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1

Shield Through Rejuvenated Stage Volcanism On Kauai and Niihau, Hawaii  

NASA Astrophysics Data System (ADS)

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.

Cousens, B.; Clague, D. A.

2013-12-01

2

Cloud immersion building shielding factors for US residential structures.  

PubMed

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

Dickson, E D; Hamby, D M

2014-12-01

3

Investigations of some building materials for ?-rays shielding effectiveness  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

4

Natural radioactivity in common building construction and radiation shielding materials  

Microsoft Academic Search

Commonly used building construction materials, radiation shielding bricks, hematite aggregate and other materials have been analyzed for the activity concentration of the natural radionuclides, namely 238U, 232Th and 40K, besides the radon exhalation rates. The activity concentration for 238U, 232Th and 40K varies from 29±1 to 98±4Bqkg?1, 20±2 to 112±2.8Bqkg?1, and 200±8 to 1908±15.6Bqkg?1, respectively, in various materials studied in

R. G. Sonkawade; K. Kant; S. Muralithar; R. Kumar; R. C. Ramola

2008-01-01

5

ENERGY DEPOSITION IN MAGNETS AND SHIELDING OF THE TARGET SYSTEM OF A STAGED NEUTRINO FACTORY  

E-print Network

unless the latter have adequate in- ternal shielding. As for the superconducting coils of the target-systemENERGY DEPOSITION IN MAGNETS AND SHIELDING OF THE TARGET SYSTEM OF A STAGED NEUTRINO FACTORY P. Snopok, Illinois Institute of Technology, Chicago, Illinois 60616, USA N. Souchlas, Particle Beam Lasers

McDonald, Kirk

6

Shielding study for fast-burst reactor building  

SciTech Connect

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.

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

2002-01-01

7

PLUG STORAGE BUILDING, TRA611, AWAITS SHIELDING SOIL TO BE PLACED ...  

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

PLUG STORAGE BUILDING, TRA-611, AWAITS SHIELDING SOIL TO BE PLACED OVER PLUG STORAGE TUBES. WING WALLS WILL SUPPORT EARTH FILL. MTR, PROCESS WATER BUILDING, AND WORKING RESERVOIR IN VIEW BEYOND PLUG STORAGE. CAMERA FACES NORTHEAST. INL NEGATIVE NO. 2949. Unknown Photographer, 7/30/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

8

Shielding and Build-up Considerations for Radiation Detection  

SciTech Connect

Abstract -- Shielding for gamma radiation has traditionally focused on the reduction of dose effects. For these applications, reducing the energy of the radiation is important along with reducing the actual number of photons, and therefore large masses of high Z material are typically used. However, for measurements requiring low backgrounds or for detecting low activity signals, such as in homeland security applications, the primary use of shielding is to decrease the total number of background photons (perhaps in a region of interest), and therefore the processes of buildup and down scattering become important. In these applications, where the important measure is count rate instead of dose and low background are important, improved reduction in counts from background radiation may be achieved with specially designed configurations of thin layers of different materials instead of a single thick layer. This paper briefly describes recent modeling and experimental investigations in layered-shielding methodology and provides results with comparison to single shielding material such as Pb. Application of these techniques to some real world problems, such as detector systems for homeland security, is discussed.

Ely, James H.; Kernan, Warnick J.; Kouzes, Richard T.; Siciliano, Edward R.

2008-10-19

9

Building Shielding Facility quarterly report, April, May, and June 1989  

SciTech Connect

The Bulk Shielding Reactor (BSR) remained shut down during April, May, and June. Water-quality control in both the reactor primary and secondary cooling systems was satisfactory. The Pool Critical Assembly (PCA) is shut down for shim-safety rod magnets and associated electronic components upgrading. 1 fig., 10 tabs.

Laughlin, D.L.; Hamrick, T.P.

1989-09-01

10

Implications for the early shield-stage evolution of Tenerife from K\\/Ar ages and magnetic stratigraphy  

Microsoft Academic Search

The combined use of field geology, radioisotopic dating and magnetic stratigraphy applied to the old shield volcanoes of Tenerife provides a reliable time framework for the early, shield-stage evolution of the island. The greater part of this new set of ages, obtained from sequences of lava flows is in agreement with the astronomical polarity time scale. This approach illustrates that

Hervé Guillou; Juan Carlos Carracedo; Raphael Paris; Francisco José Pérèz Torrado

2004-01-01

11

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

12

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

13

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

14

HOT CELL BUILDING, TRA632. SECTION DETAILS OF SHIELD CONCRETE, OPERATING ...  

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

HOT CELL BUILDING, TRA-632. SECTION DETAILS OF SHIELD CONCRETE, OPERATING WINDOWS, CHARGING HOLES. IDAHO OPERATIONS OFFICE MTR-632-IDO-5, 11/1950. INL INDEX NO. 531-0632-60-396-110564, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

15

PLUG STORAGE BUILDING, TRA611, AS IT LOOKED WITH EARTHEN SHIELD ...  

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

PLUG STORAGE BUILDING, TRA-611, AS IT LOOKED WITH EARTHEN SHIELD COVERING STORAGE TUBES. MTR WING, TRA-604, AT RIGHT OF VIEW. CAMERA FACES NORTHWEST. INL NEGATIVE NO. 3177. Unknown Photographer, 8/29/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

16

Three-dimensional analysis of AP600 standard plant shield building roof  

SciTech Connect

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.

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

1999-06-01

17

LPT. Shield test facility assembly and test building (TAN646). East ...  

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

LPT. Shield test facility assembly and test building (TAN-646). East facade of ebor helium wing addition. Camera facing west. Note asbestos-cement siding on stair enclosure and upper-level. Concrete siding at lower level. Metal stack. Monorail protrudes from upper level of south wall at left of view. INEEL negative no. HD-40-7-4 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

18

Isotopic geochemistry of Hualalai shield-stage tholeiitic basalts from submarine North Kona region, Hawaii  

NASA Astrophysics Data System (ADS)

The geochemical data of Hualalai tholeiitic basalts allow extension of the temporal variations established at Mauna Loa back in time, and provide important information for the long-term temporal variation of the Hawaiian lavas. We report new Hf, Pb, Nd, and Sr isotope compositions for 32 Hualalai tholeiitic basalts collected from deep submarine portions of the North Kona region. The samples were collected from the lower section of the North Kona bench (dives K218 and K219), a submarine stratigraphic section at Hualalai volcano's northwest rift zone (dive S690), and an elongate ridge outboard of the central section of the bench (dive S692), during two JAMSTEC Hawaii cruises in 2001 and 2002. The Hualalai shield-stage tholeiitic basalts have magma source isotopic signatures similar to Mauna Loa. The new data shows temporal Pb and Sr isotope trends that correspond to the long-term temporal variations in Loa-trend lavas, and the Hualalai-Mauna Loa lavas seem to show inter-shield geochemical excursions. Variation in Pb and Sr isotopes at Hualalai appears to take place over a longer time scale than at Mauna Loa. The merged Hualalai-Mauna Loa isotopic trends support models where heterogeneous material in the plume conduit is distributed chaotically, with variable cross-sectional density and length scale.

Yamasaki, Seiko; Kani, Tomomi; Hanan, Barry B.; Tagami, Takahiro

2009-09-01

19

Saturn IB S-IVB Stage at Vehicle Assembly Building  

NASA Technical Reports Server (NTRS)

Workmen remove the Saturn IB S-IVB-206, the second flight stage for the Skylab 2 mission, from the vehicle assembly building at the Kennedy Space Center. Designed and developed by the Marshall Space Flight Center and the Douglas Aircraft Company in Sacramento, California, the stage was powered by a single J-2 engine, which produced 200,000 pounds of thrust, later uprated to 230,000 pounds for the Saturn V launch vehicle.

1967-01-01

20

Performances of single and two-stage pulse tube cryocoolers under different vacuum levels with and without thermal radiation shields  

NASA Astrophysics Data System (ADS)

Single and two-stage Pulse Tube Cryocoolers (PTC) have been designed, fabricated and experimentally studied. The single stage PTC reaches a no-load temperature of ~ 29 K at its cold end, the two-stage PTC reaches ~ 2.9 K in its second stage cold end and ~ 60 K in its first stage cold end. The two-stage Pulse Tube Cryocooler provides a cooling power of ~ 250 mW at 4.2 K. The single stage system uses stainless steel meshes along with Pb granules as its regenerator materials, while the two-stage PTC uses combinations of Pb along with Er3Ni / HoCu2 as the second stage regenerator materials. Normally, the above systems are insulated by thermal radiation shields and mounted inside a vacuum chamber which is maintained at high vacuum. To evaluate the performance of these systems in the possible conditions of loss of vacuum with and without radiation shields, experimental studies have been performed. The heat-in-leak under such severe conditions has been estimated from the heat load characteristics of the respective stages. The experimental results are analyzed to obtain surface emissivities and effective thermal conductivities as a function of interspace pressure.

Kasthurirengan, Srinivasan; Behera, Upendra; Nadig, D. S.; Krishnamoorthy, V.

2012-06-01

21

The TRADE experiment: shielding calculations for the building hosting the subcritical system.  

PubMed

The TRADE project (TRiga Accelerator Driven Experiment), to be performed at the existing TRIGA reactor at ENEA Casaccia, has been proposed as a validation of the accelerator-driven system (ADS) concept. TRADE will be the first experiment in which the three main components of an ADS--the accelerator, spallation target and sub-critical blanket--are coupled at a power level sufficient to encounter reactivity feedback effects. As such, TRADE represents the necessary intermediate step in the development of hybrid transmutation systems, its expected outcomes being considered crucial--in terms of proof of stability of operation, dynamic behaviour and licensing issues--for the subsequent realisation of an ADS Transmutation Demonstrator. An essential role in the feasibility study of the experiment is played by radioprotection calculations. Such a system exhibits new characteristics with respect to a traditional reactor, owing to the presence of the proton accelerator. As beam losses always occur under normal operating conditions of an accelerator, shielding studies need to be performed not only around the reactor but also along the beam line from the accelerator to the spallation target. This paper illustrates a preliminary evaluation, using Monte Carlo methods, of the additional shielding to be located around the reactor structures, the beam transport line and the existing reactor building to allow access into the reactor hall and to restrict the doses outside to their legal limits. PMID:16381710

Burn, K W; Carta, M; Casalini, L; Kadi, Y; Monti, S; Nava, E; Palomba, M; Petrovich, C; Picardi, L; Rubbia, C; Troiani, F

2005-01-01

22

Pb, Hf, Nd, and Sr Isotopic Variations of Hualalai Shield Stage Tholeiites from the Submarine North Kona Region  

NASA Astrophysics Data System (ADS)

We present the isotope and trace element compositions of tholeiitic lavas collected from deep submarine portions of North Kona region, the west flank of Hualalai volcano. The samples were collected from the lower section of the North Kona bench (dives K218 and K219), a submarine section at Hualalai volcano's northwest rift zone (dive S690), and an elongate ridge below the central section of the bench (dive S692) during 2001 and 2002 JAMSTEC Hawaii cruises. Hualalai volcano is presently in the post-shield alkalic stage and most of its subaerial surface is covered by alkalic basalt. All analyzed samples of the pillow lavas are tholeiites that erupted during Hualalai shield stage. It is important to identify source materials involved in the volumetrically dominant stage of Hualalai volcano in order to provide constraints for the size and distribution of compositional heterogeneities of Hawaiian plume. The isotopic compositions of the submarine North Kona tholeiites are similar to the data previously reported for Mauna Loa tholeiites. The data trends define clear mixing relationships that require at least three mantle source components. The mixing is dominated by a Koolau-like enriched component and a Kea-like depleted component. The K219 data trend toward higher epsilon Hf and 87Sr/86Sr relative to the K218, S690, and S692 arrays, requiring another component similar to that observed in post-shield lavas of Hualalai volcano. Pb isotopic compositions for samples from dive K218 and K219 form distinct non-overlapping Pb-Pb arrays suggesting further source heterogeneity. Samples from dive S690 and S692 plot on both of these trends. These findings suggest small-scale compositional heterogeneity in the source regions that can be attributed to anomalous irregular 'blobs' involved in late shield stage magmatism of Mauna Loa reported in previous works.

Yamasaki, S.; Kani, T.; Hanan, B. B.; Tagami, T.

2007-12-01

23

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

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…

Knott, Albert

24

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

NASA Technical Reports Server (NTRS)

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.

Robinson, David W.

2002-01-01

25

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

E-print Network

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 ...

Mandelbaum, Andrew (Andrew Joseph)

2014-01-01

26

The Initial Stage of a School's Capacity Building  

ERIC Educational Resources Information Center

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…

Stocklin, Sacha

2010-01-01

27

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

SciTech Connect

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.

NONE

1996-02-09

28

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

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

29

Thermodynamic modelling of Sol Hamed serpentinite, South Eastern Desert of Egypt: implication for two serpentinization stages in the Arabian-Nubian Shield ophiolites  

NASA Astrophysics Data System (ADS)

The Arabian-Nubian Shield is the largest tract of juvenile continental crust of Neoproterozoic age on Earth. This crust was generated due to arc-arc collision associated with the closing of the Mozambique Ocean. Distribution of ophiolitic rocks marks fossils suture zones in the shield. Petrological, mineral chemistry, whole-rock chemistry and thermodynamic studies are carried out to examine the serpentinite component of Sol Hamed ophiolite in south Eastern Desert of Egypt. The protolith mantle was harzburgite and formed in subduction zone of forearc setting. Serpentinization occurred in two stages. The first by intrusion of high concentrated CO2 fluid released from carbonate-bearing sediments and altered basalt at the subduction zone. The serpentinization achieved during isobaric cooling path at pressure of 1 kbar and before the emplacement. The minimum temperature limit of the serpentinization is above the breakdown of lizardite to antigorite and brucite (170 °C). The fluid composition during the isobaric cooling path was buffered by the metamorphic reactions. The second stage of serpentinization took place through prograde path which led to formation of chrysotile after lizardite. The increasing in the pressure during this stage occurred as a result of extensive duplex array and thrusting of oceanic crust. The crust in the forearc basin was overloaded by 28 km of obducted and thrusted oceanic crust from both mid-oceanic and forearc basins, respectively.

Abu-Alam, T.; Hamdy, M.

2012-04-01

30

39Ar– 40Ar ages and geochemistry of the basaltic shield stage of Tenerife, Canary Islands, Spain  

Microsoft Academic Search

We report the first 39Ar–40Ar ages from the three early basic shield-like massifs of Tenerife, Canary islands, and couple these with detailed major and trace element chemistry to constrain the nature and timing of the mantle melting processes. The massifs have chemically different sources, and independent evolutionary histories. The Teno and Roque del Conde massifs appear chemically to represent the

M. F Thirlwall; B. S Singer; G. F Marriner

2000-01-01

31

On the developmenet of multi-linear regression analysis to assess energy consumption in the early stages of building design  

NASA Astrophysics Data System (ADS)

Modeling of energy consumption in buildings is essential for different applications such as building energy management and establishing baselines. This makes building energy consumption estimation as a key tool to achieve the goals on energy consumption and emissions reduction. Energy performance of building is complex, since it depends on several parameters related to the building characteristics, equipment and systems, weather, occupants, and sociological influences. This paper presents a new model to predict and quantify energy consumption in commercial buildings in the early stages of the design. eQUEST and DOE-2 building simulation software was used to build and simulate individual building configuration that were generated using Monte Carlo simulation technique. Ten thousands simulations for seven building shapes were performed to create a comprehensive dataset covering the full ranges of design parameters. The present study considered building materials, their thickness, building shape, and occupant schedule as design variables since building energy performance is sensitive to these variables. Then, the results of the energy simulations were implemented into a set of regression equation to predict the energy consumption in each design scenario. The difference between regression-predicted and DOE-simulated annual building energy consumption are largely within 5%. It is envisioned that the developed regression models can be utilized to estimate the energy savings in the early stages of the design when different building schemes and design concepts are being considered. Keywords: eQUEST simulation, DOE-2 simulation, Monte Carlo simulation, Regression equations, Building energy performance

Shams Amiri, Shideh

32

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)

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.

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

2013-05-01

33

The Immature Stages and Shelter Building Behavior of Falgo Jeconia Ombra Evans, 1955 in eastern Ecuador (Lepidoptera: Hesperiidae: Hesperiinae)  

PubMed Central

We describe the immature stages and shelter building behavior of Falga jeconia ombra Evans, 1955 from eastern Ecuador. Chusquea scandens (Poaceae, Bambusoidea) is the larval food plant. Larvae in all stadia build shelters and forcibly eject frass with the aid of an anal comb. Later instars possess an eversible prothoracic “neck” gland. Larvae are associated with moving water. PMID:19613872

Greeney, Harold F.; Warren, Andrew D.

2009-01-01

34

Late CryogenianEdiacaran history of the ArabianNubian Shield: A review of depositional, plutonic, structural, and tectonic events in the closing stages  

E-print Network

Late Cryogenian­Ediacaran history of the Arabian­Nubian Shield: A review of depositional, plutonic Available online 23 July 2011 Keywords: Arabian­Nubian Shield Cryogenian Ediacaran Tectonics Magmatism Deposition a b s t r a c t During the late Cryogenian­Ediacaran (650­542 Ma), the Arabian­Nubian Shield (ANS

Stern, Robert J.

35

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

SciTech Connect

The Whole-Building Energy Design Targets project is being conducted for the US Department of Energy (DOE) by the Pacific Northwest Laboratory (PNL). The objective of the project is to develop a flexible methodology for setting energy performance guidelines with which architects, engineers, planners, and owners can assess energy efficiency in commercial building design. This volume, the third in the four-volume report on the Targets project concept stage, contains the minutes of the workshops as well as summaries of the expert's written comments prepared at the close of each workshop. In Section 2, the building energy simulation workshop is summarized. Section 3 provides a summary of the building cost workshop.

Jones, J.W. (American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (USA)); Deringer, J.J. (Deringer Group, Riva, MD (USA)); Hall, J.D. (American Inst. of Architects, Washington, DC (USA)) (comps.)

1990-09-01

36

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

PubMed Central

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

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

2014-01-01

37

Early stage design decisions: the way to achieve sustainable buildings at lower costs.  

PubMed

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

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

2014-01-01

38

Consequences of the instar stage for behavior in a pit-building antlion.  

PubMed

Pit-building antlion larvae are opportunistic predators that dig conical pits in loose soils, and prey on small arthropods that fall into their traps. We investigated different behavioral traits of second and third instar larvae selected for similar body masses, while also exploring the behavioral consistency and personalities of the third instar stage. Second instar larvae constructed smaller pits than third instar larvae. The former also responded more slowly to prey and exploited prey less efficiently. Notably, all these instar-based differences disappeared after molting into the third instar stage. In addition, third instar larvae exhibited consistent behavior in their pit size, response times to prey and to less extent in relocation distances. We detected two axes of behavior. The first axis included a correlation between pit size, response time and prey exploitation efficiency, thus reflecting investment in foraging activity. The second axis seemed to represent a trade-off between response time and relocation distance, implying that individuals that responded more slowly to prey, relocated over larger distances. These results point to coordinated behavior reflecting different levels of investment in foraging, while also emphasizing the importance of instar stage, in addition to body mass, when studying the behavior of such organisms characterized by a complex life cycle. PMID:24315799

Alcalay, Yehonatan; Barkae, Erez David; Ovadia, Ofer; Scharf, Inon

2014-03-01

39

RADIATION MULTILAYER SHIELD IN THE REACTOR  

Microsoft Academic Search

The design of the reactor radiation shield is an integrated multistep process and consists of interdependent stages. On it's early stages the approximate calculation methods with different accuracy may be applied. We consider here a semi-empirical calculation model of radiation multilayer shield in the reactor having the core and shield configuration-infinite slab. Numerical calculations for three different geometrical configurations (infinite

LE VAN NGOC

2002-01-01

40

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

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.

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

1994-12-01

41

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

SciTech Connect

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.

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

42

Modular shield  

DOEpatents

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.

Snyder, Keith W. (Sandia Park, NM)

2002-01-01

43

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)

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.

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

2005-12-01

44

The MIT Design Advisor : simple and rapid energy simulation of early-stage building designs  

E-print Network

Simulation tools, when applied early in the design process, can considerably reduce the energy demand of newly constructed buildings. For a simulation tool to assist with design, it must be easy to use, provide feedback ...

Urban, Bryan J. (Bryan James)

2007-01-01

45

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.

46

Solar shield  

SciTech Connect

A flexible shield material having the characteristic of not transmitting solar heat, is supported on a frame which extends from end to end of an automobile or the like vehicle and is adjustable in length, having means on the opposite ends to be hooked to the front and rear bumpers and adapted to be locked, the longitudinal frame members including telescopic members so that the entire frame can be collapsed to a size adapted to be stored in the trunk of the average vehicle, and when extended space the sun shield from the vehicle body.

Johnson, B.L.

1980-01-22

47

The influence of immersion and presence in early stage engineering designing and building  

E-print Network

This paper explores the role of a designer's sense of engagement in early stage design. In the field of virtual reality, presence and immersion are standard measures of an individual's sense of engagement and involvement ...

Faas, Daniela

48

Thermocouple shield  

DOEpatents

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.

Ripley, Edward B. (Knoxville, TN)

2009-11-24

49

Drip Shield Emplacement Gantry Concept  

SciTech Connect

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.

Silva, R.A.; Cron, J.

2000-03-29

50

Prudhoe Bay Oil Production Optimization: Using Virtual intelligence Techniques, Stage One: Neural Model Building  

E-print Network

between the production separation facilities and central gas compression plant. The trained modelSPE 77659 Prudhoe Bay Oil Production Optimization: Using Virtual intelligence Techniques, Stage One and at the gas compression plant. The correlation coefficient for rate and pressure were 0.997 and 0

Mohaghegh, Shahab

51

Approaches to building single-stage AC/AC conversion switch-mode audio power Petar Ljusev and Michael A.E. Andersen  

E-print Network

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers Petar Ljusev and Michael A.E. Andersen �rsted · DTU, Automation, Technical University of Denmark Elektrovej, DTU Building 325, DK-2800 Kgs. Lyngby, Denmark E-mail: pl@oersted.dtu.dk, ma@oersted.dtu.dk Abstract

52

Sound shield  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

53

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

54

Skylab Solar Shield  

NASA Technical Reports Server (NTRS)

A sail like sunshade for possible use as a sunscreen for the Skylab Orbital Workshop (OWS) is shown being fabricated in the GE Building across the street from Johnson Space Center, Houston Texas. Three people help the steamstress feed the material through the sewing machine. The three-layered sunshade will be composed of a top layer of aluminized mylar, a middle layer of laminated nylon ripstop, and a bottom layer of thin nylon. Working on the sunshade are from left to right: Dale Gentry, Elizabeth Gauldin, Alyene Baker, and James H. Barnett Jr. Mrs. Baker, a GE employee, operates the double needle Singer sewing machine. Barnett is head of the Crew Equipment Development Section of JSC Crew Systems Division. Mrs. Gauldin is also with the Crew Systems Division. Gentry works for GE. The work shown here is part of the crash program underway to prepare a sunshield for Skylab to replace the orginal shield which was lost when Skylab 1 was launched on May 14, 1973. The improvised solar shield selected to be used will be carried to Earth orbit by the Skylab 2 crewman who will then deploy the reflective parasol to shade part of the OWS from the hot rays of the sun. Loss of the orginal sun shield has caused an overheating problem. in the Orbital Work Shop.

1973-01-01

55

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

NASA Technical Reports Server (NTRS)

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 is the fabrication methods for applying face sheets to aliphatic polymer closed-cell foams.

Wilson, John W.; Jensen, Brian J.; Thibeault, Sheila A.; Hou, Tan-Hung; Saether, Erik; Glaessgen, Edward H.; Humes, Donald H.; Chang, Chie K.; Badavi, Francis F.; Kiefer, Rrichard L.; Adams, Dan O.

2004-01-01

56

Policy Building Blocks: Helping Policymakers Determine Policy Staging for the Development of Distributed PV Markets: Preprint  

SciTech Connect

There is a growing body of qualitative and a limited body of quantitative literature supporting the common assertion that policy drives development of clean energy resources. Recent work in this area indicates that the impact of policy depends on policy type, length of time in place, and economic and social contexts of implementation. This work aims to inform policymakers about the impact of different policy types and to assist in the staging of those policies to maximize individual policy effectiveness and development of the market. To do so, this paper provides a framework for policy development to support the market for distributed photovoltaic systems. Next steps include mathematical validation of the framework and development of specific policy pathways given state economic and resource contexts.

Doris, E.

2012-04-01

57

Corium shield  

DOEpatents

A shield for restricting molten corium from flowing into a water sump disposed in a floor of a containment vessel includes upper and lower walls which extend vertically upwardly and downwardly from the floor for laterally bounding the sump. The upper wall includes a plurality of laterally spaced apart flow channels extending horizontally therethrough, with each channel having a bottom disposed coextensively with the floor for channeling water therefrom into the sump. Each channel has a height and a length predeterminedly selected for allowing heat from the molten corium to dissipate through the upper and lower walls as it flows therethrough for solidifying the molten corium therein to prevent accumulation thereof in the sump.

McDonald, Douglas B. (Pleasanton, CA); Buchholz, Carol E. (San Jose, CA)

1994-01-01

58

Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment  

NASA Technical Reports Server (NTRS)

Deep space missions must contend with a harsh radiation environment Impacts to crew and electronics. Need to invest in multifunctionality for spacecraft optimization. MMOD shield. Goals: Increase radiation mitigation potential. Retain overall MMOD shielding performance.

Rojdev, Kristina; Christiansen, Eric

2013-01-01

59

Magnetic shielding  

DOEpatents

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.

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

1985-02-12

60

Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment  

NASA Technical Reports Server (NTRS)

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

Rojdev, Kristina; Christiansen, Eric

2011-01-01

61

Space reactor shielding fabrication  

NASA Technical Reports Server (NTRS)

The fabrication of space reactor neutron shielding by a melting and casting process utilizing lithium hydride is described. The first neutron shield fabricated is a large pancake shape 86 inches in diameter, containing about 1700 pounds of lithium hydride. This shield, fabricated by the unique melting and casting process, is the largest lithium hydride shield ever built.

Welch, F. H.

1972-01-01

62

Low-cost Shielding to Minimize Radiation Errors of Temperature Sensors in the Field  

Microsoft Academic Search

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 and effective shields for replicated field experiments. Using the general physical principles that govern radiation shielding, a number of low-cost, passively ventilated radiation shields built in-house was assessed for the measurement of air temperature against

Julie M. Tarara

2007-01-01

63

Principles of quasistatic magnetic shielding with cylindrical and spherical shields  

Microsoft Academic Search

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

J. F. Hoburg; J. F. Hobug

1995-01-01

64

Meteoroid/Debris Shielding  

NASA Technical Reports Server (NTRS)

This report provides innovative, low-weight shielding solutions for spacecraft and the ballistic limit equations that define the shield's performance in the meteoroid/debris environment. Analyses and hypervelocity impact testing results are described that have been used in developing the shields and equations. Spacecraft shielding design and operational practices described in this report are used to provide effective spacecraft protection from meteoroid and debris impacts. Specific shield applications for the International Space Station (ISS), Space Shuttle Orbiter and the CONTOUR (Comet Nucleus Tour) space probe are provided. Whipple, Multi-Shock and Stuffed Whipple shield applications are described.

Christiansen, Eric L.

2003-01-01

65

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

E-print Network

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... in DOE-2, EnergyPlus and TRNSYS programs. 2. Introduction Foundation heat transfer is a significant load component for low-rise residential buildings. For a contemporary code or above code house, ground-coupled heat losses may account for 30...

Andolsun, S.; Culp, C.

2011-01-01

66

MINIMUM WEIGHT SHIELD SYNTHESIS  

Microsoft Academic Search

A simple model for radiation production and attenuation in a spherical ; multilayer reactor-shield assembly is introduced. Variational methods are ; applied to this model to minimize the weight subject to given specifications on ; the dose at the outside of the shield and on the properties of shielding ; materials. The method provides guidance in the choice of the

Troubetzkoy

1962-01-01

67

Enhanced Whipple Shield  

NASA Technical Reports Server (NTRS)

A hypervelocity impact (HVI) Whipple Shield and a method for shielding a wall from penetration by high velocity particle impacts where the Whipple Shield is comprised of spaced apart inner and outer metal sheets or walls with an intermediate cloth barrier arrangement comprised of ceramic cloth and high strength cloth which are interrelated by ballistic formulae.

Crews, Jeanne L. (Inventor); Christiansen, Eric L. (Inventor); Williamsen, Joel E. (Inventor); Robinson, Jennifer R. (Inventor); Nolen, Angela M. (Inventor)

1997-01-01

68

Collagen Corneal Shields  

Microsoft Academic Search

Collagen corneal shields were developed as a corneal bandage lens and are currently indicated for ocular surface protection following surgery and in traumatic and nontraumatic corneal conditions. Collagen shields are manufactured from porcine or bovine collagen and three different collagen shields are currently available with dissolution times of 12, 24, and 72 hours. The theoretical, experimental, and clinical evidence supports

C. E Willoughby; M Batterbury; S. B Kaye

2002-01-01

69

Rotating shielded crane system  

DOEpatents

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.

Commander, John C. (Idaho Falls, ID)

1988-01-01

70

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)

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.

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

2011-10-01

71

Flow-By-Flow Mapping on Fogo, Cape Verde Islands, Reveals Long Term Variations in Eruption Distributions and Volcanic Edifice Structure at a Shield-Stage Oceanic Island Volcano  

NASA Astrophysics Data System (ADS)

Most maps of large oceanic island shield volcanoes show the lava flows and scoria cones of individual historic and subhistoric eruptions as individual units but then resort to grouping older rocks into larger stratigraphic units. This grouping makes it difficult to characterize long-term progressive trends in volumes of individual eruptions and distributions of eruptive vents, but is commonly made necessary by poor exposure, limited compositional variation between individual eruptions, and burial of older by younger volcanic rocks. In contrast, work on Fogo, Cape Verde Islands has involved flow-by-flow mapping of rocks erupted over an extended period of tens of thousands of years, as part of the process of mapping the island and producing a 1:25 000 scale geological map for research and hazard management purposes. Around three-quarters of the island is characterized by low rainfall and limited vegetation cover, with erosion restricted to narrow gullies. Only in small areas on the windward side of the island do higher rainfall, thick vegetation and deeper erosion combine to prevent flow-by-flow mapping. The map of the island is accompanied by a rigorous representation of direct and inferred age relationships between lavas and scoria cones of different eruptions using a novel type of age correlation diagram. The time period covered by the flow-by-flow mapping includes both the final stages of growth of an older shield volcano (Monte Amarelo volcano) prior to its collapse and the subsequent growth of a new volcano (Cha das Caldeiras volcano). The latter forms a thick infill and summit cone within the Monte Amarelo collapse scar together with partial covering of the outer flanks of the Monte Amarelo volcano with a veneer of younger lavas and scoria cones. The erupted rocks are compositionally varied (ankaramitic nephelinites, basanites, tephrites) and often highly porphyritic. Petrographic criteria were therefore used to aid field mapping, define lithostratigraphic units and demonstrate systematic changes in compositions of erupted magmas through time. Some of these changes, particularly eruptions of ankaramitic magmas, coincide with similar sequences of volcano-structural changes that have occurred prior to the Monte Amarelo collapse and again during the Holocene (beginning around 11 000 years before present; Foeken et al, 2009). The flow-by-flow mapping approach has allowed reconstruction and comparison of the sequences of these structural changes, and thus provides insights into the inferred progressive destabilization of the eastern flank of Fogo during the Holocene, as well as into wide variations in eruption and resurfacing rates that have occurred on decade to century timescales in more recent times. Foeken, J.P.T., Day, S.J. & Stuart, F.M. (2009) Cosmogenic 3He exposure dating of the Quaternary basalts from Fogo, Cape Verdes: Implications for rift zone and magmatic reorganization. Quaternary Geology 4 (2009) 37 - 49.

Day, S. J.

2011-12-01

72

ELECTROMAGNETIC CONSTRUCTION OF A 1 KM-RADIUS RADIATION SHIELD  

E-print Network

1 ELECTROMAGNETIC CONSTRUCTION OF A 1 KM-RADIUS RADIATION SHIELD Ganesh, B.A., Wanis, S A fundamental obstacle to building human settlements in orbit is the construction of the massive outer radiation shield. This problem is used to illustrate the relevance of a comprehensive plan in developing a Space

73

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

74

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

SciTech Connect

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.

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

75

RIS-M-2339 SHIELDING FACTORS FOR VEHICLES TO GAMMA RADIATION FROM  

E-print Network

RISÃ?-M-2339 SHIELDING FACTORS FOR VEHICLES TO GAMMA RADIATION FROM ACTIVITY DEPOSITED ON STRUCTURES Repro 1982 #12;CONTENTS Page 1. INTRODUCTION 5 2. STRUCTURAL SHIELDING AGAINST RADIATION FROM A SURFACE determined for gamma radiation from deposited 1 ^7 Cs. Corrections for mut.'al shielding by nearby buildings

76

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...

77

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

"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…

Actuarial Foundation, 2013

2013-01-01

78

Shielding calculations at dismantled synchrocyclotron  

SciTech Connect

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.

Yalcintas, M.G.

1987-01-01

79

RF shielded connectors  

NASA Technical Reports Server (NTRS)

Gap, where cable joins connector housing, is shielded effectively by composite RF shielding made from suitable potting resin material (fumed silica, thixotropic prepolymer composition), conductive coating (silver-filled, flexible, polyurethane resin), and protective jacket (wax coated housing formed around another wax form having contours shaped to match configuration).

Fisher, A.; Clatterbuck, C.

1974-01-01

80

Shielding for thermal neutrons.  

PubMed

The problem of calculating the neutron capture gamma-ray dose rate due to thermal neutron capture in a boron or cadmium rectangular shield is considered. An example is given for shielding for a door at the exit of medical accelerator room maze in order to determine the optimum location of lead relative to the borated polyethylene. PMID:9029548

McCall, R C

1997-01-01

81

REACTOR SHIELD PENETRATION CALCULATIONS  

Microsoft Academic Search

Application of point-to-point attenuation functions to the calculation ; of fast neutron and gamma ray dose and energy absorption rates in and around ; reactor shields is described. A description of IBM-704 programs capable of ; evaluating attenuation functions along source-receiver paths in complex shields ; and performing a final integration over a source region is presented. (auth);

W. E. Edwards; J. E. MacDonald

1958-01-01

82

Whipple shield sizing equations  

NASA Technical Reports Server (NTRS)

Wipple shield sizing equations are given for use in current Space Station Freedom (SSF) Work Package 2 (WP-2) trade study activities. These equations are modifications of the 1969 Cour-Palais predictor equations which were used by McDonnell Douglas to size WP-2 meteoroid and debris shielding for the SSF preliminary design review. Recent hypervelocity impact (HVI) test results have shown that the original 1969 Cour-Palais predictor improperly scales to the particle sizes that the WP-2 shields must be designed to protect against. The original equations have been redesigned to correct this scaling deficiency. Substantial increases to WP-2 shielding weight estimates are indicated by the modified equations. Several possibilities exist, however, to reduce the weight of WP-2 shielding. These equations will be updated in the future as warranted by the results of ultra-high speed (greater than 19 km/sec) HVI tests and further analysis.

Christiansen, Eric L.

1991-01-01

83

Ariane 5 upper stage thermal protection system  

NASA Astrophysics Data System (ADS)

The thermal protection system of the Ariane 5 upper stage tank section development program is described with special emphasis on the heat shield. The optimization process is given, beginning with material selection combined with analysis and followed by test verification. Attention is given to the storable propellant stage (SPS) thermal design, heat shield component thermal performance tests, SPS heat shield verification test results, and the manufacturing and integration approach.

Schwarz, B.; Menn, F.; Gutschmidt, K.

1991-07-01

84

Radiation Shielding Materials  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

85

9. BUILDING NO. 620B, FRICTION PENDULUM BUILDING. 29FOOT DROP TOWER ...  

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

9. BUILDING NO. 620-B, FRICTION PENDULUM BUILDING. 29-FOOT DROP TOWER SITS BEHIND BLAST SHIELD IN FRONT OF BUILDING. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

86

iSHIELD - A Line Source Application of SHIELD11  

SciTech Connect

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.

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

2006-04-27

87

Alternate shield material feasibility  

SciTech Connect

The feasibility and cost/benefit of using materials other than stainless steel for in-vessel neutron shielding in large LMFBRs were investigated. Canned vibratorally compacted B/sub 4/C powder shields were found to be much more economical than stainless steel (a savings of $1.1M in loop plant designs and $9.4M in pool plant designs). The helium gas pressure buildup in B/sub 4/C shields placed around LMFBR in-vessel components (direct reactor heat exchangers in a loop reactor and intermediate heat exchangers in a pool reactor) would only be 0.04 atm after 40 y of reactor operation (with 80% dense powder). The irradiation-induced swelling of the B/sub 4/C would only be 0.002%. No adverse reactor impact would occur if the B/sub 4/C escaped from the B/sub 4/C shields.

Specht, E.R.; Levitt, L.B.

1984-04-01

88

Side Shield for Wall Support  

NASA Technical Reports Server (NTRS)

Method employs curved shield on each side of mining machine. In stowed position, shield folded against roof-support columns on one side. In deployed position, shield raised and braced against coal-seam wall by hydraulic cylinder. Shield supports wall until roof and wall properly secured by bolting and cement coating.

Lewis, E. V.

1985-01-01

89

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

90

Dynamic rotating-shield brachytherapy  

SciTech Connect

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.

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

91

Dynamic rotating-shield brachytherapy  

PubMed Central

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 D90 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 192Ir-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 D2cc 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 Ci192Ir source, and the average HR-CTV D90 was 78.9 Gy. In order to match the HR-CTV D90 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 D90 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 D90 over IS + ICBT and S-RSBT without violating the tolerance doses to the bladder, rectum, or sigmoid. The D90 improvements from D-RSBT depend on the patient, the delivery time budget, and the applicator structure. PMID:24320489

Liu, Yunlong; Flynn, Ryan T.; Kim, Yusung; Yang, Wenjun; Wu, Xiaodong

2013-01-01

92

Shield sizing and response equations  

NASA Technical Reports Server (NTRS)

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.

Christiansen, Eric L.

1991-01-01

93

Refurbishment of industrial buildings  

Microsoft Academic Search

When a building is subject for refurbishment, there is a golden opportunity to change its behavior as an energy system. This paper shows the importance of careful investigations of the processes, the climate shield and the heating systems already present in the building before measures are implemented in reality. A case study is presented dealing with a carpentry factory. The

Stig-Inge Gustafsson

2006-01-01

94

Shielded, Automated Umbilical Mechanism  

NASA Technical Reports Server (NTRS)

Umbilical mechanism automatically connects and disconnects various fluid couplings and/or electrical contacts while shielding mating parts from debris. Reacts mating and demating loads internally, without additional supporting structures. All functions - extension of plug, mating, and movement of debris shields - actuated by single motor. If mechanism jams or fails at any point in sequence, override feature in drive train allows manual operation. Designed for service in outer space, where its shields protect against micrometeoroids, debris, ultraviolet radiation, and atomic oxygen. Used on Earth to connect or disconnect fluid or electrical utilities in harsh environments like those of nuclear powerplants or undersea construction sites, or in presence of radioactive, chemical, or biological hazards, for example.

Barron, Daniel R.; Morrill, Brion F.; Jasulaitis, Vytas

1995-01-01

95

Shielded planar write head  

NASA Astrophysics Data System (ADS)

Field calculation with a finite-element method was performed for optimization of the shielded planar head composed of a tapered pole in both down and cross track directions and a wrap-around shield. Especially, effect of the taper angle of the main pole and the gap length and the height of the shield on head field was investigated to obtain a strong head field with a sharp distribution. In order to explore potential of the planar head, comparison with a conventional head with a normal main pole with a short throat was made and feasibility of 1 Tbit/in 2 recording with patterned media was discussed in terms of magnetization reversals of aimed track and thermal stability of magnetization on adjacent tracks.

Yamakawa, K.; Ise, K.; Takahashi, S.; Honda, N.; Ouchi, K.

96

Radiation shielding composition  

DOEpatents

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.

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

2000-12-26

97

Radiation shielding composition  

DOEpatents

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.

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

1998-07-28

98

Radiation shielding composition  

DOEpatents

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.

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

1998-01-01

99

Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures.  

PubMed

The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. 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 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building's radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology. PMID:24487195

Dickson, E D; Hamby, D M

2014-03-01

100

Composition for radiation shielding  

DOEpatents

A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

Kronberg, James W. (Aiken, SC)

1994-01-01

101

Glove box shield  

DOEpatents

According to the present invention, a shield for a glove box housing radioactive material is comprised of spaced apart clamping members which maintain three overlapping flaps in place therebetween. There is a central flap and two side flaps, the side flaps overlapping at the interior edges thereof and the central flap extending past the intersection of the side flaps in order to insure that the shield is always closed when the user withdraws his hand from the glove box. Lead loaded neoprene rubber is the preferred material for the three flaps, the extent of lead loading depending upon the radiation levels within the glove box.

Brackenbush, Larry W. (Richland, WA); Hoenes, Glenn R. (Richland, WA)

1981-01-01

102

SHIELDING COMPUTER PROGRAM 14-0, REACTOR SHIELD ANALYSIS  

Microsoft Academic Search

Shielding Computer Program 14-0 evaluates point-topoint attenuation ; functions and integrates over source regions to perform reactor-shield ; penetration calculations for neutrons and gamma rays. Neutron dose rates and ; gamma ray flux and dose and energy absorption rates can be computed for positions ; in and around complex reactor shields containing multiple sources described in a ; cylindrical coordinate

J. T. Martin; J. P. Yalch; W. E. Edwards

1958-01-01

103

Lightweight blast shield  

DOEpatents

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.

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

104

Multilayer radiation shield  

Microsoft Academic Search

A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced

John Arthur Urbahn; Evangelos Trifon Laskaris

2009-01-01

105

Project BioShield  

Microsoft Academic Search

Summary Many potential biological terrorism agents lack available countermeasures. President Bush proposed Project BioShield to encourage companies to develop new bioterror countermeasures. The main provisions of that proposal include: (1) relaxing procedures for bioterrorism-related procurement and peer review; (2) guaranteeing a market through contract authority granted to the Secretary of Health and Human Services (HHS) to buy countermeasures following Presidential

Frank Gottron

106

Jupiter: Earth's Shield  

NSDL National Science Digital Library

Jupiter's immense gravity protects Earth from asteroids. In this video segment adapted from NOVA, scientists searching for signs of life in the universe identify solar systems with Jupiter-like planets that may be shielding smaller nearby Earth-like planets from comets and asteroids.

2005-12-17

107

Shields for small molecules  

PubMed Central

Nucleic acid aptamers have been employed to shield small molecules so that one among many similar reactive functional groups can be modified. This provides access to new chemical entities with potentially interesting properties while avoiding the use of covalent protecting groups. PMID:23000986

Silverman, Scott K.

2012-01-01

108

Shield against radiations  

SciTech Connect

This patent describes a shield against ionizing radiations that comprises at least one layer of an aggregate-containing cement-based conglomerate or an aggregate-containing cement-based mortar wherein the aggregate consists essentially of floated galena or mixtures thereof which at least one boron mineral.

Grifoni, S.

1988-02-23

109

Materials for electromagnetic interference shielding  

Microsoft Academic Search

Materials for the electromagnetic interference (EMI) shielding of electronics and radiation sources are reviewed, with emphasis\\u000a on composite materials and resilient EMI gasket materials, which shield mainly by reflection of the radiation at a high frequency.

D. D. L. Chung

2000-01-01

110

President Clinton Defers Missile Shield Decision  

NSDL National Science Digital Library

President Clinton will announce in a speech at Georgetown University today that he will not begin the initial steps to deploy a national missile defense shield, leaving the final decision to his successor. The decision to not begin construction of a radar site in Alaska, designed to track incoming missiles, was apparently the product of several factors. These include the failure of recent tests, strong opposition from Russia and some US allies, and fears that any decision would inevitably become politicized with the election nearing. Vice-President Al Gore has expressed conditional support for a missile shield, while George W. Bush has called for an even more extensive system. The President made his decision after receiving competing advice on the missile shield. William S. Cohen, the defense secretary, had recommended Mr. Clinton begin, while Samuel R. Berger, the President's national security advisor, and others recommended against construction at this point. Work on the project will continue nonetheless, including additional tests of the "kill vehicle" and a new booster rocket. The next President will decide not only whether to build the radar station and other elements of a missile shield infrastructure, but also whether to field the system and break the 1972 Antiballistic Missile Treaty.

de Nie, Michael Willem.

111

SSC environmental radiation shielding  

SciTech Connect

The environmental radiation shielding requirements of the SSC have been evaluated using currently available computational tools that incorporate the well known processes of energy loss and degradation of high energy particles into Monte Carlo computer codes. These tools permit determination of isodose contours in the matter surrounding a source point and therefore the specification of minimum thicknesses or extents of shielding in order to assure annual dose equivalents less than some specified design amount. For the general public the annual dose equivalent specified in the design is 10 millirem, small compared to the dose from naturally occurring radiation. The types of radiation fall into two classes for the purposes of shielding determinations-hadrons and muons. The sources of radiation at the SSC of concern for the surrounding environment are the interaction regions, the specially designed beam dumps into which the beams are dumped from time to time, and beam clean-up regions where stops remove the beam halo in order to reduce experimental backgrounds. A final, unlikely source of radiation considered is the accidental loss of the full beam at some point around the ring. Conservative choices of a luminosity of 10{sup 34} cm{sup {minus}2}s{sup {minus}1} and a beam current three times design have been made in calculating the required shielding and boundaries of the facility. In addition to determination of minimum distances for the annual dose equivalents, the question of possible radioactivity produced in nearby wells or in municipal water supplies is addressed. The designed shielding distances and beam dumps are such that the induced radioactivity in ground water is safely smaller than the levels permitted by EPA and international agencies.

Jackson, J.D. [ed.

1987-07-01

112

Flexible Multi-Shock Shield  

NASA Technical Reports Server (NTRS)

Flexible multi-shock shield system and method are disclosed for defending against hypervelocity particles. The flexible multi-shock shield system and method may include a number of flexible bumpers or shield layers spaced apart by one or more resilient support layers, all of which may be encapsulated in a protective cover. Fasteners associated with the protective cover allow the flexible multi-shock shield to be secured to the surface of a structure to be protected.

Christiansen, Eric L. (Inventor); Crews, Jeanne L. (Inventor)

2005-01-01

113

Improved ferrous shielding for flat cables  

NASA Technical Reports Server (NTRS)

To improve shielding of flat multicore cables, a thin, seamless ferrous shield around all cores optimizes low frequency magnetic shielding. Such shielding is covered with an ultrathin seamless coat of highly conductive nonferrous material.

Drechsler, R. J.

1969-01-01

114

Radiation shielding for the Fermilab Vertical Cavity Test Facility  

SciTech Connect

The results of radiation shielding studies for the vertical test cryostat VTS1 at Fermilab performed with the codes FISHPACT and MARS15 are presented and discussed. The analysis is focused on operations with two RF cavities in the cryostat. The vertical cavity test facility (VCTF) for superconducting RF cavities in Industrial Building 1 at Fermilab has been in operation since 2007. The facility currently consists of a single vertical test cryostat VTS1. Radiation shielding for VTS1 was designed for operations with single 9-cell 1.3 GHz cavities, and the shielding calculations were performed using a simplified model of field emission as the radiation source. The operations are proposed to be extended in such a way that two RF cavities will be in VTS1 at a time, one above the other, with tests for each cavity performed sequentially. In such a case the radiation emitted during the tests from the lower cavity can, in part, bypass the initially designed shielding which can lead to a higher dose in the building. Space for additional shielding, either internal or external to VTS1, is limited. Therefore, a re-evaluation of the radiation shielding was performed. An essential part of the present analysis is in using realistic models for cavity geometry and spatial, angular and energy distributions of field-emitted electrons inside the cavities. The calculations were performed with the computer codes FISHPACT and MARS15.

Ginsburg, Camille; Rakhno, Igor; /Fermilab

2010-03-01

115

Grounding and shielding techniques  

SciTech Connect

Grounding and shielding of electrical components and subsystems have always been a source of nuisance problems. In systems where large amounts of energy are moved in short, high power pulses, these problems may no longer be of nuisance value, but may become critical to the survival and well being of sensitive subsystems and adjacent electronics which may be functionally unreleated to the pulse power system. As it happens, most of the problems associated with grounding and shielding turn out to be conceptually simple but, similar to computer systems, become lost in a maze of complexity and a jungle of confusion. It is the intention of this presentation to illuminate those practices which will lead to problems later and to remove some of the apparent mystery from the sources of electromagnetic interference (EMI). Also, a set of rules will be presented which hopefully will help to prevent or solve problems derived from EMI.

Burkes, T.R.

1980-01-01

116

Gas shielding apparatus  

DOEpatents

An apparatus is disclosed 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. 3 figs.

Brandt, D.

1985-12-31

117

Composition for radiation shielding  

DOEpatents

A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

Kronberg, J.W.

1994-08-02

118

Gas shielding apparatus  

DOEpatents

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.

Brandt, Daniel (Los Alamos, NM)

1985-01-01

119

Gas shielding apparatus  

DOEpatents

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.

Brandt, D.

1984-06-05

120

NEUTRON SHIELDING STRUCTURE  

Microsoft Academic Search

A lightweight neutron shielding structure comprises a honeycomb core ; which is filled with a neutron absorbing powder. The honeycomb core is faced ; with parallel planar facing sheets to form a lightweight rigid unit. Suitable ; absorber powders are selected from among the following: B, BâC, BâO\\/; sub 3\\/, CaBâ, LiâCO3, LiOH, LiBOâ, Li\\/s ub 2\\/O. The facing ;

Mattingly

1962-01-01

121

Justification for Shielded Receiver Tube Additional Lead Shielding  

SciTech Connect

In order to reduce high radiation dose rates encountered when core sampling some radioactive waste tanks the addition of 240 lbs. of lead shielding is being considered to the shielded receiver tube on core sample trucks No.1, No.3 and No.4. The lead shielding is 4 inch diameter x 1/2 inch thick half rounds that have been installed around the SR tube over its' full length. Using three unreleased but independently reviewed structural analyses HNF-6018 justifies the addition of the lead shielding.

BOGER, R.M.

2000-04-11

122

DARHT : integration of shielding design and analysis with facility design /  

SciTech Connect

The design of the interior portions of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility incorporated shielding and controls from the beginning of the installation of the Accelerators. The purpose of the design and analysis was to demonstrate the adequacy of shielding or to determine the need for additional shielding or controls. Two classes of events were considered: (1) routine operation defined as the annual production of 10,000 2000-ns pulses of electrons at a nominal energy of 20 MeV, some of which are converted to the x-ray imaging beam consisting of four nominal 60-ns pulses over the 2000-ns time frame, and (2) accident case defined as up to 100 2000-ns pulses of electrons accidentally impinging on some metallic surface, thereby producing x rays. Several locations for both classes of events were considered inside and outside of the accelerator hall buildings. The analysis method consisted of the definition of a source term for each case studied and the definition of a model of the shielding and equipment present between the source and the dose areas. A minimal model of the fixed existing or proposed shielding and equipment structures was used for a first approximation. If the resulting dose from the first approximation was below the design goal (1 rem/yr for routine operations, 5 rem for accident cases), then no further investigations were performed. If the result of the first approximation was above our design goals, the model was refined to include existing or proposed shielding and equipment. In some cases existing shielding and equipment were adequate to meet our goals and in some cases additional shielding was added or administrative controls were imposed to protect the workers. It is expected that the radiation shielding design, exclusion area designations, and access control features, will result in low doses to personnel at the DARHT Facility.

Boudrie, R. L. (Richard L.); Brown, T. H. (Thomas H.); Gilmore, W. E. (Walter E.); Downing, J. N. (James N.), Jr.; Hack, Alan; McClure, D. A. (Donald A.); Nelson, C. A. (Christine A.); Wadlinger, E. Alan; Zumbro, M. V. (Martha V.)

2002-01-01

123

Noise Shielding Efficiency in AN Urban System  

NASA Astrophysics Data System (ADS)

To estimate the shielding efficiency of buildings, a model which simulates noise propagation in an urban area has been used. The simulation model assumes the equivalent highway model where vehicles are replaced by equivalent point sources which emit typical traffic noise. Interactions of acoustical waves with obstacles, on the path from the source to the observation point, are reduced to specular reflections from surfaces and diffraction at edges (wedges) of obstacles. The prepared PROP3 computer program allows estimation of sound equivalent level in dB(A) at the observation point in a built-up area, for a highway of known vehicles rate flow and vehicle average speed.

Walerian, E.; Janczur, R.

1998-04-01

124

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

125

Spacecraft ceramic protective shield  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

126

Radiation shielding study for superconducting RF cavity test facility at Fermilab  

SciTech Connect

The results of Monte Carlo radiation shielding study performed with the MARS15 code for the vertical test cryostat facility to be installed in the Industrial Building 1 at Fermilab are presented and discussed.

Rakhno, I.; /Fermilab

2006-04-01

127

EXAMPLES OF RADIATION SHIELDING MODELS  

SciTech Connect

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.

Willison, J

2006-07-27

128

Actively driven thermal radiation shield  

DOEpatents

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.

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

2002-01-01

129

Analytical model of jet shielding  

NASA Technical Reports Server (NTRS)

An analytical model of the shielding of a stationary point noise source by a cylindrical jet is developed. The directivity function is derived which estimates the normalized sound pressure level at a far field receiver. The shielding model is compared to experimental data for a point noise source impinging on an unheated air jet and on a simulated hot air jet. The model compares favorably to measured shielding at receiver locations away from the jet axis. The trend of the estimated shielding diverges from the measured data as the jet axis is approached. Refinement of the model is discussed.

Gerhold, C. H.

1982-01-01

130

SHIELD verification and validation report  

SciTech Connect

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.

Boman, C.

1992-02-01

131

Hypervelocity impact shield  

NASA Technical Reports Server (NTRS)

A hypervelocity impact shield and method for protecting a wall structure, such as a spacecraft wall, from impact with particles of debris having densities of about 2.7 g/cu cm and impact velocities up to 16 km/s are disclosed. The shield comprises a stack of ultra thin sheets of impactor disrupting material supported and arranged by support means in spaced relationship to one another and mounted to cover the wall in a position for intercepting the particles. The sheets are of a number and spacing such that the impacting particle and the resulting particulates of the impacting particle and sheet material are successively impact-shocked to a thermal state of total melt and/or vaporization to a degree as precludes perforation of the wall. The ratio of individual sheet thickness to the theoretical diameter of particles of debris which may be of spherical form is in the range of 0.03 to 0.05. The spacing between adjacent sheets is such that the debris cloud plume of liquid and vapor resulting from an impacting particle penetrating a sheet does not puncture the next adjacent sheet prior to the arrival thereat of fragment particulates of sheet material and the debris particle produced by a previous impact.

Cour-Palais, Burton G. (inventor); Crews, Jeanne Lee (inventor)

1991-01-01

132

SHIELDING ANALYSES FOR THE HNPF FUEL ELEMENT SHIELD PLUGS  

Microsoft Academic Search

The shielding of the HNPF fuel element shield plug was analyzed and ; reviewed. The direct gamma radiation penetrating the fuel plug was 0.32 mr\\/hr. ; The dose rate due to the direct penetration by fast and thermal neutrons was ; negligible. Gamma radiation streaming up the 1\\/16-in. annular gap between the ; fuel plug and the cavity liner was

Bergar

1960-01-01

133

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

134

Topographic evidence for shield volcanism on Io  

SciTech Connect

Similarities between terrestrial shield volcanoes and a volcano on Io observed in Voyager I imagery of the satellite at 30/sup 0/ S, 246/sup 0/ W are delineated. A photoclinometry model was used to numerically estimate the slope based on the Minnaert photometric function. The slope values are accurate to within 10 deg on the sun-facing slope and 1 deg on the shadow side. As found with shield volcanoes, the feature has a central edifice, 40-50 km in diameter, and a broad, elliptical base, 77 x 90 km across. The summit of the Io volcano is 2.2-2.8 km above the surrounding plane and contains a caldera about 5 km in diameter. The similarity in shape between basaltic terrestrial shield volcanoes and the Io volcano indicates that the Io feature may also be composed of basalt. The composition could be sulfur if the heat flow was under 0.05 W/sq m, as it might have been in later stages of formation. 9 references.

Moore, J.M.; Mcewen, A.S.; Albin, E.F.; Greeley, R.

1986-07-01

135

Design experience: CRBRP radiation shielding  

Microsoft Academic Search

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

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

1978-01-01

136

Radiation Shielding Optimization on Mars  

NASA Technical Reports Server (NTRS)

Future space missions to Mars will require radiation shielding to be optimized for deep space transit and an extended stay on the surface. In deep space, increased shielding levels and material optimization will reduce the exposure from most solar particle events (SPE) but are less effective at shielding against galactic cosmic rays (GCR). On the surface, the shielding provided by the Martian atmosphere greatly reduces the exposure from most SPE, and long-term GCR exposure is a primary concern. Previous work has shown that in deep space, additional shielding of common materials such as aluminum or polyethylene does not significantly reduce the GCR exposure. In this work, it is shown that on the Martian surface, almost any amount of aluminum shielding increases exposure levels for humans. The increased exposure levels are attributed to neutron production in the shield and Martian regolith as well as the electromagnetic cascade induced in the Martian atmosphere. This result is significant for optimization of vehicle and shield designs intended for the surface of Mars.

Slaba, Tony C.; Mertens, Chris J.; Blattnig, Steve R.

2013-01-01

137

EMP coupling to shielded cables  

NASA Astrophysics Data System (ADS)

Electromagnetic coupling to shielded cables is analyzed in terms of two electromagnetically coupled transmission lines excited by distributed sources. This analysis results in two traveling waves on the shield and four traveling waves in the core of the cable. Transient waveforms are reported from EMP coupling on an overhead RG-58 cable.

Agouridis, D. C.

138

The effect of breast shielding during lumbar spine radiography  

PubMed Central

Background The aim of the study was to determine the influence of lead shielding on the dose to female breasts in conventional x-ray lumbar spine imaging. The correlation between the body mass index and the dose received by the breast was also investigated. Materials and methods Breast surface dose was measured by thermoluminescent dosimeters (TLD). In the first phase measurements of breast dose with and without shielding from lumbar spine imaging in two projections were conducted on an anthropomorphic phantom. In the second stage measurements were performed on 100 female patients, randomly divided into two groups of 50, with breast shielding only used in one group. Results On average, breast exposure dose in lumbar spine imaging in both projections (anteroposterior (AP) and lateral) was found reduced by approximately 80% (p < 0,001) when shielding with 0.5 mm lead equivalent was used (from 0.45±0.25 mGy to 0.09±0.07 mGy on the right and from 0.26±0.14 mGy to 0.06±0.04 mGy on the left breast). No correlation between the body mass index (BMI) and the breast surface radiation dose was observed. Conclusions Although during the lumbar spine imaging breasts receive low-dose exposure even when shielding is not used, the dose can be reduced up to 80% by breast shielding with no influence on the image quality. PMID:23450158

Mekis, Nejc; Zontar, Dejan; Skrk, Damijan

2013-01-01

139

Portable convertible blast effects shield  

DOEpatents

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping 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 by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

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)

2011-03-15

140

Welding shield for coupling heaters  

DOEpatents

Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

Menotti, James Louis (Dickinson, TX)

2010-03-09

141

Portable convertible blast effects shield  

SciTech Connect

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.

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

142

Portable convertible blast effects shield  

DOEpatents

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.

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

143

Shielded enclosures for experimental studies of shielding topology  

NASA Astrophysics Data System (ADS)

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.

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

1984-11-01

144

Saturn IB Second Stage (S-IVB Stage)  

NASA Technical Reports Server (NTRS)

This cutaway drawing shows the S-IVB stage in its Saturn IB configuration. As a part of the Marshall Space Flight Center's (MSFC) 'building block' approach to the Saturn development, the S-IVB stage was utilized in the Saturn IB launch vehicle as a second stage and, later, the Saturn V launch vehicle as a third stage. The stage was powered by a single J-2 engine, initially capable of 200,000 pounds of thrust.

1968-01-01

145

Preliminary design of magnetic shielding by FEM  

SciTech Connect

In this paper, the authors propose an optimization method for magnetic shielding. The main purpose is the weight reduction of shield material. Assuming that the permeability of shield material is infinite, they simplify the magnetic shielding problem. Under this assumption, they design optimal passage for magnetic flux through the shield. They apply this method to designing the magnetic shielding for Maglev and show the effectiveness of this method by experimental and numerical data.

Sasakawa, Takashi; Tagawa, Naoto; Herai, Toshiki; Tomita, Masaru [Railway Technical Research Inst., Kokubunji, Tokyo (Japan)] [Railway Technical Research Inst., Kokubunji, Tokyo (Japan)

1997-03-01

146

Static Aerodynamic Performance Investigation of a Fluid Shield Nozzle  

NASA Technical Reports Server (NTRS)

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.

Balan, C.; Askew, J. W.

2005-01-01

147

Lunar Surface Reactor Shielding Study  

NASA Astrophysics Data System (ADS)

A nuclear reactor system could provide power to support long term human exploration of the moon. Such a system would require shielding to protect astronauts from its emitted radiations. Shielding studies have been performed for a Gas Cooled Reactor system because it is considered to be the most suitable nuclear reactor system available for lunar exploration, based on its tolerance of oxidizing lunar regolith and its good conversion efficiency. The goals of the shielding studies were to determine a material shielding configuration that reduces the dose (rem) to the required level in order to protect astronauts, and to estimate the mass of regolith that would provide an equivalent protective effect if it were used as the shielding material. All calculations were performed using MCNPX, a Monte Carlo transport code. Lithium hydride must be kept between 600 K and 700 K to prevent excessive swelling from large amounts of gamma or neutron irradiation. The issue is that radiation damage causes separation of the lithium and the hydrogen, resulting in lithium metal and hydrogen gas. The proposed design uses a layer of B4C to reduce the combined neutron and gamma dose to below 0.5Grads before the LiH is introduced. Below 0.5Grads the swelling in LiH is small (less than about 1%) for all temperatures. This approach causes the shield to be heavier than if the B4C were replaced by LiH, but it makes the shield much more robust and reliable.

Kang, Shawn; Lipinski, Ronald; McAlpine, William

2006-01-01

148

New Materials for EMI Shielding  

NASA Technical Reports Server (NTRS)

Graphite fibers intercalated with bromine or similar mixed halogen compounds have substantially lower resistivity than their pristine counterparts, and thus should exhibit higher shielding effectiveness against electromagnetic interference. The mechanical and thermal properties are nearly unaffected, and the shielding of high energy x-rays and gamma rays is substantially increased. Characterization of the resistivity of the composite materials is subtle, but it is clear that the composite resistivity is substantially lowered. Shielding effectiveness calculations utilizing a simple rule of mixtures model yields results that are consistent with available data on these materials.

Gaier, James R.

1999-01-01

149

Radiation Shielding Properties of Some Marbles in Turkey  

SciTech Connect

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.

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

2011-12-26

150

Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes  

SciTech Connect

The radiation although has hazardous effects for human health, developing technologies bring lots of usage fields to radiation like in medicine and nuclear power station buildings. In this case protecting from undesirable radiation is a necessity for human health. Heavyweight concrete is one of the most important materials used in where radiation should be shielded, like those areas. In this study, used heavyweight aggregates of different mineral origin (Limonite, Siderite), in order to prepare different series in concrete mixtures and investigated radiation shielding properties. The experimental results on measuring the radiation shielding, the heavyweight concrete prepared with heavyweight aggregates of different mineral origin show that, are useful radiation absorbents when they used in concrete mixtures.

Basyigit, Celalettin; Uysal, Volkan; Kilincarslan, Semsettin; Akkas, Ayse [Department of Construction Education, Technical Education Faculty, Suleyman Demirel University, Isparta (Turkey); Mavi, Betuel [Department of Physics, Science Faculty, Suleyman Demirel University, Isparta (Turkey); Department of Physics, Science Faculty, Amasya University, Amasya (Turkey); Guenoglu, Kadir; Akkurt, Iskender [Department of Physics, Science Faculty, Suleyman Demirel University, Isparta (Turkey)

2011-12-26

151

Design of Cassegrain light shields.  

PubMed

A Fortran program has been written for the optimum design of light shields for Cassegrain optical systems with finite field. The techniques employed are described, and results are shown. PMID:20062125

Young, A T

1967-06-01

152

Structural/Radiation-Shielding Epoxies  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

153

Radiation Shielding and Radiological Protection  

E-print Network

Radiation Shielding and Radiological Protection J. Kenneth Shultis Richard E. Faw Department@triad.rr.com Radiation Fields and Sources ................................................ . Radiation Field Variables........................................................... .. Direction and Solid Angle Conventions ......................................... .. Radiation Fluence

Shultis, J. Kenneth

154

Composite Aerogel Multifoil Protective Shielding  

NASA Technical Reports Server (NTRS)

New technologies are needed to survive the temperatures, radiation, and hypervelocity particles that exploration spacecraft encounter. Multilayer insulations (MLIs) have been used on many spacecraft as thermal insulation. Other materials and composites have been used as micrometeorite shielding or radiation shielding. However, no material composite has been developed and employed as a combined thermal insulation, micrometeorite, and radiation shielding. By replacing the scrims that have been used to separate the foil layers in MLIs with various aerogels, and by using a variety of different metal foils, the overall protective performance of MLIs can be greatly expanded to act as thermal insulation, radiation shielding, and hypervelocity particle shielding. Aerogels are highly porous, low-density solids that are produced by the gelation of metal alkoxides and supercritical drying. Aerogels have been flown in NASA missions as a hypervelocity particle capture medium (Stardust) and as thermal insulation (2003 MER). Composite aerogel multifoil protective shielding would be used to provide thermal insulation, while also shielding spacecraft or components from radiation and hypervelocity particle impacts. Multiple layers of foil separated by aerogel would act as a thermal barrier by preventing the transport of heat energy through the composite. The silica aerogel would act as a convective and conductive thermal barrier, while the titania powder and metal foils would absorb and reflect the radiative heat. It would also capture small hypervelocity particles, such as micrometeorites, since it would be a stuffed, multi-shock Whipple shield. The metal foil layers would slow and break up the impacting particles, while the aerogel layers would convert the kinetic energy of the particles to thermal and mechanical energy and stop the particles.

Jones, Steven M.

2013-01-01

155

Magnetic Shield for Adiabatic Demagnetization Refrigerators (ADR)  

NASA Technical Reports Server (NTRS)

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.

Chui, Talso C.; Haddad, Nicolas E.

2013-01-01

156

THE PLUTONIUM RECYCLE TEST REACTOR SHIELDING EVALUATION  

Microsoft Academic Search

The x-ray film studies of the top and bottom primary shields displayed ; definlte gamma radiation streaming from around the shim control shroud tubes, ; monitor tubes, and other access holes, but showed effective shielding above and ; below the process tubes and primary shields. The biological shielding displayed ; no leaks or weak spots except for areas around all

1962-01-01

157

Transient heat flux shielding using thermal metamaterials  

NASA Astrophysics Data System (ADS)

We have developed a heat shield based on a metamaterial engineering approach to shield a region from transient diffusive heat flow. The shield is designed with a multilayered structure to prescribe the appropriate spatial profile for heat capacity, density, and thermal conductivity of the effective medium. The heat shield was experimentally compared to other isotropic materials.

Narayana, Supradeep; Savo, Salvatore; Sato, Yuki

2013-05-01

158

SHIELDING THE ENRICO FERMI FAST BREEDER REACTOR  

Microsoft Academic Search

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

H. E. Hungerford; R. F. Mantey

1958-01-01

159

Thermal neutron shield and method of manufacture  

DOEpatents

A thermal neutron shield comprising boron shielding panels with a high percentage of the element Boron. The panel is least 46% Boron by weight which maximizes the effectiveness of the shielding against thermal neutrons. The accompanying method discloses the manufacture of boron shielding panels which includes enriching the pre-cursor mixture with varying grit sizes of Boron Carbide.

Metzger, Bert Clayton; Brindza, Paul Daniel

2014-03-04

160

Shielding Strategies for Human Space Exploration  

Microsoft Academic Search

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

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

1997-01-01

161

Jet Noise Shielding Provided by a Hybrid Wing Body Aircraft  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

162

Staging Airliner Service  

NASA Technical Reports Server (NTRS)

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.

Hahn, Andrew S.

2007-01-01

163

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

SciTech Connect

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.

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

2009-07-01

164

Cancer Staging  

MedlinePLUS

... is called metastasis. 2. What are the common elements of staging systems? Staging systems for cancer have ... others focus on a particular type. The common elements considered in most staging systems are as follows: ...

165

Electrodynamic Dust Shield Demonstrator  

NASA Technical Reports Server (NTRS)

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

Stankie, Charles G.

2013-01-01

166

Neutron beamline shielding calculations at the SNS  

NASA Astrophysics Data System (ADS)

A world-class accelerator driven short pulsed neutron source is in the final stages of construction at the Oak Ridge National Laboratory. A 1.4 MW proton beam at 1 GeV energy directed on a mercury target will free neutrons through spallation reactions that will be moderated to thermal and subthermal energies and serve neutron scattering instruments at up to 24 beamlines. At spallation neutron sources, the neutron beams are contaminated by a large fraction of fast neutrons with energies up to the energy of the proton beam incident on the mercury target. Results of design calculations for the Cold Neutron Chopper Spectrometer are presented as an example to demonstrate the neutronics design analyses that are being performed to optimize the lateral beamline shielding as well as the sample and detector area with regard to guaranteeing personal safety, minimizing neutron background and cost.

Gallmeier, Franz X.; Ferguson, Phillip D.; Iverson, Erik B.; Popova, Irina I.; Lu, Wei

2006-06-01

167

Optimization of building blocks for multi-stage 17-44 dB 6.1-9.6 mW 90-nm K-band front-ends  

NASA Astrophysics Data System (ADS)

In this article, five two-stage ˜6-mW and four three-stage ˜9-mW matched amplifier architectures are proposed to establish optimization procedure and quantify relative merits of cascode (CC), common-gate (CG), and commonsource (CS) building blocks for low-voltage low-power multi-stage front-ends. The circuits are simulated with a 90-nm CMOS technology including modeling of layout parasites. Integrated bias trees and passive port matching networks are incorporated in the K-band designs. In the face of process mismatch, variability in noise and gain figures remains <0.39 dB and <7.1 dB from the design values. The five combinations of building blocks in twostage low-power (6.1-6.6 mW) amplifiers achieve linearity (IIP3) in the range of -5.2˜-13.5 dBm, good reverse isolation (better than -26 dB), 2.89-3.82 dB noise penalties, and 17.2-25.5 dB peak forward gain. In case of threestage front-ends built with CS, CC, and CG blocks (power rating 9.2-9.6 mW), forward gain and optimized noise figures are found as >33 dB and <3.26 dB, respectively. They achieve -2.5˜18.3 dBm IIP3, <-39 dB reverse isolation, and <-17 dB minimum IRL. The results are compared with reported simulated findings on CMOS multistage amplifiers to highlight their relative advantages in terms of power requirement and decibel(gain)-per-watt.

Roy, Apratim; Harun Rashid, A.

2013-12-01

168

Theoretical and experimental evaluation of the electromagnetic radiation from apertures in shielded enclosure  

Microsoft Academic Search

The problem of the radiated emission from apertures in metallic enclosures has been theoretically and experimentally investigated. In particular, the tangential electric field in the aperture has been evaluated by two methods: the first is helpful during the design stage and the second during the prototype development stage of electronic equipment shielded by a metallic box. The first method is

Graziano Cerri; Roberto De Leo; V. M. Primiani

1992-01-01

169

Radiation shielding materials and containers incorporating same  

DOEpatents

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.

Mirsky, Steven M. (Greenbelt, MD); Krill, Stephen J. (Arlington, VA); Murray, Alexander P. (Gaithersburg, MD)

2005-11-01

170

Radiation Shielding Materials and Containers Incorporating Same  

DOEpatents

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.

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

2005-11-01

171

Shielding Design Aspects of SR Beamlines for 3-GeV And 8-GeV Class Synchrotron Radiation Facilities  

SciTech Connect

Differences in synchrotron radiation beamline shielding design between the facilities of 3 GeV class and 8 GeV class are discussed with regard to SLAC SSRL and SPring-8 beamlines. Requirements of beamline shielding as well as the accelerator shielding depend on the stored electron energy, and here some factors in beamline shielding depending on the stored energy in particular, are clarified, namely the effect of build up, the effect of double scattering of photons at branch beamlines, and the spread of gas bremsstrahlung.

Asano, Yoshihiro; /JAERI-RIKEN, Hyogo; Liu, James C.; Rokni, Sayed; /SLAC

2007-09-24

172

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

E-print Network

and results of the comparative studies on the basement heat transfer models of the same programs. Introduction Foundation heat transfer is a significant load component for low-rise residential buildings. For a contemporary code or above code house, ground...-coupled heat losses may account for 30%–50% of the total heat loss [1]. Comparative studies on ground coupled heat transfer models of current simulation tools showed a high degree of variation for basements and slab-on-grade floors. For an uninsulated slab...

Andolsun, S.; Culp, C.

2011-01-01

173

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

E-print Network

Qsoil/slab heat transfer between the soil and the slab Qfm(s) monthly average floor heat flux(es) Tam(s) monthly average outside air temperature(s) Tg(s) monthly average deep ground temperature(s) calculated by DOE-2 using Kasuda approach [21] Tslab... 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...

Andolsun, S.; Culp, C.

2012-01-01

174

Ionization waves in electron-beam-assisted, shielded capillary discharge  

Microsoft Academic Search

A theory of propagation of cathode-directed ionization waves during the early stages of an electrical breakdown in a shielded, low-pressure capillary is developed. The discharge process occurs due to the ionization of the low-density gas in the capillary by an electron beam that is emanating from a hollow cathode. Due to the strong electric field in the capillary the electrons

I. Rutkevich; M. Mond; Y. Kaufman; P. Choi; M. Favre

2000-01-01

175

Microscopic and early stage ovarian cancers in BRCA1/2 mutation carriers: building a model for early BRCA-associated tumorigenesis  

PubMed Central

Risk-reducing salpingo-oophorectomy (RRSO) is the cornerstone of ovarian cancer prevention in BRCA1/2 mutation carriers. Occult fallopian tube and ovarian cancers have been reported in a small percentage of BRCA1/2 mutation carriers undergoing RRSO. Here, we review our single institution experience with RRSO in BRCA1/2 mutation carriers to characterize cases of microscopic cancers in these patients. At the time of RRSO, 7.9% of BRCA1 mutation carriers were diagnosed with microscopic fallopian tube or ovarian cancers and zero cases were diagnosed in BRCA2 mutation carriers. The majority of the microscopic cancers include cases that were confined to the fallopian tubes, although there were also cases involving ovaries only or peritoneal washings only. This suggests that the site of origin may be in the ovary, fallopian tube, or peritoneum for BRCA-associated serous cancers. However, an analysis of early stage (stage I and II) ovarian and fallopian tube cancers diagnosed in BRCA1/2 mutation carriers confirms that the ovary is a preferred site for tumor growth with 11 of 14 early stage cancers having a dominant ovarian mass. Overall, these data suggest that cancer initiation may occur in the ovary, fallopian tube, or peritoneum, but tumor growth and progression is favored in the ovary. We present an updated model for BRCA1/2-associated ovarian and fallopian tube carcinogenesis, which may aid in identifying improved prevention strategies for high-risk women that delay or decline RRSO. PMID:21278312

Yates, Melinda S.; Meyer, Larissa A.; Deavers, Michael T.; Daniels, Molly S.; Keeler, Elizabeth R.; Mok, Samuel C.; Gershenson, David M.; Lu, Karen H.

2011-01-01

176

Shielding vacuum fluctuations with graphene  

E-print Network

The Casimir-Polder interaction of ground-state and excited atoms with graphene is investigated with the aim to establish whether graphene systems can be used as a shield for vacuum fluctuations of an underlying substrate. We calculate the zero-temperature Casimir-Polder potential from the reflection coefficients of graphene within the framework of the Dirac model. For both doped and undoped graphene we show limits at which graphene could be used effectively as a shield. Additional results are given for AB-stacked bilayer graphene.

Sofia Ribeiro; Stefan Scheel

2014-03-14

177

The Embedded Self-Shielding Method  

SciTech Connect

The embedded self-shielding method (ESSM) is described for computing resonance-shielded cross sections used in multigroup neutron transport calculations with the SCALE code system. The ESSM - embeds the self-shielding computation within the transport solution. The transport solution provides information for treating heterogeneous self-shielding effects, and the resulting shielded cross sections are fed back to the transport calculation. Iterations are done to obtain self-consistency. This allows self-shielded cross sections to be generated directly in the transport geometry without requiring external computation of Dancoff factors. The ESSM theory and example calculations are presented.

Williams, Mark L [ORNL; Kim, Kang Seog [ORNL

2012-01-01

178

Concepts and Tests for the Remote-Controlled Dismantling of the Biological Shield and Form work of the KNK Reactor - 13425  

SciTech Connect

The compact sodium-cooled nuclear reactor facility Karlsruhe (KNK), a prototype Fast Breeder, is currently in an advanced stage of dismantling. Complete dismantling is based on 10 partial licensing steps. In the frame of the 9. decommissioning permit, which is currently ongoing, the dismantling of the biological shield is foreseen. The biological shield consists of heavy reinforced concrete with built-in steel fitments, such as form-work of the reactor tank, pipe sleeves, ventilation channels, and measuring devices. Due to the activation of the inner part of the biological shield, dismantling has to be done remote-controlled. During a comprehensive basic design phase a practical dismantling strategy was developed. Necessary equipment and tools were defined. Preliminary tests revealed that hot wire plasma cutting is the most favorable cutting technology due to the geometrical boundary conditions, the varying distance between cutter and material, and the heavy concrete behind the steel form-work. The cutting devices will be operated remotely via a carrier system with an industrial manipulator. The carrier system has expandable claws to adjust to the varying diameter of the reactor shaft during dismantling progress. For design approval of this prototype development, interaction between manipulator and hot wire plasma cutting was tested in a real configuration. For the demolition of the concrete structure, an excavator with appropriate tools, such as a hydraulic hammer, was selected. Other mechanical cutting devices, such as a grinder or rope saw, were eliminated because of concrete containing steel spheres added to increase the shielding factor of the heavy concrete. Dismantling of the biological shield will be done in a ring-wise manner due to static reasons. During the demolition process, the excavator is positioned on its tripod in three concrete recesses made prior to the dismantling of the separate concrete rings. The excavator and the manipulator carrier system will be operated alternately. Main boundary condition for all the newly designed equipment is the decommissioning housing of limited space within the reactor building containment. To allow for a continuous removal of the concrete rubble, an additional opening on the lowest level of the reactor shaft will be made. All equipment and the interaction of the tools have to be tested before use in the controlled area. Therefore a full-scale model of the biological shield will be provided in a mock-up. The tests will be performed in early 2014. The dismantling of the biological shield is scheduled for 2015. (authors)

Neff, Sylvia; Graf, Anja; Petrick, Holger; Rothschmitt, Stefan [WAK Rueckbau- und Entsorgungs- GmbH, P.O.Box 12 63, 76339 Eggenstein- Leopoldshafen (Germany)] [WAK Rueckbau- und Entsorgungs- GmbH, P.O.Box 12 63, 76339 Eggenstein- Leopoldshafen (Germany); Klute, Stefan [Siempelkamp Nukleartechnik GmbH, Am Taubenfeld 25/1, 69123 Heidelberg (Germany)] [Siempelkamp Nukleartechnik GmbH, Am Taubenfeld 25/1, 69123 Heidelberg (Germany); Stanke, Dieter [Siempelkamp NIS Ingenieurgesellschaft mbH, Industriestrasse 13, 63755 Alzenau (Germany)] [Siempelkamp NIS Ingenieurgesellschaft mbH, Industriestrasse 13, 63755 Alzenau (Germany)

2013-07-01

179

Thermal Degradation of Lead Monoxide Filled Polymer Composite Radiation Shields  

NASA Astrophysics Data System (ADS)

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 & 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.

Harish, V.; Nagaiah, N.

2011-07-01

180

D0 Silicon Upgrade: Muon Shield Conceptual Design Report  

SciTech Connect

The nominal overall dimensions are 71-inch high x 71-inch wide x 144-inch long and has a 25-inch square hole throughout. The shield consists of three different materials, steel (inner most section), polycarbonate (central section) and lead (outer most section). The material thicknesses are, steel=15-inch, poly=6-inch and lead=2-inch. The estimated weight is {approx}69 tons. The shield is centered about the Tev beam line and the 25-inch square hole provides clearance to the low Beta quad, which is nominally 20-inch square. During beamline operation, the shield is in contact with Samus magnet core at the detector end and with the Main Ring shield wall on the MR side (with some small clearance {approx}2-inch-3-inch). The need for the clearance will be discussed later. The shield support structure consists steel structural members appropriately sized for loads encountered in the design. The structure must not only support the shield but, must be designed for rolling the entire assembly into position in the collision hall. It must provide for cylinders to lift the assembly, Hilman rollers and also connections for moving the entire assembly. The movement is considered to be similar to that with which the calorimeters were moved from the clean room to the sidewalk staging area, i.e. hydraulic cylinder and chain (see dwg. 3740.000-ME294017,3 sheets). This method will be used for the East to West motion and a hydraulic scheme will be used for any North-South motion. Since the shield is 144-inch long and the sidewalk structural support is {approx}96-inch, there is a section of the shield that is cantilevered (48-inch). Further, the EF toroid must open {approx}40+ inch for access to the detector during operations and this requires that the shield or some part of it must also move. This conceptual design suggests that the shield be designed in two pieces axially. These two pieces are identical in cross section but, the lengths are divided into 48-inch nearest EF and 96-inch nearest the MR tunnel. The 96-inch section is designed to clam shell, i.e. split vertically along the beam line, with each half moving {approx}36-inch East/West. The opening created with this motion (72-inch) is 1-inch greater than the width of the shield, 71 If. Now the forward section can be moved, North/South, within the opened end section, a full 48-inch. The forward section will be support at one end by the basic shield support structure and at the EF end by a member welded to EF. Rails will be extended from the basic structure to EF and these rails will be collapsible within the basic structure. The shield sections will be mounted on Hilman rollers and all motions will be provided by hydraulic cylinders.

Stredde, Herman J.; /Fermilab

1996-05-14

181

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

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

182

6500 Staticide ESD Safety Shield  

E-print Network

aerosol spray can; 12 per case. Note: This formula is available in quarts or gal- lons as a liquid. Get true long-lasting* ESD protection in an aerosol spray! The reliable performance of Staticide® ESD Safety Shield is now available in a convenient aerosol spray. This static electricity prob- lem solver

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

183

Material Effectiveness for Radiation Shielding  

NASA Technical Reports Server (NTRS)

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.

2003-01-01

184

Improved space radiation shielding methods  

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

185

Combustor bulkhead heat shield assembly  

Microsoft Academic Search

This paper describes a gas turbine engine having an annular combustion chamber defined by an annular, inner liner, a concentric outer liner, and an upstream annular combustor head, wherein the head includes a radially extending bulkhead having circumferentially distributed openings for each receiving an individual fuel nozzle therethrough. It comprises: a segmented heat shield assembly, disposed between the combustion chamber

Zeisser

1990-01-01

186

Predictions for Radiation Shielding Materials  

NASA Technical Reports Server (NTRS)

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.

Kiefer, Richard L.

2002-01-01

187

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 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...

2011-01-01

188

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 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...

2012-01-01

189

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 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...

2014-01-01

190

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 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...

2013-01-01

191

Rotary stripper for shielded and unshielded FCC  

NASA Technical Reports Server (NTRS)

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.

Angele, W.; Chambers, C. M.

1971-01-01

192

Reliability-Based Electronics Shielding Design Tools  

NASA Technical Reports Server (NTRS)

Shielding design on large human-rated systems allows minimization of radiation impact on electronic systems. Shielding design tools require adequate methods for evaluation of design layouts, guiding qualification testing, and adequate follow-up on final design evaluation.

Wilson, J. W.; O'Neill, P. J.; Zang, T. A.; Pandolf, J. E.; Tripathi, R. K.; Koontz, Steven L.; Boeder, P.; Reddell, B.; Pankop, C.

2007-01-01

193

Concerning superconducting inertial guidance gyroscopes inside superconducting magnetic shields  

SciTech Connect

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.}

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

194

Shielding techniques for communication cable - An update  

NASA Astrophysics Data System (ADS)

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.

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

195

Design of magnets inside cylindrical superconducting shields  

NASA Technical Reports Server (NTRS)

The design of magnets inside closed, cylindrical, superconducting shields is discussed. The Green function is given for the magnetic vector potential for cylindrically symmetric currents inside such a shield. The magnetic field everywhere inside the shield can be obtained from this function, which includes the effects of the induced shield currents exactly. The field is given for a thin solenoid as an example and the convergence of the series solution for this case is discussed. The shield can significantly reduce the strength and improve the homogeneity of a magnet. The improvement in homogeneity is of particular importance in the design of correction coils. These effects, and the maximum field on the shield, are examined for a typical solenoid. The results given are also useful, although not exact, for long shields with one or two open ends.

Rigby, K. W.

1988-01-01

196

Light shield for solar concentrators  

DOEpatents

A solar receiver unit including a housing defining a recess, a cell assembly received in the recess, the cell assembly including a solar cell, and a light shield received in the recess and including a body and at least two tabs, the body defining a window therein, the tabs extending outward from the body and being engaged with the recess, wherein the window is aligned with the solar cell.

Plesniak, Adam P.; Martins, Guy L.

2014-08-26

197

Photonic Bandgap (PBG) Shielding Technology  

NASA Technical Reports Server (NTRS)

Photonic Bandgap (PBG) shielding technology is a new approach to designing electromagnetic shielding materials for mitigating Electromagnetic Interference (EM!) with small, light-weight shielding materials. It focuses on ground planes of printed wiring boards (PWBs), rather than on components. Modem PSG materials also are emerging based on planar materials, in place of earlier, bulkier, 3-dimensional PBG structures. Planar PBG designs especially show great promise in mitigating and suppressing EMI and crosstalk for aerospace designs, such as needed for NASA's Constellation Program, for returning humans to the moon and for use by our first human visitors traveling to and from Mars. Photonic Bandgap (PBG) materials are also known as artificial dielectrics, meta-materials, and photonic crystals. General PBG materials are fundamentally periodic slow-wave structures in I, 2, or 3 dimensions. By adjusting the choice of structure periodicities in terms of size and recurring structure spacings, multiple scatterings of surface waves can be created that act as a forbidden energy gap (i.e., a range of frequencies) over which nominally-conductive metallic conductors cease to be a conductor and become dielectrics. Equivalently, PBG materials can be regarded as giving rise to forbidden energy gaps in metals without chemical doping, analogous to electron bandgap properties that previously gave rise to the modem semiconductor industry 60 years ago. Electromagnetic waves cannot propagate over bandgap regions that are created with PBG materials, that is, over frequencies for which a bandgap is artificially created through introducing periodic defects

Bastin, Gary L.

2007-01-01

198

Space vehicle meteoroid shielding design  

NASA Technical Reports Server (NTRS)

Design principles of spaced, multiwall meteoroid protection are investigated in the light of experimental data generated during the Apollo Program. The outer wall or shield is shown to be the most important element in the meteoroid-spacecraft interaction. The condition of the debris is primarily a function of the shock pressure, the melting points of the meteoroid and the shield, and the length of the meteoroid and thickness of the shield. Spacing between the walls is effective up to approximately 100 times the length of the meteoroid. The required thickness of the second wall is shown to be proportional to the meteoroid mass, velocity, and density, and to the spacing between the walls, taken with exponents dependent upon the condition of the debris. The effects of placing additional elements (insulation or honeycomb cells) between the two walls are discussed, and the efficiency of various protective configurations is presented. An analysis of the meteoroid protection proposed for the Comet Halley probe is included as an appendix.

Cour-Palais, B. G.

1979-01-01

199

University Buildings Landmark Buildings  

E-print Network

Sciences Building 3 Human Resources 11 Information Services 34 Institute of Professional Legal Studies (IPLS) 4 International and Postgraduate Student Centre 1n International Office 33 INTO at Queen's 13 and Student Affairs 3 Administration Building 32 Ashby Building 27 Belfast City Hospital 28 Bernard Crossland

Paxton, Anthony T.

200

University Buildings Landmark Buildings  

E-print Network

Accommodation) 5 Harty Room, School of Music 26 Health Sciences Building 3 Human Resources 11 Information Services 34 Institute of Professional Legal Studies (IPLS) 4 International and Postgraduate Student Centre's University Belfast Campus Map The Lanyon Building The Students' Union The David Keir Building School Offices

Paxton, Anthony T.

201

Flexible Shields for Protecting Spacecraft Against Debris  

NASA Technical Reports Server (NTRS)

A report presents the concept of Flexshield a class of versatile, lightweight, flexible shields for protecting spacecraft against impacts by small meteors and orbiting debris. The Flexshield concept incorporates elements of, but goes beyond, prior spacecraft-shielding concepts, including those of Whipple shields and, more recently, multi-shock shields and multi-shock blankets. A shield of the Flexshield type includes multiple outer layers (called bumpers in the art) made, variously, of advanced ceramic and/or polymeric fibers spaced apart from each other by a lightweight foam. As in prior such shields, the bumpers serve to shock an impinging hypervelocity particle, causing it to disintegrate vaporize, and spread out over a larger area so that it can be stopped by an innermost layer (back sheet). The flexibility of the fabric layers and compressibility of the foam make it possible to compress and fold the shield for transport, then deploy the shield for use. The shield can be attached to a spacecraft by use of snaps, hook-and-pile patches, or other devices. The shield can also contain multilayer insulation material, so that it provides some thermal protection in addition to mechanical protection.

Christiansen, Eric L.; Crews, Jeanne Lee

2004-01-01

202

The Feasibility of Multipole Electrostatic Radiation Shielding  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

203

Exploratory Environmental Tests of Several Heat Shields  

NASA Technical Reports Server (NTRS)

Exploratory tests have been conducted with several conceptual radiative heat shields of composite construction. Measured transient temperature distributions were obtained for a graphite heat shield without insulation and with three types of insulating materials, and for a metal multipost heat shield, at surface temperatures of approximately 2,000 F and 1,450 F, respectively, by use of a radiant-heat facility. The graphite configurations suffered loss of surface material under repeated irradiation. Temperature distribution calculated for the metal heat shield by a numerical procedure was in good agreement with measured data. Environmental survival tests of the graphite heat shield without insulation, an insulated multipost heat shield, and a stainless-steel-tile heat shield were made at temperatures of 2,000 F and dynamic pressures of approximately 6,000 lb/sq ft, provided by an ethylene-heated jet operating at a Mach number of 2.0 and sea-level conditions. The graphite heat shield survived the simulated aerodynamic heating and pressure loading. A problem area exists in the design and materials for heat-resistant fasteners between the graphite shield and the base structure. The insulated multipost heat shield was found to be superior to the stainless-steel-tile heat shield in retarding heat flow. Over-lapped face-plate joints and surface smoothness of the insulated multi- post heat shield were not adversely affected by the test environment. The graphite heat shield without insulation survived tests made in the acoustic environment of a large air jet. This acoustic environment is random in frequency and has an overall noise level of 160 decibels.

Goodman, George P.; Betts, John, Jr.

1961-01-01

204

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

205

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

206

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

Microsoft Academic Search

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

S. Cristina; A. Orlandi

1991-01-01

207

Thermal shielding of multilayer walls with phase change materials under different transient boundary conditions  

Microsoft Academic Search

A numerical model is presented to determine the thermal shielding performance of an exterior wall (e.g., building envelope) containing layers of PCMs. The model is exploited to perform a parametric study to assess the influence of the position and melting temperature of one PCM layer. Results showed that benefits are to be expected when the interior and exterior temperatures are

François Mathieu-Potvin; Louis Gosselin

2009-01-01

208

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

SciTech Connect

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.

T. Downar

2009-03-31

209

Ballistic limit equations for spacecraft shielding  

Microsoft Academic Search

This paper provides equations describing the ballistic performance capability of meteoroid\\/orbital debris (M\\/OD) shield systems employed on the International Space Station (ISS). Hypervelocity impact (HVI) tests and analysis were used in developing the semi-empirical ballistic limit equations (BLE). A description of each type of shield system, HVI tests and analysis performed to assess shield performance, and ballistic limit equations that

Eric L. Christiansen; Justin H. Kerr

2001-01-01

210

Hot Cell Window Shielding Analysis Using MCNP  

SciTech Connect

The Idaho National Laboratory Materials and Fuels Complex nuclear facilities are undergoing a documented safety analysis upgrade. In conjunction with the upgrade effort, shielding analysis of the Fuel Conditioning Facility (FCF) hot cell windows has been conducted. This paper describes the shielding analysis methodology. Each 4-ft thick window uses nine glass slabs, an oil film between the slabs, numerous steel plates, and packed lead wool. Operations in the hot cell center on used nuclear fuel (UNF) processing. Prior to the shielding analysis, shield testing with a gamma ray source was conducted, and the windows were found to be very effective gamma shields. Despite these results, because the glass contained significant amounts of lead and little neutron absorbing material, some doubt lingered regarding the effectiveness of the windows in neutron shielding situations, such as during an accidental criticality. MCNP was selected as an analysis tool because it could model complicated geometry, and it could track gamma and neutron radiation. A bounding criticality source was developed based on the composition of the UNF. Additionally, a bounding gamma source was developed based on the fission product content of the UNF. Modeling the windows required field inspections and detailed examination of drawings and material specifications. Consistent with the shield testing results, MCNP results demonstrated that the shielding was very effective with respect to gamma radiation, and in addition, the analysis demonstrated that the shielding was also very effective during an accidental criticality.

Chad L. Pope; Wade W. Scates; J. Todd Taylor

2009-05-01

211

The ORNL-SNAP shielding program  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

212

Shielding analyses for repetitive high energy pulsed power accelerators  

NASA Astrophysics Data System (ADS)

Sandia National Laboratories (SNL) designs, tests and operates a variety of accelerators that generate large amounts of high energy Bremsstrahlung radiation over an extended time. Typically, groups of similar accelerators are housed in a large building that is inaccessible to the general public. To facilitate independent operation of each accelerator, test cells are constructed around each accelerator to shield it from the radiation workers occupying surrounding test cells and work-areas. These test cells, about 9 ft. high, are constructed of high density concrete block walls that provide direct radiation shielding. Above the target areas (radiation sources), lead or steel plates are used to minimize skyshine radiation. Space, accessibility and cost considerations impose certain restrictions on the design of these test cells. SNL Health Physics division is tasked to evaluate the adequacy of each test cell design and compare resultant dose rates with the design criteria stated in DOE Order 5480.11. In response, SNL Health Physics has undertaken an intensive effort to assess existing radiation shielding codes and compare their predictions against measured dose rates. This paper provides a summary of the effort and its results.

Jow, H. N.; Rao, D. V.

213

Development of Flexible Neutron-Shielding Resin as an Additional Shielding Material  

Microsoft Academic Search

A soft-type neutron-shielding resin has been developed by improving an existing hard-type neutronshielding material using the epoxy-based resin as an additional shielding material. A flexible heat-resistant neutron-shielding material has been developed, which consists of a new polymer-based resin with boron. The neutron shielding performance of the developed flexible heat-resistant resin with the Cf neutron source is almost the same as

Atsuhiko M. SUKEGAWA; Yoshimasa ANAYAMA; Seiki OHNISHI; Shinji SAKURAI; Atsushi KAMINAGA; Koichi OKUNO

2011-01-01

214

SARP shielding analysis at the Oak Ridge Y-12 plant  

SciTech Connect

Shipments of radioactive and fissile material from the Oak Ridge Y-12 plant, managed by Martin Marietta Energy Systems, Inc., must be in accordance with governing regulations from the Department of Transportation and the US Nuclear Regulatory Commission (NRC) and orders from the US Department of Energy (DOE). The safety requirements addressed by these regulations and orders pertain to the containment of radioactive material, radiation shielding, and subcriticality of fissile material. A safety analysis report for packaging (SARP) must be prepared by the company for each material-container combination and approved by DOE prior to shipment. When shielding calculations are required for a SARP, the analysis is done by the Radiation Shielding Information Center at Oak Ridge National Laboratory, and survey measurements are made at various stages in the packing and shipment procedures by Y-12 plant health physics personnel. The analysis aid in the design of the shipping containers prior to fabrication, and the dose measurements at the time of shipment have always been well below regulatory limits.

Cramer, S.N.; Dabbs, R.D. (Oak Ridge National Lab., TN (United States)); Cain, V.R. (Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States))

1991-01-01

215

Radiation environment and shielding for early manned Mars missions  

NASA Technical Reports Server (NTRS)

The problem of shielding a crew during early manned Mars missions is discussed. Requirements for shielding are presented in the context of current astronaut exposure limits, natural ionizing radiation sources, and shielding inherent in a particular Mars vehicle configuration. An estimated range for shielding weight is presented based on the worst solar flare dose, mission duration, and inherent vehicle shielding.

Hall, Stephen B.; Mccann, Michael E.

1986-01-01

216

High Density Perpendicular Recording With Wrap-Around Shielded Writer  

Microsoft Academic Search

Wrap-around shielded writers combining both trailing shield and side shield have been studied both by modeling and by experiments. WAS design is demonstrated to have superior performance over its predecessor trailing shielded writer in perpendicular magnetic recording systems. While maintaining the down-track performance, the side shield significantly reduces the side fringing field, thus enabling high track densities. In this paper,

Daniel Z. Bai; Yan Wu; Moris Dovek; Yue Liu; Xiaofeng Zhang; Kowang Liu; Kenichi Takano; Yuchen Zhou

2010-01-01

217

University Buildings Landmark Buildings  

E-print Network

(Student Accommodation) 5 Harty Room, School of Music 26 Health Sciences Building 3 Human Resources 11 Information Services 34 Institute of Professional Legal Studies (IPLS) 4 International and Postgraduate Accommodation Queen's University Belfast Campus Map The Lanyon Building The Students' Union The David Keir

Müller, Jens-Dominik

218

Underground barrier construction apparatus with soil-retaining shield  

DOEpatents

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.

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

219

Underground barrier construction apparatus with soil-retaining shield  

DOEpatents

An apparatus is described 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. 17 figs.

Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.

1998-08-04

220

The Radiation Shielding Competition Sponsored by  

E-print Network

: A radiation shield, simply put, is anything that blocks radiation from an intended target. It can doThe Radiation Shielding Competition Sponsored by: The American Nuclear Society (MNS) Introduction this by absorbing the energy from the radiation. As unstable elements decay, they typically release some sort

Wang, Xiaorui "Ray"

221

International Space Station Radiation Shielding Model Development  

Microsoft Academic Search

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 reconfig- uration 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

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

222

Deep Space Mission Radiation Shielding Optimization  

Microsoft Academic Search

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 missions. In the present report, we present methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and duty

R. K. Tripathi; J. W. Wilson; F. A. Cucinotta; M. S. Clowdsley; M.-H. Y. Kim

2001-01-01

223

Thermal radiation shields for radiant coolers  

Microsoft Academic Search

Thermal radiation shields in the form of low-emissivity surfaces spaced on low-conductance supports can be used to advantage as a replacement for multilayer insulation in radiant coolers. A view factor between adjacent shields of less than unity increases the insulation factor when the surfaces terminate with an external view. An analytical model that accounts for unequal areas as well as

R. V. Annable

1976-01-01

224

Beam Plug for Radiation Shielding Penetrations  

Microsoft Academic Search

A beam line plug has been designed to fill the cylindrical hole formed by beam lines which pass through radiation shielding walls. The plug consists of multiple steel discs held together along their cylindrical axis by a steel cable forming a flexible snake-like structure. Other disc materials including laminates may be used to solve a variety of radiation shielding problems.

M. A. Manni; K. F. Minati

1971-01-01

225

Shield tunneling method and machine therefor  

Microsoft Academic Search

A method is disclosed for excavating a tunnel wherein the muck from the tunnel face is admitted into the shield; the muck is pressed by a pressure of a predetermined level higher than an active earth pressure in the face and lower than a passive earth pressure as the shield body is moved forward, thereby establishing the balance between the

Akesaka

1983-01-01

226

Plastron Shielding Technologies Liquid Repellent Surface Coating  

E-print Network

Plastron Shielding Technologies Liquid Repellent Surface Coating Plastron Shielding Technologies provides coatings that cause treated surfaces to repel dust, dirt, and liquids, making them easy to clean com- pared to existing products. Technology Most current technologies in the surface-coating arena

Jawitz, James W.

227

SHLDUTIL: A Code for Useful Shielding Data  

E-print Network

of our texts (1) Radiation Shielding, ISBN 0-89448-456-7, American Nuclear Society, La Grange Park, IL for Radiation Shielding and "RA" for Radiological Assessment. The primary sources for the data bases used can albedos 7 neutron & sec. gamma albedos 8 proton/electron ranges 9 fission product decay power 10 th

Shultis, J. Kenneth

228

Current status of methods for shielding analysis  

SciTech Connect

Current methods used in shielding analysis and recent improvements in those methods are discussed. The status of methods development is discussed based on needs cited at the 1977 International Conference on Reactor Shielding. Additional areas where methods development is needed are discussed.

Engle, W.W.

1980-01-01

229

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

NASA Astrophysics Data System (ADS)

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.

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

1996-01-01

230

SINEX: SCALE shielding analysis GUI for X-Windows  

SciTech Connect

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.

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

1997-12-01

231

Spacesuit Radiation Shield Design Methods  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

232

Foam Core Shielding for Spacecraft  

NASA Technical Reports Server (NTRS)

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.

Adams, Marc

2007-01-01

233

GFR Sub-Assembly Shielding Design Studies  

SciTech Connect

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.

J. R. Parry

2006-01-01

234

Repository Waste Package Transporter Shielding Weight Optimization  

SciTech Connect

The Yucca Mountain repository requires the use of a waste package (WP) transporter to transport a WP from a process facility on the surface to the subsurface for underground emplacement. The transporter is a part of the waste emplacement transport systems, which includes a primary locomotive at the front end and a secondary locomotive at the rear end. The overall system with a WP on board weights over 350 metric tons (MT). With the shielding mass constituting approximately one-third of the total system weight, shielding optimization for minimal weight will benefit the overall transport system with reduced axle requirements and improved maneuverability. With a high contact dose rate on the WP external surface and minimal personnel shielding afforded by the WP, the transporter provides radiation shielding to workers during waste emplacement and retrieval operations. This paper presents the design approach and optimization method used in achieving a shielding configuration with minimal weight.

C.E. Sanders; Shiaw-Der Su

2005-02-02

235

21 CFR 886.4750 - Ophthalmic eye shield.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...Surgical Devices § 886.4750 Ophthalmic eye shield. (a) Identification. An ophthalmic eye shield is a device that consists of a...

2014-04-01

236

21 CFR 886.4750 - Ophthalmic eye shield.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...Surgical Devices § 886.4750 Ophthalmic eye shield. (a) Identification. An ophthalmic eye shield is a device that consists of a...

2011-04-01

237

21 CFR 886.4750 - Ophthalmic eye shield.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...Surgical Devices § 886.4750 Ophthalmic eye shield. (a) Identification. An ophthalmic eye shield is a device that consists of a...

2013-04-01

238

21 CFR 886.4750 - Ophthalmic eye shield.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...Surgical Devices § 886.4750 Ophthalmic eye shield. (a) Identification. An ophthalmic eye shield is a device that consists of a...

2012-04-01

239

21 CFR 886.4750 - Ophthalmic eye shield.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...Surgical Devices § 886.4750 Ophthalmic eye shield. (a) Identification. An ophthalmic eye shield is a device that consists of a...

2010-04-01

240

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2011-07-01

241

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2013-07-01

242

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2013-07-01

243

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2014-07-01

244

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2014-07-01

245

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2011-07-01

246

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2012-07-01

247

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2012-07-01

248

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2010-07-01

249

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2010-07-01

250

Smart buildings  

Microsoft Academic Search

Can building automation systems overcome interoperability problems to assert control over our offices, hotels, and airports? Efforts to make buildings smarter are focusing on cutting costs by streamlining building operations like air conditioning and lighting. Building automation is critical to these efforts, mainly because it could reduce the annual operating costs of buildings. This article outlines the latest building automation

D. Snoonian

2003-01-01

251

Performance of Whipple Shields at Impact Velocities above 9 km/s  

NASA Technical Reports Server (NTRS)

Whipple shields were first proposed as a means of protecting spacecraft from the impact of micrometeoroids in 1947 [1] and are currently in use as micrometeoroid and orbital debris shields on modern spacecraft. In the intervening years, the function of the thin bumper used to shatter or melt threatening particles has been augmented and enhanced by the use of various types and configurations of intermediate layers of various materials. All shield designs serve to minimize the threat of a spall failure or perforation of the main wall of the spacecraft as a result of the impact of the fragments. With increasing use of Whipple shields, various ballistic limit equations (BLEs) for guiding the design and estimating the performance of shield systems have been developed. Perhaps the best known and most used are the "new" modified Cour-Palais (Christiansen) equations [2]. These equations address the three phases of impact: (1) ballistic (<3 km/s), where the projectile is moving too slowly to fragment and essentially penetrates as an intact projectile; (2) shatter (3 to 7 km/s), where the projectile fragments at impact and forms an expanding cloud of debris fragments; and (3) melt/vaporization (>7 km/s), where the projectile melts or vaporizes at impact. The performance of Whipple shields and the adequacy of the BLEs have been examined for the first two phases using the results of impact tests obtained from two-stage, light-gas gun test firings. Shield performance and the adequacy of the BLEs has not been evaluated in the melt/vaporization phase until now because of the limitations of launchers used to accelerate projectiles with controlled properties to velocities above 7.5 km/s. A three-stage, light-gas gun, developed at the University of Dayton Research Institute (UDRI) [3], is capable of launching small, aluminum spheres to velocities above 9 km/s. This launcher was used to evaluate the ballistic performance of two Whipple shield systems, various thermal protection system materials, and other spacecraft-related materials to the impact of 1.6-mm- to 2.6-mm-diameter, 2017-T4 aluminum spheres at impact velocities ranging from 8.91 km/s to 9.28 km/s. Test results, details of the shield systems, and nominal ballistic limits for the two Whipple shields are shown in Figures 1 and 2.

Christiansen, Eric L.; Davis, Bruce A.; Piekutowski, Andrew J.; Poormon, Kevin L.

2009-01-01

252

International Space Station Radiation Shielding Model Development  

NASA Technical Reports Server (NTRS)

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.

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

253

Caisson shield for arctic offshore production platform  

SciTech Connect

A caisson shield for the protection of an offshore production platform and, more particularly, a caisson shield for use in an arctic environment for the protection of the offshore structure in iceberg-infested waters which is capable of absorbing the destructive forces of an impact produced by a large iceberg. The caisson shield consists of an essentially annular concrete structure encircling at least the submerged support section of the offshore production platform including vertically upstanding concentrically spaced, annular side walls, a horizontal slab base resting on the marine bottom on which the side walls are supported, and a slab top supported on the side walls, and including annularly spaced internal radial partition walls whereby the entire overall caisson shield structure provides a generally toroidal configuration incorporating a plurality of closed compartments. In one embodiment of the invention, located along the outer annular wall is a plurality of arcuate wall sections forming a series of arches and enclosed compartments between each arcuate wall section and the outer annular wall, which impart a ''scallop-like'' configuration to the outer circumference of the caisson shield. The ''scallop-like'' outer walls are capable of resisting and absorbing extremely high ice loads by being adapted to progressively crush the leading edge of an impacting iceberg and to thereby minimize the crush of the iceberg against the caisson shield before coming to rest against the shield.

Clinton, J. D.; Reusswig, G. H.

1985-03-12

254

Performance of multilayer insulation with slotted shield  

NASA Astrophysics Data System (ADS)

Thermal and evacuating performance can be improved by means of slotting a number of one dimension slots on reflection shields of the multilayer insulation (MLI). The influence of slots on thermal radiation and gas conduction heat fluxes are theoretically studied. Based on the analysis and test, the optimum slot rate and length have been obtained. Experiments also show that the performance of MLI with slotted shield will be further improved if a combination of slotted shields with different slot rate can be used to fit the interstitial pressure distribution.

Chen, Guobang; Sun, Tao; Zheng, Jianyao; Huang, Zhixue; Yu, Jianping

255

The SHIELD Multi-Wavelength Archive  

NASA Astrophysics Data System (ADS)

We present WCS-registered data products from the "Survey of HI in Extremely Low-Mass Dwarfs" (SHIELD). This ALFALFA follow-up program targets sources that inhabit the faint end of the HI luminosity function. The final SHIELD data suite includes UV, optical, infrared, and HI imaging, providing a unique opportunity to study the panchromatic properties of low-mass, gas-rich galaxies. Ongoing analysis of the rotational dynamics and patterns of star formation in these systems will be disseminated in forthcoming manuscripts. The final SHIELD data products will be made available to the public on an archival website.

McNichols, Andrew; Teich, Yaron; Cannon, John M.; Adams, Elizabeth A.; Dolphin, Andrew E.; Elson, Edward C.; Giovanelli, Riccardo; Haynes, Martha P.; McQuinn, Kristen B.; Ott, Juergen; Saintonge, Amelie; Salzer, John Joseph; Skillman, Evan D.

2015-01-01

256

Radiation shielding concrete made of Basalt aggregates.  

PubMed

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

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

2013-04-01

257

Seismic Crystals And Earthquake Shield Application  

E-print Network

We theoretically demonstrate that earthquake shield made of seismic crystal can damp down surface waves, which are the most destructive type for constructions. In the paper, seismic crystal is introduced in aspect of band gaps (Stop band) and some design concepts for earthquake and tsunami shielding were discussed in theoretical manner. We observed in our FDTD based 2D elastic wave simulations that proposed earthquake shield could provide about 0.5 reductions in magnitude of surface wave on the Richter scale. This reduction rate in magnitude can considerably reduce destructions in the case of earthquake.

B. Baykant Alagoz; Serkan Alagoz

2009-02-09

258

Hot cell shield plug extraction apparatus  

DOEpatents

An apparatus is provided for moving shielding plugs into and out of holes in concrete shielding walls in hot cells for handling radioactive materials without the use of external moving equipment. The apparatus provides a means whereby a shield plug is extracted from its hole and then swung approximately 90 degrees out of the way so that the hole may be accessed. The apparatus uses hinges to slide the plug in and out and to rotate it out of the way, the hinge apparatus also supporting the weight of the plug in all positions, with the load of the plug being transferred to a vertical wall by means of a bolting arrangement.

Knapp, Philip A. (Moore, ID); Manhart, Larry K. (Pingree, ID)

1995-01-01

259

Commercial Building Partners Catalyze High Performance Buildings Across the Nation  

SciTech Connect

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.

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

2012-08-01

260

Ablative shielding for hypervelocity projectiles  

NASA Technical Reports Server (NTRS)

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.

Rucker, Michelle A. (inventor)

1993-01-01

261

Technical specifications for the bulk shielding reactor  

SciTech Connect

This report provides information concerning the technical specifications for the Bulk Shielding Reactor. Areas covered include: safety limits and limiting safety settings; limiting conditions for operation; surveillance requirements; design features; administrative controls; and monitoring of airborne effluents. 10 refs.

Not Available

1986-05-01

262

Boron-10 loaded inorganic shielding material  

NASA Technical Reports Server (NTRS)

Shielding material containing Boron 10 and gadoliunium for neutron absorption has been developed to reduce interference from low energy neutrons in measurement of fission neutron spectrum using Li-6 fast neutron spectrometer.

Baker, S. I.; Ryskiewicz, R. S.

1972-01-01

263

Resonance self-shielding methodology in MPACT  

SciTech Connect

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)

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

264

Shield Design for Lunar Surface Applications  

SciTech Connect

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.

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

265

Thermal Shield and Reactor Structure Temperatures  

SciTech Connect

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.

Collier, A.R.

2001-07-31

266

Shield Design for Lunar Surface Applications  

NASA Astrophysics Data System (ADS)

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.

Johnson, Gregory A.

2006-01-01

267

Investigation of steel--sodium--iron shields  

Microsoft Academic Search

An analysis of experimental data from 21 fast reactor shield configurations containing steel, sodium, and iron were made as part of a study of the upper axial shielding needs of the Clinch River Breeder Reactor. The measured data were analyzed using both one- and two-dimensional discrete ordinates transport codes and several cross section libraries based on ENDF\\/B-IV data with group

E. M. Oblow; R. E. Maerker

1978-01-01

268

X-ray transmissive debris shield  

DOEpatents

A composite window structure is described for transmitting x-ray radiation and for shielding radiation generated debris. In particular, separate layers of different x-ray transmissive materials are laminated together to form a high strength, x-ray transmissive debris shield which is particularly suited for use in high energy fluences. In one embodiment, the composite window comprises alternating layers of beryllium and a thermoset polymer.

Spielman, Rick B. (Albuquerque, NM)

1994-01-01

269

Nuclear reactor shield including magnesium oxide  

DOEpatents

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.

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

1981-01-01

270

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

271

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

272

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

273

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

274

Experimental results on MgB2 used as ADR magnetic shields, and comparison to NbTi  

NASA Astrophysics Data System (ADS)

Adiabatic Demagnetization Refrigerator (ADR) is an efficient way to obtain sub-Kelvin temperatures in space environments. The SAFARI instrument for the Japanese spaceborne SPICA mission features detectors which will be cooled down to 50 mK. This cooling will be done by a hybrid cooler comprising a 300 mK sorption stage and a 50 mK ADR stage. For this cooler and ADR in general, the main contribution to the overall mass is in the magnetic system and particularly in the magnetic shielding required to keep the stray field within acceptable values. In order to reduce this mass, superconducting materials can be used as active magnetic shields thanks to un-attenuated eddy currents generated while ramping the magnet current. In this way they could reduce the need of heavy ferromagnetic material shields and increase the shielding efficiency to reach very low parasitic values. In the framework of SAFARI we have built a numerical model of a superconductor magnetic shield. The good results regarding the weight gain lead us to an experimental confirmation. In this paper we present an experimental study on MgB2 and NbTi superconducting materials. 2 pairs of rings of typical diameter of 80 mm have been tested using a superconducting magnet matching closely the dimensions of the SAFARI ADR cooler. The magnetic shielding measurements have been compared to a numerical model.

Prouvé, T.; Duval, J. M.; Luchier, N.; D'escrivan, S.

2014-11-01

275

Far infrared spectroscopy telescope (FIRST) inflatable thermal shield, phase 1  

Microsoft Academic Search

Inflatable space rigidized structures (ISRS) were assessed for the FIRST satellite thermal shield. The baseline shield configuration, the so called obliquely cut cylindrical shield configuration, has a diameter of 10 m, a maximum height of 10 m, and a cut angle of 30 deg. This shield consists of an ISRS skeleton of tubes of diameter 0.45 m carrying the thermal

S. Kose

1987-01-01

276

Beam extraction from a synchrotron through a magnetic shield  

Microsoft Academic Search

A new beam extraction scheme from a synchrotron is put forward. The main difference from other schemes of extraction is the use of magnetic shields instead of a septum. Magnetic shields are located in the central dipole magnets of a pulsed chicane. The magnetic shield is a multilayer copper–iron tube. Numerical simulations and experimental results for the magnetic shield are

A. V. Bondarenko; N. A. Vinokurov

2009-01-01

277

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.

278

PBF Reactor Building (PER620) basement, inside cubicle 13. Lead bricks ...  

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

PBF Reactor Building (PER-620) basement, inside cubicle 13. Lead bricks shield the fission product detection system (FPDS). The system detected fission products in pressure loop from in-pile tube. shielding was to prevent other radiation in cubicle from interfering. Assembly of bricks in foreground will slide back to enclose and shield equipment in the three chambers. Date: 1982. INEEL negative no. 82-6376 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

279

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

280

Optimum shell separation for closed axial cylindrical magnetic shields  

NASA Astrophysics Data System (ADS)

The effect of shell separation on the axial shielding with closed double-shell cylindrical shields is investigated numerically. It is found that the optimum shell separation for practical, equal-thickness shields of the above type is considerably smaller than that for transverse spherical and infinitely long cylindrical shields: in most cases, air gaps equal 5%-10% of the inner shell diameter are wide enough to bring the shielding to 90% of its maximum. This indicates that closely spaced axial shields can be used without much sacrifice in performance. Taking into account the computed optimum shell separation for double-shell shields, one can easily optimize and design a compact and effective multishell shield. Based on the numerical study, an analytical approximation is suggested for the axial shielding with narrowly spaced double-shell cylindrical shields.

Paperno, Eugene; Peliwal, Saee; Romalis, Michael V.; Plotkin, Anton

2005-05-01

281

Late precambrian volcanism in NE Sudan and the evolution of the Nubian shield  

NASA Astrophysics Data System (ADS)

Two recent models: the intra-cratonic and the ensimatic island-arc for the evolution of the "Pan-African" (1200-500 M.a) Arabian-Nubian Shield have emerged from work mainly in Arabia and Eastern Egypt. To test these models, this study has focused on some of the late Precambrian metavolcanics and associated batholithic granitoids of the Nubian Shield, NE Sudan. New geochemical and mineralogical data indicate that the volcanism was predominantly calc-alkaline, representing a mature island-arc that evolved above possibly a westerly-dipping subduction zone. This tectonic setting is emphasised on a new discriminant diagram by the geochemical pattern displayed by the metavolcanic rocks occurring in the main study area, here named the Gebeit Mine arc. Trace and REE studies suggest that the rocks were derived from partial melting of modified garnet-free peridotite. The batholithic granitoids, dominated by tonalites, are geochemically similar to the metavolcanic rocks. A plate-tectonic evolutionary model for the Nubian Shield is devised in relation to the whole of the Arabian-Nubian Shield. Within-plate magmatism, the younger "granites" were formed in the late stage of cratonisation. Evidence for mineralisation related to plate-tectonic regimes in the Nubian Shield is also reported.

El-Nadi, A. H.

282

[Verification of the protective effect of a testicular shield in postoperative radiotherapy for seminoma].  

PubMed

In postoperative radiotherapy for seminoma, control of the testicular absorbed dose is important, since exposure of the testis can lead to temporary or permanent infertility. In this case, instead of using a dog-leg-shaped field, treatment using a field focused near the aorta was provided in several disease stages of seminoma. However, the precise need for testicular shielding during treatment and dose of testis exposure was not clear. We examined these questions by measuring the testicular absorbed dose with and without a testicular shield using two clinical treatment plans and a phantom. The distance from the testis phantom and the lower end of the irradiation field was varied. Where the total dose for the tumor was 20 Gy, the testicular absorbed dose was below 0.1 Gy, the threshold dose for temporary infertility. At this dosage, the distance between the testis phantom and the edge of the irradiation field was 14.6 cm without the shield and 9.99 cm with the shield. Using a testes shield, it was thus possible to reduce the dose by 58.5%. PMID:25242597

Matsumoto, Yoshitsugu; Umezu, Yoshiyuki; Fujibuchi, Toshioh; Noguchi, Yoshitaka; Fukunaga, Jyunichi; Kimura, Tomoko; Hirano, Naomi; Hirose, Takaaki; Sonoda, Shinjiro; Matsumoto, Ryoji

2014-09-01

283

Modelling of the shielding capabilities of the existing solid radioactive waste storages at Ignalina NPP.  

PubMed

There is only one nuclear power plant in Lithuania--Ignalina NPP (INPP). The INPP operates two similar units with design electrical power of 1500 MW. The units were commissioned in 1983 and 1987 respectively. From the beginning of the INPP operation all generated solid radioactive waste was collected and stored at the Soviet type solid radwaste facility located at INPP site. The INPP solid radwaste storage facility consists of four buildings, namely building No. 155, No. 155/1, No. 157 and No. 157/1. The buildings of the INPP solid radwaste storage facility are reinforced concrete structures above ground. State Nuclear Safety Inspectorate (VATESI) has specified that particular safety analysis must be performed for existing radioactive waste storage facilities of the INPP. As part of the safety analysis, shielding capabilities of the walls and roofs of these buildings were analysed. This paper presents radiation shielding analysis of the buildings No. 157 and No. 157/1 that are still in operation. The buildings No. 155 and No. 155/1 are already filled up with the waste and no additional waste loading is expected. PMID:16604672

Smaizys, Arturas; Poskas, Povilas; Ragaisis, Valdas

2005-01-01

284

Simulating Building Fires for Movies  

NASA Technical Reports Server (NTRS)

Fire scenes for cinematography staged at relatively low cost in method that combines several existing techniques. Nearly realistic scenes, suitable for firefighter training, produced with little specialized equipment. Sequences of scenes set up quickly and easily, without compromising safety because model not burned. Images of fire, steam, and smoke superimposed on image of building to simulate burning of building.

Rodriguez, Ricardo C.; Johnson, Randall P.

1987-01-01

285

Space Shielding Materials for Prometheus Application  

SciTech Connect

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.

R. Lewis

2006-01-20

286

Shielding of manned space vehicles against protons and alpha particles  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

287

Magnetic shielding of interplanetary spacecraft against solar flare radiation  

NASA Technical Reports Server (NTRS)

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.

Cocks, Franklin H.; Watkins, Seth

1993-01-01

288

A' Brief. History of the Tower Shielding Facility and Tower Shielding Facility  

E-print Network

A' Brief. History of the Tower Shielding Facility and Programs Tower Shielding Facility Hoisting of radiation from reactor. 0 Guyed steel structure 315 feet high 0 Conform to AISC specifications for steel 200 fl with 80 mph wind 0 Two-inch plow steel guys (16) stressed to 75,000 lbs each to minimize tower

289

ETR HEAT EXCHANGER BUILDING, TRA644. A PRIMARY COOLANT PUMP AND ...  

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

ETR HEAT EXCHANGER BUILDING, TRA-644. A PRIMARY COOLANT PUMP AND 24-INCH CHECK VALVE ARE MOUNTED IN A SHIELDED CUBICLE. NOTE CONNECTION AT RIGHT THROUGH SHIELD WALL TO PUMP MOTOR ON OTHER SIDE. INL NEGATIVE NO. 56-4177. Jack L. Anderson, Photographer, 12/21/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

290

Archaean TTG of Vodlozero Terrain, Fennoscandian Shield  

NASA Astrophysics Data System (ADS)

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.

Chekulaev, Valery; Arestova, Natalia

2014-05-01

291

Shielding Structures for Interplanetary Human Mission  

NASA Astrophysics Data System (ADS)

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.

Tracino, Emanuele; Lobascio, Cesare

2012-07-01

292

Composite materials microstructure for radiation shielding  

NASA Technical Reports Server (NTRS)

Shielding against radiation is a concern for applications on earth, in space, and on extraterrestrial surfaces. On earth EMI is an important factor, while in space and on extraterrestrial surfaces particle (high charge-Z and high energy-E) radiation is a critical issue. Conventional metallic materials currently used for EMI shielding incur large weight penalties. To overcome this weight penalty, ultra-lightweight composite materials utilizing fillers ranging from carbon microballoons to silver coated ceramic microballoons are proposed. The crucial shielding requirement is conductivity of the constituent materials, while the hollow microballoon geometry is utilized to yield low weight. Methods of processing and composition effects are examined and these results are compared to the effectiveness of varying the conductive microballoon material. The resulting ultralightweight materials, developed for EMI shielding, can be tailored through the application of the understanding of the relative effects of variables such as those tested. Initial experimental results reveal that these tailored ultralightweight composite materials are superior to traditional aluminum shielding at only a small fraction of the weight.

Radford, Donald W.; Sadeh, Willy Z.; Cheng, Boyle C.

1992-01-01

293

Advances in space radiation shielding codes  

NASA Technical Reports Server (NTRS)

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.

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

294

Correlated Uncertainties in Radiation Shielding Effectiveness  

NASA Technical Reports Server (NTRS)

The space radiation environment is composed of energetic particles which can deliver harmful doses of radiation that may lead to acute radiation sickness, cancer, and even death for insufficiently shielded crew members. Spacecraft shielding must provide structural integrity and minimize the risk associated with radiation exposure. The risk of radiation exposure induced death (REID) is a measure of the risk of dying from cancer induced by radiation exposure. Uncertainties in the risk projection model, quality factor, and spectral fluence are folded into the calculation of the REID by sampling from probability distribution functions. Consequently, determining optimal shielding materials that reduce the REID in a statistically significant manner has been found to be difficult. In this work, the difference of the REID distributions for different materials is used to study the effect of composition on shielding effectiveness. It is shown that the use of correlated uncertainties allows for the determination of statistically significant differences between materials despite the large uncertainties in the quality factor. This is in contrast to previous methods where uncertainties have been generally treated as uncorrelated. It is concluded that the use of correlated quality factor uncertainties greatly reduces the uncertainty in the assessment of shielding effectiveness for the mitigation of radiation exposure.

Werneth, Charles M.; Maung, Khin Maung; Blattnig, Steve R.; Clowdsley, Martha S.; Townsend, Lawrence W.

2013-01-01

295

Asymmetric Electrostatic Radiation Shielding for Spacecraft  

NASA Technical Reports Server (NTRS)

A paper describes the types, sources, and adverse effects of energetic-particle radiation in interplanetary space, and explores a concept of using asymmetric electrostatic shielding to reduce the amount of such radiation impinging on spacecraft. Typically, such shielding would include a system of multiple inflatable, electrically conductive spheres deployed in clusters in the vicinity of a spacecraft on lightweight structures that would maintain the spheres in a predetermined multipole geometry. High-voltage generators would maintain the spheres at potential differences chosen in conjunction with the multipole geometry so that the resulting multipole field would gradually divert approaching energetic atomic nuclei from a central region occupied by the spacecraft. The spheres nearest the center would be the most positive, so as to repel the positively charged impinging nuclei from the center. At the same time, the monopole potential of the overall spacecraft-and-shielding system would be made negative so as to repel thermal electrons. The paper presents results of computational simulations of energetic-particle trajectories and shield efficiency for a trial system of 21 spheres arranged in three clusters in an overall linear quadrupole configuration. Further development would be necessary to make this shielding concept practical.

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

2005-01-01

296

Faraday Shield Development on DIII--D  

NASA Astrophysics Data System (ADS)

DIII--D has been the proving ground for a number of innovative Faraday shield developments over the past ten years. The first Faraday shield used had two tiers of copper-plated Inconel rods of circular cross section with 3 mm thick graphite tiles brazed to the plasma-facing side of the front tier. Later antennas used shields with thin coatings of Ti (C,N) and boron carbide. All the coatings proved effective in reducing impurity influx from the antennas during RF operation. There are two shield designs in use currently. One is a single-tier of horizontal Inconel rods with a 6 ?m layer of boron carbide applied by physical vapor deposition. The other design has molybdenum rods with a plasma-sprayed boron carbide coating approximately 100 ?m thick. Based on comparative performance the thinner coating obtained with physical vapor deposition is preferred for future applicatrions. All Faraday shields have been passively cooled. Future plans call for tests of vanadium elements and of porous-metal helium-cooled elements.

Baity, F. W.; Goulding, R. H.; Hoffman, D. J.; Ryan, P. M.; Taylor, D. J.; Callis, R. W.; Pinsker, R. I.; Lindemuth, J. E.; Rosenfeld, J. H.

1997-11-01

297

Saturn IB First Stage (S-IB Stage) at MSFC  

NASA Technical Reports Server (NTRS)

Workers at the Marshall Space Flight Center (MSFC) begin hoisting S-IB-200D, a dynamic test version of the Saturn IB launch vehicle's first stage (S-IB stage), into the Center's Dynamic Test Stand on January 11, 1965. Test Laboratory persornel assembled a complete Saturn IB to test the structural soundness of the launch vehicle. Developed by the MSFC as an interim vehicle in MSFC's 'building block' approach to Saturn rocket development, the Saturn IB utilized Saturn I technology to further develop and refine large boosters and the Apollo spacecraft capabilities required for the manned lunar missions.

1965-01-01

298

Saturn IB First Stage (S-IB Stage) at MSFC  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center (MSFC) workers lower S-IB-200D, a dynamic test version of the Saturn IB launch vehicle's first stage (S-IB stage), into the Center's Dynamic Test Stand on January 12, 1965. Test Laboratory persornel assembled a complete Saturn IB to test the structural soundness of the launch vehicle. Developed by the MSFC as an interim vehicle in MSFC's 'building block' approach to Saturn rocket development, the Saturn IB utilized Saturn I technology to further develop and refine large boosters and the Apollo spacecraft capabilities required for the manned lunar missions.

1965-01-01

299

The influence of radiation shielding on reusable nuclear shuttle design  

NASA Technical Reports Server (NTRS)

Alternate reusable nuclear shuttle configurations were synthesized and evaluated. Particular attention was given to design factors which reduced tank exposure to direct and scattered radiation, increased payload-engine separation, and improved self-shielding by the LH2 propellant. The most attractive RNS concept in terms of cost effectiveness consists of a single conical aft bulkhead tank with a high fineness ratio. Launch is accomplished by the INT-21 with the tank positioned in the inverted attitude. The NERVA engine is delivered to orbit separately where final stage assembly and checkout are accomplished. This approach is consistent with NERVA definition criteria and required operating procedures to support an economically viable nuclear shuttle transportation program in the post-1980 period.

Littman, T. M.; Garcia, D.

1972-01-01

300

Design and Development of an In-Space Deployable Sun Shield for the Atlas Centaur  

NASA Technical Reports Server (NTRS)

The Centaur, by virtue of its use of high specific-impulse (Isp) LO2/LH2 propellants, has initial mass-to-orbit launch requirements less than half of those upper stages using storable propellants. That is, for Earth escape or GSO missions the Centaur is half the launch weight of a storable propellant upper stage. A drawback to the use of Liquid oxygen and liquid hydrogen, at 90 K and 20 K respectively, over storable propellants is the necessity of efficient cryogen storage techniques that minimize boil-off from thermal radiation in space. Thermal blankets have been used successfully to shield both the Atlas Centaur and Titan Centaur. These blankets are protected from atmospheric air loads during launch by virtue of the fact that the Centaur is enclosed within the payload fairing. The smaller Atlas V vehicle, the Atlas 400, has the Centaur exposed to the atmosphere during launch, and therefore, to date has not flown with thermal blankets shielding the Centaur. A design and development effort is underway to fly a thermal shield on the Atlas V 400 vehicle that is not put in place until after the payload fairing jettisons. This can be accomplished by the use of an inflatable and deployable thermal blanket referred to as the Centaur Sun Shield (CSS). The CSS design is also scalable for use on a Delta upper stage, and the technology potentially could be used for telescope shades, re-entry shields, solar sails and propellant depots. A Phase I effort took place during 2007 in a partnership between ULA and ILC Dover which resulted in a deployable proof-of-concept Sun Shield being demonstrated at a test facility in Denver. A Phase H effort is underway during 2008 with a partnership between ULA, ILC, NASA Glenn Research Center (GRC) and NASA Kennedy Space Center (KSC) to define requirements, determine materials and fabrication techniques, and to test components in a vacuum chamber at cold temperatures. This paper describes the Sun Shield development work to date, and the future plans leading up to a flight test in the 2011 time frame.

Dew, Michael; Allwein, Kirk; Kutter, Bernard; Ware, Joanne; Lin, John; Madlangbayan, Albert; Willey, Cliff; Pitchford, Brian; O'Neil, Gary

2008-01-01

301

Shakespeare's Staging  

NSDL National Science Digital Library

The University of California at Berkeley's English Department has undertaken the enormous task of presenting "a survey of current information, opinions and visuals about...the original nature of Shakespearean performance during his lifetime, and of its development through four centuries thereafter." Visitors can click on "Performance Galleries" at the top of the homepage to be taken to ten albums of over 900 images. Some of the topics of the albums that you can link to are "Productions from the Sixteenth through the Twentieth Century", "Productions in Britain 1960-1998", and "Unusual Representations of Shakespeare Performances". The albums contain items such as playbills, photos and drawings of performances, and photos of the rebuilt Globe Theatre. On the far left side of the homepage, visitors can click on "Videos" to view a documentary series about Elizabethan life, as well as excerpts of performances staged by the Shakespeare Program of UC Berkeley at Shakespeare's Globe Theatre. The videos can be viewed by "Latest", "Most Viewed", "Highest Rated", and "Featured". Visitors interested in other websites that explore Shakespeare performance will want to click on "Relevant Websites" on the far left side of the homepage, to access a link that has 27 Shakespeare performance related websites.

302

Development of a high-performance cryogenic radiator with V-groove radiation shields  

Microsoft Academic Search

A feasibility demonstration model of a new-technology, high-performance, cryogenic radiative cooler has been successfully tested in a helium-cooled vacuum chamber. Thermal isolation of the radiator cold stage from the warm spacecraft and instrument is achieved by a novel arrangement of lightweight radiation shields which form large V-groove cavities, and by the use of low-conductance structural supports. The vacuum chamber experiments

Steven Bard

1987-01-01

303

Electronics Shielding and Reliability Design Tools  

NASA Technical Reports Server (NTRS)

It is well known that electronics placement in large-scale human-rated systems provides opportunity to optimize electronics shielding through materials choice and geometric arrangement. For example, several hundred single event upsets (SEUs) occur within the Shuttle avionic computers during a typical mission. An order of magnitude larger SEU rate would occur without careful placement in the Shuttle design. These results used basic physics models (linear energy transfer (LET), track structure, Auger recombination) combined with limited SEU cross section measurements allowing accurate evaluation of target fragment contributions to Shuttle avionics memory upsets. Electronics shielding design on human-rated systems provides opportunity to minimize radiation impact on critical and non-critical electronic systems. Implementation of shielding design tools requires adequate methods for evaluation of design layouts, guiding qualification testing, and an adequate follow-up on final design evaluation including results from a systems/device testing program tailored to meet design requirements.

Wilson, John W.; ONeill, P. M.; Zang, Thomas A., Jr.; Pandolf, John E.; Koontz, Steven L.; Boeder, P.; Reddell, B.; Pankop, C.

2006-01-01

304

Overview of SNS accelerator shielding analyses  

SciTech Connect

The Spallation Neutron Source is an accelerator driven neutron scattering facility for materials research. During all phases of SNS development, including design, construction, commissioning and operation, extensive neutronics work was performed in order to provide adequate shielding, to assure safe facility operation from radiation protection point of view, and to optimize performance of the accelerator and target facility. Presently, most of the shielding work is concentrated on the beam lines and instrument enclosures to prepare for commissioning, safe operation and adequate radiation background in the future. Although the accelerator is built and in operation mode, there is extensive demand for shielding and activation analyses. It includes redesigning some parts of the facility, facility upgrades, designing additional structures, storage and transport containers for accelerator structures taken out of service, and performing radiation protection analyses and studies on residual dose rates inside the accelerator. (authors)

Popova, I.; Gallmeier, F. X.; Ferguson, P.; Iverson, E.; Lu, W. [ORNL/SNS, MS6475, PO Box 2008, Oak Ridge, TN 37831-6471 (United States)

2012-07-01

305

Radiation shielding effectiveness of newly developed superconductors  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

306

Phenomenological calculations of shielding spallation neutron sources  

NASA Astrophysics Data System (ADS)

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.

Fragopoulou, M.; Zamani, M.

2013-06-01

307

High purity silica reflective heat shield development  

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

308

First Wall, Blanket, Shield Engineering Technology Program  

SciTech Connect

The First Wall/Blanket/Shield Engineering Technology Program sponsored by the Office of Fusion Energy of DOE has the overall objective of providing engineering data that will define performance parameters for nuclear systems in advanced fusion reactors. The program comprises testing and the development of computational tools in four areas: (1) thermomechanical and thermal-hydraulic performance of first-wall component facsimiles with emphasis on surface heat loads; (2) thermomechanical and thermal-hydraulic performance of blanket and shield component facsimiles with emphasis on bulk heating; (3) electromagnetic effects in first wall, blanket, and shield component facsimiles with emphasis on transient field penetration and eddy-current effects; (4) assembly, maintenance and repair with emphasis on remote-handling techniques. This paper will focus on elements 2 and 4 above and, in keeping with the conference participation from both fusion and fission programs, will emphasize potential interfaces between fusion technology and experience in the fission industry.

Nygren, R.E.

1982-01-01

309

SCHEDA OFFERTA DI STAGE/LAVORO: X STAGE (durata mesi: 6 mesi )  

E-print Network

controllo, sistemi di home e building automation, Il/La tiocinante sarà inserito/a in stage per un periodo Products, Power Systems, Low Voltage Products, Process Automation, Discrete Automation and Motion. All

Segatti, Antonio

310

Scale-PC shielding analysis sequences  

SciTech Connect

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.

Bowman, S.M.

1996-05-01

311

Tectonic evolution of the Western Australian Shield  

NASA Technical Reports Server (NTRS)

Geological and geochronological studies in the Western Australian Shield were updated. This terrane bears many similarities to the Indian Shield since they were neighboring parts of Gondwanaland. Western Australia consists of two cratons (Pilbara and Yilgarn) and four orogenic belts (Capricorn, Pingarra, Albany-Fraser, and Patterson), as well as some relatively young (1.6 to 0.75 Ga) sedimentary rocks. The two cratonic blocks are both older than about 2.5 Ga, and the orogenic belts range in age from 2.0 to 0.65 Ga.

Myers, John S.

1988-01-01

312

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.

1997-01-01

313

Hysteresis prediction inside magnetic shields and application  

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

314

Hysteresis prediction inside magnetic shields and application.  

PubMed

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

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

2014-07-01

315

Energy efficient buildings: A world of possibilities  

Microsoft Academic Search

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

Kuliasha

1991-01-01

316

A building elements selection system for architects  

Microsoft Academic Search

This paper explains the development stages of an expert system BES for the evaluation and selection of the building elements. The work covers all kinds of building elements that are available in building construction including retaining walls, foundations, external walls, internal walls, floors, external stairs, internal stairs, roofs, external chimneys, internal chimneys, windows, and external doors and internal doors. The

Halil Z Alibaba; Mesut B Özdeniz

2004-01-01

317

Effects of bumper size on high velocity impact damage to Whipple shield  

NASA Astrophysics Data System (ADS)

With the increasing number of space mission the impact risk on spacecraft at hypervelocity by space debris is increasing A collision with space debris can cause damage to a spacecraft in low Earth orbit For designing spacecraft protection constructions and developing advanced debris shieldsLhypervelocity impact simulation experiments on the ground and the computer simulation of hypervelocity impact is the important means The choice of shields modle sizes is a important step both in the experiments and computer simulation Whipple shields are the basic structure configuration for protecting spacecraft from meteoroid and orbital debris and are still extensively adopted This paper explores the bumper size effects on the damage produced by high velocity impacts on Wipple shields Tests were performed using the non-powder two-stage light gas gun facilities at Hypervelocity Impact Research Center at Harbin Institute of Technology The configuration of Wipple shields consisted of various sizes 1 mm thickness bumpers and constant size 3 mm thickness rear wall with 10 cm space btween the bumper and the rear wall The bumpers used for the tests were made up of 8 12 16 and 20 cm square plate made from 2A12 Aluminum All tests were performed with 4 mm in diameter aluminum projectile at velocity ranging from 1 45 to 1 71 km s The limit velocity of projectile impacting on the Whipple shields in over 0 8 probability of penetration of rear wall in probability of no-penetration of rear wall and on critical penetration condition of rear wall was shown to

Ha, Y.; Guan, G. S.; Pang, B. J.; Zhang, W.

318

Building America  

SciTech Connect

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.

Brad Oberg

2010-12-31

319

Building Bingo  

NSDL National Science Digital Library

In this on site "field trip" activity (located on pages 6-9 of PDF), learners get hands-on experience identifying building materials by playing "Building Bingo". To play, teams of learners locate interior and exterior building materials at their site, use the Natural Materials chart to complete the Building Materials Facts label, and cross off the boxes on their Bingo cards. This lesson guide includes suggestions/tips and game hand-outs.

2012-05-09

320

Stages of Adolescence  

MedlinePLUS

... Stages of Adolescence Ages & Stages Listen Stages of Adolescence Article Body Adolescence, these years from puberty to adulthood, may be roughly divided into three stages: early adolescence, generally ages eleven to fourteen; middle adolescence, ages ...

321

Solar-Flare Shielding With Regolith at  

E-print Network

Solar-Flare Shielding With Regolith at a Lunar-Base Site _T jo_m E. Nealy, John W. Wilson are envisioned, environmental parameters such as high-energy, charged-particle radiation from solar flares and galactic cosmic rays become very impor- tant. Large solar flares can release great quantities of high-energy

Rathbun, Julie A.

322

Passive magnetic shielding in static gradient fields  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

323

Radiation shielding device for nuclear facilities  

Microsoft Academic Search

A pressure vessel of a nuclear reactor is bodily enclosed by an inner layer made of a heat insulating material and an outer layer made of a radiation shielding material, and a nozzle joined by welding to the pressure vessel and a pipe joined by welding to the nozzle projected outwardly from the pressure vessel to extend through openings formed

Aoki

1978-01-01

324

Radiation Shielding for Manned Deep Space Missions  

NASA Technical Reports Server (NTRS)

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.

Adams, James H., Jr.

2003-01-01

325

Ford Motor Company NDE facility shielding design.  

PubMed

Ford Motor Company proposed the construction of a large non-destructive evaluation laboratory for radiography of automotive power train components. The authors were commissioned to design the shielding and to survey the completed facility for compliance with radiation doses for occupationally and non-occupationally exposed personnel. The two X-ray sources are Varian Linatron 3000 accelerators operating at 9-11 MV. One performs computed tomography of automotive transmissions, while the other does real-time radiography of operating engines and transmissions. The shield thickness for the primary barrier and all secondary barriers were determined by point-kernel techniques. Point-kernel techniques did not work well for skyshine calculations and locations where multiple sources (e.g. tube head leakage and various scatter fields) impacted doses. Shielding for these areas was determined using transport calculations. A number of MCNP [Briesmeister, J. F. MCNPCA general Monte Carlo N-particle transport code version 4B. Los Alamos National Laboratory Manual (1997)] calculations focused on skyshine estimates and the office areas. Measurements on the operational facility confirmed the shielding calculations. PMID:16604635

Metzger, Robert L; Van Riper, Kenneth A; Jones, Martin H

2005-01-01

326

New shield for gamma-ray spectrometry  

NASA Technical Reports Server (NTRS)

Gamma-ray shield that can be evacuated, refilled with a clean gas, and pressurized for exclusion of airborne radioactive contaminants effectively lowers background noise. Under working conditions, repeated evacuation and filling procedures have not adversely affected the sensitivity and resolution of the crystal detector.

Brar, S. S.; Gustafson, P. F.; Nelson, D. M.

1969-01-01

327

Performance of multilayer insulation with slotted shield  

Microsoft Academic Search

Thermal and evacuating performance can be improved by means of slotting a number of one dimension slots on reflection shields of the multilayer insulation (MLI). The influence of slots on thermal radiation and gas conduction heat fluxes are theoretically studied. Based on the analysis and test, the optimum slot rate and length have been obtained. Experiments also show that the

Guobang Chen; Tao Sun; Jianyao Zheng; Zhixue Huang; Jianping Yu

1994-01-01

328

Multi-Shielded p-FET Dosimeter  

NASA Technical Reports Server (NTRS)

A compact device was developed for dose measurements where each of four p-FETs has a different shield. Radiation data from the STRV-1b shows that p-FETs can be used to map the radiation inside a spacecraft.

Buehler, M.; Blaes, B.; Martin, D.; Bowman, C.; Bogorad, A.

1995-01-01

329

The Tower Shielding Facility: Its glorious past  

SciTech Connect

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.

Muckenthaler, F.J.

1997-05-07

330

FAST NEUTRON PENETRATION THROUGH REACTOR SHIELDS  

Microsoft Academic Search

Measurements of the penetration of reactor fast neutrons as a function ; of energy have been made in a thermal shield mock-up. The investigation was ; restricted to neutrons in the 2 to 10 Mev energy region A neutron energy ; spectrometer employing a Li⁶I(Eu) scintillation crystal was used. Relative ; spectral distributions are preserted for distances up to 12

N. Hartmann; G. R. Hopkins

1959-01-01

331

Electromagnetic interference shielding effectiveness of carbon materials  

Microsoft Academic Search

Carbon materials for electromagnetic interference (EMI) shielding are reviewed. They include composite materials, colloidal graphite and flexible graphite. Carbon filaments of submicron diameter are effective for use in composite materials, especially after electroplating with nickel. Flexible graphite is attractive for EMI gaskets.

D. D. L. Chung

2001-01-01

332

Oxygen Abundance Measurements of SHIELD Galaxies  

E-print Network

We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. H$\\alpha$ images from the WIYN 3.5m telescope show that these 8 SHIELD galaxies each possess one or two active star-forming regions which were targeted with long-slit spectral observations using the Mayall 4m telescope at KPNO. We obtained a direct measurement of the electron temperature by detection of the weak [O III] $\\lambda$4363 line in 2 of the HII regions. Oxygen abundances for the other HII regions were estimated using a strong-line method. When the SHIELD galaxies are plotted on a B-band luminosity-metallicity diagram they appear to suggest a slightly shallower slope to the relationship than normally seen. However, that offset is systematically reduced when the near-infrared luminosity is used ins...

Haurberg, Nathalie C; Cannon, John M; Marshall, Melissa V

2015-01-01

333

PET/CT shielding design comparisons  

E-print Network

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 two methods agreed...

Coker, Audra Lee

2007-09-17

334

Review of active radiation shielding developments  

NASA Astrophysics Data System (ADS)

The radiation risk due to ionizing particles is a critical issue for long duration manned space missions. The ionization losses in the materials of the spacecraft provide passive shielding effectively stopping low energy particles. However, the estimates of the material required to obtain an acceptable level of radiation result in a prohibitive mass. Active electromagnetic shields, which deflect the charged particles, have been considered as an alternative solution. During the last 10 years the interest in this area has grown. A study of active magnetic shielding based on high-temperature superconductors (HTS) was initiated in an ESA study in 2010, continued in the context of the NASA Innovative Advanced Concepts (NIAC) programs (2011-2014) as well as within a dedicated FP7 EU program, SR2S (2013-2015). The aim of these effort was to provide a realistic evaluation of the possibilities based on current technology levels as well extrapolating to reasonable technology advances expected during the next decade. The different configurations considered were assessed in terms of their technical feasibility and shielding efficiency. We present here a status report of the ongoing work and some preliminary results.

Battiston, Roberto

335

Charge and Potential Distributions in Shielded Striplines  

Microsoft Academic Search

A new method is presented for calculating the charge and potential distribution in shielded microstrip lines with stratified dielectric fillings. The boundary value problem associated with this structure is formulated in a rigorous manner and the solution is constructed by an extension of the function-theoretic technique. Several advantages of this method are pointed out. The most important of these is

RAJ MITTRA; TATSUO ITOH

1970-01-01

336

SP100 reactor and shield design update  

Microsoft Academic Search

The SP-100 technical specification for the generic flight system has been updated to eliminate design specific and unnecessarily restrictive requirements. Relaxation of these requirements allows considerably more flexibility to the reactor and shield designer to minimize the mass of the system. Ground Engineering System (GES) Program test results are also beginning to become available to the designer. Some of these

Nelson A. Deane; Samuel L. Stewart; Thomas F. Marcille; Douglas W. Newkirk

1992-01-01

337

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. ...

2010-03-30

338

Healthy Buildings?  

ERIC Educational Resources Information Center

Health problems related to school buildings can be categorized in five major areas: sick-building syndrome; health-threatening building materials; environmental hazards such as radon gas and asbestos; lead poisoning; and poor indoor air quality due to smoke, chemicals, and other pollutants. This paper provides an overview of these areas,…

Grubb, Deborah

339

Logic circuitry used to automatically test shielded cables  

NASA Technical Reports Server (NTRS)

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.

Dibb, G.

1966-01-01

340

Early test facilities and analytic methods for radiation shielding: Proceedings  

SciTech Connect

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.

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

1992-11-01

341

Benchmark experiments for space Reactor neutron shielding of mission electronics  

Microsoft Academic Search

Experiments and calculations simulating the neutron shadow shield for a reactor-powered space vehicle are described, including calculations for a variety of shield configurations and materials, and an experimental benchmark test using a bare fast reactor.

John G. Williams; Insoo Jun; Wesley W. Sallee; Michael Cherng

2004-01-01

342

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

E-print Network

will be ready soon (ca. 1900 specimens). #12;Georeferencing Plants of the Guiana Shield Google Earth uses KML files to share the information. When a user downloads a KML file it appears on the Places panel

Mathis, Wayne N.

343

Shielding consideration for the SSCL experimental halls  

SciTech Connect

The Superconducting Super Collider which is being designed and built in Waxahachie, Texas consists Of series of proton accelerators, culminating in a 20 Te proton on proton collider. The collider will be in a tunnel which will be 87 km in circumference and. on average about 30 meters underground. The present design calls for two large interaction halls on the east side of the ring. The shielding for these halls is being designed for an interaction rate of 10{sup 9} Hz or 10{sup 16} interactions per year, based on 10{sup 7} seconds per operational year. SSC guidelines require that the shielding be designed to meet the criterion of 1mSv per year for open areas off site 2mSv per year for open areas on site, and 2mSv per year for controlled areas. Only radiation workers will be routinely allowed to work in controlled areas. It should be pointed that there is a potential for an accidental full beam loss in either of the experimental halls, and this event would consist of the loss of the full circulating beam up to 4 {times} 10{sup 14} protons. With the present design. the calculated dose equivalent for this event is about 10% of the annual dose equivalent for the normal p-p interactions, so that die accident condition does not control the shielding. If, for instance, local shielding within the experimental hall is introduced into the calculations, this could change. The shielding requirements presented here are controlled by the normal p-p interactions. Three important questions were addressed in the present calculations. They are (1) the thickness of the roof over the experimental halls, (2) the configuration of the shafts and adits which give access to the halls, and (3) the problem of ground water and air activation.

Bull, J.; Coyne, J.; Mokhov, N.; Stapleton, G.

1994-03-01

344

Family Life Cycle Stages  

Microsoft Academic Search

Individual life stages happen within the context of family life. This article describes Betty Carter's and Monica McGoldrick's Family Life Cycle stages as a context for Eric Erikson's stages of psychosocial development, Daniel Levinson's Stages of a Man's Life, and Jean Piaget's stages of cognitive development. The author juxtaposes the tasks of each family life stage with the individual life

M. A. Armour

1995-01-01

345

Designing dual-plate meteoroid shields: A new analysis  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

346

The design of asymmetric 4 pi shields for space reactors  

NASA Technical Reports Server (NTRS)

A one dimensional shield optimization program based on the method of discrete ordinates has been developed and is used to determine material thicknesses used in asymmetric 4 pion shields for space power reactors. The two dimensional discrete ordinates program DOT is used to check the design, and the information generated in the DOT calculation is used as a guide in shaping the shield which may be considered a first step in two dimensional shield optimization.

Engle, W. W., Jr.; Childs, R. L.; Mynatt, F. R.

1972-01-01

347

A lightweight debris shield using high strength fibers  

Microsoft Academic Search

The purpose of this study was to develop a new lightweight shield using high strength fibers against hypervelocity impacts from space debris (in particular, 1 to 10 cm in diameter). We developed the new lightweight shield using Vectran fibers. The experimental results showed that the developed shield could stop the polycarbonate projectile with 14 mm in diameter, 1 gram in

Yoko Moritaka; Yoko Ogawa; Makoto Tanaka; Yasuhiro Akahoshi; Ryuta Nakamura; Daigo Watanabe; Akira Yamori; Susumu Sasaki

2001-01-01

348

Ballistic limit evaluation of advanced shielding using numerical simulations  

Microsoft Academic Search

The advanced shielding concept employed for the Columbus module of the International Space Station consists of an aluminum bumper and an intermediate shield of Nextel and Kevlar-epoxy. Until recently, the lack of adequate material models for the Nextel cloth and Kevlar-epoxy has precluded the practical usage of hydrocodes in evaluating the response of these shields to hypervelocity impact threats. Recently

Colin J. Hayhurst; Iain H. G. Livingstone; Richard A. Clegg; Roberto Destefanis; Moreno Faraud

2001-01-01

349

A radiation-shielding device for craniofacial implant placement  

Microsoft Academic Search

The use of radiation shields in the head and neck cancer patient receiving adjuvant radiation therapy is a treatment alternative for protecting anticipated prosthetic implant sites. Shields can be fabricated easily as part of an interdisciplinary treatment protocol. In this article, the methods used to fabricate an extraoral radiation shield are described, and a patient treatment that illustrates possible uses

Regina B. Hatfield; V. Vladimir Frias; Jack J. Wazen; Steven R. Isaacson; Eric S. Asher; Robert F. Wright

2001-01-01

350

PLASMA RADIATION SHIELD: CONCEPT AND APPLICATIONS TO SPACE VEHICLES  

Microsoft Academic Search

The plasma radiation shield is an active device using free electrons, electric and magnetic fields for the purpose of shielding astronauts from energetic solar flare-produced protons. The concept of plasma radiation shielding is reviewed in the light of current studies. The available evidence indicates that the concept is physically sound, but important practical questions remain in at least two areas;

RICHARD H. LEVY; FRANCIS W. FRENCH

1968-01-01

351

Space Radiation Shielding Program http://radiationshielding.nasa.gov  

E-print Network

Space Radiation Shielding Program http://radiationshielding.nasa.gov #12;Multi-Functional Material Physical Modeling #12;Space Radiation Shielding Program Radiation Transport Codes Cross Section of radiation shielding materials for spacecraft, habitat, and space suits ­ Testing and maturation of new

Shepherd, Simon

352

Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon  

E-print Network

Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon Nanotube Epoxy Composites Ning (SWNT)-polymer composites have been fabricated to evaluate the electromagnetic interference (EMI EMI shielding materials. Composites with greater than 20 dB shielding efficiency were obtained easily

Gao, Hongjun

353

Radiation shielding for underground low-background experiments  

Microsoft Academic Search

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment

D. Y. Stewart; P. F. Harrison; B. Morgan; Y. Ramachers

2007-01-01

354

Radiation shielding for underground low-background experiments  

Microsoft Academic Search

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment

D. Y. Stewart; P. F. Harrison; B. Morgan; Y. A. Ramachers

2006-01-01

355

Dose buildup factor formula for double-layered shields  

Microsoft Academic Search

In radiation shielding, health physics, and radioactive waste management, it is very important to know buildup factors for various materials and their combinations used as multilayer shields. In this work, a general formula that computes buildup factors for double-layer shields was developed on the basis of Monte Carlo photon transport using the MCNP code. Formulas for buildup factors for double-layer

M. Guvendik; N. Tsoulfanidis

1999-01-01

356

Packed rod neutron shield for fast nuclear reactors  

Microsoft Academic Search

A fast neutron nuclear reactor including a core and a plurality of vertically oriented neutron shield assemblies surrounding the core. Each assembly includes closely packed cylindrical rods within a polygonal metallic duct. The shield assemblies are less susceptible to thermal stresses and are less massive than solid shield assemblies, and are cooled by liquid coolant flow through interstices among the

John E. Eck; Alvin H. Kasberg

1978-01-01

357

Packed rod neutron shield for fast nuclear reactors  

Microsoft Academic Search

A fast neutron nuclear reactor including a core and a plurality of vertically oriented neutron shield assemblies surrounding the core is disclosed. Each assembly includes closely packed cylindrical rods within a polygonal metallic duct. The shield assemblies are less susceptible to thermal stresses and are less massive than solid shield assemblies, and are cooled by liquid coolant flow through interstices

J. E. Eck; A. H. Kasberg

1978-01-01

358

Fast neutron penetration through an axially-symmetrical shield  

Microsoft Academic Search

The shield is broken up into arbitrary layers with twofold attenuation ; of neutrons and with corresponding equalization of the neutron attenuation over ; the shield depth. This procedure was programmed on a computer for shielding ; computations. From this program it is possible to calculate integral fluxes of ; neutrons with energies of 0.1 to 14 MeV both within

A. N. Kozhevnikov; V. A. Khodakov; A. V. Khrustalev

1973-01-01

359

SHIELDING ASTRONAUTS FROM COSMIC RAYS E. N. Parker  

E-print Network

1 SHIELDING ASTRONAUTS FROM COSMIC RAYS E. N. Parker Dept. of Physics and Dept. of Astronomy shielding of an astronaut by surrounding mass involves too much total mass to be practical for launching into space. Magnetic shielding requires transverse field of about 107 Gauss cm (to deflect particles up to 2

Shepherd, Simon

360

Engineering of Ferrite-Graphite Composite Media for Microwave Shields  

E-print Network

Engineering of Ferrite-Graphite Composite Media for Microwave Shields Marina Koledintseva, PoornaAA@mpei.ru Abstract-- An electromagnetic shielding of objects using ferrite-graphite composites is considered- shielding; dielectric base material; ferrite- graphite composite, Maxwell Garnett formulation I

Koledintseva, Marina Y.

361

Application of Modal Analysis to Braided-Shield Cables  

Microsoft Academic Search

Transmission-line equations are derived for a braidedshield cable by modal analysis. The parameters of the braided shield appear in the coefficients as well as in the source terms of the equations. The source terms also depend on the currents and charges on the outer surface of the shield with all the shield's apertures shortcircuited.

K. S. H. Lee; CARL E. BAUM

1975-01-01

362

Refractory metal shielding /insulation/ increases operating range of induction furnace  

NASA Technical Reports Server (NTRS)

Thermal radiation shield contains escaping heat from an induction furnace. The shield consists of a sheet of refractory metal foil and a loosely packed mat of refractory metal fibers in a concentric pattern. This shielding technique can be used for high temperature ovens, high temperature fluid lines, and chemical reaction vessels.

Ebihara, B. T.

1965-01-01

363

DARHT : integration of shielding design and analysis with facility design  

Microsoft Academic Search

The design of the interior portions of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility incorporated shielding and controls from the beginning of the installation of the Accelerators. The purpose of the design and analysis was to demonstrate the adequacy of shielding or to determine the need for additional shielding or controls. Two classes of events were considered: (1) routine

R. L. Boudrie; T. H. Brown; W. E. Gilmore; Downing J. N. Jr; Alan Hack; D. A. McClure; C. A. Nelson; E. Alan Wadlinger; M. V. Zumbro

2002-01-01

364

How stable are the 'stable ancient shields'?  

NASA Astrophysics Data System (ADS)

"Archean cratons are relatively flat, stable regions of the crust that have remained undeformed since the Precambrian, forming the ancient cores of the continents" (King, EPSL, 2005). While this type of statement is supported by a wealth of constraints in the case of episodes of thoroughgoing ductile deformation affecting shield regions of Archean and also Peleoproterozoic age, a growing amount of research indicates that shields are not nearly as structurally stable within the broad field of environmental conditions leading to brittle deformation. In fact, old crystalline basements usually present compelling evidence of long brittle deformation histories, often very complex and challenging to unfold. Recent structural and geochronological studies point to a significant mechanical instability of the shield areas, wherein large volumes of 'stable' rocks actually can become saturated with fractures and brittle faults soon after regional cooling exhumes them to below c. 300-350° C. How cold, rigid and therefore strong shields respond to applied stresses remains, however, still poorly investigated and understood. This in turn precludes a better definition of the shallow rheological properties of large, old crystalline blocks. In particular, we do not yet have good constraints on the mechanisms of mechanical reactivation that control the partial (if not total) accommodation of new deformational episodes by preexisting structures, which remains a key to untangle brittle histories lasting several hundred Myr. In our analysis, we use the Svecofennian Shield (SS) as an example of a supposedly 'stable' region with Archean nucleii and Paleoproterozoic cratonic areas to show how it is possible to unravel the details of brittle histories spanning more than 1.5 Gyr. New structural and geochronological results from Finland are integrated with a review of existing data from Sweden to explore how the effects of far-field stresses are partitioned within a shield, which was growing progressively saturated with fractures as time passed from its initial consolidation. The comparison of time-constrained paleostress data derived from three different locations of the shield shows a remarkably similar stress evolution through time, despite the different geological frameworks of the investigated areas. This suggests that the southern SS has behaved as a coherent rigid crustal block since the Late Mesoproterozoic. By that time, the SS had already reached structural maturity with respect to the saturation of brittle structural features. Therefore, structural reactivation rather than generation of new faults and fractures is the key mechanism that has controlled the mechanical evolution of the shield and that will steer its future evolution within the brittle regime. Comparable brittle structural histories within parts of the shield that are far apart also imply that far-field stresses can propagate over large distances and can lead to similar deformational histories, with the local geological conditions only playing a second-order role on the final brittle strain pattern recorded by the rock.

Viola, Giulio; Mattila, Jussi

2014-05-01

365

Shielding, Levitation, Propulsion G. W. Jewell, Chariman Method for expanding the uniformly shielded area in a short-length  

E-print Network

of supercon- ducting quantum interference device SQUID gradiometers if its axial shielding factor is increased allows the construction of rela- tively compact, lightweight, open-ended cylindrical magnetic shields shields employing magnetic shaking are relatively compact, available space does not al- ways allow

Paperno, Eugene

366

LL/ILW: Post-Qualification of Old Waste through Non-Destructive Extraction of Barrels from Cement Shields - 13535  

SciTech Connect

Currently there is a large number of radioactive waste drums entombed in cement shields at German nuclear power plants. These concrete containers used in the past for the waste are not approved for the final repository. Compliance with current acceptance criteria of the final repository has to be proven by qualification measures on the waste. To meet these criteria, a new declaration and new packing is necessary. A simple non-destructive extraction of about 2000 drums from their concrete shields is not possible. So different methods were tested to find a way of non-destructive extraction of old waste drums from cement shields and therefore reduce the final repository volume and final repository costs by using a container accepted and approved for Konrad. The main objective was to build a mobile system to offer this service to nuclear plant stations. (authors)

Oehmigen, Steffen [GNS Gesellschaft fuer Nuklear-Service mbH (Germany)] [GNS Gesellschaft fuer Nuklear-Service mbH (Germany); Ambos, Frank [Sat. Kerntechnik GmbH (Germany)] [Sat. Kerntechnik GmbH (Germany)

2013-07-01

367

Potential Polymeric Sphere Construction Materials for a Spacecraft Electrostatic Shield  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

368

Passive Superconducting Shielding: Experimental Results and Computer Models  

NASA Technical Reports Server (NTRS)

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.

Warner, B. A.; Kamiya, K.

2003-01-01

369

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

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

370

Supplemental heating of deposition tooling shields  

DOEpatents

A method of reducing particle generation from the thin coating deposited on the internal surfaces of a deposition chamber which undergoes temperature variation greater than 100.degree. C. comprising maintaining the temperature variation of the internal surfaces low enough during the process cycle to keep thermal expansion stresses between the coating and the surfaces under 500 MPa. For titanium nitride deposited on stainless steel, this means keeping temperature variations under approximately 70.degree. C. in a chamber that may be heated to over 350.degree. C. during a typical processing operation. Preferably, a supplemental heater is mounted behind the upper shield and controlled by a temperature sensitive element which provides feedback control based on the temperature of the upper shield.

Ohlhausen, James A. (Albuquerque, NM); Peebles, Diane E. (Albuquerque, NM); Hunter, John A. (Albuquerque, NM); Eckelmeyer, Kenneth H. (Albuquerque, NM)

2000-01-01

371

Active Neutron Shielding for Dark Matter Searches  

NASA Astrophysics Data System (ADS)

Neutrons are a dangerous background to direct dark matter detection searches because they can mimic exactly the signal signature. Recent studies find that the few existing underground measurements of the fast, muon-induced neutron flux disagree at the 30%-50% level with predictions. Given this level of uncertainty, it is desirable to measure the neutron flux in-situ, as well as to reduce the number of neutrons incident on a dark matter detector. Towards these ends, we are developing a neutron veto system for both active and passive shielding. The goals of this R&D are (i) a measurement of the neutron energy spectrum underground above 10 MeV neutron kinetic energies, and (ii) measurements of the attenuation vs. energy of these neutrons in 1 meter of water, concrete, and liquid scintillator. These measurements will provide valuable input for simulation and design of shields for low-background experiments underground.

Monroe, Jocelyn; Yamamoto, Richard; Fisher, Peter; Cornell, Brett; Robinson, Mareena; Cowern, Dianna; Eyers, Richard; Henderson, Shawn

2009-05-01

372

Analytic Ballistic Performance Model of Whipple Shields  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

373

Debye shielding in a nonextensive plasma  

SciTech Connect

The phenomenon of Debye Shielding is revisited within the theoretical framework of the Tsallis statistical mechanics. The plasma consists of nonextensive electrons and ions. Both the effective Debye length {lambda}{sub D}{sup q} and the fall-off of the electrostatic potential {Phi} are considered and a parameter study conducted. Owing to electron nonextensivity, the critical Mach number derived from the modified Bohm sheath criterion may become less than unity allowing therefore ions with speed less than ion-acoustic speed to enter the sheath from the main body of the plasma. Considering the wide relevance of collective processes, our analysis may be viewed as a first step toward a more comprehensive Debye shielding and electrostatic plasma sheath in nonequilibrium plasmas.

Ait Gougam, Leila; Tribeche, Mouloud [Faculty of Sciences-Physics, Theoretical Physics Laboratory (TPL), University of Bab-Ezzouar, U.S.T.H.B, B.P. 32, El Alia, Algiers 16111 (Algeria)

2011-06-15

374

Electronically shielded solid state charged particle detector  

DOEpatents

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.

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

1996-08-20

375

Electronically shielded solid state charged particle detector  

DOEpatents

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.

Balmer, David K. (155 Coral Way, Broomfield, CO 80020); Haverty, Thomas W. (1173 Logan, Northglenn, CO 80233); Nordin, Carl W. (7203 W. 32nd Ave., Wheatridge, CO 80033); Tyree, William H. (1977 Senda Rocosa, Boulder, CO 80303)

1996-08-20

376

A low-relief shield volcano origin for the South Kaua`i Swell  

NASA Astrophysics Data System (ADS)

The South Kaua`i Swell (SKS) is a 110 km x 80 km ovoid bathymetric feature that stands >2 km high and abuts the southern flank of the island of Kaua`i. The origin of the SKS was investigated using multibeam bathymetry and acoustic backscatter, gravity data, radiometric ages, and geochemistry of rock samples. Most of the SKS rock samples are tholeiitic in composition with ages of 3.9-5.4 Ma indicating they were derived from shield volcanism. The ages and compositions of the SKS rocks partially overlap with those of the nearby Ni`ihau, Kaua`i and West Ka`ena volcano complexes. The SKS was originally described as a landslide; however, this interpretation is problematic given the ovoid shape of SKS, its relatively smooth, flat-to-convex surface, and the lack of an obvious source region that could accommodate what would be one of Earth's most voluminous (6 x 103 km3) landslides. The morphology, size, and the surrounding gravity anomaly are more consistent with the SKS being a low-relief shield volcano, which was partially covered with a small volume of landside debris from south Kaua`i and later with some secondary volcanic seamounts. A shield origin would imply that Hawaiian and possibly other hotspot shield volcanoes can take on a wider variety of forms than is commonly thought, ranging from tall island-building shields, to smaller edifices such as Ka`ena Ridge and Mahukona, to even lower-relief volcanoes represented by the SKS and possibly the South West O`ahu Volcanic Field.

Ito, Garrett; Garcia, Michael O.; Smith, John R.; Taylor, Brian; Flinders, Ashton; Jicha, Brian; Yamasaki, Seiko; Weis, Dominique; Swinnard, Lisa; Blay, Chuck

2013-07-01

377

Radiation shielding of concretes containing different aggregates  

Microsoft Academic Search

The shielding of ?-rays by concrete has been investigated for concretes containing different amounts of barite and normal weight aggregates. The linear attenuation coefficients (?, cm?1) have been calculated at photon energies of 1keV to 100GeV using XCOM and the obtained results compared with the measurements at the photon energies of 0.66MeV and 1.33MeV. It is shown that the type

I. Akkurt; C. Basyigit; S. Kilincarslan; B. Mavi; A. Akkurt

2006-01-01

378

Target Magnets & Shielding Particle Beam Lasers, Inc.  

E-print Network

Engineering, LLC. March 5, 2012 1 #12;Isometric View of Three TargetMagnet Designs Design IDS120h (top), IDS; Outer 30 tons/m; Inner 8 tons/m. 4 #12;Isometric View of Meshed Shielding Vessels of IDS120h 5 #12;Sag /B Desired fieldTotal field SC magnet Resistive magnet Distance along axis [cm] On-axisfield[T] 10

McDonald, Kirk

379

Hypervelocity impact simulations of Whipple shields  

NASA Technical Reports Server (NTRS)

The problem associated with protecting space vehicles from space debris impact is described. Numerical simulation is espoused as a useful complement to experimentation: as a means to help understand and describe the hypervelocity impact phenomena. The capabilities of a PC-based hydrocode, ZeuS, are described, for application to the problem of hypervelocity impact. Finally, results of ZeuS simulations, as applied to the problem of bumper shield impact, are presented and compared with experimental results.

Segletes, Steven B.; Zukas, Jonas A.

1992-01-01

380

New Electromagnetic Interference Shielding Material Demonstrated  

NASA Technical Reports Server (NTRS)

A demonstration electromagnetic interference (EMI) shielding cover that has a potential mass savings in excess of 80 percent over conventional aluminum has been fabricated and tested. It was the culmination of a 3-yr effort involving Hughes Space and Communications (Los Angeles), Applied Sciences, Inc. (Cedarville, Ohio), and the NASA Lewis Research Center. The cover was fabricated from a composite of polycyanate ester resin and graphite fibers that had been chemically modified by intercalation to enhance their electrical conductivity.

Gaier, James R.

1997-01-01

381

Shielding analyses: the rabbit vs the turtle?  

SciTech Connect

This paper compares solutions using Monte Carlo and discrete- ordinates methods applied to two actual shielding situations in order to make some general observations concerning the efficiency and advantages/disadvantages of the two approaches. The discrete- ordinates solutions are performed using two-dimensional geometries, while the Monte Carlo approaches utilize three-dimensional geometries with both multigroup and point cross-section data.

Broadhead, B.L.

1996-12-31

382

SINBAD: Shielding integral benchmark archive and database  

SciTech Connect

SINBAD is a new electronic database developed to store a variety of radiation shielding benchmark data so that users can easily retrieve and incorporate the data into their calculations. SINBAD is an excellent data source for users who require the quality assurance necessary in developing cross-section libraries or radiation transport codes. The future needs of the scientific community are best served by the electronic database format of SINBAD and its user-friendly interface, combined with its data accuracy and integrity.

Hunter, H.T.; Ingersoll, D.T.; Roussin, R.W. [and others

1996-04-01

383

Linear nodal method for shielding applications  

Microsoft Academic Search

The linear nodal (LN) method for the discrete-ordinates form of the (X-Y) geometry transport equation has previously been described by Walters and O'Dell. The work described here develops new fixups to prevent the calculation of negative fluxes and compares the performance of the LN method and the weighted-difference methods available in DOT for several typical shielding problems. The LN method

R. L. Childs; W. A. Rhoades

1984-01-01

384

SQUID holder with high magnetic shielding  

SciTech Connect

We discuss a SQUID holder designed for high magnetic shielding. We show 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{sup 9} at the SQUID input. With the SQUID input shorted, the response to external fields is 10{sup {minus}5} {Phi}{sub 0}/G.

Rigby, K.W.; Marek, D.; Chui, T.C.P. (Department of Physics, Stanford University, Stanford, California 94305 (US))

1990-02-01

385

SQUID holder with high magnetic shielding  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

386

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

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…

American Inst. of Architects, Washington, DC.

387

Building Together  

NSDL National Science Digital Library

In this Bob the Builder(TM)-themed activity, learners explore what it means to work together as a team. Learners repeat the phrase “Can We Build It?(TM) Yes We Can!” until they can chant it together as a team. Then, learners repeat the chant at each activity station. Learners rotate through the stations where they build with blocks, LEGO® bricks or other small manipulatives, hammer nails and wood, pump with water, and construct a building site by moving sand with toy trucks. This activity is featured on page 9 of the "Bob the Builder(TM) — Project: Build It" unit of study.

The Children's Museum of Indianapolis

2006-01-01

388

Building Houses  

NSDL National Science Digital Library

Build a house you can fit inside, using cardboard tubes. Variations of this activity include building for a toy (easier) or building a house the right size for a stuffed animal or a garage for a toy car. Also included is an option to build houses inspired by those around the world (harder). This activity focuses on the understanding of sizes and shapes: Can I fit in this if I stand up? if I sit? Do we have enough cardboard tubes to make a triangular roof? This activity is available as a webpage and a downloadable pdf. Students should have the ability to use scissors and tape well.

2010-01-01

389

Shielded silicon gate complementary MOS integrated circuit.  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

390

GRAVITATIONAL FIELD SHIELDING AND SUPERNOVA EXPLOSIONS  

SciTech Connect

A new mechanism for supernova explosions called gravitational field shielding is proposed, in accord with a five-dimensional fully covariant Kaluza-Klein theory with a scalar field that unifies the four-dimensional Einsteinian general relativity and Maxwellian electromagnetic theory. It is shown that a dense compact collapsing core of a star will suddenly turn off or completely shield its gravitational field when the core collapses to a critical density, which is inversely proportional to the square of mass of the core. As the core suddenly turns off its gravity, the extremely large pressure immediately stops the core collapse and pushes the mantle material of supernova moving outward. The work done by the pressure in the expansion can be the order of energy released in a supernova explosion. The gravity will resume and stop the core from a further expansion when the core density becomes less than the critical density. Therefore, the gravitational field shielding leads a supernova to impulsively explode and form a compact object such as a neutron star as a remnant. It works such that a compressed spring will shoot the oscillator out when the compressed force is suddenly removed.

Zhang, T. X. [Physics Department, Alabama A and M University, Normal, AL 35762 (United States)

2010-12-20

391

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

SciTech Connect

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.

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

2008-10-31

392

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

393

Building Technology  

NSDL National Science Digital Library

From residential houses to hundred-story skyscrapers, many different technologies come together to make a building safe and comfortable. Building design is a continually changing industry, and new advances are being made possible as research progresses.Sustainable development is gaining popularity worldwide in an effort to minimize environmental impact. The Center for Resourceful Building Technology (1) maintains an online guide that describes building practices that are resource-efficient; some information on the center's research projects is also available. Similar in topic is this report from the National Association of Home Builders Research Center (2). The 70-page document is the final report of an April 2003 conference on green building; it gives day-by-day summaries of presentations and activities in which the conference participants were involved. Office buildings have a number of design issues that need to be considered to make a productive work environment. One such issue is the acoustics in a cubicle workspace. The Canadian Institute for Research in Construction (3) discusses some design factors that can improve privacy even in the very open atmosphere of closely spaced cubicles. In the wake of the 2001 anthrax scare, a research project at Pennsylvania State University has garnered significant attention. This paper (4) introduces immune buildings, which have advanced ventilation and air filtration systems that can mitigate the danger caused by airborne pathogens. Experimental results from the project are also presented. The US Department of Energy High Performance Building Initiative (5) is investigating new technologies to make commercial buildings more comfortable and cost effective. Several interesting technical papers and introductory reports are given on the initiative's homepage, including a technology road map for high performance buildings. This essay from the June 2003 issue of Constructech Magazine (6) highlights a movement toward integrated control systems for all types of buildings. The author notes that having a unified system that automatically manages security, lighting, energy, and several other building operations can save time and money in the long run. Another article, written by a member of the Partnership for Advanced Technology in Housing (7), discusses building materials and practices that can improve residential installation's resistance to major storms and natural disasters. An example of an area that is using these weather resistant designs is in Florida; the article cites the vulnerability of coastal homes to hurricanes and outlines some efforts to build them in a more structurally sound manner. Lastly, the Commercial Modular Construction Magazine (8) is a quarterly publication that centers on permanent and temporary modular building design. The second issue of 2003 has, among other things, a good article that describes the basics and benefits of modular construction.

Leske, Cavin.

394

Residential building energy analysis : development and uncertainty assessment of a simplified model  

E-print Network

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 ...

Spindler, Henry C. (Henry Carlton), 1970-

1998-01-01

395

Cervical Cancer Stage IIIB  

MedlinePLUS

... Browse Search Quick Search Image Details Cervical Cancer Stage IIIB View/Download: Small: 684x636 View Download Add to My Pictures Title: Cervical Cancer Stage IIIB Description: Stage IIIB cervical cancer; drawing shows ...

396

Cervical Cancer Stage IB  

MedlinePLUS

... Browse Search Quick Search Image Details Cervical Cancer Stage IB View/Download: Small: 774x576 View Download Add to My Pictures Title: Cervical Cancer Stage IB Description: Stage IB1 and IB2 cervical cancer ...

397

Cervical Cancer Stage IIIA  

MedlinePLUS

... 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; drawing shows ...

398

Cervical Cancer Stage IVA  

MedlinePLUS

... 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; drawing and ...

399

Cervical Cancer Stage IVB  

MedlinePLUS

... 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; drawing shows ...

400

Cervical Cancer Stage IA  

MedlinePLUS

... Browse Search Quick Search Image Details 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; ...

401

Ovarian Cancer Stage IIIC  

MedlinePLUS

... My Pictures Browse Search Quick Search Image Details Ovarian Cancer Stage IIIC View/Download: Small: 734x648 View Download Add to My Pictures Title: Ovarian Cancer Stage IIIC Description: Stage IIIC ovarian cancer; ...

402

Ovarian Cancer Stage IV  

MedlinePLUS

... My Pictures Browse Search Quick Search Image Details Ovarian Cancer Stage IV View/Download: Small: 528x757 View Download Add to My Pictures Title: Ovarian Cancer Stage IV Description: Stage IV ovarian cancer; ...

403

Pancreatic Cancer Stage 4  

MedlinePLUS

... My Pictures Browse Search Quick Search Image Details Pancreatic Cancer Stage 4 View/Download: Small: 533x576 View Download Add to My Pictures Title: Pancreatic Cancer Stage 4 Description: Stage IV pancreatic cancer; drawing ...

404

Pancreatic Cancer Stage 3  

MedlinePLUS

... My Pictures Browse Search Quick Search Image Details Pancreatic Cancer Stage 3 View/Download: Small: 720x576 View Download Add to My Pictures Title: Pancreatic Cancer Stage 3 Description: Stage III pancreatic cancer; drawing ...

405

Preventing Accidental Ignition of Upper-Stage Rocket Motors  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

406

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

407

Effect on de-greasing solvents on conductive separable connector shields and semiconductive cable shields  

SciTech Connect

A study has been conducted to determine the effects of commercial degreasing solvents on the conductivity of an EPDM separable connector shield and two types of cable shields based on EPR and XLPE, respectively. Solvents tested included a chlorinated solvent based on 1,1,1-trichloroethane and several so-called citrus solvents consisting of the natural terpene, limonene, or blends of limonene with other hydrocarbons. All the solvents significantly degraded the conductivity of the EPR and EPDM materials, but had little effect on the XLPE cable shield. The solvents differed, however, in the extent of their effects, the rate of recovery of conductivity after removal of the solvent, and the degree to which the original conductivity of the material was restored. The consequences of these results in terms of appropriate field use of these types of solvents by utility personnel are discussed.

Perry, D.D.; Bolcar, J.P. (Amerace Corp., Hackettstown, NJ (USA). Elastimold Div.)

1990-04-01

408

Building Green  

NSDL National Science Digital Library

There's a great deal of talk about "building green" in the architecture and design world, but to many, this phrase may not mean a great deal. This website, created by the Building Green company, can help the uninitiated learn more about this subject. First-time visitors should click on the "Green Building Information" area. Here they can get answers to such question as "What is green?" and also learn more about green design strategies and the LEED rating system. Right next to this section is the "Case Studies" area, which features green building projects like elementary schools, commercial facilities, and university buildings. The site is rounded out by a "News" area and a detailed bibliography of websites, print resources, and so on.

409

Analysis and improvement of cyclotron thallium target room shield.  

PubMed

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

Hajiloo, N; Raisali, G; Aslani, G

2008-01-01

410

Saturn IB First Stage (S-IB Stage) at MSFC  

NASA Technical Reports Server (NTRS)

S-IB-200D, a dynamic test version of the Saturn IB launch vehicle's first stage (S-IB), makes its way to the Marshall Space Flight Center (MSFC) East Test Area on January 4, 1965. Test Laboratory persornel assembled a complete Saturn IB to test the structural soundness of the launch vehicle in the Dynamic Test Stand. Developed by the MSFC as an interim vehicle in MSFC's 'building block' approach to the Saturn rocket development, the Saturn IB utilized Saturn I technology to further develop and refine the larger boosters and the Apollo spacecraft capabilities required for the manned lunar missions.

1965-01-01

411

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

412

Radiation shielding for future space exploration missions  

NASA Astrophysics Data System (ADS)

Scope and Method of Study. The risk to space crew health and safety posed by exposure to space radiation is regarded as a significant obstacle to future human space exploration. To countermand this risk, engineers and designers in today's aerospace community will require detailed knowledge of a broad range of possible materials suitable for the construction of future spacecraft or planetary surface habitats that provide adequate protection from a harmful space radiation environment. This knowledge base can be supplied by developing an experimental method that provides quantitative information about a candidate material's space radiation shielding efficacy with the understanding that (1) shielding is currently the only practical countermeasure to mitigate the effects of space radiation on human interplanetary missions, (2) any mass of a spacecraft or planetary surface habitat necessarily alters the incident flux of ionizing radiation on it, and (3) the delivery of mass into LEO and beyond is expensive and therefore may benefit from the possible use of novel multifunctional materials that could in principle reduce cost as well as ionizing radiation exposure. The developed method has an experimental component using CR-39 PNTD and Al2O3:C OSLD that exposes candidate space radiation shielding materials of varying composition and depth to a representative sample of the GCR spectrum that includes 1 GeV 1H and 1 GeV/n 16O, 28Si, and 56Fe heavy ion beams at the BNL NSRL. The computer modeling component of the method used the Monte Carlo radiation transport code FLUKA to account for secondary neutrons that were not easily measured in the laboratory. Findings and Conclusions. This study developed a method that quantifies the efficacy of a candidate space radiation shielding material relative to the standard of polyethylene using a combination of experimental and computer modeling techniques. The study used established radiation dosimetry techniques to present an empirical weighted figure of merit (WFoM) approach that quantifies the effectiveness of a candidate material to shield space crews from the whole of the space radiation environment. The results of the WFoM approach should prove useful to designers and engineers in seeking alternative materials suitable for the construction of spacecraft or planetary surface habitats needed for long-term space exploration missions. The dosimetric measurements in this study have confirmed the principle of good space radiation shielding design by showing that low-Z¯ materials are most effective at reducing absorbed dose and dose equivalent while high-Z¯ materials are to be avoided. The relatively high WFoMs of carbon composite and lunar- and Martian-regolith composite could have important implications for the design and construction of future spacecraft or planetary surface habitats. The ground-based measurements conducted in this study have validated the heavy ion extension of FLUKA by producing normalized differential LET fluence spectra that are in good agreement with experiment.

DeWitt, Joel Michael

413

Moderately shielded high-Tc SQUID system for rat MCG  

NASA Astrophysics Data System (ADS)

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.

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

2010-06-01

414

Computer Assistance for Sustainable Building Design  

Microsoft Academic Search

The greatest opportunity for sustainable building design strategies occur in the early stages of design when the most important\\u000a decisions are taken. Nevertheless, it is the stage with the least computer support. This paper presents recent research efforts\\u000a at ETS toward the long term goal of developing the next generation of computer assistance to designers of sustainable buildings.\\u000a Two research

Hugues Rivard

2006-01-01

415

Building Big  

NSDL National Science Digital Library

Building Big is a very informative site about the engineering principles required to build large structures, including bridges, domes, skyscrapers, dams, and tunnels. The interactive labs presented on the site discuss the various factors (e.g. forces, materials, loads, shapes) that need to be considered when designing large buildings. Fun challenges test these concepts for each of the five structures by putting students in charge of various construction projects. The student needs to weigh the pros and cons of particular designs and choose which is best for a given scenario. There are also many interviews with different structural engineers that will help students understand what working in this field is like.

2000-01-01

416

Remediation of the site of a former active handling building at UKAEA Winfrith  

Microsoft Academic Search

Available in abstract form only. Full text of publication follows: Since July 2000, NUKEM Limited has been carrying out the decommissioning of the former Active Handling Building, A59 at Winfrith, Dorset, United Kingdom (UK) under contract from the nuclear site licence holder, United Kingdom Atomic Energy Authority, (UKAEA). The building contained two heavily shielded suites of caves originally used to

Jack Armitage; Nick Brown; Rowland Cornell; Gareth Jessop

2007-01-01

417

Rotating-shield brachytherapy for cervical cancer  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

418

Accelerator-based validation of shielding codes  

SciTech Connect

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.

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

2002-08-12

419

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

Microsoft Academic Search

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

1998-01-01

420

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

Microsoft Academic Search

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

Adkins

1996-01-01

421

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

SciTech Connect

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.

Adkins, H.E.

1996-10-29

422

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

SciTech Connect

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.

Smith, R.J.

1998-03-31

423

Radiation shielding for underground low-background experiments  

E-print Network

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields.

D. Y Stewart; P. F. Harrison; B. Morgan; Y. A. Ramachers

2006-07-31

424

Radiation shielding for underground low-background experiments  

E-print Network

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields.

Stewart, D Y; Morgan, B; Ramachers, Y A

2006-01-01

425

Radiation shielding for underground low-background experiments  

NASA Astrophysics Data System (ADS)

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields. Note that these proceedings are a short version of a recently submitted, more detailed discussion.

Stewart, D. Y.; Harrison, P. F.; Morgan, B.; Ramachers, Y.

2006-11-01

426

Radiation shielding for underground low-background experiments  

SciTech Connect

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields. Note that these proceedings are a short version of a recently submitted, more detailed discussion.

Stewart, D. Y.; Harrison, P. F.; Morgan, B.; Ramachers, Y. [University of Warwick, Coventry, CV4 7AL (United Kingdom)

2006-11-17

427

Radiation shielding for underground low-background experiments  

NASA Astrophysics Data System (ADS)

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields.

Stewart, D. Y.; Harrison, P. F.; Morgan, B.; Ramachers, Y.

2007-02-01

428

Dose distribution under external eye shields for high energy electrons.  

PubMed

Effectiveness of eye shields in reducing the dose to the eye lens from 6 and 9 MeV electron beams from a linear accelerator has been evaluated. The thickness of the shields made from cerrobend was such that only bremsstrahlung photons were transmitted. A shield with a diameter of 1.3 cm and thickness of 1 cm was adequate for the 9 MeV electron beam. The optimum shield to phantom surface distance was 1 cm or less. The same shield with a thickness of 0.5 cm was found to be ineffective with a 6 MeV electron beam. The dose under the shield is greater than predicted by transmission measurements because of the contribution of phantom and electron cone generated scattered electrons. PMID:3080389

Rustgi, S N

1986-01-01

429

Ablative heat shield design for space shuttle  

NASA Technical Reports Server (NTRS)

Ablator heat shield configuration optimization studies were conducted for the orbiter. Ablator and reusable surface insulation (RSI) trajectories for design studies were shaped to take advantage of the low conductance of ceramic RSI and high temperature capability of ablators. Comparative weights were established for the RSI system and for direct bond and mechanically attached ablator systems. Ablator system costs were determined for fabrication, installation and refurbishment. Cost penalties were assigned for payload weight penalties, if any. The direct bond ablator is lowest in weight and cost. A mechanically attached ablator using a magnesium subpanel is highly competitive for both weight and cost.

Seiferth, R. W.

1973-01-01

430

Radiation-Shielding Polymer/Soil Composites  

NASA Technical Reports Server (NTRS)

It has been proposed to fabricate polymer/ soil composites primarily from extraterrestrial resources, using relatively low-energy processes, with the original intended application being that habitat structures constructed from such composites would have sufficient structural integrity and also provide adequate radiation shielding for humans and sensitive electronic equipment against the radiation environment on the Moon and Mars. The proposal is a response to the fact that it would be much less expensive to fabricate such structures in situ as opposed to transporting them from Earth.

Sen, Subhayu

2007-01-01

431

Equivalent-spherical-shield neutron dose calculations  

SciTech Connect

Neutron doses through 162-cm-thick spherical shields were calculated to be 1090 and 448 mrem/h for regular and magnetite concrete, respectively. These results bracket the measured data, for reinforced regular concrete, of /approximately/600 mrem/h. The calculated fraction of the high-energy (>20 MeV) dose component also bracketed the experimental data. The measured and calculated doses were for a graphite beam stop bombarded with 100 nA of 800-MeV protons. 6 refs., 2 figs., 1 tab.

Russell, G.J.; Robinson, H.

1988-01-01

432

Interstitial rotating shield brachytherapy for prostate cancer  

SciTech Connect

Purpose: To present a novel needle, catheter, and radiation source system for interstitial rotating shield brachytherapy (I-RSBT) of the prostate. I-RSBT is a promising technique for reducing urethra, rectum, and bladder dose relative to conventional interstitial high-dose-rate brachytherapy (HDR-BT). Methods: A wire-mounted 62 GBq{sup 153}Gd source is proposed with an encapsulated diameter of 0.59 mm, active diameter of 0.44 mm, and active length of 10 mm. A concept model I-RSBT needle/catheter pair was constructed using concentric 50 and 75 ?m thick nickel-titanium alloy (nitinol) tubes. The needle is 16-gauge (1.651 mm) in outer diameter and the catheter contains a 535 ?m thick platinum shield. I-RSBT and conventional HDR-BT treatment plans for a prostate cancer patient were generated based on Monte Carlo dose calculations. In order to minimize urethral dose, urethral dose gradient volumes within 0–5 mm of the urethra surface were allowed to receive doses less than the prescribed dose of 100%. Results: The platinum shield reduced the dose rate on the shielded side of the source at 1 cm off-axis to 6.4% of the dose rate on the unshielded side. For the case considered, for the same minimum dose to the hottest 98% of the clinical target volume (D{sub 98%}), I-RSBT reduced urethral D{sub 0.1cc} below that of conventional HDR-BT by 29%, 33%, 38%, and 44% for urethral dose gradient volumes within 0, 1, 3, and 5 mm of the urethra surface, respectively. Percentages are expressed relative to the prescription dose of 100%. For the case considered, for the same urethral dose gradient volumes, rectum D{sub 1cc} was reduced by 7%, 6%, 6%, and 6%, respectively, and bladder D{sub 1cc} was reduced by 4%, 5%, 5%, and 6%, respectively. Treatment time to deliver 20 Gy with I-RSBT was 154 min with ten 62 GBq {sup 153}Gd sources. Conclusions: For the case considered, the proposed{sup 153}Gd-based I-RSBT system has the potential to lower the urethral dose relative to HDR-BT by 29%–44% if the clinician allows a urethral dose gradient volume of 0–5 mm around the urethra to receive a dose below the prescription. A multisource approach is necessary in order to deliver the proposed {sup 153}Gd-based I-RSBT technique in reasonable treatment times.

Adams, Quentin E., E-mail: quentin-adams@uiowa.edu; Xu, Jinghzu; Breitbach, Elizabeth K.; Li, Xing; Rockey, William R.; Kim, Yusung; Wu, Xiaodong; Flynn, Ryan T. [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); Enger, Shirin A. [Medical Physics Unit, McGill University, 1650 Cedar Ave, Montreal, Quebec H3G 1A4 (Canada)] [Medical Physics Unit, McGill University, 1650 Cedar Ave, Montreal, Quebec H3G 1A4 (Canada)

2014-05-15

433

X-ray transmissive debris shield  

DOEpatents

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.

Spielman, R.B.

1996-05-21

434

X-ray transmissive debris shield  

DOEpatents

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.

Spielman, Rick B. (Albuquerque, NM)

1996-01-01

435

CHESS upgrade 1995: Improved radiation shielding (abstract)  

NASA Astrophysics Data System (ADS)

The Cornell Electron Storage Ring (CESR) stores electrons and positrons at 5.3 GeV for the production and study of B mesons, and, in addition, it supplies synchrotron radiation for CHESS. The machine has been upgraded for 300 mA operation. It is planned that each beam will be injected in about 5 minutes and that particle beam lifetimes will be several hours. In a cooperative effort, staff members at CHESS and LNS have studied sources in CESR that produce radiation in the user areas. The group has been responsible for the development and realization of new tunnel shielding walls that provide a level of radiation protection from 20 to ?100 times what was previously available. Our experience has indicated that a major contribution to the environmental radiation is not from photons, but results from neutrons that are generated by particle beam loss in the ring. Neutrons are stopped by inelastic scattering and absorption in thick materials such as heavy concrete. The design for the upgraded walls, the development of a mix for our heavy concrete, and all the concrete casting was done by CHESS and LNS personnel. The concrete incorporates a new material for this application, one that has yielded a significant cost saving in the production of over 200 tons of new wall sections. The material is an artificially enriched iron oxide pellet manufactured in vast quantities from hematite ore for the steel-making industry. Its material and chemical properties (iron and impurity content, strength, size and uniformity) make it an excellent substitute for high grade Brazilian ore, which is commonly used as heavy aggregate in radiation shielding. Its cost is about a third that of the natural ore. The concrete has excellent workability, a 28 day compressive strength exceeding 6000 psi and a density of 220 lbs/cu.ft (3.5 gr/cc). The density is limited by an interesting property of the pellets that is motivated by efficiency in the steel-making application. The pellets are made to be porous, with about 28% of the volume consisting of connected pores of size typically from 1-10 microns. The porosity may have some useful implications for neutron radiation shielding including the possibility of holding a lot more water than a conventional mix, and the opportunity to impregnate the pellets with a good neutron absorber such as boron. This paper will discuss these developments and report the latest results on the effectiveness of the upgraded shielding at Cornell.

Finkelstein, K. D.

1996-09-01

436

Radiation Shielding at High-Energy Electron and Proton Accelerators  

SciTech Connect

The goal of accelerator shielding design is to protect the workers, general public, and the environment against unnecessary prompt radiation from accelerator operations. Additionally, shielding at accelerators may also be used to reduce the unwanted background in experimental detectors, to protect equipment against radiation damage, and to protect workers from potential exposure to the induced radioactivity in the machine components. The shielding design for prompt radiation hazards is the main subject of this chapter.

Rokni, Sayed H.; /SLAC; Cossairt, J.Donald; /Fermilab; Liu, James C.; /SLAC

2007-12-10

437

Evergreen trees as inexpensive radiation shields for temperature sensors  

Microsoft Academic Search

Evergreen trees provide temperature sensors with shielding from solar radiation and an elevated location above the snowpack. Sensors were deployed with simple funnel radiation shields in the Sierra Nevada, California, and Rocky Mountains, Colorado. Compared with unaspirated, Gill-shielded thermistors, inexpensive self-recording temperature sensors hung in dense stands of trees have less than 0.8°C (0.4°C) mean difference in daily maximum (mean)

Jessica D. Lundquist; Brian Huggett

2008-01-01

438

Methods and Procedures for Shielding Analyses for the SNS  

SciTech Connect

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.

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

439

Radiation shield analysis for a manned Mars rover  

Microsoft Academic Search

Radiation shielding for unmanned space missions has been extensively studied; however, designs of man-rated shields are minimal. Engle et al.'s analysis of a man-rated, multilayered shield composed of two and three cycles (a cycle consists of a tungsten and a lithium hydride layer) is the basis for the work reported in this paper. The authors present the results of a

N. J. Morley; M. S. ElGenk

1991-01-01

440

Polyethylene/Boron Composites for Radiation Shielding Applications  

NASA Astrophysics Data System (ADS)

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.

Harrison, Courtney; Burgett, Eric; Hertel, Nolan; Grulke, Eric

2008-01-01

441

Experimental tests of neutron shielding for the ATLAS forward region  

Microsoft Academic Search

Experimental tests devoted to the optimization of the neutron shielding for the ATLAS forward region were performed at the CERN-PS with a 4GeV\\/c proton beam. Spectra of fast neutrons, slow neutrons and gamma rays escaping a block of iron (40×40×80cm3) shielded with different types of neutron and gamma shields (pure polyethylene – PE; borated polyethylene – BPE; lithium filled polyethylene

S. Posp??šil; I. Štekl; T. ?echák; P. ?ermák; J. Kluso?; J. Kon???ek; J. Konícek; V. Linhart; M. Ši?or; C. Leroy; Z. Doležal; R. Leitner; G. Lukhanin; K. Soustružn??k; M. Lokaj???ek; S. N?me?ek; J. Palla; J. Sodomka

1999-01-01

442

Fast neutron shielding and neutron transport studies at YAYOI  

Microsoft Academic Search

The fast neutron shielding experiments at the fast neutron source reactor YAYOI of the University of Tokyo were summarized. The experiments were grouped into the following four types; 1.(1)|experiments for shield design of fast breeder reactor,2.(2)|fast neutron transmission experiments,3.(3)|fast neutron streaming experiments,4.(4)|neutron skyshine experiment. The experimental data are useful for shield design and assessing the accuracy of the calculational methods.The

Y. Oka; K. Furuta; S. An

1998-01-01

443

Experimental Tests of Neutron Shielding for the ATLAS Forward Region  

Microsoft Academic Search

Experimental tests devoted to the optimization of the neutron shielding for the ATLAS forward region were performed at the CERN-PS with a 4 GeV\\/c proton beam. Spectra of fast neutrons, slow neutrons and gamma rays escaping a block of iron (40$\\\\times$40$\\\\times$80 cm$^3$) shielded with different types of neutron and gamma shields (pure polyethylene - PE, borated polyethylene - BPE, lithium

S Pospísil; I Stekl; T Cechák; P Cermák; J Jakubek; J Kluson; J Konícek; J Kubasta; V Linhart; M Sinor; C Leroy; Z Dolezal; R Leitner; G A Lukianov; K Soustruznik; M Lokajícek; S Némécek; G Pálla; J Sodomka

1998-01-01

444

Polyethylene/Boron Composites for Radiation Shielding Applications  

SciTech Connect

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.

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

445

Retro rocket plume actuated heat shield exhaust ports  

Microsoft Academic Search

A preliminary scheme was developed for base-mounted solid-propellant retro rocket motors to self-penetrate the Orion Crew Module heat shield for configurations with the heat shield retained during landings on Earth. In this system the motors propel impactors into structural push plates, which in turn push through the heat shield ablator material. The push plates are sized such that the port

Colleen Marrese-Reading; J. St. Vaughn; R. Frisbee; P. Zell; K. Hamm; J. Corliss; S. Gayle; R. Pain; D. Rooney; A. Ramos; D. Lewis; J. Shepherd; K. Inaba

2009-01-01

446

Calculation of the shielding effect of solid shell enclosures  

NASA Astrophysics Data System (ADS)

A program which determines the shielding effect of solid-shell enclosures against EMP, which presents results as tables and graphs, is presented. Knowledge of shield permeability and conductivity, the basic model to be used, and the dimensions of the model are required. A standard field pulse is incorporated in the program, but the pulse parameters may be changed by the user. The program plots graphs of the external field pulse, the field pulse within the enclosure and the shielding efficiency.

Garthwaite, F. G. L.

1983-04-01

447

Our Buildings, Ourselves.  

ERIC Educational Resources Information Center

Reviews in detail environmental impacts associated with buildings. Discusses building construction, internal environments, building life spans, building materials, protection from climate, and amenities. (LZ)

Roodman, David Malin; Lenssen, Nicholas

1994-01-01

448

Development of special radiation shielding concretes using natural local materials and evaluation of their shielding characteristics  

Microsoft Academic Search

Two types of typical concretes widely used in Syria (in Damascus and Aleppo) and four other types of concretes, using aggregates from different regions, have been prepared. The shielding properties of these six types were studied for gamma ray (from Cs-137 and Co-60 sources) and for neutrons (from Am–Be source). A reduction of about 10% in the HVL was obtained

M. H. Kharita; M. Takeyeddin; M. Alnassar; S. Yousef

2008-01-01

449

Better Buildings  

E-print Network

on capital ? Delaware State University secured construction financing via the Delaware Sustainable Energy Utility?s Energy Efficiency Construction Bonds for an energy services performance contract across 26 buildings that will result in 25 percent...

Neukomm, M.

2012-01-01

450

Mothers modify eggs into shields to protect offspring from parasitism  

PubMed Central

Eggs are an immobile, vulnerable stage of development and their success often depends on the oviposition decisions of the mother. Studies show that female animals, and sometimes males, may invest parental resources in order to increase the survival of their offspring. Here, we describe a unique form of parental investment in offspring survival. The seed beetle Mimosestes amicus may lay eggs singly, or may cover eggs with additional egg(s). This egg stacking serves to significantly reduce the mortality of the protected egg from parasitism by the parasitic wasp, Uscana semifumipennis. The smaller top eggs serve only as protective shields; they are inviable, and wasps that develop in them suffer negative fitness consequences. Further, we found egg stacking to be inducible; M. amicus increase the number of stacks they lay when parasitoids are present. However, stacking invokes a cost. When wasps are absent, beetles lay more single eggs, and produce more offspring, highlighting the adaptive value of this extraordinary example of behavioural plasticity in parental investment. PMID:21920977

Deas, Joseph B.; Hunter, Martha S.

2012-01-01

451

Optimum structure of Whipple shield against hypervelocity impact  

NASA Astrophysics Data System (ADS)

Hypervelocity impact of a spherical aluminum projectile onto two spaced aluminum plates (Whipple shield) was simulated to estimate an optimum structure. The Smooth Particle Hydrodynamics (SPH) code which has a unique migration scheme from a rectangular coordinate to an axisymmetic coordinate was used. The ratio of the front plate thickness to sphere diameter varied from 0.06 to 0.48. The impact velocities considered here were 6.7 km/s. This is the procedure we explored. To guarantee the early stage simulation, the shapes of debris clouds were first compared with the previous experimental pictures, indicating a good agreement. Next, the debris cloud expansion angle was predicted and it shows a maximum value of 23 degree for thickness ratio of front bumper to sphere diameter of 0.23. A critical sphere diameter causing failure of rear wall was also examined while keeping the total thickness of two plates constant. There exists an optimum thickness ratio of front bumper to rear wall, which is identified as a function of the size combination of the impacting body, front and rear plates. The debris cloud expansion-correlated-optimum thickness ratio study provides a good insight on the hypervelocity impact onto spaced target system.

Lee, M.

2014-05-01

452

Gravity Scaling of a Power Reactor Water Shield  

NASA Technical Reports Server (NTRS)

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.

Reid, Robert S.; Pearson, J. Boise

2008-01-01

453

Modelling of electromagnetic shielding structures for radiated EMI analysis.  

E-print Network

??Electromagnetic (EM) shielding has been used extensively in electronic products to reduce the radiated electromagnetic interference (EMI) from high-speed digital circuits so that the products… (more)

Wang, Zheng.

2008-01-01

454

Beam extraction from a synchrotron through a magnetic shield  

NASA Astrophysics Data System (ADS)

A new beam extraction scheme from a synchrotron is put forward. The main difference from other schemes of extraction is the use of magnetic shields instead of a septum. Magnetic shields are located in the central dipole magnets of a pulsed chicane. The magnetic shield is a multilayer copper-iron tube. Numerical simulations and experimental results for the magnetic shield are presented. A good accordance between them has been shown. The advantages and the area of application of the new extraction scheme are discussed. The proposed scheme will be used for extraction from a booster synchrotron to a storage ring in a new synchrotron radiation source in Novosibirsk.

Bondarenko, A. V.; Vinokurov, N. A.

2009-05-01

455

Gravity Scaling of a Power Reactor Water Shield  

SciTech Connect

Water based reactor shielding is being considered as an affordable option for potential use on initial lunar surface reactor power systems. Heat dissipation in the shield from nuclear sources must be rejected by an auxillary 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, 2006). 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.

Reid, Robert S.; Pearson, J. Boise [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

2008-01-21

456

Shield Design for a Space Based Vapor Core Reactor  

SciTech Connect

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)

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

457

Graphene shield enhanced photocathodes and methods for making the same  

DOEpatents

Disclosed are graphene shield enhanced photocathodes, such as high QE photocathodes. In certain embodiments, a monolayer graphene shield membrane ruggedizes a high quantum efficiency photoemission electron source by protecting a photosensitive film of the photocathode, extending operational lifetime and simplifying its integration in practical electron sources. In certain embodiments of the disclosed graphene shield enhanced photocathodes, the graphene serves as a transparent shield that does not inhibit photon or electron transmission but isolates the photosensitive film of the photocathode from reactive gas species, preventing contamination and yielding longer lifetime.

Moody, Nathan Andrew

2014-09-02

458

Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields  

NASA Astrophysics Data System (ADS)

Metglas 2705M is a low-cost commercially available, high-permeability cobalt-based magnetic alloy, provided as a 5.08-cm wide and 20.3-?m thick ribbon foil. We present an optimized construction technique for single-shell, large-scale (human-size), thin, open-ended cylindrical Metglas magnetic shields. The measured dc axial and transverse magnetic shielding factors of our 0.61-m diameter and 1.83-m long shields in the Earth's magnetic field were 267 and 1500, for material thicknesses of only 122 ?m (i.e., 6 foil layers). The axial shielding performance of our single-shell Metglas magnetic shields, obtained without the use of magnetic shaking techniques, is comparable to the performance of significantly thicker, multiple-shell, open-ended Metglas magnetic shields in comparable-magnitude, low-frequency applied external fields reported previously in the literature.

Malkowski, S.; Adhikari, R.; Hona, B.; Mattie, C.; Woods, D.; Yan, H.; Plaster, B.

2011-07-01

459

Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields.  

PubMed

Metglas 2705M is a low-cost commercially available, high-permeability cobalt-based magnetic alloy, provided as a 5.08-cm wide and 20.3-?m thick ribbon foil. We present an optimized construction technique for single-shell, large-scale (human-size), thin, open-ended cylindrical Metglas magnetic shields. The measured dc axial and transverse magnetic shielding factors of our 0.61-m diameter and 1.83-m long shields in the Earth's magnetic field were 267 and 1500, for material thicknesses of only 122 ?m (i.e., 6 foil layers). The axial shielding performance of our single-shell Metglas magnetic shields, obtained without the use of magnetic shaking techniques, is comparable to the performance of significantly thicker, multiple-shell, open-ended Metglas magnetic shields in comparable-magnitude, low-frequency applied external fields reported previously in the literature. PMID:21806224

Malkowski, S; Adhikari, R; Hona, B; Mattie, C; Woods, D; Yan, H; Plaster, B

2011-07-01

460

New Orleans Sees School Building Boom  

ERIC Educational Resources Information Center

Efforts to reinvent public education in New Orleans after Hurricane Katrina have drawn such interest that it's easy to lose sight of some very concrete changes that will become obvious over time: A generation of brand-new school buildings is rising across the city. New Orleans is in the early stages of a construction spree both to build and…

Robelen, Erik W.

2010-01-01

461

SHIELDING ANALYSIS FOR PORTABLE GAUGING COMBINATION SOURCES  

SciTech Connect

Radioisotopic decay has been used as a source of photons and neutrons for industrial gauging operations since the late 1950s. Early portable moisture/density gauging equipment used Americium (Am)-241/Beryllium (Be)/Cesium (Cs)-137 combination sources to supply the required nuclear energy for gauging. Combination sources typically contained 0.040 Ci of Am-241 and 0.010 Ci of CS-137 in the same source capsule. Most of these sources were manufactured approximately 30 years ago. Collection, transportation, and storage of these sources once removed from their original device represent a shielding problem with distinct gamma and neutron components. The Off-Site Source Recovery (OSR) Project is planning to use a multi-function drum (MFD) for the collection, shipping, and storage of AmBe sources, as well as the eventual waste package for disposal. The MFD is an approved TRU waste container design for DOE TRU waste known as the 12 inch Pipe Component Overpack. As the name indicates, this drum is based on a 12 inch ID stainless steel weldment approximately 25 inch in internal length. The existing drum design allows for addition of shielding within the pipe component up to the 110 kg maximum pay load weight. The 12 inch pipe component is packaged inside a 55-gallon drum, with the balance of the interior space filled with fiberboard dunnage. This packaging geometry is similar to the design of a DOT 6M, Type B shipping container.

J. TOMPKINS; L. LEONARD; ET AL

2000-08-01

462

MicroShield/ISOCS gamma modeling comparison.  

SciTech Connect

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.

Sansone, Kenneth R

2013-08-01

463

Liquid Vortex Shielding for Fusion Energy Applications  

SciTech Connect

Swirling liquid vortices can be used in fusion chambers to protect their first walls and critical elements from the harmful conditions resulting from fusion reactions. The beam tube structures in heavy ion fusion (HIF) must be shielded from high energy particles, such as neutrons, x-rays and vaporized coolant, that will cause damage. Here an annular wall jet, or vortex tube, is proposed for shielding and is generated by injecting liquid tangent to the inner surface of the tube both azimuthally and axially. Its effectiveness is closely related to the vortex tube flow properties. 3-D particle image velocimetry (PIV) is being conducted to precisely characterize its turbulent structure. The concept of annular vortex flow can be extended to a larger scale to serve as a liquid blanket for other inertial fusion and even magnetic fusion systems. For this purpose a periodic arrangement of injection and suction holes around the chamber circumference are used, generating the layer. Because it is important to match the index of refraction of the fluid with the tube material for optical measurement like PIV, a low viscosity mineral oil was identified and used that can also be employed to do scaled experiments of molten salts at high temperature.

Bardet, Philippe M. [University of California, Berkeley (United States); Supiot, Boris F. [University of California, Berkeley (United States); Peterson, Per F. [University of California, Berkeley (United States); Savas, Oemer [University of California, Berkeley (United States)

2005-05-15

464

Twin jet shielding. [for aircraft noise reduction  

NASA Technical Reports Server (NTRS)

For an over-the-wing/under-the-wing engine configuration on an airplane, the noise produced by the upper jet flow is partially reflected by the lower jet. An analysis has been performed which can be used to predict the distribution of perceived noise levels along the ground plane at take-off for an airplane which is designed to take advantage of the over/under shielding concept. Typical contours of PNL, the shielding benefit in the shadow zone, and the EPNL values at 3.5 nautical miles from brake release as well as EPNL values at sideline at 0.35 nautical miles have been calculated. This has been done for a range of flow parameters characteristic of engines producing inverted velocity profile jets suitable for use in a supersonic cruise vehicle. Reductions up to 6.0 EPNdB in community noise levels can be realized when the over engines are operated at higher thrust and the lower engines simultaneously operated with reduced thrust keeping the total thrust constant.

Parthasarathy, S. P.; Cuffel, R. F.; Massier, P. F.

1979-01-01

465

The sternum as an electrical shield.  

PubMed

Introduction - The TASER(®) conducted electrical weapon (CEW) delivers electrical pulses that can temporarily incapacitate subjects. We analyzed the distribution of TASER CEW currents in tissues posterior to the sternum to understand the likelihood of triggering cardiac arrhythmias. We also assessed the electrical `shielding' effects of the sternum. Methods and Results - Finite element modeling (FEM) was used to approximate the current density and electric field strength in tissues around the sternum. We analyzed 2 CEW dart deployment scenarios: (a) both darts over the anterior aspect of the sternum; and (b) a CEW dart anterior to the sternum and the other over the abdomen. In both scenarios, the sternum provided significant attenuation of CEW currents. Particularly, both FEMs predicted that the residual electrical current or charge from CEWs would be insufficient to cause either cardiac capture or induction of ventricular fibrillation at locations where cardiac tissue would reside relative to the posterior aspect of the sternum. Conclusion - The sternum offers significant `shielding' effect and protects the tissues posterior to it against effects of electrical current flow from anteriorly-placed CEW electrodes. PMID:25570983

Panescu, Dorin; Kroll, Mark; Iverson, Carlyn; Brave, Michael

2014-08-01

466

Gas Shielding Technology for Welding and Brazing  

NASA Technical Reports Server (NTRS)

Welding is a common method that allows two metallic materials to be joined together with high structural integrity. When joints need to be leak-tight, light-weight, or free of contaminant-trapping seams or surface asperities, welding tends to be specified. There are many welding techniques, each with its own advantages and disadvantages. Some of these techniques include Forge Welding, Gas Tungsten Arc Welding, Friction Stir Welding, and Laser Beam Welding to name a few. Whichever technique is used, the objective is a structural joint that meets the requirements of a particular component or assembly. A key practice in producing quality welds is the use of shielding gas. This article discusses various weld techniques, quality of the welds, and importance of shielding gas in each of those techniques. Metallic bonds, or joints, are produced when metals are put into intimate contact. In the solid-state "blacksmith welding" process, now called Forge Welding (FOW), the site to be joined is pounded into intimate contact. The surfaces to be joined usually need to be heated to make it easier to deform the metal. The surfaces are sprinkled with a flux to melt surface oxides and given a concave shape so that surface contamination can be squeezed out of the joint as the surfaces are pounded together; otherwise the surface contamination would be trapped in the joint and would weaken the weld. In solid-state welding processes surface oxides or other contamination are typically squeezed out of the joint in "flash."

Nunes, Arthur J.; Gradl, Paul R.

2012-01-01

467

Structure and metamorphism of the Antarctic Shield  

NASA Astrophysics Data System (ADS)

The information on the composition, structure, P-T conditions of metamorphic facies, evolution, and time of the metamorphic events in the largest Precambrian tectonic provinces of the Antarctic Crystalline Shield gained over more than a half-century is summarized in this paper. The joining up of the ortho- and paracrystalline rocks into complexes and groups according to their geographic position, composition, age, and the character of their metamorphism allowed us to consider the main features of the structure and evolution of the provinces including (1) the near-latitudinal polycyclic Late Precambrian-Early Paleozoic Wegener-Mawson Mobile Belt, extended for more than 4000 km, which started to evolve in the Mesoproterozoic and stabilized only at the end of Cambrian; (2) the Early Precambrian relict crystalline protocratonic blocks adjoining this mobile belt; their history is traced from the Eoarchean; and (3) the near-latitudinal Late Precambrian-Early Paleozoic aulacogen in the southern protocratonic block. The P-T conditions of the metamorphism from the pyroxene-granulite subfacies in the protocratonic blocks to the greenschist facies in aulacogen, as well as the age of the magmatic and metamorphic events in all the tectonic provinces of the shield, are characterized. This made it possible to consider the metamorphic history and conditions of the continental crust's formation in Antarctica, where the oldest crystalline rocks are dated to the Eoarchean (4060-3850 Ma) and the youngest rocks are ˜500 Ma old.

Kamenev, E. N.; Maslov, V. A.; Semenov, V. S.; Kurinin, R. G.; Mikhailov, V. M.; Alekseev, N. L.; Kamenev, I. A.; Semenov, S. V.

2013-03-01

468

Building Satellites is Easier  

NASA Technical Reports Server (NTRS)

'Building Satellites' is a story about Jim Marsh's recovery from a severe head injury told by his wife Phyllis from the moment she learned of its happening, through the ups and downs of a lengthy rehabilitation, until his return to work and daily living. It continues on, however, and narrates his battle with the more insidious Grave's disease. Told in the first person, 'Building Satellites' vividly portrays Phyllis's thoughts and feelings throughout this experience with scrupulous honestly. This is a story worth reading for many reasons. First of all, Jim was an accomplished scientist, respected by his colleagues both in this country and abroad. Secondly, it narrates the many stages of his recovery from head injury with detailed readable accuracy; it informs us as well as inspires. Finally, 'Building Satellites" also tells us the story of Phyllis Marsh's remarkable creative response to this crisis. It narrates her personal experiences as she progresses through the strange and somewhat bizarre world of medicine and rehabilitation, guided by a few basic beliefs, which she learned as a child in Iowa, that provided her with the strength to endure. 'Building Satellites' seems to reaffirm our unconscious, but settled conviction, that when confornted overnight with adversity, we are somehow given the means for coping, supported by our basic beliefs, strengthened by family and friends, and eventually learning to accept any outcome.

Marsh, Phyllis Nimmo

1996-01-01

469

Deoxyribonucleic acid-Ag nanoparticles for EMI Shielding: the effect of nanoparticle size, shape and distribution on the shielding effectiveness  

NASA Astrophysics Data System (ADS)

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.

Ouchen, Fahima; Wilson, Benjamin G.; Yaney, Perry P.; Salour, Michael M.; Grote, James G.

2014-09-01

470

Producing Ni-rich olivine phenocrysts by mixing partial melts of eclogite and peridotite: an alternative to an olivine-free source for Hawaiian shield basalts  

NASA Astrophysics Data System (ADS)

It has been posited that presence of unusually Ni-rich (2500-4000 ppm) magnesian olivine phenocrysts in SiO2-enriched Hawaiian shield-building basalts, most notably the Koolau lavas, is inconsistent with a deep, olivine-bearing source rock. Instead, Sobolev et al. (2005) proposed that these lavas are generated by a multi- stage process in which partial melts of eclogite react with peridotite within the plume to form an olivine-free source rock with high Ni concentration. As the plume continues to ascend, partial melts of this "hybrid" pyroxenite mix with peridotite melts to produce SiO2- enriched Hawaiian shield-building lavas that crystallize high-Ni olivine. This model has also been used to argue for significant amounts of "hybrid" pyroxenite in the source regions of lavas from other ocean islands, continental basalts, and even MORB, implying that the upper mantle is highly heterogeneous (Sobolev et al., 2007). New experimental results demonstrate that Ni-rich magnesian olivine crystallizes from mixtures of peridotite partial melt and Ni-poor eclogite partial melt that have equilibrated with mantle olivine. This occurs because the concentration of Ni decreases linearly as eclogite partial melt is added to peridotite partial melt, whereas changing major element composition of the mixed melts causes DNi to increase hyperbolically. Experiments were conducted in which either (1) siliceous partial melt of eclogite or (2) primitive basalt was equilibrated with San Carlos olivines at 1 bar and 1201-1350°C. Experimental results demonstrate that eclogite partial melts in equilibrium with mantle olivine retain their high SiO2, low FeO and MgO characteristics. Theoretical modeling calibrated from these experimental results suggest that reaction of siliceous eclogite melt with mantle olivine at low pressure produces a melt containing ~300 ppm Ni. Despite its low Ni content, mixing of this melt with peridotite partial melt produces a high SiO2 melt that crystallizes Ni-rich, magnesian olivine. The dependence of olivine-melt partition coefficients on melt composition also explains the enrichment or depletion of other minor element in Koolau olivines (e.g., Ca and Mn). Our results obviate the need for a multi-step melt generation process in which reaction with large amounts of siliceous eclogite partial melt exhausts olivine from portions of mantle peridotite within the Hawaiian plume. As a result, the amount of eclogite required to explain the composition of the Koolau lavas is greatly reduced. Reference Sobolev, A.V. et al., (2005), Nature, 434, 590-597 Sobolev, A.V. et al., (2007), Science, 316, 412-417

Wang, Z.; Gaetani, G.

2007-12-01

471

Reduction of radiation asymmetry with radiation shields in indirectly driven inertial confinement fusion hohlraum targets  

SciTech Connect

Using a relatively simple static model and allowing a number of additional radiation shields in an axially symmetric hohlraum having two converters, a systematic process of reducing the asymmetry of the radiation field on a fusion capsule is presented. As a result of this procedure, a hohlraum target is obtained that shows a high degree of symmetrization even in a very early stage of irradiation. The sensitivity of the symmetry to the form and the position of each hohlraum component is investigated. To increase the reliability of the results, an enhanced model of radiation reemission in a hohlraum target, including reemission of the converter, is developed. Using this enhanced model it is found that the obtained hohlraum configuration is still valid, while the simple reemission model leads to incorrect results in special cases. It is also shown that the detailed configuration of a hohlraum target, especially of the radiation shields, depends considerably on the temperature distribution of the converter surface, but it is always possible to achieve a high degree of symmetry with radiation shields. 24 refs., 15 figs., 1 tab.

Kang, K.H.; Maruhn, J.A. [Universitaet Frankfurt (Germany)

1997-05-01

472

S3G\\/S4G PRIMARY SHIELD WATER SYSTEM DESIGN DESCRIPTION  

Microsoft Academic Search

The function of the Shield Water System is to provide shielding to ; protect personnel from excessive neutron radiation. Shielding is accomplished by ; enclosing the pressure vessel sides and bottom in an annular shaped tank which is ; maintained full of water at atmospheric pressure. The Shield Water System ; consists of the neutron shield tank which surrounds the

Krauss

1957-01-01

473

Application of a dummy eye shield for electron treatment planning  

PubMed Central

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

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

474

CRYOGENIC UPPER STAGE SYSTEM SAFETY  

NASA Technical Reports Server (NTRS)

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.

Smith, R. Kenneth; French, James V.; LaRue, Peter F.; Taylor, James L.; Pollard, Kathy (Technical Monitor)

2005-01-01

475

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

476

11. BUILDING NO. 620B. INTERIOR VIEW LOOKING NORTH, SHOWING PENDULUM ...  

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

11. BUILDING NO. 620-B. INTERIOR VIEW LOOKING NORTH, SHOWING PENDULUM AND FRAME IN FOREGROUND, SHIELD FOR OPERATORS IN BACKGROUND. FRICTION TEST IS OBSERVED FROM BEHIND BLAST SHIELD BY A SERIES OF MIRRORS. ANVIL IN CENTER OF PENDULUM FRAME HOLDS EXPLOSIVE WHOSE SENSITIVITY TO FRICTION IS TO BE TESTED. PANS ON EITHER SIDE CATCH ANY UNBURNT EXPLOSIVE SLUNG FROM ANVIL DURING TEST TO PREVENT EXPLOSIVE HAZARD. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

477

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

478

Building Design  

NSDL National Science Digital Library

The Building Design site bills itself as "the architects" website", and it is a claim that is quite accurate and apropos. Designed to complement their print publication, the site is a treasure-trove of material for just about anyone who is involved in any aspect of building, including architects, design theorists, planners, and so on. As the magazine is based in the United Kingdom, there's definitely a British Isles focus. Readers probably won't mind as the site offers excellent coverage of the field in the "News" section, where they can sign up to receive email updates, watch some slideshows of new and proposed buildings, and read long-form pieces. Not surprisingly, the site is keeping up with the proverbial Joneses" by offering a smattering of intelligent and lively blogs, coupled with podcasts that mix contemporary interviews and discussions with archived materials such as talks with Buckminster Fuller on his environmental philosophy.

479

General Corrosion and Localized Corrosion of the Drip Shield  

SciTech Connect

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]).

F. Hua

2004-09-16

480

Determination of the shielding factors for gamma-ray spectrometers.  

PubMed

A method for determining the shielding factors for gamma-ray spectrometers is described. The shielding factors are expressed by decomposing the peaked background of the spectrometer into contributions of the detector, spectrometer shield and ambient radiation to the spectrometer background. The dimensions of the sample and its mass-attenuation coefficient are taken into account using a simple model. For six spectrometers, with contributions to the background quantified, the shielding factors were determined for the background based on the thorium decay series and the radon daughters. For a water sample with a diameter of 9 cm and a thickness of 4 cm and the nuclides of the thorium decay series that are in the spectrometer shields, the values of the shielding factors lie in the interval 0.95-1.00. For a spectrometer exhibiting the diffusion of radon into the shielding material, the values of the shielding factors for the same sample for gamma-rays from the radon daughters lie in the interval 0.88-1.00. PMID:24300968

Korun, M; Vodenik, B; Zorko, B

2014-05-01

481

Development of magnetic shielding system for breast hyperthermia inductive heating  

Microsoft Academic Search

In this paper, the effect of cylindrical shield to heating area and location of induction heating for breast cancer hyperthermia treatment with hyperthermia inductive heating are presented. To determine heat distribution in the breast, which electric loss density is analyzed for various aperture sizes and radius of shielded cylindrical. It is a technique to control magnetic field intensity and relocate

Thanaset Thosdeekoraphat; Chanchai Thongsopa

2012-01-01

482

Critical Analysis of Active Shielding Methods for Space Radiation Protection  

E-print Network

1 Critical Analysis of Active Shielding Methods for Space Radiation Protection Lawrence W. Townsend radiation have been carried out. The lure of active shielding methods is the possibility of providing harmful space radiations. Designs affording protection from either solar energetic particle event protons

Shepherd, Simon

483

Bulk Shielding Facility quarterly report, January, February, and March 1989  

SciTech Connect

This document discusses activities at the Bulk Shielding Facility during this reporting period. The Bulk Shielding Reactor (BSR) remained shut down during January, February, and March. Water-quality control in both the reactor primary and secondary cooling systems was satisfactory. The Pool Critical Assembly (PCA) is shut down for shim-safety rod magnets and associated electronic components upgrading.

Laughlin, D.L.; Hamrick, T.P.

1989-05-01

484

Cross Section of Coils & Shielding Vessels; Stresses & Deformations Preliminary Results  

E-print Network

the five resistive and upstream eight superconducting coils of Magnet Design IDS120h. Most annular disks, including conical one). #12; Fig. 3: Isometric view (longitudinal axis compressed) of inner and outer shielding vessels (blue) of design "Shields50mm.mph". Outlined are the five resistive and upstream eight

McDonald, Kirk