive Coupling Minimization

    E-print Network

    He, Lei

    are no longer valid with presence of inductive noise, and shield insertion is needed to minimize inductive noise there are no shielding wires (in short, shields), the noise in the quiet victims is 0.71V. As we insert one shield simultaneous shield insertion and net ordering (SINO). # of Shields Noise (% of Vdd) Ki of victims 0 0.71V (55

  5. Passive Superconducting Shielding: Experimental Results and Computer Models

    NASA Technical Reports Server (NTRS)

    Warner, Brent; Kamiya, Koki

    2003-01-01

    Passive superconducting shielding for magnetic refrigerators has advantages over active shielding and passive ferromagnetic shielding in that it is lightweight and easy to construct. However, it is not as easy to model and does not fail gracefully. Failure of a passive superconducting shield may lead to persistent flwc and persistent currents. Unfortunately, modeling software for superconducting materials is not as easily available as is software for simple coils or for ferromagnetic materials. This paper will discuss ways of using available software to model passive superconducting shielding.

  6. Passive Superconducting Shielding: Experimental Results and Computer Models

    NASA Technical Reports Server (NTRS)

    Warner, B. A.; Kamiya, K.

    2003-01-01

    Passive superconducting shielding for magnetic refrigerators has advantages over active shielding and passive ferromagnetic shielding in that it is lightweight and easy to construct. However, it is not as easy to model and does not fail gracefully. Failure of a passive superconducting shield may lead to persistent flux and persistent currents. Unfortunately, modeling software for superconducting materials is not as easily available as is software for simple coils or for ferromagnetic materials. This paper will discuss ways of using available software to model passive superconducting shielding.

  7. Potential Polymeric Sphere Construction Materials for a Spacecraft Electrostatic Shield

    NASA Technical Reports Server (NTRS)

    Smith, Joseph G., Jr.; Smith, Trent; Williams, Martha; Youngquist, Robert; Mendell, Wendell

    2006-01-01

    An electrostatic shielding concept for spacecraft radiation protection under NASA s Exploration Systems Research and Technology Program was evaluated for its effectiveness and feasibility. The proposed shield design is reminiscent of a classic quadrupole with positively and negatively charged spheres surrounding the spacecraft. The project addressed materials, shield configuration, power supply, and compared its effectiveness to that of a passive shield. The report herein concerns the identification of commercially available materials that could be used in sphere fabrication. It was found that several materials were needed to potentially construct the spheres for an electrostatic shield operating at 300 MV.

  8. BUILDING INSPECTION Building, Infrastructure, Transportation

    E-print Network

    BUILDING INSPECTION Building, Infrastructure, Transportation City of Redwood City 1017 Middlefield Sacramento, Ca 95814-5514 Re: Green Building Ordinance and the Building Energy Efficiency Standards Per of Redwood City enforce the current Title 24 Building Energy Efficiency Standards as part

  9. Structural and Radiation Shielding Properties of a Martian Habitat Material Synthesized From In-Situ Resources

    NASA Technical Reports Server (NTRS)

    Sen, S.; Caranza, S.; Bhattacharya, M.; Makel, D. B.

    2006-01-01

    The 2 primary requirements of a Martian habitat structure include sufficient structural integrity and effective radiation shielding. In addition, the capability to synthesize such building materials primarily from in-situ resources would significantly reduce the cost associated with transportation of such materials and structures from earth. To demonstrate the feasibility of such an approach we have fabricated samples in the laboratory using simulated in-situ resources, evaluated radiation shielding effectiveness using radiation transport codes and radiation test data, and conducted mechanical properties testing. In this paper we will present experimental results that demonstrate the synthesis of polyethylene from a simulated Martian atmosphere and the fabrication of a composite material using simulated Martian regolith with polyethylene as the binding material. Results from radiation transport calculations and data from laboratory radiation testing using a 500 MeV/nucleon Fe beam will be discussed. Mechanical properties of the proposed composite as a function of composition and processing parameters will also be presented.

  10. Electronically shielded solid state charged particle detector

    DOEpatents

    Balmer, D.K.; Haverty, T.W.; Nordin, C.W.; Tyree, W.H.

    1996-08-20

    An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite. 1 fig.

  11. Update on the tevatron muon shield

    SciTech Connect

    Malensek, A.; Stutte, L.

    1986-09-15

    In 1984, the dichromatic train was installed for an initial set of tests. Along with these tests of train performance, measurements of muon rates at various depths in the berm were taken in order to check Monte Carlo predictions. Data were taken at a range of train momentum settings, and from a bare target. The results of those studies are presented here and compared to predictions. In 1985, the quadrupole triplet train was installed for a wide band neutrino run. During this run, 5.5 m of 1.8 m diameter lead was installed at the request of the experimenters to harden the shield. Data obtained during this triplet run under a variety of conditions are also presented, and compared to Monte Carlo predictions. Finally, these results are used to determine how much additional shielding is needed for higher energy operation.

  12. Connecting the Dots: Lander, Heat Shield, Parachute

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This enhanced-color image from Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera shows the Phoenix landing area viewed from orbit. The spacecraft appears more blue than it would in reality. From top to bottom are the Phoenix lander with its solar panels deployed on the Martian surface, the heat shield and bounce mark the heat shield made on the Martian surface, and the top of the Phoenix parachute attached to the bottom of the back shell.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. Analytic Ballistic Performance Model of Whipple Shields

    NASA Technical Reports Server (NTRS)

    Miller, J. E.; Bjorkman, M. D.; Christiansen, E. L.; Ryan, S. J.

    2014-01-01

    The dual-wall Whipple shield is the shield of choice for lightweight, long-duration flight. The shield uses an initial sacrificial wall to initiate fragmentation and melt an impacting threat that expands over a void before hitting a subsequent shield wall of a critical component. The key parameters to this type of shield are the rear wall and its mass which stops the debris, as well as the minimum pressure generated under threat particle impact of the sacrificial wall and the amount of void that is available for expansion. Ensuring the minimum pressure is sufficiently high to achieve large scale fragmentation/melt of the threat particle enables the expansion of the threat and reduces the momentum flux of the debris on the rear wall. Three key factors in the minimum pressure achieved are the thickness of the sacrificial wall relative to the characteristic dimension of the impacting particle, the density and material cohesion contrast of the sacrificial wall relative to the threat particle and the impact speed. The mass of the rear wall and the sacrificial wall are desirable to minimize for launch costs and dynamic concerns making it important to have an understanding of the effects of density contrast and impact speed. In this paper a fourth key parameter is identified related to fragmentation, which corresponds to the ratio of the size of the projectile relative to the transition from brittle to ductile hole growth in the projectile. Ballistic limit equations have been developed to define the failure limits of a MMOD shield, generally in terms of projectile diameter (or mass), impact velocity, and angle. Within the range of impact velocities relevant for Earth-orbiting spacecraft, three distinct regions of penetration phenomenology have been identified for Whipple shields: center dot Low velocity: the projectile is eroded (and possibly deformed) during its passage through the bumper plate, but is not fragmented. Thus, perforation of the rear wall is by a fragment with a mass and speed equal to or less than the original impactor. center dot Intermediate (shatter) velocity: impact velocities are sufficient to induce projectile fragmentation upon impact with the bumper plate, resulting in a coarse debris cloud with large solid fragments. Increasing velocity within the shatter regime results in increased fragmentation, and eventually melting, of the projectile and bumper fragments, generating a finer and more evenly dispersed debris cloud. Failure of the rear wall is a complicated combination of modes observed at low- and hypervelocity. center dot Hypervelocity: the projectile and holed-out bumper material is completely, or nearly completely, melted and/or vaporized by the initial impact. The resultant debris cloud impacts over a dispersed area of the rear wall, loading it impulsively and inducing failure through rupture or petalling. While each of these regimes are well observed with extensive empirical methods to describe these regions, differences in impactor materials, configurations of shields and questions about the limitations of the attainable impact speeds have left questions that are difficult to answer from completely empirical methods.

  14. Bremsstrahlung converter debris shields: test and analysis

    Microsoft Academic Search

    E. D. Jr. Reedy; F. C. Perry

    1983-01-01

    Electron beam accelerators are commonly used to create bremsstrahlung x-rays for effects testing. Typically, the incident electron beam strikes a sandwich of three materials: (1) a conversion foil, (2) an electron scavenger, and (3) a debris shield. Several laboratories, including Sandia National Laboratories, are developing bremsstrahlung x-ray sources with much larger test areas (approx. 200 to 500 cm²) than ever

  15. The impedance of rf-shielding wires

    SciTech Connect

    Wang, T-S F.; Gluckstern, R.L.

    1999-03-29

    The authors studied the electrostatic fields due to the longitudinal and transverse perturbations of a charged particle beam with a uniform distribution propagating inside an rf-shielding cage constructed from evenly-spaced conducting wires. The beam and the rf-cage are surrounded by a concentric conducting beam pipe. Simple formulae are derived for estimating the space-charge impedances Numerical examples are given.

  16. Shielded serpentine traveling wave tube deflection structure

    DOEpatents

    Hudson, C.L.; Spector, J.

    1994-12-27

    A shielded serpentine slow wave deflection structure is disclosed having a serpentine signal conductor within a channel groove. The channel groove is formed by a serpentine channel in a trough plate and a ground plane. The serpentine signal conductor is supported at its ends by coaxial feed through connectors. A beam interaction trough intersects the channel groove to form a plurality of beam interaction regions wherein an electron beam may be deflected relative to the serpentine signal conductor. 4 figures.

  17. SQUID holder with high magnetic shielding

    NASA Technical Reports Server (NTRS)

    Rigby, K. W.; Marek, D.; Chui, T. C. P.

    1990-01-01

    A SQUID holder designed for high magnetic shielding is discussed. It is shown how to estimate the attenuation of the magnetic field from the normal magnetic modes for an approximate geometry. The estimate agrees satisfactorily with the attenuation measured with a commercial RF SQUID installed in the holder. The holder attenuates external magnetic fields by more than 10 to the 9th at the SQUID input. With the SQUID input shorted, the response to external fields is 0.00001 Phi(0)/G.

  18. Enrichment Determination of Uranium in Shielded Configurations

    SciTech Connect

    Crye, Jason Michael [ORNL] [ORNL; Hall, Howard L [ORNL] [ORNL; McConchie, Seth M [ORNL] [ORNL; Mihalczo, John T [ORNL] [ORNL; Pena, Kirsten E [ORNL] [ORNL

    2011-01-01

    The determination of the enrichment of uranium is required in many safeguards and security applications. Typical methods of determining the enrichment rely on detecting the 186 keV gamma ray emitted by {sup 235}U. In some applications, the uranium is surrounded by external shields, and removal of the shields is undesirable. In these situations, methods relying on the detection of the 186 keV gamma fail because the gamma ray is shielded easily. Oak Ridge National Laboratory (ORNL) has previously measured the enrichment of shielded uranium metal using active neutron interrogation. The method consists of measuring the time distribution of fast neutrons from induced fissions with large plastic scintillator detectors. To determine the enrichment, the measurements are compared to a calibration surface that is created from Monte Carlo simulations where the enrichment in the models is varied. In previous measurements, the geometry was always known. ORNL is extending this method to situations where the geometry and materials present are not known in advance. In the new method, the interrogating neutrons are both time and directionally tagged, and an array of small plastic scintillators measures the uncollided interrogating neutrons. Therefore, the attenuation through the item along many different paths is known. By applying image reconstruction techniques, an image of the item is created which shows the position-dependent attenuation. The image permits estimating the geometry and materials present, and these estimates are used as input for the Monte Carlo simulations. As before, simulations predict the time distribution of induced fission neutrons for different enrichments. Matching the measured time distribution to the closest prediction from the simulations provides an estimate of the enrichment. This presentation discusses the method and provides results from recent simulations that show the importance of knowing the geometry and materials from the imaging system.

  19. High purity silica reflective heat shield development

    NASA Technical Reports Server (NTRS)

    Blome, J. C.; Drennan, D. N.; Schmitt, R. J.

    1974-01-01

    Measurements were made of reflectance in the vacuum ultraviolet down to 0.15 micron. Scattering coefficients (S) and absorption coefficients (K) were also measured. These coefficients express the optical properties and are used directly in a thermodynamic analysis for sizing a heat shield. The effect of the thin silica melt layer formed during entry was also studied from the standpoint of trapped radiant energy.

  20. Shielding analysis and design of the KIPT experimental neutron source facility of Ukraine.

    SciTech Connect

    Zhong, Z.; Gohar, M. Y. A.; Naberezhnev, D.; Duo, J.; Nuclear Engineering Division

    2008-10-31

    Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility based on the use of an electron accelerator driven subcritical (ADS) facility [1]. The facility uses the existing electron accelerators of KIPT in Ukraine. The neutron source of the sub-critical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The electron beam has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Reactor physics experiments and material performance characterization will also be carried out. The subcritical assembly is driven by neutrons generated by the electron beam interactions with the target material. A fraction of these neutrons has an energy above 50 MeV generated through the photo nuclear interactions. This neutron fraction is very small and it has an insignificant contribution to the subcritical assembly performance. However, these high energy neutrons are difficult to shield and they can be slowed down only through the inelastic scattering with heavy isotopes. Therefore the shielding design of this facility is more challenging relative to fission reactors. To attenuate these high energy neutrons, heavy metals (tungsten, iron, etc.) should be used. To reduce the construction cost, heavy concrete with 4.8 g/cm{sup 3} density is selected as a shielding material. The iron weight fraction in this concrete is about 0.6. The shape and thickness of the heavy concrete shield are defined to reduce the biological dose equivalent outside the shield to an acceptable level during operation. At the same time, special attention was give to reduce the total shield mass to reduce the construction cost. The shield design is configured to maintain the biological dose equivalent during operation {le} 0.5 mrem/h inside the subcritical hall, which is five times less than the allowable dose for working forty hours per week for 50 weeks per year. This study analyzed and designed the thickness and the shape of the radial and top shields of the neutron source based on the biological dose equivalent requirements inside the subcritical hall during operation. The Monte Carlo code MCNPX is selected because of its capabilities for transporting electrons, photons, and neutrons. Mesh based weight windows variance reduction technique is utilized to estimate the biological dose outside the shield with good statistics. A significant effort dedicated to the accurate prediction of the biological dose equivalent outside the shield boundary as a function of the shield thickness without geometrical approximations or material homogenization. The building wall was designed with ordinary concrete to reduce the biological dose equivalent to the public with a safety factor in the range of 5 to 20.

  1. Shielded silicon gate complementary MOS integrated circuit.

    NASA Technical Reports Server (NTRS)

    Lin, H. C.; Halsor, J. L.; Hayes, P. J.

    1972-01-01

    An electrostatic shield for complementary MOS integrated circuits was developed to minimize the adverse effects of stray electric fields created by the potentials in the metal interconnections. The process is compatible with silicon gate technology. N-doped polycrystalline silicon was used for all the gates and the shield. The effectiveness of the shield was demonstrated by constructing a special field plate over certain transistors. The threshold voltages obtained on an oriented silicon substrate ranged from 1.5 to 3 V for either channel. Integrated inverters performed satisfactorily from 3 to 15 V, limited at the low end by the threshold voltages and at the high end by the drain breakdown voltage of the n-channel transistors. The stability of the new structure with an n-doped silicon gate as measured by the shift in C-V curve under 200 C plus or minus 20 V temperature-bias conditions was better than conventional aluminum gate or p-doped silicon gate devices, presumably due to the doping of gate oxide with phosphorous.

  2. Atlas Breached Waste Package and Drip Shield Experiments: Breached Drip Shield Tests

    SciTech Connect

    Z. P. Walton

    2003-05-28

    The Engineered Barrier System (EBS) represents one system in the performance of the Yucca Mountain high-level radioactive waste (HLW) repository to isolate and prevent the transport of radionuclides from the site to the accessible environment. Breached Waste Package and Drip Shield Experiments (BWPDSE) were performed at the Department of Energy's National Nuclear Security Administration Nevada Support Facility in North Las Vegas, NV in the A-1 lowbay between May 2, 2002 and July 25, 2002. Data collected from the BWPDSE will be used to support the flux splitting model used in Analysis and Modeling Report ANL-WIS-PA-000001 REV 00 ICN 03 ''EBS Radionuclide Transport Abstraction'' (BSC 2001a). Tests were conducted by dripping water from heights representing the drift crown or wall on a full-scale section of a drip shield with both smooth and rough surfaces. The drip shields had machined square breaches that represent the general corrosion breaches or nodes in the ''WAPDEG Analysis of Waste Package and Drip Shield Degradation'' AMR (CRWMS M&O 2000d). Tests conducted during the BWPDSE included: initial tests to determine the splash radius distances and spread factor from the line of drip impact, single patch tests to determine the amount of water collected in target breaches from splashing or rivulet flow, multiple patch tests to determine the amount of water collected in several breaches from both splashing and rivulet flow, and bounding flow rate tests. Supplemental data were collected to provide additional information for rivulet spread, pan evaporation in the test chamber, and water temperatures of the input water and drip shield surface water. The primary flow mechanism observed on both smooth and rough surfaces was rivulet flow, not film flow. Lateral rivulet spread distances were, in general, wider on the smooth drip shield surface than on the rough drip shield surface. There were substantial differences between the mechanisms of rivulet formation and movement on smooth and rough drip shield surfaces. Water collected in breaches was a function of the location of drip impact upstream from the target breach, i.e., impact breaches must be directly above or slightly to the side of the breaches in order for a substantial volume of water to collect in breaches. Splash droplets contributed a small portion of the water collected in breaches. Mass balances showed that evaporation from the drip shield was a large component of water loss. This was particularly manifested during low flow runs of the bounding flow rate tests where test duration was around five hours.

  3. Lava Cones and Shields on Intermediate-Rate Mid-Ocean Ridges

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Paduan, J. B.; Caress, D. W.

    2014-12-01

    Most eruptions of basalt along mid-ocean ridges produce either sheet flows or pillow mounds and ridges. Rare eruptions on the Juan de Fuca and Gorda Ridges and on the Alarcon Rise (northern East Pacific Rise) produce volcanic cones or shields from point sources. Bathymetric maps at 1-m resolution from an autonomous underwater vehicle enabled classification of these ~circular features. The most common are 290-510m across and <50m tall cones with craters or tumulus-like inflated flows on their summits. There are 8 of these on the upper south rift, caldera floor, and southwest caldera rim on Axial Seamount; one on North Cleft segment near the 1986 pillow mounds; and one in the axial graben on northern Endeavour Segment. Hundreds of smaller pillow mounds lack craters or tumulus-like inflated flows at their summits. Three 660-1300m across circular cones have either a crater or an inflated tumulus-like structure at their flat to slightly domed summits. One in the axial graben on the northern Endeavour Segment is dissected by extensional faulting. Cage Seamount on the Coaxial Segment south of the 1993 pillow ridge is the most voluminous at 1100m across and >200m tall. Two flat-topped cones are located near the center of Alarcon Rise. A low-relief shield volcano on the northern Alarcon Rise is ~1700m across and only ~45m tall, and is cut by numerous faults and fissures. Two other shields, 860m and 1700m across and 50-70m tall, occur south of the 1996 North Gorda pillow mounds. These shields are decorated with small pillow mounds. Five 100-250m across and 15-30m deep pits collapsed on the northern shield. These constructional cones and shields form during eruptions where the initial fissure consolidated to a point, indicative of long duration activity. They are constructed during uncommon eruptions with flux larger than produces pillow mounds and smaller than produces sheet flows. They are a submarine equivalent of subaerial shield-building eruptions.

  4. Gravity anomalies of the Northern Hawaiian Islands: Implications on the shield evolutions of Kauai and Niihau

    NASA Astrophysics Data System (ADS)

    Flinders, Ashton F.; Ito, Garrett; Garcia, Michael O.

    2010-08-01

    New land and marine gravity data reveal two positive residual gravity anomalies in the Northern Hawaiian Islands: one over Kaua'i, the other between the islands of Kaua'i and Ni'ihau. These gravitational highs are similar in size and magnitude to those of other Hawaiian volcanoes, indicating local zones of high-density crust, attributed to olivine cumulates in solidified magma reservoirs. The residual gravity high over Kaua'i is located in the L?hu'e Basin, offset 8-12 km east of Kaua'i's geologically mapped caldera. This offset suggests that the mapped caldera is a collapsed feature later filled in with lava and not the long-term center of Kaua'i shield volcanism. A second residual gravity high, in the submarine channel between Kaua'i and Ni'ihau, marks the volcanic center of the Ni'ihau shield volcano. This second residual gravity anomaly implies that Ni'ihau's eastern boundary extended ˜20 km east of its present location. Through inversion, the residual gravity anomalies were modeled as being produced by two solidified magma reservoirs with average densities of 3100 kg/m3 and volumes between 2470 and 2540 km3. Considering the locations and sizes of the residual gravity anomalies/magma reservoirs, the extent of the two islands' paleoshorelines and potassium-argon dating of shield-stage lavas, we conclude that the two islands were not connected subaerially during their respective shield stages and that Ni'ihau's topographic summit was removed by an eastern flank collapse between 4.3 and 5.6 Ma. Continued constructional volcanism on western Kaua'i likely covered much of the submerged remains of eastern Ni'ihau.

  5. Preventing Accidental Ignition of Upper-Stage Rocket Motors

    NASA Technical Reports Server (NTRS)

    Hickman, John; Morgan, Herbert; Cooper, Michael; Murbach, Marcus

    2005-01-01

    A report presents a proposal to reduce the risk of accidental ignition of certain upper-stage rocket motors or other high energy hazardous systems. At present, mechanically in-line initiators are used for initiation of many rocket motors and/or other high-energy hazardous systems. Electrical shorts and/or mechanical barriers, which are the basic safety devices in such systems, are typically removed as part of final arming or pad preparations while personnel are present. At this time, static discharge, test equipment malfunction, or incorrect arming techniques can cause premature firing. The proposal calls for a modular out-of-line ignition system incorporating detonating-cord elements, identified as the donor and the acceptor, separated by an air gap. In the safe configuration, the gap would be sealed with two shields, which would prevent an accidental firing of the donor from igniting the system. The shields would be removed to enable normal firing, in which shrapnel generated by the donor would reliably ignite the acceptor to continue the ordnance train. The acceptor would then ignite a through bulkhead initiator (or other similar device), which would ignite the motor or high-energy system. One shield would be remotely operated and would be moved to the armed position when a launch was imminent or conversely returned to the safe position if the launch were postponed. In the event of failure of the remotely operated shield, the other shield could be inserted manually to safe the system.

  6. Energy efficient buildings: A world of possibilities

    Microsoft Academic Search

    Kuliasha

    1991-01-01

    Throughout the world, buildings are a major energy consumer. However, it can be shown that buildings that save from 30 to 50% over common practice can be built using available technologies while actually increasing occupant comfort and functionality. In addition, many technologies are in the development stage that promise even further increases in energy efficiency in buildings. This paper reviews

  7. Esophageal Cancer Staging

    PubMed Central

    Rice, Thomas W.

    2015-01-01

    Accurate staging of esophageal cancer is very important to achieving optimal treatment outcomes. The AJCC (American Joint Committee on Cancer) first published TNM esophageal cancer staging recommendations in the first edition of their staging manual in 1977. Thereafter, the staging of esophageal cancer was changed many times over the years. This article reviews the current status of staging of esophageal cancer. PMID:26078921

  8. Staging of neoplasms

    SciTech Connect

    Glazer, G.M.

    1986-01-01

    This book contains 10 chapters and 10 case studies. Some of the chapter titles are: Metastatic Disease to the Thorax, CT Staging of Esophageal Carcinoma, CT Staging of Renal Carcinoma, CT Staging of Lymphoma, Staging of Non-Small Cell Lung Cancer, and Initital Experience with MRI Staging of Neoplasms.

  9. Analysis and improvement of cyclotron thallium target room shield.

    PubMed

    Hajiloo, N; Raisali, G; Aslani, G

    2008-01-01

    Because of high neutron and gamma-ray intensities generated during bombardment of a thallium-203 target, a thallium target-room shield and different ways of improving it have been investigated. Leakage of neutron and gamma ray dose rates at various points behind the shield are calculated by simulating the transport of neutrons and photons using the Monte Carlo N Particle transport computer code. By considering target-room geometry, its associated shield and neutron and gamma ray source strengths and spectra, three designs for enhancing shield performance have been analysed: a shielding door at the maze entrance, covering maze walls with layers of some effective materials and adding a shadow-shield in the target room in front of the radiation source. Dose calculations were carried out separately for different materials and dimensions for all the shielding scenarios considered. The shadow-shield has been demonstrated to be one suitable for neutron and gamma dose equivalent reduction. A 7.5-cm thick polyethylene shadow-shield reduces both dose equivalent rate at maze entrance door and leakage from the shield by a factor of 3. PMID:18417490

  10. Shielding aspects of D- sup 3 He fusion power reactors

    SciTech Connect

    El-Guebaly, L.A. (Wisconsin Univ., Madison, WI (United States). Fusion Technology Inst.)

    1992-08-01

    In this paper the implications of the D-{sup 3}He fuel cycle on shielding design are investigated for tokamak power reactors of the ARIES/Apollo class. The prime function of the shield is to protect the superconducting magnets against radiation. A variety of shield options is examined, and the various shields are optimized for the D-{sup 3}He neutron spectrum. The results demonstrate the relative merits of the various materials as a function of the shield thickness. In the first wall/shield, low-activation structural materials (such as Tenelon, modified HT-9, silicon carbide composites, and carbon-carbon composites) were employed to reduce the radioactive inventory and increase the safety margin in case of accidents. A comparison between the different shield options based on detailed neutronics, environmental/safety, and economic assessments has led to the selection of the reference shield design. The first-wall/shield structure is made of an elementally tailored ferritic steel (MHT-9), and the thermal energy is converted through an organic coolant at 44% efficiency. The safety features of the low-activation steel shield, along with the low neutron production in the D-{sup 3}He fuel cycle, enable the ARIES-III/Apollo design to achieve acceptable environmental and safety characteristics.

  11. Staging of Lung Cancer

    MedlinePLUS

    ... it important to know the stage of my lung cancer? Finding out the stage of your lung cancer ... you. How does staging differ between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC)? ...

  12. Cervical Cancer Stage IIIA

    MedlinePLUS

    ... My Pictures Browse Search Quick Search Image Details Cervical Cancer Stage IIIA View/Download: Small: 612x612 View Download Add to My Pictures Title: Cervical Cancer Stage IIIA Description: Stage IIIA cervical cancer; ...

  13. Cervical Cancer Stage IVB

    MedlinePLUS

    ... My Pictures Browse Search Quick Search Image Details Cervical Cancer Stage IVB View/Download: Small: 594x640 View Download Add to My Pictures Title: Cervical Cancer Stage IVB Description: Stage IVB cervical cancer; ...

  14. Cervical Cancer Stage IA

    MedlinePLUS

    Cervical Cancer Stage IA View/Download: Small: 720x576 View Download Add to My Pictures Title: Cervical Cancer Stage IA Description: Stage IA1 and IA2 cervical cancer; drawing shows a cross-section of the ...

  15. Cervical Cancer Stage IVA

    MedlinePLUS

    ... My Pictures Browse Search Quick Search Image Details Cervical Cancer Stage IVA View/Download: Small: 756x576 View Download Add to My Pictures Title: Cervical Cancer Stage IVA Description: Stage IVA cervical cancer; ...

  16. Building Green

    NSDL National Science Digital Library

    Information designed to help building industry professionals and policy makers to improve environmental performance and reduce the adverse impacts of buildings. Offers print and electronic resources to help industry professionals to take an integrated design approach that will minimize ecological impact and maximize economic performance. The publications related to green building include Environmental Building News - a monthly newsletter that is independently published and advertising-free; The GreenSpec Product Directory; and Green Building Advisor.

  17. Structural Monitoring of Metro Infrastructure during Shield Tunneling Construction

    PubMed Central

    Ran, L.; Ye, X. W.; Ming, G.; Dong, X. B.

    2014-01-01

    Shield tunneling construction of metro infrastructure will continuously disturb the soils. The ground surface will be subjected to uplift or subsidence due to the deep excavation and the extrusion and consolidation of the soils. Implementation of the simultaneous monitoring with the shield tunnel construction will provide an effective reference in controlling the shield driving, while how to design and implement a safe, economic, and effective structural monitoring system for metro infrastructure is of great importance and necessity. This paper presents the general architecture of the shield construction of metro tunnels as well as the procedure of the artificial ground freezing construction of the metro-tunnel cross-passages. The design principles for metro infrastructure monitoring of the shield tunnel intervals in the Hangzhou Metro Line 1 are introduced. The detailed monitoring items and the specified alarming indices for construction monitoring of the shield tunneling are addressed, and the measured settlement variations at different monitoring locations are also presented. PMID:25032238

  18. Structural monitoring of metro infrastructure during shield tunneling construction.

    PubMed

    Ran, L; Ye, X W; Ming, G; Dong, X B

    2014-01-01

    Shield tunneling construction of metro infrastructure will continuously disturb the soils. The ground surface will be subjected to uplift or subsidence due to the deep excavation and the extrusion and consolidation of the soils. Implementation of the simultaneous monitoring with the shield tunnel construction will provide an effective reference in controlling the shield driving, while how to design and implement a safe, economic, and effective structural monitoring system for metro infrastructure is of great importance and necessity. This paper presents the general architecture of the shield construction of metro tunnels as well as the procedure of the artificial ground freezing construction of the metro-tunnel cross-passages. The design principles for metro infrastructure monitoring of the shield tunnel intervals in the Hangzhou Metro Line 1 are introduced. The detailed monitoring items and the specified alarming indices for construction monitoring of the shield tunneling are addressed, and the measured settlement variations at different monitoring locations are also presented. PMID:25032238

  19. Electromagnetic interference shielding characteristics of carbon nanofiber-polymer composites.

    PubMed

    Yang, Yonglai; Guptal, Mool C; Dudley, Kenneth L; Lawrence, Roland W

    2007-02-01

    Electromagnetic interference (EMI) shielding characteristics of carbon nanofiber-polystyrene composites were investigated in the frequency range of 12.4-18 GHz (Ku-band). It was observed that the shielding effectiveness of such composites was frequency independent, and increased with increasing carbon nanofiber loading within Ku-band. The experimental data exhibited that the shielding effectiveness of the polymer composite containing 20 wt% carbon nanofibers could reach more than 36 dB in the measured frequency region, indicating such composites can be applied to the potential EMI shielding materials. In addition, the results showed that the contribution of reflection to the EMI shielding effectiveness was much larger than that of absorption, implying the primary EMI shielding mechanism of such composites was reflection of electromagnetic radiation within Ku-band. PMID:17450793

  20. Radiation shielding properties of barite coated fabric by computer programme

    NASA Astrophysics Data System (ADS)

    Akarslan, F.; Üncü, I. S.; K?l?ncarslan, S.; Akkurt, I.; Molla, T.

    2015-03-01

    With the development of technology radiation started to be used in variety of different fields. As the radiation is hazardous for human health, it is important to keep radiation dose as low as possible. This is done mainly using shielding materials. Barite is one of the important materials in this purpose. As the barite is not used directly it can be used in some other materials such as fabric. For this purposes barite has been coated on fabric in order to improve radiation shielding properties of fabric. Determination of radiation shielding properties of coated fabric has been done by using computer program written C# language. With this program the images obtained from digital Rontgen films is used to determine radiation shielding properties in terms of image processing numerical values. Those values define radiation shielding and in this way the coated barite effect on radiation shielding properties of fabric has been obtained.

  1. Rotating-shield brachytherapy for cervical cancer

    NASA Astrophysics Data System (ADS)

    Yang, Wenjun; Kim, Yusung; Wu, Xiaodong; Song, Qi; Liu, Yunlong; Bhatia, Sudershan K.; Sun, Wenqing; Flynn, Ryan T.

    2013-06-01

    In this treatment planning study, the potential benefits of a rotating shield brachytherapy (RSBT) technique based on a partially-shielded electronic brachytherapy source were assessed for treating cervical cancer. Conventional intracavitary brachytherapy (ICBT), intracavitary plus supplementary interstitial (IS+ICBT), and RSBT treatment plans for azimuthal emission angles of 180° (RSBT-180) and 45° (RSBT-45) were generated for five patients. For each patient, high-risk clinical target volume (HR-CTV) equivalent dose in 2 Gy fractions (EQD2) (?/? = 10 Gy) was escalated until bladder, rectum, or sigmoid colon tolerance EQD2 values were reached. External beam radiotherapy dose (1.8 Gy × 25) was accounted for, and brachytherapy was assumed to have been delivered in 5 fractions. IS+ICBT provided a greater HR-CTV D90 (minimum EQD2 to the hottest 90%) than ICBT. D90 was greater for RSBT-45 than IS+ICBT for all five patients, and greater for RSBT-180 than IS+ICBT for two patients. When the RSBT-45/180 plan with the lowest HR-CTV D90 that was greater than the D90 the ICBT or IS+ICBT plan was selected, the average (range) of D90 increases for RSBT over ICBT and IS+ICBT were 16.2 (6.3-27.2)and 8.5 (0.03-20.16) Gy, respectively. The average (range) treatment time increase per fraction of RSBT was 34.56 (3.68-70.41) min over ICBT and 34.59 (3.57-70.13) min over IS+ICBT. RSBT can increase D90 over ICBT and IS+ICBT without compromising organ-at-risk sparing. The D90 and treatment time improvements from RSBT depend on the patient and shield emission angle.

  2. Accelerator-based validation of shielding codes

    SciTech Connect

    Zeitlin, Cary; Heilbronn, Lawrence; Miller, Jack; Wilson, John W.

    2002-08-12

    The space radiation environment poses risks to astronaut health from a diverse set of sources, ranging from low-energy protons and electrons to highly-charged, high-energy atomic nuclei and their associated fragmentation products, including neutrons. The low-energy protons and electrons are the source of most of the radiation dose to Shuttle and ISS crews, while the more energetic particles that comprise the Galactic Cosmic Radiation (protons, He, and heavier nuclei up to Fe) will be the dominant source for crews on long-duration missions outside the earth's magnetic field. Because of this diversity of sources, a broad ground-based experimental effort is required to validate the transport and shielding calculations used to predict doses and dose-equivalents under various mission scenarios. The experimental program of the LBNL group, described here, focuses principally on measurements of charged particle and neutron production in high-energy heavy-ion fragmentation. Other aspects of the program include measurements of the shielding provided by candidate spacesuit materials against low-energy protons (particularly relevant to extra-vehicular activities in low-earth orbit), and the depth-dose relations in tissue for higher-energy protons. The heavy-ion experiments are performed at the Brookhaven National Laboratory's Alternating Gradient Synchrotron and the Heavy-Ion Medical Accelerator in Chiba in Japan. Proton experiments are performed at the Lawrence Berkeley National Laboratory's 88'' Cyclotron with a 55 MeV beam, and at the Loma Linda University Proton Facility with 100 to 250 MeV beam energies. The experimental results are an important component of the overall shielding program, as they allow for simple, well-controlled tests of the models developed to handle the more complex radiation environment in space.

  3. Diamagnetic shielding correction for protons in water

    NASA Astrophysics Data System (ADS)

    Fei, Xiang

    1996-05-01

    The diamagnetic shielding correction of the H_2O molecule is determined by combining the following results: (a) the deduced diamagnetic shielding factor of gaseous hydrogen^1; (b) the ratio of the NMR frequencies of helions and protons for a gaseous mixture of ^3He and hydrogen^2; and (c) the ratio of the NMR frequencies of helions in ^3He gas compared to that of protons in a spherical water sample^3. The new result, ? (H_2O, spherical, 25^oC) = 25.702 ppm (the uncertainty is 12 ppb if the error quoted in the Ref. 2 is doubled) is in good agreement with the recommended value^4 ?(H_2O, spherical, 25^oC) = 25.689 (15) ppm and provides an independent verification for the previous measurement^5. The diamagnetic shielding correction is useful for an absolute determination of the free proton spin precession frequency^6 with an accuracy of 0.03 ppm. Other related results will be presented and discussed. ^1W.T. Raynes and N. Panteli, Mol. Phys.48, 439 (1983). ^2Yu.I. Neronov and A.E. Barzakh, Sov. Phys. JETP.48, 769 (1978). ^3J.L. Flowers, B.W.Petley,and M.G.Richards, Metrologia30, 75(1993). ^4E.R. Cohen and B.N. Taylor, Rev. Mod. Phys.59, 1121 (1987). ^5W.D. Phillips, W.E.Cooke, and D.Kleppner, Metrologia13, 179(1977). ^6X. Fei, IEEE Trans. Instrum. Meas.44, 501 (1995).

  4. Moderately shielded high-Tc SQUID system for rat MCG

    NASA Astrophysics Data System (ADS)

    Bechstein, S.; Kim, I.-S.; Drung, D.; Novikov, I.; Schurig, Th

    2010-06-01

    Recently, we have developed a 5-channel high-Tc SQUID system with one signal channel intended for rat magnetocardiography (MCG) in moderately shielded or "quiet" real environment. This system is an adapted version of a human MCG system which has been improved with respect to user-friendliness and stability. A dewar with a cold-warm distance of 7 mm and a refill cycle time of up to one week is utilized. The implemented high-Tc SQUIDs are single-layer devices with grain boundary junctions fabricated at KRISS with laser ablation on 10 mm × 10 mm STO substrates. In order to cancel environmental magnetic noise, three of the five SQUIDs are arranged to build an axial software first-order or second-order gradiometer with a base line of 35 mm. The other two SQUIDs are used for balancing. To overcome previous system instabilities, we have implemented an Earth field compensation for each SQUID. For this, the SQUIDs were mounted in capsules containing integrated field compensation coils. The three Earth field components are measured with an additional triaxial fluxgate, and compensated at the SQUID locations using the low-noise current source of the SQUID readout electronics. This way, the SQUIDs can be cooled and operated in a low residual field that improves system stability and reduces low-frequency SQUID noise. It is even possible to slowly move the dewar in the Earth field (dynamic field compensation). Different noise cancellation procedures were optimized and compared employing a periodic signal source.

  5. Safety evaluation for packaging (onsite) for concrete-shielded RHTRU waste drum for the 327 postirradiation testing laboratory

    SciTech Connect

    Adkins, H.E.

    1996-10-29

    This safety evaluation for packaging authorizes onsite transport of Type B quantities of radioactive material in the Concrete- Shielded Remote-Handled Transuranic Waste (RH TRU) Drum per WHC-CM-2-14, Hazardous Material Packaging and Shipping. The drum will be used for transport of 327 Building legacy waste from the 300 Area to the Transuranic Waste Storage and Assay Facility in the 200 West Area and on to a Solid Waste Storage Facility, also in the 200 Area.

  6. Safety evaluation for packaging (onsite) for the concrete-shielded RH TRU drum for the 327 Postirradiation Testing Laboratory

    SciTech Connect

    Smith, R.J.

    1998-03-31

    This safety evaluation for packaging authorizes onsite transport of Type B quantities of radioactive material in the Concrete Shielded Remote-Handled Transuranic Waste (RH TRU) Drum per HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments. The drum will be used for transport of 327 Building legacy waste from the 300 Area to a solid waste storage facility on the Hanford Site.

  7. Optimal Shielding for Minimum Materials Cost of Mass

    SciTech Connect

    Woolley, Robert D. [PPPL

    2014-08-01

    Material costs dominate some shielding design problems. This is certainly the case for manned nuclear power space applications for which shielding is essential and the cost of launching by rocket from earth is high. In such situations or in those where shielding volume or mass is constrained, it is important to optimize the design. Although trial and error synthesis methods may succeed a more systematic approach is warranted. Design automation may also potentially reduce engineering costs.

  8. Polyethylene/Boron Composites for Radiation Shielding Applications

    SciTech Connect

    Harrison, Courtney; Grulke, Eric [Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506 (United States); Burgett, Eric; Hertel, Nolan [Neely Nuclear Research Center, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2008-01-21

    Multifunctional composites made with boron are absorbers of low energy nuetrons, and could be used for structural shielding materials. Polyethylene/boron carbide composites were fabricated using conventional polymer processing techniques, and were evaluated for mechanical and radiation shielding properties. Addition of neat boron carbide (powder and nanoparticles) to an injection molding grade HPDE showed superior mechanical properties compared to neat HDPE. Radiation shielding measurements of a 2 wt% boron carbide composite were improved over those of the neat polyethylene.

  9. Shielding Methodologies in the Presence of Power/Ground Noise

    E-print Network

    Friedman, Eby G.

    , shield insertion and physical spacing, are discussed in [6] with- out considering P/G noise on the shieldShielding Methodologies in the Presence of Power/Ground Noise Selc¸uk K¨ose, Emre Salman, and Eby G in the presence of power/ground (P/G) noise are presented in this paper. The effect of noise in the P/G network

  10. Methods and Procedures for Shielding Analyses for the SNS

    SciTech Connect

    Gallmeier, Franz X [ORNL] [ORNL; Iverson, Erik B [ORNL] [ORNL; Remec, Igor [ORNL] [ORNL; Lu, Wei [ORNL] [ORNL; Popova, Irina [ORNL] [ORNL

    2014-01-01

    In order to provide radiologically safe Spallation Neutron Source operation, shielding analyses are performed according to Oak Ridge National Laboratory internal regulations and to comply with the Code of Federal Regulations. An overview of on-going shielding work for the accelerator facility and neutrons beam lines, methods, used for the analyses, and associated procedures and regulations is presented. Methods used to perform shielding analyses are described as well.

  11. Hypervelocity impact simulation for micrometeorite and debris shield design

    NASA Technical Reports Server (NTRS)

    Fahrenthold, Eric P.

    1992-01-01

    A new capability has been developed for direct computer simulation of hypervelocity impacts on multi-plate orbital debris shields, for combinations of low shield thickness and wide shield spacing which place extreme demands on conventional Eulerian analysis techniques. The modeling methodology represents a novel approach to debris cloud dynamics simulation, a problem of long term interest in the design of space structures. Software implementation of the modeling methodology provides a new design tool for engineering analysis of proposed orbital debris protection systems.

  12. Gravitational Shielding Effects in Gauge Theory of Gravity

    Microsoft Academic Search

    Ning Wu

    2003-01-01

    In 1992, E.E.Podkletnov and R.Nieminen find that, under certain conditions, ceramic superconductor with composite structure has revealed weak shielding properties against gravitational force. In classical Newton's theory of gravity and even in Einstein's general theory of gravity, there are no grounds of gravitational shielding effects. But in quantum gauge theory of gravity, the gravitational shielding effects can be explained in

  13. Electromagnetic interference shielding of graphene\\/epoxy composites

    Microsoft Academic Search

    Jiajie Liang; Yan Wang; Yi Huang; Yanfeng Ma; Zunfeng Liu; Jinming Cai; Chendong Zhang; Hongjun Gao; Yongsheng Chen

    2009-01-01

    Composites based on graphene-based sheets have been fabricated by incorporating solution-processable functionalized graphene into an epoxy matrix, and their electromagnetic interference (EMI) shielding studies were studied. The composites show a low percolation threshold of 0.52vol.%. EMI shielding effectiveness was tested over a frequency range of 8.2–12.4GHz (X-band), and 21dB shielding efficiency was obtained for 15wt% (8.8vol.%) loading, indicating that they

  14. Longwall shield design: is bigger better?

    SciTech Connect

    Barczak, T.M.; Tadolini, S.C. [NIOSH-PRL, Pittsburgh, PA (United States)

    2008-05-15

    This article evaluates the bigger is better design philosophy for longwall shields. The conventional support design approach based on simplistic models of supporting the full dead weight detached rock masses is replaced by a ground reaction design approach. Here, the goal is to match the support characteristics to the ground response, and not to try and overpower the ground forces with some massive support capability. The ground reaction concept embodies both the force and displacement controlled loading aspects, and therefore provides a more accurate representation of the support loading requirements. 7 figs.

  15. X-ray transmissive debris shield

    DOEpatents

    Spielman, R.B.

    1996-05-21

    An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

  16. X-ray transmissive debris shield

    DOEpatents

    Spielman, Rick B. (Albuquerque, NM)

    1996-01-01

    An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

  17. Nutrient Shielding in Clusters of Cells

    E-print Network

    Maxim O. Lavrentovich; John H. Koschwanez; David R. Nelson

    2013-06-13

    Cellular nutrient consumption is influenced by both the nutrient uptake kinetics of an individual cell and the cells' spatial arrangement. Large cell clusters or colonies have inhibited growth at the cluster's center due to the shielding of nutrients by the cells closer to the surface. We develop an effective medium theory that predicts a thickness $\\ell$ of the outer shell of cells in the cluster that receives enough nutrient to grow. The cells are treated as partially absorbing identical spherical nutrient sinks, and we identify a dimensionless parameter $\

  18. A MODEL BUILDING CODE ARTICLE ON FALLOUT SHELTERS WITH RECOMMENDATIONS FOR INCLUSION OF REQUIREMENTS FOR FALLOUT SHELTER CONSTRUCTION IN FOUR NATIONAL MODEL BUILDING CODES.

    ERIC Educational Resources Information Center

    American Inst. of Architects, Washington, DC.

    A MODEL BUILDING CODE FOR FALLOUT SHELTERS WAS DRAWN UP FOR INCLUSION IN FOUR NATIONAL MODEL BUILDING CODES. DISCUSSION IS GIVEN OF FALLOUT SHELTERS WITH RESPECT TO--(1) NUCLEAR RADIATION, (2) NATIONAL POLICIES, AND (3) COMMUNITY PLANNING. FALLOUT SHELTER REQUIREMENTS FOR SHIELDING, SPACE, VENTILATION, CONSTRUCTION, AND SERVICES SUCH AS ELECTRICAL…

  19. Radiation dose and shielding for the space station

    NASA Technical Reports Server (NTRS)

    Mccormack, Percival D.

    1988-01-01

    Significant differences in dose prediction for Space Station arise depending on whether or not the magnetic field model is extrapolated into the future. The basis for these calculations is examined in detail, and the importance of the residual atmospheric layer at altitudes below 1000 km, with respect to radiation attenuation, is emphasized. Dosimetry results from Shuttle flights are presented and compared with the computed results. It is recommended that, at this stage, no extrapolation of the magnetic field into the future be included in the calculations. A model adjustment, to replace this arbitrary procedure, is presented. Dose predictions indicate that, at altitudes below 500 km and at low inclination, and with nominal module wall thickness (0.125 in. aluminum), orbit stay times of 90 days in Space Station would result in quarterly radiation doses to the crew, which are well within present limits for both males and females. Countermeasures would be required for stay times of a year or more and the measure of increasing shielding is examined.

  20. THEMIS discovers holes in Earth's solar shield - Duration: 27 seconds.

    NASA Video Gallery

    This animation shows the latest findings from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. Earth's magnetic field; which shields our planet from severe ...

  1. Shield Design for a Space Based Vapor Core Reactor

    SciTech Connect

    Knight, Travis; Anghaie, Samim [Innovative Nuclear Space Power and Propulsion Institute (INSPI), PO Box 116502, University of Florida, Gainesville, FL 32611-6502 (United States)

    2002-07-01

    Innovative shielding strategies were sought to reduce the mass of the required shielding for a space based vapor core reactor system with magnetohydrodynamic energy conversion. Gamma-rays directly resultant from fission were found to play no role in the dose rate, while secondary gamma-rays from fission neutron interactions were the dominant contributor to the dose rate. Hydrogen containing materials such as polyethylene were utilized to provide shielding of both radiation from the reactor complex and also solar and galactic cosmic radiation. This shield design was found to contribute 0.125 kg/kWe to the baseline vapor core reactor system specific mass. (authors)

  2. Space Radiation Shielding Program http://radiationshielding.nasa.gov

    E-print Network

    Shepherd, Simon

    suggested reasonable scalability, also looked plausible for propulsion Feasibility and shielding, that cast considerable doubt on the possibility of producing the required magnetic field configurations

  3. Gravity Scaling of a Power Reactor Water Shield

    NASA Technical Reports Server (NTRS)

    Reid, Robert S.; Pearson, J. Boise

    2008-01-01

    Water based reactor shielding is being considered as an affordable option for use on initial lunar surface power systems. Heat dissipation in the shield from nuclear sources must be rejected by an auxiliary thermal hydraulic cooling system. The mechanism for transferring heat through the shield is natural convection between the core surface and an array of thermosyphon radiator elements. Natural convection in a 100 kWt lunar surface reactor shield design has been previously evaluated at lower power levels (Pearson, 2007). The current baseline assumes that 5.5 kW are dissipated in the water shield, the preponderance on the core surface, but with some volumetric heating in the naturally circulating water as well. This power is rejected by a radiator located above the shield with a surface temperature of 370 K. A similarity analysis on a water-based reactor shield is presented examining the effect of gravity on free convection between a radiation shield inner vessel and a radiation shield outer vessel boundaries. Two approaches established similarity: 1) direct scaling of Rayleigh number equates gravity-surface heat flux products, 2) temperature difference between the wall and thermal boundary layer held constant on Earth and the Moon. Nussult number for natural convection (laminar and turbulent) is assumed of form Nu = CRa(sup n). These combined results estimate similarity conditions under Earth and Lunar gravities. The influence of reduced gravity on the performance of thermosyphon heat pipes is also examined.

  4. Illustration of the Skylab Parasol Thermal Shield Deployment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This image illustrates the deployment of the Skylab parasol thermal shield. Skylab lost its thermal protection shield during its launch on May 14, 1973. The Skylab-2 crew deployed a parasol thermal shield to protect the workshop from overheating. The crew attached the canister containing the parasol to the scientific airlock and extended the folded shield through the opening and into space. Slowly, the struts extended and the sunshade took shape and was in place over the workshop's outer surface. This illustration shows the parasol at partial extension. Emergency procedures to repair and salvage the damaged Skylab were a joint effort of the Marshall Space Flight Center, other NASA centers, and contractors.

  5. Deoxyribonucleic acid-Ag nanoparticles for EMI Shielding: the effect of nanoparticle size, shape and distribution on the shielding effectiveness

    NASA Astrophysics Data System (ADS)

    Ouchen, Fahima; Wilson, Benjamin G.; Yaney, Perry P.; Salour, Michael M.; Grote, James G.

    2014-09-01

    This study focuses on the use of silver based nanoparticle as fillers in DNA host materials to form nancomposites for applications in Electro-Magnetic Interferences (EMI) shielding. For relatively low-conductivity EMI shielding nanocomposites, silver-oxide coated cenospheres are investigated as fillers. The filler loadings are varied to determine a percolation threshold for the desired low conductivity and shielding effectiveness. Microwave absorption as well as DC surface resistivity measurements are undertaken to characterize the obtained films.

  6. SHIELDING REQUIREMENTS FOR NSLS-II.

    SciTech Connect

    JOB,P.K.; CASEY, W.R.

    2008-01-02

    Brookhaven National Laboratory is in the process of designing a new Electron Synchrotron for scientific research using synchrotron radiation. This facility, called the 'National Synchrotron Light Source II' (NSLS-II), will provide x-ray radiation of ultra-high brightness and exceptional spatial and energy resolution. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. The project scope includes the design, construction, installation, and commissioning of the following accelerators: a 200 MeV linac, a booster accelerator operating from 200 MeV to 3.0 GeV, and the storage ring which stores a maximum of 500 mA current of electrons at an energy of 3.0 GeV. It is planned to operate the facility primarily in a top-off mode, thereby maintaining the maximum variation in stored beam current to < 1%. Because of the very demanding requirements for beam emittance and synchrotron radiation brilliance, the beam life-time is expected to be low, on the order of 2-3 hours. Analysis of the bulk shielding for operating this facility and the input parameters used for this analysis are discussed in this paper. The characteristics of each of the accelerators and their operating modes are summarized with the input assumptions for the bulk shielding analysis.

  7. System for imaging plutonium through heavy shielding

    SciTech Connect

    Kuckertz, T.H.; Cannon, T.M.; Fenimore, E.E.; Moss, C.E.; Nixon, K.V.

    1984-04-01

    A single pinhole can be used to image strong self-luminescent gamma-ray sources such as plutonium on gamma scintillation (Anger) cameras. However, if the source is weak or heavily shielded, a poor signal to noise ratio can prevent acquisition of the image. An imaging system designed and built at Los Alamos National Laboratory uses a coded aperture to image heavily shielded sources. The paper summarizes the mathematical techniques, based on the Fast Delta Hadamard transform, used to decode raw images. Practical design considerations such as the phase of the uniformly redundant aperture and the encoded image sampling are discussed. The imaging system consists of a custom designed m-sequence coded aperture, a Picker International Corporation gamma scintillation camera, a LeCroy 3500 data acquisition system, and custom imaging software. The paper considers two sources - 1.5 mCi /sup 57/Co unshielded at a distance of 27 m and 220 g of bulk plutonium (11.8% /sup 240/Pu) with 0.3 cm lead, 2.5 cm steel, and 10 cm of dense plastic material at a distance of 77.5 cm. Results show that the location and geometry of a source hidden in a large sealed package can be determined without having to open the package. 6 references, 4 figures.

  8. MicroShield/ISOCS gamma modeling comparison.

    SciTech Connect

    Sansone, Kenneth R

    2013-08-01

    Quantitative radiological analysis attempts to determine the quantity of activity or concentration of specific radionuclide(s) in a sample. Based upon the certified standards that are used to calibrate gamma spectral detectors, geometric similarities between sample shape and the calibration standards determine if the analysis results developed are qualitative or quantitative. A sample analyzed that does not mimic a calibrated sample geometry must be reported as a non-standard geometry and thus the results are considered qualitative and not quantitative. MicroShieldR or ISOCSR calibration software can be used to model non-standard geometric sample shapes in an effort to obtain a quantitative analytical result. MicroShieldR and Canberra's ISOCSR software contain several geometry templates that can provide accurate quantitative modeling for a variety of sample configurations. Included in the software are computational algorithms that are used to develop and calculate energy efficiency values for the modeled sample geometry which can then be used with conventional analysis methodology to calculate the result. The response of the analytical method and the sensitivity of the mechanical and electronic equipment to the radionuclide of interest must be calibrated, or standardized, using a calibrated radiological source that contains a known and certified amount of activity.

  9. Building America

    SciTech Connect

    Brad Oberg

    2010-12-31

    IBACOS researched the constructability and viability issues of using high performance windows as one component of a larger approach to building houses that achieve the Building America 70% energy savings target.

  10. Application of a dummy eye shield for electron treatment planning

    PubMed Central

    Kang, Sei-Kwon; Park, Soah; Hwang, Taejin; Cheong, Kwang-Ho; Han, Taejin; Kim, Haeyoung; Lee, Me-Yeon; Kim, Kyoung Ju; Oh, Do Hoon; Bae, Hoonsik

    2013-01-01

    Metallic eye shields have been widely used for near-eye treatments to protect critical regions, but have never been incorporated into treatment plans because of the unwanted appearance of the metal artifacts on CT images. The purpose of this work was to test the use of an acrylic dummy eye shield as a substitute for a metallic eye shield during CT scans. An acrylic dummy shield of the same size as the tungsten eye shield was machined and CT scanned. The BEAMnrc and the DOSXYZnrc were used for the Monte Carlo (MC) simulation, with the appropriate material information and density for the aluminum cover, steel knob and tungsten body of the eye shield. The Pinnacle adopting the Hogstrom electron pencil-beam algorithm was used for the one-port 6-MeV beam plan after delineation and density override of the metallic parts. The results were confirmed with the metal oxide semiconductor field effect transistor (MOSFET) detectors and the Gafchromic EBT2 film measurements. For both the maximum eyelid dose over the shield and the maximum dose under the shield, the MC results agreed with the EBT2 measurements within 1.7%. For the Pinnacle plan, the maximum dose under the shield agreed with the MC within 0.3%; however, the eyelid dose differed by –19.3%. The adoption of the acrylic dummy eye shield was successful for the treatment plan. However, the Pinnacle pencil-beam algorithm was not sufficient to predict the eyelid dose on the tungsten shield, and more accurate algorithms like MC should be considered for a treatment plan. PMID:22915776

  11. Rangitoto Volcano Drilling Project: Life of a Small 'Monogenetic' Basaltic Shield in the Auckland Volcanic Field

    NASA Astrophysics Data System (ADS)

    Shane, P. A. R.; Linnell, T.; Lindsay, J. M.; Smith, I. E.; Augustinus, P. M.; Cronin, S. J.

    2014-12-01

    Rangitoto is a small basaltic shield volcano representing the most recent and most voluminous episode of volcanism in the Auckland Volcanic Field, New Zealand. Auckland City is built on the field, and hence, Rangitoto's importance in hazard-risk modelling. The symmetrical edifice, ~6 km wide and 260 m high, has volume of 1.78 km3. It comprises summit scoria cones and a lava field. However, the lack of deep erosion dissection has prevented the development of an eruptive stratigraphy. Previous studies suggested construction in a relatively short interval at 550-500 yrs BP. However, microscopic tephra have been interpreted as evidence of intermittent activity from 1498 +/- 140 to 504 +/- 6 yrs BP, a longevity of 1000 years. A 150-m-deep hole was drilled through the edifice in February 2014 to obtain a continuous core record. The result is an unparalleled stratigraphy of the evolution of a small shield volcano. The upper 128 m of core comprises at least 27 lava flows with thicknesses in the range 0.3-15 m, representing the main shield-building phase. Underlying marine sediments are interbedded with 8 m of pyroclastic lapilli, and a thin lava flow, representing the explosive phreatomagmatic birth of the volcano. Preliminary geochemical analyses reveal suite of relatively uniform transitional basalts (MgO = 8.1 to 9.7 wt %). However, 4 compositional groups are distinguished that were erupted in sequential order. High-MgO magmas were erupted first, followed by a two more heterogeneous groups displaying differentiation trends with time. Finally, distinct low-MgO basalts were erupted. Each magma type appears to represent a new magma batch. The core places the magma types in a time series, which can be correlated to the surface lava field. Hence, allowing a geometrical reconstruction of the shield growth. Additional petrologic investigations are providing insight to magmatic ascent processes, while radiocarbon and paleomagnetic secular variation studies will reveal the duration of activity.

  12. Collapsed Building

    USGS Multimedia Gallery

    This masonry office building in the downtown area of Concepcion, Chile collapsed as a result of the M 8.8 earthquake on Feb. 27, 2010. The construction of this building predates the establishment of strict building codes in Chile, put in place following the devastating earthquake of 1960. ...

  13. Building Resonance

    NSDL National Science Digital Library

    Jeffrey Barker

    This demonstration of how buildings respond to seismic shaking uses cardboard and stiff paper (such as postcards or computer cards). The effects of building resonance can be found by experimenting with taller and shorter buildings, and varying the frequency of shaking.

  14. Residential building energy analysis : development and uncertainty assessment of a simplified model

    E-print Network

    Spindler, Henry C. (Henry Carlton), 1970-

    1998-01-01

    Effective design of energy-efficient buildings requires attention to energy issues during the preliminary stages of design. To aid in the early consideration of a building's future energy usage, a simplified building energy ...

  15. 9. Historic American Buildings Survey Alex Bush, Photographer, July 31, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Historic American Buildings Survey Alex Bush, Photographer, July 31, 1936 STAGE IN SOUTH END OF AUDITORIUM - Old Southern University, University Avenue (College Street), Greensboro, Hale County, AL

  16. 1. Northeast face of missile site control building, commonly known ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Northeast face of missile site control building, commonly known as the missile site radar building, showing open blast door #BD2. This emergency escape, at stair no. 12, is NEMP/RFI-shielded and 16" thick. The large circle in the center is the radar face, also known as the antennae array aperture. The small circle to the right of the radar face is the "Q" channel. The antennae atop the turret provided lightning protection for the building - Stanley R. Mickelsen Safeguard Complex, Missile Site Control Building, Northeast of Tactical Road; southeast of Tactical Road South, Nekoma, Cavalier County, ND

  17. 8. Early stage of power house construction at Dam No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Early stage of power house construction at Dam No. 4, showing two stiff leg derricks used to excavate limestone for power house building. Photo c. 1907. Credit PEM. - Dam No. 4 Hydroelectric Plant, Potomac River, Martinsburg, Berkeley County, WV

  18. Shielding of electromagnetic fields of current sources by hemispherical enclosures

    Microsoft Academic Search

    S. V. K. Shastry; K. N. Shamanna; V. R. Katti

    1985-01-01

    A theory of electromagnetic shielding of fields by an imperfectly conducting, hemispherical, open shell, with its rim in contact with a perfectly conducting infinite ground plane, is presented. The derivation of the equations for the shielding effectiveness (SE) of the enclosure excited by Hertizian dipole sources are provided. The values of SE obtained are compared with a similarly excited imperfectly

  19. Computer program optimizes design of nuclear radiation shields

    NASA Technical Reports Server (NTRS)

    Lahti, G. P.

    1971-01-01

    Computer program, OPEX 2, determines minimum weight, volume, or cost for shields. Program incorporates improved coding, simplified data input, spherical geometry, and an expanded output. Method is capable of altering dose-thickness relationship when a shield layer has been removed.

  20. Inverse source problem and active shielding for composite domains

    Microsoft Academic Search

    V. S. Ryaben; S. V. Tsynkov; S. V. Utyuzhnikov

    The problem of active shielding (AS) for a multiply connected domain consists of constructing additional sources of the field (e.g., acoustic) so that all individual subdomains can either communicate freely with one another or otherwise be shielded from their peers. This problem can be interpreted as a special inverse source problem for the differential equation (or system) that governs the

  1. General Corrosion and Localized Corrosion of the Drip Shield

    SciTech Connect

    F. Hua

    2004-09-16

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847]).

  2. Thermal radiation shields for piping in vacuum environments

    NASA Technical Reports Server (NTRS)

    Spagnuolo, A. C.

    1969-01-01

    System of thermal radiation shielding reduces radiant heat transfer in vacuum installations containing piping which carries working fluids. Method employs successive layers of spacers and rolled metal shields which are easily installed or removed, expedites efficient removal of entrapped gases, and adapts easily to small pipings.

  3. Simple formula for multiple mu-metal shields

    NASA Astrophysics Data System (ADS)

    Dubbers, D.

    1986-03-01

    A simple approximate formula is derived for the calculation of multiple concentric magnetic shields, which is accurate on the one percent level for all relevant cases, and which replaces the cumbersome recursion procedures used so far. The new formula allows the parametrization of the problem such that the optimum shield configuration is readily obtained for all applications.

  4. Tungsten-based composite materials for fusion reactor shields

    Microsoft Academic Search

    E. Greenspan; Y. Karni

    1985-01-01

    Composite tungsten-based materials were recently proposed for the heavy constituent of compact fusion reactor shields. These composite materials will enable the incorporation of tungsten - the most efficient nonfissionable inelastic scattering (as well as good neutron absorbing and very good photon attenuating) material - in the shield in a relatively cheap way and without introducing voids (so as to enable

  5. Effects of Source Redistribution on Jet Noise Shielding Salvador Mayoral*

    E-print Network

    Papamoschou, Dimitri

    between the insertion loss and the axial location of peak noise source. The aggressive chevrons causeEffects of Source Redistribution on Jet Noise Shielding Salvador Mayoral* and Dimitri Papamoschou University of California, Irvine, CA 92697, USA The potential of jet noise shielding from the Hybrid Wing

  6. High Voltage Transmission Line Protection Using Shielding Method

    Microsoft Academic Search

    Zar Ni Tun; Tun Naing

    2009-01-01

    This paper describes shielding method for lightning protection on high voltage transmission line and also how to protect lightning effects on the line. If the fault is present, additional power system will be damaged and minimizing system reliability. This shielding method used in transmission line bases the unequal lightning ground flash density all over the country. This paper is tend

  7. Prediction of Jet Noise Shielding with Forward Flight Salvador Mayoral

    E-print Network

    Papamoschou, Dimitri

    thus be used to "shield" the power-plant noise emitted towards communities. The prediction approachPrediction of Jet Noise Shielding with Forward Flight Effects Salvador Mayoral and Dimitri of propulsion noise sources by the airframe. The focus of this study is the diffraction of a wavepacket noise

  8. Shielding Effectiveness and Closeout Methods for Composite Spacecraft Structural Panels

    Microsoft Academic Search

    Alexander L. Bogorad; Matthew P. Deeter; Kevin A. August; Graham Doorley; Justin J. Likar; Roman Herschitz

    2008-01-01

    Increasingly, the latest spacecraft designs utilize partially conducting composite materials such as graphite epoxy or carbon-loaded Kevlar panels. These materials provide significant weight and mechanical advantages compared to conventional metallic structures, but their radio-frequency (RF) shielding properties are not well understood. In order to maintain a specified level of electromagnetic shielding on the spacecraft, it is necessary to use these

  9. The effect of tip shields on a horizontal tail surface

    NASA Technical Reports Server (NTRS)

    Dronin, Paul V; Ramsden, Earl I; Higgins, George J

    1928-01-01

    A series of experiments made in the wind tunnel of the Daniel Guggenheim School of Aeronautics, New York University, on the effect of tip shields on a horizontal tail surface are described and discussed. It was found that some aerodynamic gain can be obtained by the use of tip shields though it is considered doubtful whether their use would be practical.

  10. Plasma shield for in-air beam processes

    SciTech Connect

    Hershcovitch, Ady [Collider-Accelerator Department, Building 901A, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2008-05-15

    A novel concept/apparatus, the Plasma Shield, is introduced in this paper. The purpose of the Plasma Shield is designed to shield a target object chemically and thermally by engulfing an area subjected to beam treatment with inert plasma. The shield consists of a vortex-stabilized arc that is employed to shield beams and workpiece area of interaction from an atmospheric or liquid environment. A vortex-stabilized arc is established between a beam generating device (laser, ion or electron gun) and a target object. The arc, which is composed of a pure noble gas, engulfs the interaction region and shields it from any surrounding liquids like water or reactive gases. The vortex is composed of a sacrificial gas or liquid that swirls around and stabilizes the arc. The successful Plasma Shield was experimentally established and very high-quality electron beam welding with partial plasma shielding was performed. The principle of the operation and experimental results are discussed in the paper.

  11. Radiation protection and shielding design--strengthening the link.

    PubMed

    Hobson, John; Cooper, Andrew

    2005-01-01

    The improvement in quality and flexibility of shielding methods and data has been progressive and beneficial in opening up new opportunities for optimising radiation protection in design. The paper describes how these opportunities can best be seized by taking a holistic view of radiation protection, with shielding design being an important component part. This view is best achieved by enhancing the role of 'shielding assessors' so that they truly become 'radiation protection designers'. The increase in speed and efficiency of shielding calculations has been enormous over the past decades. This has raised the issue of how the assessor's time now can be best utilised; pursuing ever greater precision and accuracy in shielding/dose assessments, or improving the contribution that shielding assessment makes to radiological protection and cost-effective design. It is argued in this paper that the latter option is of great importance and will give considerable benefits. Shielding design needs to form part of a larger radiation protection perspective based on a deep understanding/appreciation of the opportunities and constraints of operators and designers, enabling minimal design iterations, cost optimisation of alternative designs (with a 'lifetime' perspective) and improved realisation of design intent in operations. The future of shielding design development is argued to be not in improving the 'toolkit', but in enhanced understanding of the 'product' and the 'process' for achieving it. The holistic processes being developed in BNFL to realise these benefits are described in the paper and will be illustrated by case studies. PMID:16381722

  12. Space nuclear reactor shields for manned and unmanned applications

    NASA Technical Reports Server (NTRS)

    Mckissock, Barbara I.; Bloomfield, Harvey S.

    1989-01-01

    Missions which use nuclear reactor power systems require radiation shielding of payload and/or crew areas to predetermined dose rates. Since shielding can become a significant fraction of the total mass of the system, it is of interest to show the effect of various parameters on shield thickness and mass for manned and unmanned applications. Algorithms were developed to give the thicknesses needed if reactor thermal power, separation distances, and dose rates are given as input. The thickness algorithms were combined with models for four different shield geometries to allow tradeoff studies of shield volume and mass for a variety of manned and unmanned missions. Shield design tradeoffs presented in this study include the effects of: higher allowable dose rates; radiation hardened electronics; shorter crew exposure times; shield geometry; distance of the payload and/or crew from the reactor; and changes in the size of the shielded area. Specific NASA missions that were considered in this study include unmanned outer planetary exploration, manned advanced/evolutionary space station, and advanced manned lunar base.

  13. Modeling of Substation Shielding Against Direct Lightning Strikes

    Microsoft Academic Search

    Farouk A. M. Rizk

    2010-01-01

    The paper comprises the first application of the concept of upward leader inception and propagation to meet the downward negative leader in a final jump, to assess shielding of substations against direct lightning strikes. Expressions for the attractive radius of a slender mast and the lateral attractive distance of a shield wire are used to determine the respective protection zones.

  14. 5. VIEW OF INTERIOR OF BUILDING 220, DECORATIVE FLOOR AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF INTERIOR OF BUILDING 220, DECORATIVE FLOOR AT ENTRANCE. VINYL TILE INLAID FLOOR WITH A RED BACKGROUND, GREEN EMBLEM, BROWN AND WHITE EAGLE, RED AND WHITE SHIELD, BLACK ANCHOR, RED ARROWS AND LETTERING. - U.S. Naval Base, Pearl Harbor, Brig, Neville Way near Ninth Street at Marine Barracks, Pearl City, Honolulu County, HI

  15. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Shield or armor ground resistance measurements. 1755...CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall...

  16. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Shield or armor ground resistance measurements. 1755...CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall...

  17. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Shield or armor ground resistance measurements. 1755...CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall...

  18. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Shield or armor ground resistance measurements. 1755...CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall...

  19. An Evaluation of Shadow Shielding for Lunar System Waste Heat Rejection

    E-print Network

    Worn, Cheyn

    2012-07-16

    Shadow shielding is a novel and practical concept for waste heat rejection from lunar surface spacecraft systems. A shadow shield is a light shield that shades the radiator from parasitic thermal radiation emanating from the sun or lunar surface...

  20. PROCESS WATER BUILDING, TRA605. FORMS AR SET TO CREATE THREE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PROCESS WATER BUILDING, TRA-605. FORMS AR SET TO CREATE THREE SHIELDED CELLS FOR THE PUMPS THAT WILL BE IN WEST HALF OF THE BUILDING. PUMPS WILL LIFT WATER TO WORKING RESERVOIR. CAMERA FACES NORTHEAST. INL NEGATIVE NO. 1465. Unknown Photographer, 2/13/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. Analytic flux formulas and tables of shielding functions

    SciTech Connect

    Wallace, O.J.

    1981-06-01

    Hand calculations of radiation flux and dose rates are often useful in evaluating radiation shielding and in determining the scope of a problem. The flux formulas appropriate to such calculations are almost always based on the point kernel and allow for at most the consideration of laminar slab shields. These formulas often require access to tables of values of integral functions for effective use. Flux formulas and function tables appropriate to calculations involving homogeneous source regions with the shapes of lines, disks, slabs, truncated cones, cylinders, and spheres are presented. Slab shields may be included in most of these calculations, and the effect of a cylindrical shield surrounding a cylindrical source may be estimated. Detector points may be located axially, laterally, or interior to a cylindrical source. Line sources may be tilted with respect to a slab shield. All function tables are given for a wide range of arguments.

  2. A proposed performance index for galactic cosmic ray shielding materials

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Wood, J. S.; Shinn, Judy L.; Cucinotta, Francis A.; Nealy, John E.

    1993-01-01

    In past studies, the reductions in absorbed dose and dose equivalent due to choice of material composition have been used to indicate shield effectiveness against exposure to galactic cosmic rays. However, these quantities are highly inaccurate in assessing shield effectiveness for protection against the biological effects of long-term exposure to the galactic heavy ions. A new quantity for shield performance is defined that correlates well with cell killing and cell transformation behind various shield thicknesses and materials. In addition, a relative performance index is identified that is inversely related to biological injury for different materials at a fixed shield mass and is directly related to the ratio of the fourth- and the second-order linear energy transfer (LET) moments.

  3. Carpet cloak with photonic crystal shield that permits information exchange

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Wang, Shenyun; Wen, Geyi

    2014-10-01

    Carpet cloaks designed by optical transformation usually include a perfect shield, which exclude the electromagnetic fields from the under cloaked region. Due to the shield, observers in the cloaked area cannot “see” the outside. In this article, we report a flat carpet cloak that permits information exchange with outer environment by using one- or two-dimensional photonic crystal structures as substitutes for the perfect shield. The lateral shifts at the reflecting surface of the effective shields, which make the carpet cloak detectable, are considered and calculated with a Gaussian beam illumination. In order to counteract the lateral shifts, we redesign the parameters of the cloaking slab based on the coordinate transformation. Good agreements have been obtained between the adjusted carpet and ideal carpet with a perfect shield.

  4. Shielding Effectiveness of Metallic Enclosures at Oblique and Arbitrary Polarizations

    NASA Technical Reports Server (NTRS)

    Deshpande, Manohar D.; Khan, Zulfiqar Ali; Bunting, Charles F.

    2006-01-01

    Shielding effectiveness of metallic enclosures with apertures when illuminated by an oblique incidence arbitrary polarized plane wave has been studied by using an efficient hybrid modal/moment technique. Shielding effectiveness of rectangular enclosures with one, two, and four apertures at multiple points inside the enclosures for various frequencies has been calculated when the illuminating source flies by the front of the enclosure. The work shows that the shielding effectiveness is seriously affected by frequency, angle of incidence and polarization of the illuminating field; the number and orientation of apertures; and the location inside the cavity. It has been shown that the usual assumption about the normal incidence being the worst-case scenario for shielding effectiveness values may not be valid when there is more than one aperture in the cavity. The paper emphasizes the need for the statistical investigation of shielding effectiveness problem of metallic enclosures with apertures.

  5. Magnetic shielding effect of grounded superconducting niobium layers

    NASA Astrophysics Data System (ADS)

    Mizugaki, Y.; Kashiwa, R.

    2008-02-01

    Magnetic isolation is an important issue in the realization of superconducting LSIs including more than ten thousands Josephson junctions. In this paper, we present mutual inductances of two superconducting strip lines coupled through a grounded shield layer. A conventional dc-superconducting quantum interference device (dc-SQUID) method on Nb/AlOx/Nb Josephson IC chips is employed. We have tested one dc-SQUID layout with a floating shield layer for reference, and ten dc-SQUID layouts with grounded shield layers. Four superconducting niobium layers are used as a ground plane, a SQUID line, a shield layer, and a control line from bottom to top. We have confirmed that the number, positions, and dimensions of ground contacts make differences in the mutual inductances. Ground contacts should be placed to enhance the shielding current for effective magnetic isolation.

  6. Mariner 9 views of shield volcano

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A Martian shield volcano, approximately 25 miles across at the crater, photographed consecutively by Mariner 9 with the wide-angle and telephoto lenses. The summit crater and groves down the flank probably were produced by subsidence flowing subsurface movement of magma.

    Mariner 9 was the first spacecraft to orbit another planet. The spacecraft was designed to continue the atmospheric studies begun by Mariners 6 and 7, and to map over 70% of the Martian surface from the lowest altitude (1500 kilometers [900 miles])and at the highest resolutions (1 kilometer per pixel to 100 meters per pixel) of any previous Mars mission

    Mariner 9 was launched on May 30, 1971 and arrived on November 14, 1971.

  7. Superconducting magnetic shielding apparatus and method

    DOEpatents

    Clem, John R. (Ames, IA); Clem, John R. (Ames, IA)

    1983-01-01

    Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

  8. Fan-fold shielded electrical leads

    DOEpatents

    Rohatgi, Rajeev R. (Mountain View, CA); Cowan, Thomas E. (Livermore, CA)

    1996-01-01

    Fan-folded electrical leads made from copper cladded Kapton, for example, with the copper cladding on one side serving as a ground plane and the copper cladding on the other side being etched to form the leads. The Kapton is fan folded with the leads located at the bottom of the fan-folds. Electrical connections are made by partially opening the folds of the fan and soldering, for example, the connections directly to the ground plane and/or the lead. The fan folded arrangement produces a number of advantages, such as electrically shielding the leads from the environment, is totally non-magnetic, and has a very low thermal conductivity, while being easy to fabricate.

  9. Superconducting magnetic shielding apparatus and method

    DOEpatents

    Clem, J.R.

    1982-07-09

    Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

  10. Optimized shielding for space radiation protection

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Cucinotta, F. A.; Kim, M. H.; Schimmerling, W.

    2001-01-01

    Future deep space mission and International Space Station exposures will be dominated by the high-charge and -energy (HZE) ions of the Galactic Cosmic Rays (GCR). A few mammalian systems have been extensively tested over a broad range of ion types and energies. For example, C3H10T1/2 cells, V79 cells, and Harderian gland tumors have been described by various track-structure dependent response models. The attenuation of GCR induced biological effects depends strongly on the biological endpoint, response model used, and material composition. Optimization of space shielding is then driven by the nature of the response model and the transmission characteristics of the given material.

  11. Standardized Radiation Shield Design Methods: 2005 HZETRN

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Tripathi, Ram K.; Badavi, Francis F.; Cucinotta, Francis A.

    2006-01-01

    Research committed by the Langley Research Center through 1995 resulting in the HZETRN code provides the current basis for shield design methods according to NASA STD-3000 (2005). With this new prominence, the database, basic numerical procedures, and algorithms are being re-examined with new methods of verification and validation being implemented to capture a well defined algorithm for engineering design processes to be used in this early development phase of the Bush initiative. This process provides the methodology to transform the 1995 HZETRN research code into the 2005 HZETRN engineering code to be available for these early design processes. In this paper, we will review the basic derivations including new corrections to the codes to insure improved numerical stability and provide benchmarks for code verification.

  12. Protective shield for an instrument probe

    DOEpatents

    Johnsen, Howard A.; Ross, James R.; Birtola, Sal R.

    2004-10-26

    A shield is disclosed that is particularly useful for protecting exposed optical elements at the end of optical probes used in the analysis of hazardous emissions in and around an industrial environment from the contaminating effects of those emissions. The instant invention provides a hood or cowl in the shape of a right circular cylinder that can be fitted over the end of such optical probes. The hood provides a clear aperture through which the probe can perform unobstructed analysis. The probe optical elements are protected from the external environment by passing a dry gas through the interior of the hood and out through the hood aperture in sufficient quantity and velocity to prevent any significant mixing between the internal and external environments. Additionally, the hood is provided with a cooling jacket to lessen the potential for damaging the probe due to temperature excursions.

  13. SHIELDING STUDIES FOR IDS80 (NO IRON PLUG/YOKE), ADDING SHIELDING WC/H20 GRADUALLY FROM

    E-print Network

    McDonald, Kirk

    SHIELDING STUDIES FOR IDS80 (NO IRON PLUG/YOKE), ADDING SHIELDING WC/H20 GRADUALLY FROM 50 TO 80 cm deposition from MARS+MCNP (10-11 MeV NEUTRON ENERGY CUTOFF). IDS80 GEOMETRY WITHOUT IRON PLUG AND YOKE WITH AND WITHOUT IRON PLUG AND YOKE. NEW: SC#1-7 -300

  14. CRYOGENIC UPPER STAGE SYSTEM SAFETY

    NASA Technical Reports Server (NTRS)

    Smith, R. Kenneth; French, James V.; LaRue, Peter F.; Taylor, James L.; Pollard, Kathy (Technical Monitor)

    2005-01-01

    NASA s Exploration Initiative will require development of many new systems or systems of systems. One specific example is that safe, affordable, and reliable upper stage systems to place cargo and crew in stable low earth orbit are urgently required. In this paper, we examine the failure history of previous upper stages with liquid oxygen (LOX)/liquid hydrogen (LH2) propulsion systems. Launch data from 1964 until midyear 2005 are analyzed and presented. This data analysis covers upper stage systems from the Ariane, Centaur, H-IIA, Saturn, and Atlas in addition to other vehicles. Upper stage propulsion system elements have the highest impact on reliability. This paper discusses failure occurrence in all aspects of the operational phases (Le., initial burn, coast, restarts, and trends in failure rates over time). In an effort to understand the likelihood of future failures in flight, we present timelines of engine system failures relevant to initial flight histories. Some evidence suggests that propulsion system failures as a result of design problems occur shortly after initial development of the propulsion system; whereas failures because of manufacturing or assembly processing errors may occur during any phase of the system builds process, This paper also explores the detectability of historical failures. Observations from this review are used to ascertain the potential for increased upper stage reliability given investments in integrated system health management. Based on a clear understanding of the failure and success history of previous efforts by multiple space hardware development groups, the paper will investigate potential improvements that can be realized through application of system safety principles.

  15. Ares I Crew Launch Vehicle Upper Stage/Upper Stage Engine Element Overview

    NASA Technical Reports Server (NTRS)

    McArthur, J. Craig

    2008-01-01

    The Ares I upper stage is an integral part of the Constellation Program transportation system. The upper stage provides guidance, navigation and control (GN and C) for the second stage of ascent flight for the Ares I vehicle. The Saturn-derived J-2X upper stage engine will provide thrust and propulsive impulse for the second stage of ascent flight for the Ares I launch vehicle. Additionally, the upper stage is responsible for the avionics system of the the entire Ares I. This brief presentation highlights the requirements, design, progress and production of the upper stage. Additionally, test facilities to support J-2X development are discussed and an overview of the operational and manufacturing flows are provided. Building on the heritage of the Apollo and Space Shuttle Programs, the Ares I Us and USE teams are utilizing extensive lessons learned to place NASA and the US into another era of space exploration. The NASA, Boeing and PWR teams are integrated and working together to make progress designing and building the Ares I upper stage to minimize cost, technical and schedule risks.

  16. Formation of the Archean crust of the ancient Vodlozero domain (Baltic shield)

    NASA Astrophysics Data System (ADS)

    Arestova, N. A.; Chekulaev, V. P.; Lobach-Zhuchenko, S. B.; Kucherovskii, G. A.

    2015-03-01

    The available geological, petrological, and isotopic data on Archean rocks of the Baltic shield are used to analyze the formation of the crust of the ancient Vodlozero domain. This made it possible to reveal the succession of endogenic processes in different parts of the domain and correlate them between each other. Several stages of magmatic processes reflecting changes in magma-generation environments are definable in the crust formation. The earliest stages of magmatism (3.24 and 3.13-3.15 Ga) are mostly represented by rocks of the tonalite-trondhjemite-granodiorite association. The next stage of endogenic activity (3020-2900 Ma) was marked by the formation of volcanics of the komatiite-basalt and andesite-dacite associations constituting greenstone belts in marginal parts of the Vodlozero domain and basic dikes accompanied by layered pyroxenite-norite-diorite intrusion in its central part. These basic bodies crossing earlier tonalities were formed in extension settings related to the formation of the mantle plume, which is confirmed by the rock composition. This stage culminated in the formation of trondhjemites at margins of greenstone structure. The next stage of endogenic activity commenced at 2890-2840 Ma by the emplacement of high-magnesian gabbro and diorite dikes in the western margin of the domain, where they cross rocks of the tonalitetrondhjemite association. This stage was marked by the formation of intermediate-acid subvolcanic bodies and dikes as well as basite intrusions including the layered and differentiated Semch intrusion, the largest one in the Vodlozero domain. The stage culminated at approximately 2850 Ma in the emplacement of tonalities of the limited distribution being represented by the Shilos massif in the north of the domain and Shal'skii massif on the eastern shore of Lake Onega. The important stage in the geological history of the Vodlozero domain is the formation of the intracratonic Matkalakhta greenstone belt at approximately 2.8 Ga, which includes arenite quartzite and graywackes and polymictic conglomerates developed in the Lake Oster area in addition to volcanics. These rocks indicate a stable tectonic regime, which resulted in deep erosion of the crust. The emplacement of sanukitoids (2.73-2.74 Ga) as well as subsequent two-feldspar granites (2.68-2.70 Ga) and basite dikes (2.61-2.65 Ga) may be considered as resulting from the plume influence on the relatively stabilized sialic crust of the Baltic shield.

  17. Cervical Cancer Stage IIIB

    MedlinePLUS

    ... Cancer Stage IIIB Description: Stage IIIB cervical cancer; drawing shows cancer in the cervix, the vagina, and ... that connect the kidneys to the bladder). The drawing shows the ureter on the right blocked by ...

  18. Novel cryogen-free actively shielded superconducting magnets for maglev vehicles. Final report, August 1991-June 1992

    SciTech Connect

    Vermilyea, M.E.

    1992-06-01

    The report presents the results of a research effort into the design of a shielded superconducting magnet system for a maglev vehicle. The magnet design is based on a novel cryogen-free technology which allows operation without the use of any cryogenic fluids. This is accomplished by the use of a two-stage Gifford-McMahon (G-M) cryogenic refrigerator to provide cooling of the coil and a single cryostat thermal radiation shield by conduction. The design operating temperature of the magnet is 7.5 K, and that of the shield is 43 K. The magnet is wound with a tape form of niobium tin superconductor which allows operation at a module current density of 8100 A/sq cm at a flux density of 3.4 T at the 7.5 K temperature with a margin of 4.5 K to critical temperature. The magnet design is coupled with a linear synchronous motor and null-flux sidewall levitation system to provide a workable maglev system design. Costs for several components of the design, including coils and cryostat, shielding, and power conditioning apparatus are estimated.

  19. Control System Commissioning for Enhanced Building Operations 

    E-print Network

    Salsbury, T. I.; Singhal, A.

    2003-01-01

    This paper highlights the import role control systems play in the operation of modern buildings and describes ways to improve the final stage of commissioning. We also describe practical issues associated with modern IT-oriented control systems...

  20. Cetuximab, Cisplatin, and Radiation Therapy in Treating Patients With Stage IB, Stage II, Stage III, or Stage IVA Cervical Cancer

    ClinicalTrials.gov

    2014-12-29

    Cervical Adenocarcinoma; Cervical Adenosquamous Carcinoma; Cervical Small Cell Carcinoma; Cervical Squamous Cell Carcinoma; Stage IB Cervical Cancer; Stage IIA Cervical Cancer; Stage IIB Cervical Cancer; Stage III Cervical Cancer; Stage IVA Cervical Cancer

  1. How Is Ovarian Cancer Staged?

    MedlinePLUS

    ... stage grouping to determine the stage, expressed in Roman numerals from stage I (the least advanced stage) ... adding letters and sometimes additional numbers to the Roman numerals. Stage I The cancer is only within ...

  2. A HTc superconducting quantum interference device preamplifier stage to detect 3He nuclear precession

    NASA Astrophysics Data System (ADS)

    Sassier, E.; Monfort, Y.; Gunther, C.; Robbes, D.; Moreau, O.; Gilles, H.

    1999-07-01

    We built a HTc superconducting quantum interference device (SQUID) preamplifier stage to pick up the free precession signal of the 3He nucleus in Earth's magnetic field at room temperature. The SQUID is coupled to the precession field by a copper-made flux transformer. It is operated without any magnetic shield.

  3. Biological and taxonomic investigations concerning early stages of Heliothis zea (Boddie) and Heliothis virescens (F.

    E-print Network

    Talati, Govind Motilal

    1969-01-01

    'len t, on head &!;-. ps '. & e ce;vical plate. thorac' c an?r bde o &ical s&", , '!e:;s en I nn:I'. e a&;ai shield showed no 'i&" i?. ". . nces P3 in any larval stages of the two species. Garman (1920) has reported that I!eyrick (1395) is right...

  4. Staging ovaries of Haddock (Melanogrammus aeglefinus): implications for maturity indices

    E-print Network

    90 Staging ovaries of Haddock (Melanogrammus aeglefinus): implications for maturity indices Service, NOAA. Abstract--We build on recent efforts to standardize maturation staging methods through the development of a field-proof macroscopic ovarian maturity index for Haddock (Me- lanogrammus aeglefinus

  5. 32. DETAIL OF BASE OF SIDE SUPPORT FOR MOVABLE STAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. DETAIL OF BASE OF SIDE SUPPORT FOR MOVABLE STAGE SECTIONS RESTING ON I-BEAM FLANGES. PINS WHICH ENGAGED IN THE THE GROOVE OF THE SIDE SUPPORT LIMITED LATERAL MOVEMENT OF THE STAGE SECTIONS. - Auditorium Building, 430 South Michigan Avenue, Chicago, Cook County, IL

  6. Thick Galactic Cosmic Radiation Shielding Using Atmospheric Data

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C.; Nurge, Mark A.; Starr, Stanley O.; Koontz, Steven L.

    2013-01-01

    NASA is concerned with protecting astronauts from the effects of galactic cosmic radiation and has expended substantial effort in the development of computer models to predict the shielding obtained from various materials. However, these models were only developed for shields up to about 120 g!cm2 in thickness and have predicted that shields of this thickness are insufficient to provide adequate protection for extended deep space flights. Consequently, effort is underway to extend the range of these models to thicker shields and experimental data is required to help confirm the resulting code. In this paper empirically obtained effective dose measurements from aircraft flights in the atmosphere are used to obtain the radiation shielding function of the earth's atmosphere, a very thick shield. Obtaining this result required solving an inverse problem and the method for solving it is presented. The results are shown to be in agreement with current code in the ranges where they overlap. These results are then checked and used to predict the radiation dosage under thick shields such as planetary regolith and the atmosphere of Venus.

  7. The SRB heat shield: Aeroelastic stability during reentry

    NASA Technical Reports Server (NTRS)

    Ventres, C. S.; Dowell, E. H.

    1977-01-01

    Wind tunnel tests of a 3% scale model of the aft portion of the SRB equipped with partially scaled heat shields were conducted for the purpose of measuring fluctuating pressure levels in the aft skirt region. During these tests, the heat shields were observed to oscillate violently, the oscillations in some instances causing the heat shields to fail. High speed films taken during the tests reveal a regular pattern of waves in the fabric starting near the flow stagnation point and progressing around both sides of the annulus. The amplitude of the waves was too great, and their pattern too regular, for them to be attributed to the fluctuating pressure levels measured during the tests. The cause of the oscillations observed in the model heat shields, and whether or not similar oscillations will occur in the full scale SRB heat shield during reentry were investigated. Suggestions for modifying the heat shield so as to avoid the oscillations are provided, and recommendations are made for a program of vibration and wind tunnel tests of reduced-scale aeroelastic models of the heat shield.

  8. Small domes on Venus: probable analogs of Icelandic lava shields

    USGS Publications Warehouse

    Garvin, James B.; Williams, Richard S., Jr.

    1990-01-01

    On the basis of observed shapes and volumetric estimates, we interpret small, dome-like features on radar images of Venus to be analogs of Icelandic lava-shield volcanoes. Using morphometric data for venusian domes in Aubele and Slyuta (in press), as well as our own measurements of representative dome volumes and areas from Tethus Regio, we demonstrate that the characteristic aspect ratios and flank slopes of these features are consistent with a subclass of low Icelandic lava-shield volcanoes (LILS ). LILS are slightly convex in cross-section with typical flank slopes of ?3°. Plausible lava-shield-production rates for the venusian plains suggest formation of ?53 million shields over the past 0.25 Ga. The cumulative global volume of lava that would be associated with this predicted number of lava shields is only a factor of 3–4 times that of a single oceanic composite shield volcano such as Mauna Loa. The global volume of all venusian lava shields in the 0.5–20-km size range would only contribute a meter of resurfacing over geologically significant time scales. Thus, venusian analogs to LILS may represent the most abundant landform on the globally dominant plains of Venus, but would be insignificant with regard to the global volume of lava extruded. As in Iceland, associated lavas from fissure eruptions probably dominate plains volcanism and should be evident on the higher resolution Magellan radar images.

  9. Green Buildings

    NSDL National Science Digital Library

    From the Department of Energy's Center of Excellence for Sustainable Development, this Green Buildings site serves as a detailed metapage for environmentally conscious architects, engineers, and builders. As the introduction to the site points out, "The design, construction, and maintenance of buildings has a tremendous impact on our environment and our natural resources." The site offers carefully summarized links to relevant Websites and publications on topics such as building principles, building programs, rating systems, affordable housing, codes/ordinances, educational materials, and more. This site may be of interest to those who want practical applications for protecting the environment.

  10. ETR BUILDING, TRA642, INTERIOR. BASEMENT. CAMERA FACES SOUTH AND LOOKS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ETR BUILDING, TRA-642, INTERIOR. BASEMENT. CAMERA FACES SOUTH AND LOOKS AT DOOR TO M-3 CUBICLE. CUBICLE WALLS ARE MADE OF LEAD SHIELDING BRICKS. VALVE HANDLES AND STEMS PERTAIN TO SAMPLING. METAL SHIELDING DOOR. NOTE GLOVE BOX TO RIGHT OF CUBICLE DOOR. INL NEGATIVE NO. HD-46-21-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. LOFT. Containment and service building (TAN650). Section through north/south axis. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOFT. Containment and service building (TAN-650). Section through north/south axis. Shows basement and four additional levels of pre-amp tower, shielded roadway, chambers below reactor floor, railroad door, sumps, shielding. Section C shows basement sumps and chambers below reactor floor. Kaiser engineers 6413-11-STEP/LOFT-650-A-5. Date: October 1964. INEEL index code no. 036-650-00-486-122217 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  12. LOFT. Containment and service building (TAN650). South elevation, details, section. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOFT. Containment and service building (TAN-650). South elevation, details, section. Shows part of duct enclosure, railroad door opening, roof ventilators, shielded personnel entrance, and change room. Section F shows view from west looking toward shielding around airlock door on main floor. Kaiser engineers 6413-11-STEP/LOFT-650-A-9. Date: October 1964. INEEL index code no. 036-650-00-486-122221 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  13. Investigation of the fire endurance of borated polyethylene shielding material

    SciTech Connect

    Foote, K.L.

    1988-06-17

    We conducted nine experiments to investigate the fire endurance of a borated polyethylene shielding material to be used in the Engineering Demonstration System. Several chemistry tests were also done. The shielding material was found to melt at 93.5/degree/C, decompose at 230/degree/C, and ignite at 350/degree/C. Five fire tests were done in a realistic configuration and four tests in a pessimistic configuration. The material easily passed all nine tests. In each case, the shielding material never reached ignition temperature and was found acceptable in this proposed application. 7 refs., 10 figs., 3 tabs.

  14. Superconducting shield for solenoid of electron cooling system

    NASA Astrophysics Data System (ADS)

    Agapov, N. N.; Donets, D. E.; Drobin, V. M.; Kulikov, E. A.; Malinovski, H.; Pivin, R. V.; Smirnov, A. V.; Prokofichev, Yu. V.; Trubnikov, G. V.; Dorofeev, G. L.

    2012-07-01

    Ensuring the high homogeneity of a magnetic field in the straight solenoid of an electron cooling system is a very important task. In the electron cooling system of the collider in the NICA project, it is planned to use superconducting solenoids for the generation of a longitudinal magnetic field. Using of the superconducting shield is proposed to achieve the required homogeneity of the magnetic field in the cooling section. This article discusses the design of the superconducting shield and presents experimental and numerical studies into the homogeneity of the magnetic field in solenoids with the superconducting shield.

  15. CONCEPTS FOR CAPACITIVELY RF-SHIELDED BELLOWS IN CRYOGENIC STRUCTURES.

    SciTech Connect

    ZHAO,Y.HAHN,H.

    2004-03-24

    Bellows are frequently required in accelerators and colliders. Usually RF-shields with spring fingers are employed to screen the bellows. The lack of accessibility in cryogenic systems can be a problem and asks for alternate solutions to eliminate possible overheating, sparking, etc that occurred in intensive beams. This note addresses an alternate kind of RF shield, which uses capacitive contact instead of mechanical contact. The analysis, as well as numerical example of a superconducting cavity structure, shows that the capacitive RF shield satisfies the impedance requirements of both beam and HOMs. The capability of thermal isolation is also analyzed.

  16. Inhibited Shaped Charge Launcher Testing of Spacecraft Shield Designs

    NASA Technical Reports Server (NTRS)

    Grosch, Donald J.

    1996-01-01

    This report describes a test program in which several orbital debris shield designs were impact tested using the inhibited shaped charge launcher facility at Southwest Research Institute. This facility enables researchers to study the impact of one-gram aluminum projectiles on various shielding designs at velocities above 11 km/s. A total of twenty tests were conducted on targets provided by NASA-MSFC. This report discusses in detail the shield design, the projectile parameters and the test configuration used for each test. A brief discussion of the target damage is provided, as the detailed analysis of the target response will be done by NASA-MSFC.

  17. Magnetic shielding for a spaceborne adiabatic demagnetization refrigerator (ADR)

    NASA Technical Reports Server (NTRS)

    Warner, Brent A.; Shirron, Peter J.; Castles, Stephen H.; Serlemitsos, Aristides T.

    1991-01-01

    The Goddard Space Flight Center has studied magnetic shielding for an adiabatic demagnetization refrigerator. Four types of shielding were studied: active coils, passive ferromagnetic shells, passive superconducting coils, and passive superconducting shells. The passive superconducting shells failed by allowing flux penetration. The other three methods were successful, singly or together. Experimental studies of passive ferromagnetic shielding are compared with calculations made using the Poisson Group of programs, distributed by the Los Alamos Accelerator Code Group of the Los Alamos National Laboratory. Agreement between calculation and experiment is good. The ferromagnetic material is a silicon iron alloy.

  18. Characteristics of YBaCuO magnetic shields

    SciTech Connect

    Hurben, M.J.; Symko, O.G. (Utah Univ., Salt Lake City, UT (United States). Dept. of Physics); Yeh, W.J. (Idaho Univ., Moscow, ID (United States). Dept. of Physics); Kulkarni, S. (AVX Corp., Myrtle Beach, SC (US)); Novak, M. (Dept. of Physics, Univ. Federal of Rio de Janeiro, Fondao, Rio de Janeiro (BR))

    1991-03-01

    This paper reports on magnetic shielding properties of YBaCuO tubes studied at temperatures of 77 K and 4 K. Shielding effectiveness was determined by measuring the magnetic field inside the tube in the presence of external magnetic fields. A high degree of shielding was achieved up to a critical external field which is determined by the critical current density of the material. Typically this critical field is 23 Oe at 77 K extending up to 105 Oe at 4 K. Tubes made with material containing 10% silver exhibited much stronger flux pinning behavior when the external magnetic field started to penetrate the tubes.

  19. Galactic heavy-ion shielding using electrostatic fields

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1984-01-01

    The shielding of spacecraft against galactic heavy ions, particularly high-energy Fe(56) nuclei, by electrostatic fields is analyzed for an arrangement of spherical concentric shells. Vacuum breakdown considerations are found to limit the minimum radii of the spheres to over 100 m. This limitation makes it impractical to use the fields for shielding small spacecraft. The voltages necessary to repel these Fe(56) nuclei exceed present electrostatic generating capabilities by over 2 orders of magnitude and render the concept useless as an alternative to traditional bulk-material shielding methods.

  20. Lunar Cold Traps: Effects of Double Shielding

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Coradini, A.

    1999-12-01

    This paper deals with the problem of water permanence on the surface of the Moon. Possible zones where water ice can survive are called cold traps (K. Watson, B. C. Murray, and H. Brown 1961, J. Geophys. Res.66, 3033-3045). These are zones of the Moon permanently obscured where the temperatures are low enough to preserve ice for billions of years. In this work we developed a model for the topographic temperatures of complex craters whose shape was approximated by a capsized frustum of a circular right cone. Double-shaded areas were simulated by embedding a small hemispherical crater in the shadowed part of the previous one. Their temperatures were calculated using the R. R. Hodges, Jr. (1980, Proc. Lunar Planet. Sci. Conf. 11th, 2463-2477) model. First we verified that our results were in agreement with those of previous models. Our results confirm those obtained by J. R. Salvail and F. P. Fanale (1994, Icarus111, 441-445), and in agreement with Hodges (1980), we found that the lowest temperatures are reached by Tycho-like craters that are the larger and shallower among the examined cases. When small craters are embedded in the shaded area of larger ones, their temperatures are low enough to preserve other volatiles like CO 2 (Hodges 1980). In particular, if we consider double-shaded areas in Biot-like craters, the temperatures are lower than 103 K in a shell of almost 20° around the poles, thus allowing the preservation of ices. For geometrical reasons a hemispherical crater embedded in the bottom of a Biot-like crater cold remain in the shadowed area for latitude values lower than those reached by an analogous crater embedded in Sosigene or Tycho-like craters. Therefore the latitudinal radius of polar frost caps could be greater than that predicted by previous models that did not consider double-shaded areas. However, double shielding occurs in only a fraction of the secondary craters; therefore, in this case eventual deposits of ice would be of smaller dimensions compared with the case of primary shielding. Analysis of the Clementine radar data (S. Nozette, C. L. Lichtenberg, P. Spudis, R. Bonner, W. Ort, E. Malaret, M. Robinson, and E. M. Shoemaker 1996, Science274, 5292-5300) and the Lunar Prospector neutron spectrometer data seems to be consistent with the presence of water ice in very low concentrations across a significant number of craters, thus confirming the old hypothesis of Watson et al. (1961).