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1

Em Shielding of Building Materials.  

National Technical Information Service (NTIS)

This report covers the results of a program for measuring the shielding effectiveness (SE) of building materials. Part 1 of the report describes a number of techniques which were used to make radiated measurements of magnetic field SE from 10 Hz to 50 KHz...

C. M. Brennan C. C. Lambert C. G. Conner G. F. Roberts W. T. Flannery

1968-01-01

2

WASTE HANDLING BUILDING SHIELD WALL ANALYSIS  

SciTech Connect

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

D. Padula

2000-01-13

3

Slipforming of reinforced concrete shield building  

SciTech Connect

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

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

1982-03-01

4

Gamma -Ray Shielding Effect of Various Building Materials.  

National Technical Information Service (NTIS)

It is necessary to know the gamma -ray attenuation coefficients and the dose buildup factors for various building materials in order to evaluate the gamma -ray shielding factor of the residential houses in a reactor accident. As a matter of fact, however,...

Y. Yamaguchi K. Minami S. Ohtani

1985-01-01

5

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

6

Natural radioactivity in common building construction and radiation shielding materials  

NASA Astrophysics Data System (ADS)

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±4 Bq kg -1, 20±2 to 112±2.8 Bq kg -1, and 200±8 to 1908±15.6 Bq kg -1, respectively, in various materials studied in the present work. Radon activity in the various samples varies from 190±11 to 313±14 Bq m -3, the mass exhalation rate for radon varies from 1.05±0.07 to 1.92±0.09 mBq kg -1 h -1 and surface exhalation rate varies from 9.0±0.30 to 19.8±22 mBq m -2 h -1 for materials under investigation. The activity concentrations of uranium, thorium and potassium and radon exhalation rates vary from material to material. Thorium and potassium activity in the granite materials is higher, followed by radiation shielding material compared to other common construction materials. Uranium activity concentration is higher in cement as compared to radiation shielding material and other common construction materials. The absorbed dose varies from 23 to 185 nGy h -1 and the indoor annual effective dose varies from 0.11 to 0.91 mSv. The outdoor annual effective dose varies from 0.03 to 0.23 mSv. The absorbed dose and the effective dose equivalent are found to be higher in the granite, followed by radiation shielding material and other common construction materials. In all the samples, the activity concentration of 238U, 232Th and 40K is found below the permissible levels. A strong correlation coefficient has been observed between radon activity and surface exhalation rate (correlation coefficient=0.899).

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

7

LPT. Shield test control building (TAN645). Typical interior of office/conference ...  

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

LPT. Shield test control building (TAN-645). Typical interior of office/conference area. Camera facing northeast. INEEL negative no. HD-40-6-1 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

8

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

9

Shielding and build-up considerations for radiation detection  

Microsoft Academic Search

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

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

2008-01-01

10

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

11

Hawaiian Shield Stage Submarine Volcaniclastics: Insights From HSDP Core  

NASA Astrophysics Data System (ADS)

Ocean island volcanoes are traditionally associated with the non-explosive eruption of fluid lavas, but volcaniclastic rocks comprise a significant portion of many submarine shield volcanoes. Deep drilling (3,098 m) by the Hawaiian Scientific Drilling Project (HSDP) into the flank of Mauna Kea volcano has exposed the volcaniclastics within the pedestals of a Hawaiian volcano that were previously poorly known. The HSDP continuously cored 2,019 m of submarine Mauna Kea deposits with ˜95% recovery and revealed that volcaniclastics comprise ˜55% of this section. The shallow submarine section consists of ˜80% volcaniclastics interbedded with thin ( ˜3 m) massive lava flows and the deep section is ˜35% volcaniclastics interbedded with packages of pillow lavas up to 180 m thick. Throughout the submarine section, the volcaniclastics can occur in thick packages up to ˜100 m. The emplacement of submarine volcaniclastics is not well understood. Possible origins include primary fragmentation of lava via magmatic explosivity and magma-water interactions, and secondary fragmentation via erosion. Secondary transport of material down the steep submarine flanks by gravity flows is expected to be common, as is reworking by currents. Emplacement processes are predicted to evolve as the volcano shoals. In this study major element analyses of glassy clasts in the volcaniclastics are used to distinguish monomict and polymict assemblages, which can indicate primary versus secondary fragmentation. Clast shapes reflect fragmentation mechanisms and secondary processes and this study attempts to improve on this approach with quantitative analysis of clast shapes for the HSDP volcaniclastics and for samples of known origin. The first documentation of the textures of the Mauna Kea volcaniclastics, integrated with geochemistry, petrography, and quantitative clast shape analysis and inferences about their origins and modes of transport and deposition will be presented to better understand the shoaling of Hawaiian volcanoes.

Bridges, K. P.; Garcia, M.; Houghton, B.; Thordarson, T.

2003-12-01

12

Multivariate modeling for a multi-stage green building framework  

Microsoft Academic Search

Green building is a sustainable concept to reduce enviromental impact. Decision-making for green building is a complex task. We present a multi-stage green building framework that will guide future development of a comprehensive multiple stage, multiple objective (MSMO) decision-making framework. Various software tools can assist in studying components of our multi-stage framework. We seek to simultaneously explore building options via

Pin Kung; Victoria C. P. Chen; Anthony Robinson

2011-01-01

13

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

14

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

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

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

15

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

16

LPT. Shield test facility assembly and test building (TAN646), south ...  

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

LPT. Shield test facility assembly and test building (TAN-646), south end of EBOR helium wing. Camera facing north. Monorail protrudes from upper-level door. Rust marks on concrete wall are from stack. Metal shed is post-1970 addition. INEEL negative no. HD-40-8-1 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

17

LPT. Shield test facility test building interior (TAN646). Camera facing ...  

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

LPT. Shield test facility test building interior (TAN-646). Camera facing south. Distant pool contained EBOR reactor; near pool was intended for fuel rod storage. Other post-1970 activity equipment remains in pool. INEEL negative no. HD-40-9-4 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

18

FET. Control and equipment building (TAN630). Sections. Earth cover. Shielded ...  

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

FET. Control and equipment building (TAN-630). Sections. Earth cover. Shielded access entries for personnel and vehicles. Ralph M. Parsons 1229-2 ANP/GE-5-630-A-3. Date: March 1957. Approved by INEEL Classification Office for public release. INEEL index code no. 036-0630-00-693-107082 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

19

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

20

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

21

Geochronology of Gran Canaria, Canary Islands: Age of shield building volcanism and other magmatic phases  

Microsoft Academic Search

Forty-six new K-Ar age determinations are presented on whole rock samples and mineral separates from volcanic and subvolcanic\\u000a rocks of Gran Canaria. The main subaerial shield building basaltic volcanism with estimated volume of about 1000 km3 was confined to the interval about 13.7 m.y. to 13.5 m.y. ago in the middle Miocene. Substantial volume (?100 km3) of silicic volcanics (trachyte

I. McDougall; H.-U. Schmincke

1976-01-01

22

BAC: A computer program for calculating shielding in buildings against initial radiation  

NASA Astrophysics Data System (ADS)

Calculation methodology and transmission data for BAC in the event of a nuclear explosion are considered. The shielding factor is the rate between the radiation dose at one point in the building and the dose in open air. It is separately calculated for neutrons, gamma rays from fission products, and secondary gamma rays. For this calculation, BAC uses data for radiation transmission in concrete. This program is utilized for fallout shelters and other buildings where walls and floors/roofs are mostly made of concrete and bricks. Instructions for the program are given, and BAC results and values are in certain cases compared with those obtained with the Monte Carlo method.

Danielson, G.

1980-10-01

23

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

24

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

NASA Astrophysics Data System (ADS)

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 previous K-Ar data collected without a comprehensive stratigraphy should be viewed with caution, and in some cases discarded altogether. The shield volcanoes of Tenerife encompass a relatively small number of magnetozones, an observation consistent with the relatively short periods of growth shown by the new ages (1-2 my). The island was constructed by the aggregation of three successive shields: the Roque del Conde (Central shield), between about 11.9 and 8.9 Ma, and the Teno (6.2-5.6 Ma) and Anaga (4.9-3.9 Ma) volcanoes. This new oldest subaerial age of Tenerife fits with the others obtained in the Canaries in a clear west to east monotonous age progression, one of the main restrictions for hotspot-related island chains.

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

2004-05-01

25

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

26

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

27

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

National Technical Information Service (NTIS)

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 p...

D. W. Robinson

2002-01-01

28

Building a new kind of graded-Z shield for Swift's burst alert telescope  

Microsoft Academic Search

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

David W. Robinson

2003-01-01

29

92. Neg. No. F142, Mar 29, 1932, INTERIORASSEMBLY BUILDING, STAGE ...  

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

92. Neg. No. F-142, Mar 29, 1932, INTERIOR-ASSEMBLY BUILDING, STAGE AND EXHIBITION ROOM - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

30

Shielding material for public buildings against the electromagnetic field radiation of the base station antennas  

Microsoft Academic Search

Wireless communication systems have developed well for the last ten years. Since EM fields are important for human health and electronic systems' safety, shielding materials are becoming of great interest. Different types of electromagnetic isolation materials have been developed. These are commonly based on copper, nickel, ferrite, etc., or their composites. However they are not optimum for public use due

Refet Ramiz

2003-01-01

31

Petrology and geochemistry of shield-building and post-erosional lava series of Samoa: implications for mantle heterogeneity and magma genesis  

SciTech Connect

Samoan shield-building lavas are more alkalic than Hawaiian shield basalts, but a transition from less- to more-alkalic flows may be identified in the Pago Shield of Tutuila. This transition is not gradational, but rather consists of alternating less- and more-alkalic interbedded flows, indicating little magma mixing during this period, a conclusion supported by extreme isotopic heterogeneity in these flows. Further evolution of the Pago shield lava compositions is controlled by fractionation of olivine to produce increasingly Si-enriched differentiates. Samoan post-erosional lavas are distinct from Samoan shield-building lavas. They are strongly Si-undersaturated and unfractionated, and show higher YXSr/YWSr and SXPb/SUPb and lower UTNd/ UUNd isotopic ratios than shield-building lavas. Whereas shield-building lavas have isotopic compositions similar to the Society Islands, post-erosional lavas may represent mixing of this shield source with an enriched end member, tentatively identified as recycled crustal material. Compositional variation within the post-erosional lavas is controlled by source differences evident in rare earth element and isotopic compositions, and minor fractionation of olivine, Ti-magnetite, and clinopyroxene. The close spacing of vents along a 282-km-long rift zone parallel to the trend of the island chain, and the anomalously large volume of post-erosional lavas are inconsistent with a plume origin. Two types of ultramafic xenoliths are included in Samoan post-erosional lavas: harzburgite-lherzoilite nodules showing porphyroclastic and equigranular-mosaic textures, and wehrlite-dunites showing tectonized cumulate textures.

Wright, E.

1986-01-01

32

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

Microsoft Academic Search

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

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

1994-01-01

33

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

34

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

35

Shielding Analysis of a Small Compact Space Nuclear Reactor.  

National Technical Information Service (NTIS)

The SP-100 reactor concept, currently in its developmental stage, has layered tungsten--lithium hydride shield. Studies indicate that this shield configuration is the lightest weight shield. This configuration and three other shielding concepts were analy...

L. L. Woodrow

1987-01-01

36

Creating Socionas: Building creative understanding of people's experiences in the early stages of new product development  

Microsoft Academic Search

This work presents the research into Creating Socionas, a step-by-step approach to building creative understanding of user experience in the early stages of new product development (NPD). Creative understanding is the combination of a rich, cognitive and affective understanding of the other, and the ability to translate this understanding into products and services that are pleasurable and easy to use

C. E. Postma

2012-01-01

37

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

38

Residents and windows. 1. Shielding of windows  

SciTech Connect

In order to assess the influence of the shielding of windows performed by occupants in residential buildings on the heat balance of the building, the shielding of 40,000 windows was determined by observation during two heating seasons. It is shown that the demand for privacy has a large effect on the degree of window-shielding. There are also indications that many occupants trying to save energy use window-shielding as one of their means to achieve this.

Lyrberg, M.D.

1983-06-01

39

Analysis of shield tunnel  

Microsoft Academic Search

SUMMARY This paper proposes a two-dimensional finite element model for the analysis of shield tunnels by taking into account the construction process which is divided into four stages. The soil is assumed to behave as an elasto-plastic medium whereas the shield is simulated by beam-joint discontinuous model in which curved beam elements and joint elements are used to model the

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

2004-01-01

40

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.

Greeney, Harold F.; Warren, Andrew D.

2009-01-01

41

Seismic stratigraphy of Detroit Seamount, Hawaiian-Emperor seamount chain: Post-hot-spot shield-building volcanism and deposition of the Meiji drift  

NASA Astrophysics Data System (ADS)

Detroit Seamount, one of the northernmost seamounts of the Hawaiian-Emperor seamount chain, was formed at ca. 76 Ma. New seismic data suggest renewed volcanism as late as 25 m.y. after initial seamount formation. We use high-resolution single-channel seismic (SCS) data acquired over the summit of Detroit Seamount in 2001 on Ocean Drilling Program (ODP) Leg 197, supplemented by older SCS data acquired as part of the GLORIA mapping program of the U.S. Geological Survey, to characterize the seismic stratigraphy of Detroit Seamount. Volcanic edifices occur on the summit of the seamount and are older than the oldest beds of the Meiji drift (early Oligocene: ca. 34 Ma). On the basis of ash layers in ODP drill holes, we suggest the edifices were active throughout much of the Eocene (ca. 52-34 Ma), with activity possibly extending into the early Oligocene (<34 Ma). Hence the age difference between the shield-building lavas and the postshield cones on Detroit is far greater than the shield/postshield age differences observed on the Hawaiian Islands, suggesting that renewed volcanic activity and tectonic collapse may be possible on any of the Hawaiian Islands. We confirm earlier assertions that the thick sediment cap, Oligocene and younger in age, was deposited by an ocean-bottom current with a southeastward flow direction, along the northeast facing flank of the Emperor Seamount chain. This sediment cap, the Meiji drift, was deposited by a lower-velocity current than many other sediment drifts. A low-angle normal fault, dipping ˜19°, suggests topographic collapse of Detroit seamount sometime during the Eocene or late Cretaceous.

Kerr, Bryan C.; Scholl, David W.; Klemperer, Simon L.

2005-07-01

42

Composite Chemostratigraphy of Lavas From the Casitas Shield, Descabezado Grande-Cerro Azul Volcanic Complex, Chilean Andes  

Microsoft Academic Search

The Descabezado Grande-Cerro Azul (DGCA) volcanic complex is located at approximately 35.5 degrees S in the transitional Southern Volcanic Zone (SVZ) of the Chilean Andes. The complex is characterized by two large latest Pliocene to early Holocene volcanic edifices and many smaller vents rising above a plateau comprising lavas of an earlier shield-building stage, the Casitas Shield. This plateau has

A. H. Wulff

2003-01-01

43

A New Approach to Predicting the Thermal Environment in Buildings at the Early Design Stage. Building Research Establishment Current Paper 2/74.  

ERIC Educational Resources Information Center

|The paper argues that existing computer programs for thermal predictions do not produce suitable information for architects, particularly at the early stages of design. It reviews the important building features that determine the thermal environment and the need for heating and cooling plant. Graphical design aids are proposed, with examples to…

Milbank, N. O.

44

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

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

GCFR Plenum Shield Design: Shield Heterogeneity Experiment.  

National Technical Information Service (NTIS)

This report presents measurements of neutron fluxes made in the Shield Heterogeneity Study of at the Tower Shielding Facility (TSF) for the Gas Cooled Breeder Reactor (GCFR) shielding program. The study consisted of mockups of selective neutron streaming ...

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

1981-01-01

47

Spallation Neutron Source Beam Dump Radiation Shielding Analysis  

SciTech Connect

Preliminary shielding calculations were performed to establish the dimensions of the radiation shielding surrounding the three Spallation Neutron Source (SNS) beam stops. Steel shielding thicknesses were sized to give dose levels of 1, 2, and 5 mrem/h at the top of the shield, and, to provide enough shielding along the sides and bottom of the beam dump so that soil activation is not a problem. It was concluded that 144 in. of steel shielding is needed above the beam stop. The thickness of the concrete floor in the service building above the dump was not a part of these calculations. This shielding design is current as of January 2000.

Johnson, J.O.

2000-02-21

48

PATHFINDER ATOMIC POWER PLANT SHIELDING ANALYSIS  

Microsoft Academic Search

Shielding for the Pathfinder Atomic Power Plant, which incorporates a ; direct-cycle controlled-recirculation boiling-water reactor with an integral ; nuclear superheater, was designed. Information is presented on the shield ; design, dose levels for all areas of the plant, and methods of calculation. ; Major sources are the reactor complex in the reactor building, the main steam ; line, turbine,

R. J. Holl; D. W. Stephen

1962-01-01

49

66. CORBELS, BLIND ARCHES & SHIELDS, COMMONS EAST WALL, LOOKING ...  

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

66. CORBELS, BLIND ARCHES & SHIELDS, COMMONS EAST WALL, LOOKING EAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

50

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

51

Shielding Benchmark Computational Analysis  

SciTech Connect

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

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

2000-09-17

52

Shielding effects of a building structure on the energy deposit of cosmic rays in a simple wavelength shifter-based scintillator  

Microsoft Academic Search

An experimental setup, based on a plastic scintillator with an embedded wavelength shifter fibre and photosensors at the two ends, has been used to detect cosmic muons in undergraduate laboratory activities. Time and amplitude information from the two photosensors were measured using the time-over-threshold technique. The distribution of the energy deposit in the scintillator was measured under different shielding conditions

Salvatore Aiola; Paola La Rocca; Francesco Riggi; Simone Riggi

2012-01-01

53

Heat shielding: a task for youngsters  

Microsoft Academic Search

Heat shielding is a recently identified mechanism used by worker honey bees (Apis mellifera) to help maintain constant hive temperatures. Only workers perform this behavior; in our experiment, drones actively avoided heated hive regions. Observations of marked day-old cohorts within broodcomb regions indicate that heat shielding is performed by young bees to preferentially protect advanced stage larvae and pupae. As

Philip T. Starks; Rebecca N. Johnson; Adam J. Siegel; Meridith M. Decelleb

2005-01-01

54

Investigation of Lightning Rod Shielding Angle  

NASA Astrophysics Data System (ADS)

This paper studies those parameters affecting the shielding angle of the lightning rod (Franklin Rod) above very tall buildings. It was recommended that the shielding angle of the lightning rod is about 45°?60°. The downward lightning leader is modeled by using discrete line charges to consider the exponential distribution of charges through the downward leader. The voltage condition used by Rizk is used to investigate the inception of the upward lightning leader. Different air conditions (relative air density and air humidity) are considered for more practical simulation. The influences of lightning parameters and lightning rod height on the shielding angle are studied. The results shows that, lightning leader parameters, lightning rod height and ground slope have series effects on the lightning rod shielding angle. Based on the results, a lightning rod shielding angle for shielding design is recommended to decrease the lightning stroke to the lightning rod.

Nayel, Mohamed

55

Rootless Shield -- Lava Flow  

USGS Multimedia Gallery

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

2010-07-19

56

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

57

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 magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines. 3 figs.

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

1987-10-06

58

INTOR Radiation Shielding for Personnel Access.  

National Technical Information Service (NTIS)

The INTOR reactor shield system consists of the blanket, bulk shield, penetration shield, component shield, and biological shield. The bulk shield consists of two parts: (a) the inboard shield; and (b) the outboard shield. The distinction between the diff...

Y. Gohar M. Abdou

1981-01-01

59

THE SHIELD-BACKED BUG, PACHYCORIS STALLII UHLER (HETEROPTERA: SCUTELLERIDAE) - DESCRIPTION OF IMMATURE STAGES, EFFECT OF MATERNAL CARE ON NYMPHS, AND NOTES ON LIFE HISTORY  

Technology Transfer Automated Retrieval System (TEKTRAN)

The life history of Pachycoris stallii Uhler immatures was studied on its host plant, Croton californicus Muell.-Arg. Immature stages of the bug were described and illustrated. Pachycoris stallii is bi- or multivoltine and occurs in xeric areas with sandy soil where. Nymphs and adults feed on see...

60

Consensus Building on Access to Controlled Medicines: A Four-Stage Delphi Consensus Procedure.  

PubMed

CONTEXT: In 2011, the World Health Organization (WHO) published the policy guidelines Ensuring Balance in National Controlled Substances Policies-Guidance for Availability and Accessibility of Controlled Medicines, presenting a revised version of the previous guidelines from 2000. OBJECTIVES: To describe the consensus process that guided the revision of the guidelines. METHODS: A four-stage revision process was undertaken with a panel of 29 international experts from palliative care, public health, and harm reduction: 1) a qualitative inventory of required changes by means of a structured checklist, 2) & 3) a two-round online consensus Delphi process about the draft revision of the guidelines, and 4) a WHO advisory meeting for the discussion of remaining controversies and final issues. RESULTS: The qualitative inventory resulted in a draft revision of the guidelines meeting requirements on different levels, such as a broader focus and more accurate evidence. Operationalization of the guidelines was improved by specifying measures, procedures, and responsibilities. The Delphi procedure provided concrete indications for the rewording of both the guidelines and the associated text. During the advisory meeting, any persistent disagreements were systematically discussed to achieve consensus on the new version of the guidelines. CONCLUSION: The four-stage multimethod consensus process resulted in a substantial revision to the WHO guidelines. This takes into account the increase in knowledge about opioid medication since the first edition of the guidelines. Disagreement emerging from the process underlines the complexity of preparing guidance because of the delicate balance between need and control. PMID:23706904

Jünger, Saskia; Brearley, Sarah; Payne, Sheila; Mantel-Teeuwisse, Aukje K; Lynch, Thomas; Scholten, Willem; Radbruch, Lukas

2013-05-21

61

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

62

Heat shields: Materials and cost considerations  

NASA Astrophysics Data System (ADS)

Heat shields reduce the operating cost of a system by intercepting radiated heat that would otherwise add to the load on the low-temperature stage of the system. While always a consideration, recent fluctuations in the cost of helium have made the use of effective heat shields all the more critical to the cost effective operation of liquid helium systems. Heat shields come in many forms; they may be completely passive; relying on a low emissivity for effective operation, or they may be actively cooled by helium vapor, an intermediate stage of a refrigerator or by liquid nitrogen. For actively cooled heat shields a high thermal conductivity as well as a low emissivity is desirable. Structural considerations, such as the need to support the cold stage of the system, as well as space limitations may also factor in to heat shield design. Heat shields have traditionally been fabricated from copper and aluminum, when the highest possible thermal conductivity is required, and to a lesser extent from stainless steel. These materials have very different mechanical properties, are assembled with different fabrication techniques and have very different installed costs. In this paper we examine heat shield design options over a range of conditions and compare the costs of different materials and design options

Seely, Mikell Lee; Bonnema, Edward; Cunningham, Eileen

2012-06-01

63

Shielding Effectiveness of Braided-Wire Shields  

Microsoft Academic Search

An analysis of the shielding effectiveness of braidedwire shields is made using the parameters of the woven wire and the theory of electromagnetic coupling through small irises. The coupling through the rhombic-shaped holes in the braid is approximated by using the electric and magnetic polarizabilities of elliptical holes of the same width and length as the rhombus. The analysis develops

EDWARD F. VANCE

1975-01-01

64

GCFR Plenum Shield Design: Exit Shield Experiment.  

National Technical Information Service (NTIS)

This report describes the integral flux, energy spectra, and dose rate measurements made for the Exit Shield Experiment at the Oak Ridge National Laboratory Tower Shielding Facility as part of the Gas Cooled Fast Breeder Reactor program. The source was th...

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

1981-01-01

65

Magnetic shielding design analysis  

SciTech Connect

Two passive magnetic-shielding-design approaches for static external fields are reviewed. The first approach uses the shielding solutions for spheres and cylinders while the second approach requires solving Maxwell's equations. Experimental data taken at LLNL are compared with the results from these shieldings-design methods, and improvements are recommended for the second method. Design considerations are discussed here along with the importance of material gaps in the shield.

Kerns, J.A.; LaPaz, A.D.; Fabyan, J.

1983-12-27

66

Drip Shield Emplacement Gantry Concept.  

National Technical Information Service (NTIS)

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 Gant...

2005-01-01

67

New facility shield design criteria  

SciTech Connect

The purpose of the criteria presented here is to provide standard guidance for the design of nuclear radiation shields thoughout new facilities. These criteria are required to assure a consistent and integrated design that can be operated safely and economically within the DOE standards. The scope of this report is confined to the consideration of radiation shielding for contained sources. The whole body dose limit established by the DOE applies to all doses which are generally distributed throughout the trunk of the body. Therefore, where the whole body is the critical organ for an internally deposited radionuclide, the whole body dose limit applies to the sum of doses received must assure control of the concentration of radionuclides in the building atmosphere and thereby limit the dose from internal sources.

Howell, W.P.

1981-07-01

68

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

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

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

69

Neoproterozoic tectonics of the Arabian-Nubian Shield  

Microsoft Academic Search

The Neoproterozoic tectonic development of the Arabian-Nubian Shield (ANS) can be divided in three parts: 1) the oceanic stage; 2) the arc-accretion stage; 3) the extensional stage. Three key-areas in the Arabian-Nubian Shield, namely the Bi'r Umq Complex, The Tabalah and Tarj Complex and the Wadi Kid Complex, were studied in the framework of this research with the aim to

B. B. Blasband

2006-01-01

70

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

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

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

71

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

72

Consider Stages of Development in Preventing Terrorism: Does Government Building Fail and Terrorism Result when Developmental Stages of Governance are Skipped?  

Microsoft Academic Search

Countries, governments, and cultures must move through each of the stages of human development (Commons et al. (1998). Developmental Review, 8(3), 237–278) sequentially. Each stage must be achieved, and failure to recognize this may be a major contributing factor\\u000a to the rise of terrorism and crime in a society. For example, in a war-like situation, an occupying country’s attempts to\\u000a have

Michael Lamport Commons; Eric Andrew Goodheart

2007-01-01

73

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

SciTech Connect

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

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

1990-09-01

74

RADIATION SHIELDING DEVICE  

DOEpatents

ABS>A radiation shield that is suitable for the protection of personnel from both gamma rays and nentrons is described. The shield is comprised of a hollow wall and an aggregate consisting of iron and water in approximately equal amounts by volume substantially filling the wall. A means is provided to circulate the water through the wall to cool the shield when in use.

Wigner, E.P.; Young, G.J.

1958-09-23

75

RADIATION SHIELDING COMPOSITION  

DOEpatents

A light weight radiation shielding composition is described whose mechanical and radiological properties can be varied within wide limits. The composition of this shielding material consists of four basic ingredients: powder of either Pb or W, a plastic resin, a resin plasticizer, and a polymerization catalyst to promote an interaction of the plasticizer with the plastic resin. Air may be mixed into the above ingredients in order to control the density of the final composition. For equivalent gamma attenuation, the shielding composition weighs one-third to one-half as much as conventional Pb shielding. (AEC)

Dunegan, H.L.

1963-01-29

76

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

77

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

78

Shielding for reactors  

Microsoft Academic Search

A brief introductory discussion is given of the design of shielding for nuclear reactors. It includes consideration of design requirements, choice of materials and dimensions, nuclear reactions that affect the penetration, heating of the shielding and production of radioactivity in the coolant. Because the basic data available are insufficient for high accuracy in design calculation, the use of very complex

G C Laurence

1956-01-01

79

SHIELDING AGAINST SPACE RADIATION  

Microsoft Academic Search

A discussion of the problems in space radiation shielding is presented. ; The problem of penetrating protons is considered in an attempt to iliustrate the ; physical shieiding requirements for manned vehicles and to illuminate some of the ; gaps in present knowledge. Material and magnetic shielding are considered. ; (C.E.S.);

Madey

1963-01-01

80

NEUTRONIC REACTOR SHIELDING  

DOEpatents

A special hydrogenous concrete shielding for reactors is described. In addition to Portland cement and water, the concrete essentially comprises 30 to 60% by weight barytes aggregate for enhanced attenuation of fast neutrons. The biological shields of AEC's Oak Ridge Graphite Reactor and Materials Testing Reactor are particular embodiments.

Borst, L.B.

1961-07-11

81

Gamma ray detector shield  

DOEpatents

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

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

1985-08-26

82

Shielding requirements for mammography.  

PubMed

Shielding requirements for mammography installations have been investigated. To apply the methodologies of NCRP Report No. 49, the scatter-to-incident ratio of a typical mammography beam was measured, and the broad beam transmission was calculated for several representative beam spectra. These calculations were found to compare favorably with published low kVp tungsten-targeted x-ray transmission through a variety of shielding materials. Radiation shielding tables were developed from the calculated transmissions through Pb, concrete, gypsum, steel, plate glass, and water, using a technique which eliminates the "add one HVL" rule. It is concluded that Mo-targeted x-ray beams operated at 35 kVp require half the shielding of W-targeted beams operated at 50 kVp, and that adequate, cost-effective shielding calculations will consider alternatives to Pb. PMID:3623916

Simpkin, D J

1987-09-01

83

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

84

MEANS FOR SHIELDING REACTORS  

DOEpatents

A reactor of the heterageneous, heavy water moderated type is described. The reactor is comprised of a plurality of vertically disposed fuel element tubes extending through a tank of heavy water moderator and adapted to accommodate a flow of coolant water in contact with the fuel elements. A tank containing outgoing coolant water is disposed above the core to function is a radiation shield. Unsaturated liquid hydrocarbon is floated on top of the water in the shield tank to reduce to a minimum the possibility of the occurrence of explosive gaseous mixtures resulting from the neutron bombardment of the water in the shield tank.

Garrison, W.M.; McClinton, L.T.; Burton, M.

1959-03-10

85

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

86

Exploring the role nurses play at different stages of the birthing process. Developing strong and long-term relationships with women by examining relationship-building stages prior to delivery, during delivery, and after delivery.  

PubMed

The health care community is becoming increasingly aware of the need to develop strong and long-term relationships with the women who make up the majority of the health care market. The perceived quality of obstetric care positively impacts future revenue streams by creating "family" loyalty for an umbrella of other health services offered by the provider organization. This article examines the differential impact that various service performance dimensions have on women's perceptions of quality for different stages of the birthing process, and how relationship-marketing principles can be utilized to develop loyal partnerships. The three distinct relationship-building stages are examined--birthing experiences prior to delivery, during delivery, and after delivery--along with their implications for perceptions of quality analyzed. PMID:11185870

Peltier, J W; Schibrowski, J A; Westfall, J

2000-01-01

87

Adhesive particle shielding  

DOEpatents

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

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

2009-01-06

88

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

89

SHIELD certification package  

SciTech Connect

Certification as applied to existing computer codes includes the verification and validation process, placing the code in configuration control, establishing user qualification standards and training requirements. All software intended for use in critical calculations must be certified. This report is intended to fulfill the requirements for the certification of the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system built February, 1992, by W.S. Parks. These modules are used for burnup, cooling, separate, and edit calculations.

Boman, C.

1992-02-01

90

Fermilab booster beam collimation and shielding  

SciTech Connect

The beam power in the upgraded Booster at 8 GeV and 10 Hz will be 64 kW. Beam loss can result in high radiation loads in the ring. The purpose of a new beam halo cleaning system is to localize proton losses in specially shielded regions. Calculations show that this 2-stage collimation system will localize about 99% of beam loss in straight sections 6 and 7 and immediately downstream. Beam loss in the rest of the machine will be on average 0.1W/m. Local shielding will provide tolerable prompt and residual radiation levels in the tunnel, above the tunnel at the surface and in the sump water. Results of thorough MARS calculations are presented for a new design which includes shielding integrated with the collimators, motors and controls ensuring a high performance and facilitating maintenance. First measurements of the collimation efficiency are presented.

Nikolai V. Mokhov et al.

2003-05-28

91

Grounding and shielding in the accelerator environment  

SciTech Connect

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

Kerns, Q.

1991-01-01

92

Grounding and shielding in the accelerator environment  

SciTech Connect

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

Kerns, Q.

1991-12-31

93

Reactor head shielding apparatus  

SciTech Connect

This patent describes a nuclear reactor head shielding apparatus for mounting on spaced reactor head lifting members radially inwardly of the head bolts. It comprises a frame of sections for mounting on the lifting members and extending around the top central area of the head, mounting means for so mounting the frame sections, including downwardly projecting members on the frame sections and complementary upwardly open recessed members for fastening to the lifting members for receiving the downwardly projecting members when the frame sections are lowered thereto with lead shielding supported thereby on means for hanging lead shielding on the frame to minimize radiation exposure or personnel working with the head bolts or in the vicinity thereof.

Schukei, G.E.; Roebelen, G.J.

1992-01-28

94

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

95

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

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

Shielding of relativistic protons.  

PubMed

Protons are the most abundant element in the galactic cosmic radiation, and the energy spectrum peaks around 1 GeV. Shielding of relativistic protons is therefore a key problem in the radiation protection strategy of crewmembers involved in long-term missions in deep space. Hydrogen ions were accelerated up to 1 GeV at the NASA Space Radiation Laboratory, Brookhaven National Laboratory, New York. The proton beam was also shielded with thick (about 20 g/cm2) blocks of lucite (PMMA) or aluminium (Al). We found that the dose rate was increased 40-60% by the shielding and decreased as a function of the distance along the axis. Simulations using the General-Purpose Particle and Heavy-Ion Transport code System (PHITS) show that the dose increase is mostly caused by secondary protons emitted by the target. The modified radiation field after the shield has been characterized for its biological effectiveness by measuring chromosomal aberrations in human peripheral blood lymphocytes exposed just behind the shield block, or to the direct beam, in the dose range 0.5-3 Gy. Notwithstanding the increased dose per incident proton, the fraction of aberrant cells at the same dose in the sample position was not significantly modified by the shield. The PHITS code simulations show that, albeit secondary protons are slower than incident nuclei, the LET spectrum is still contained in the low-LET range (<10 keV/microm), which explains the approximately unitary value measured for the relative biological effectiveness. PMID:17256178

Bertucci, A; Durante, M; Gialanella, G; Grossi, G; Manti, L; Pugliese, M; Scampoli, P; Mancusi, D; Sihver, L; Rusek, A

2007-01-26

98

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

99

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

100

Bumper shield analysis  

SciTech Connect

To initially examine the effectiveness of a shield surrounding a reentry vehicle, we used the hypervelocity hydrodynamic impact code, LASOIL. We completed a four-by-four matrix of 16 two-dimensional numerical impact simulations of 1-g tungsten cylinders striking circular plates. The variable parameters were the projectile impact velocity (10, 20, 40, and 80 km/s) and the plate thickness (1, 2, 4, and 8 mm). In each case, the projectile was destroyed in the impact. The shield was penetrated but retained negliible momentum from the impact. The resultant debris cloud was low-density debris and vapor.

Oyer, A.T.

1986-07-01

101

Shielded Enclosures for Experimental Studies of Shielding Topology.  

National Technical Information Service (NTIS)

The report discusses the effort to provide shielded enclosures for EMP experimental studies of shielding topology. Section I discusses the theoretical modeling for which scattering matrices of subshields and their norms are used to relate the internal sig...

F. C. Yang K. S. H. Lee S. A. Kokorowski C. E. Baum J. Hamm

1984-01-01

102

Method for temporary shielding of reactor vessel internals  

SciTech Connect

This patent describes a method for shielding stored internals for reactor vessel annealing. It comprises removing nuclear fuel from the reactor vessel containment building; removing and storing upper and lower core internals under water in a refueling canal storage area; assembling a support structure in the refueling canal between the reactor vessel and the stored internals; introducing vertical shielding tanks individually through a hatch in the containment building and positioning each into the support structure; introducing horizontal shielding tanks individually through a hatch in the containment building and positioning each above the stored internals and vertical tanks; draining water from the refueling canal to the level of a flange of the reactor vessel; placing an annealing apparatus in the reactor vessel; pumping the remaining water from the reactor vessel; and annealing the reactor vessel.

Grimm, N.P.; Sejvar, J.

1991-04-23

103

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 W.

104

WASTE TREATMENT BUILDING SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

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

F. Habashi

2000-06-22

105

EMP Shielding Using Multilayer Film.  

National Technical Information Service (NTIS)

This program was to develop and fabricate a low cost composite shielding material (Multishield) that is capable of providing shielding against magnetic fields, including high strength fields. A continuous horizontal web production machine was manufactured...

W. J. Biter

2000-01-01

106

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

107

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

108

Aluminum Foil Shield Effectiveness for Electronic Cables.  

National Technical Information Service (NTIS)

Historically, shielding of electronic cables has been expressed in terms of shield coverage. The numeric value used to delineate shield coverage corresponded to the actual area of the conductors covered by the cable shield. Generally, the larger the perce...

M. R. Lombardo

1983-01-01

109

Shielding of substations against direct lightning strokes by shield wires  

SciTech Connect

A new analysis for shielding outdoor substations against direct lightning strokes by shield wires is proposed. The basic assumption of this proposed method is that any lightning stroke which penetrates the shields will cause damage. The second assumption is that a certain level of risk of failure must be accepted, such as one or two failures per 100 years. The proposed method, using electrogeometric model, was applied to design shield wires for two outdoor substations: (1) 161-kV/69-kV station, and (2) 500-kV/161-kV station. The results of the proposed method were also compared with the shielding data of two other substations.

Chowdhuri, P. (Tennessee Technological Univ., Cookeville, TN (United States))

1994-01-01

110

Hydrocode modeling of advanced debris shield designs  

NASA Astrophysics Data System (ADS)

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

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

1996-05-01

111

Distributed acoustic conversation shielding system  

US Patent & Trademark Office Database

A conversation shielding system comprises sensors that detect the location of a confidential conversation and the presence and location of a potential eavesdropper, audio output devices that produce masking sounds to shield the conversation from the eavesdropper, and a controller that automatically controls the operation of the output devices in response to data from the sensors. An optional portable controller may manually engage the system. A method for shielding conversation comprises identifying a conversation to be shielded, detecting a potential eavesdropper, automatically determining masking sound types, locations and volume that will shield the conversation, directing emission of masking sounds from at least one audio output device in order to shield the conversation, including adjusting the masking sound type, location, and volume in response to movement of the conversation or the eavesdropper, and continuing to shield the conversation until it ends or the eavesdropper is no longer detected.

Paradiso; Joseph A. (Medford, MA); Ono; Yasuhiro (Saitama, JP)

2012-07-24

112

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

113

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

114

Multilayer radiation shield  

DOEpatents

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 by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

Urbahn, John Arthur (Saratoga Springs, NY); Laskaris, Evangelos Trifon (Niskayuna, NY)

2009-06-16

115

Electron beam shielding  

Microsoft Academic Search

The use of electron beams (EBs), particularly for melting, evaporating, and refining metals, can produce high levels of x-rays. In fact, under ultravacuum, as generally is the case, the conditions for producing x-rays are similar to that of conventional x-rays tubes. Therefore, providing adequate shielding against these x-rays must be considered an important part of EB operations. This paper presents

1990-01-01

116

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

117

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

118

U.S. INSPECTION STATION, TECATE, EXTERIOR VIEW, PARAPET AND SHIELD DETAIL ...  

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

U.S. INSPECTION STATION, TECATE, EXTERIOR VIEW, PARAPET AND SHIELD DETAIL ON WEST FACADE, LOOKING EAST. SEPTEMBER 22, 2003. - U.S. Inspection Station, Main Building, California State Highway 188, Tecate Road, Tecate, San Diego County, CA

119

Radiation shielding issues 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 final design of the vertical test cryostat facility to be installed in the Industrial Building 1 at Fermilab are presented and discussed.

Rakhno, I.; /Fermilab

2006-11-01

120

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

121

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

122

Radiation shielding quality assurance  

NASA Astrophysics Data System (ADS)

For the radiation shielding quality assurance, the validity and reliability of the neutron transport code MCNP, which is now one of the most widely used radiation shielding analysis codes, were checked with lot of benchmark experiments. And also as a practical example, follows were performed in this thesis. One integral neutron transport experiment to measure the effect of neutron streaming in iron and void was performed with Dog-Legged Void Assembly in Knolls Atomic Power Laboratory in 1991. Neutron flux was measured six different places with the methane detectors and a BF-3 detector. The main purpose of the measurements was to provide benchmark against which various neutron transport calculation tools could be compared. Those data were used in verification of Monte Carlo Neutron & Photon Transport Code, MCNP, with the modeling for that. Experimental results and calculation results were compared in both ways, as the total integrated value of neutron fluxes along neutron energy range from 10 KeV to 2 MeV and as the neutron spectrum along with neutron energy range. Both results are well matched with the statistical error +/-20%. MCNP results were also compared with those of TORT, a three dimensional discrete ordinates code which was developed by Oak Ridge National Laboratory. MCNP results are superior to the TORT results at all detector places except one. This means that MCNP is proved as a very powerful tool for the analysis of neutron transport through iron & air and further it could be used as a powerful tool for the radiation shielding analysis. For one application of the analysis of variance (ANOVA) to neutron and gamma transport problems, uncertainties for the calculated values of critical K were evaluated as in the ANOVA on statistical data.

Um, Dallsun

123

Watching a disappearing shield  

SciTech Connect

The remote-sensing techniques used to monitor atmospheric ozone levels are reviewed, and recent results are discussed. The importance of the ozone layer as a shield for UV radiation is stressed, and the impact of human activities generating ozone-destroying compounds is considered. Ground-based, airborne, balloon-borne, and satellite remote-sensing methods are shown to complement each other to provide both global coverage and detailed structural information. Data obtained with the Nimbus-7 TOMS and solar-backscatter UV instruments are presented in graphs and briefly characterized.

Stolarski, R.S.

1988-10-01

124

Passive Shielding in CUORE  

SciTech Connect

The nature of neutrino mass is one of the friontier problems of fundamental physics. Neutrinoless Double Beta Decay (0{nu}DBD) is a powerful tool to investigate the mass hierarchy and possible extensions of the Standard Model. CUORE is a 1-Ton next generation experiment, made of 1000 Te bolometers, aiming at reaching a background of 0.01 (possibly 0.001) counts keV-1kg-1y-1 and therefore a mass sensitivity of few tens of meV The background contribution due to environmental neutrons, muon-induced neutrons in the shieldings and external gamma is discussed.

Bellini, F.; Cosmelli, C.; Dafinei, I.; Diemoz, S.; Faccini, R.; Ferroni, F.; Gargiulo, C.; Longo, E.; Morganti, S.; Tomei, C.; Vignati, M. [Dipartimento di Fisica dell'Universita di Roma La Sapienza e Sezione di Roma dell'INFN, Roma I-00185 (Italy); Alessandria, F. [INFN - Sezione di Milano, Milan I-20133 (Italy); Andreotti, E.; Foggetta, L.; Giuliani, A.; Pedretti, M.; Sangiorgio, S. [Dipartimento di Fisica e Matematica dell'Universita dell'Insubria e Sezione di Milano dell'INFN, Como I-22100 (Italy); Ardito, R. [Dipartimento di Fisica dell'Universita di Milano-Bicocca e Sezione di Milano Bicocca dell'INFN, Milan I-2016 (Italy); Dipartimento di Ingegneria Strutturale del Politecnico di Milano, Milano I-20133 (Italy); Arnaboldi, C.; Brofferio, C. [Dipartimento di Fisica dell'Universita di Milano-Bicocca e Sezione di Milano Bicocca dell'INFN, Milan I-2016 (Italy)] (and others)

2007-03-28

125

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

126

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

127

PATHFINDER ATOMIC POWER PLANT RADIATION SHIELDING STUDY  

Microsoft Academic Search

Alternate concepts studied for the various shielding requirements in the ; Pathfinder Atomic Power Plant are described. It is concluded that a concrete ; shield surrounding the reactor pressure vessel is an adequate biological shield. ; This shield is made up of two parts: an outer two foot section which is both ; shield and structaral support for the various

R. Corcoran; H. C. Crumpacker; D. M. Leppke

1959-01-01

128

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

129

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

130

EMP Coupling Through Cable Shields  

Microsoft Academic Search

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

Kendali Casey; Edward Vance

1978-01-01

131

Unintentional radiation from shielded transformers  

Microsoft Academic Search

It is shown experimentally that a typical shielded broadband transformer intended for bulk current injection measurements radiates far-field electromagnetic energy. This radiation occurs in spite of the shield and is distinct from any radiation due to common mode currents on the exterior of the coaxial feed transmission line. The radiation patterns presented here taken together with previous results which showed

James McLean; Robert Sutton

2010-01-01

132

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

133

Aerodynamic Fastener Shield for Turbomachine.  

National Technical Information Service (NTIS)

A fastener shield for use in a fluid flow path within a gas turbine engine for reducing fluid drag and heating generated by fluid flow over a plurality of circumferentially spaced fasteners. The fastener shield has a radially-extending, downstream-facing ...

J. Senyo M. J. Epstein W. C. Anderson Z. Dong

2004-01-01

134

Lunar Surface Reactor Shielding Study  

Microsoft Academic Search

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

Shawn Kang; Ronald Lipinski; William McAlpine

2006-01-01

135

REACTOR SERVICE BUILDING, TRA635. CAMERA FACING NORTHWEST. BUILDING PROJECTS FROM ...  

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

REACTOR SERVICE BUILDING, TRA-635. CAMERA FACING NORTHWEST. BUILDING PROJECTS FROM AND CONNECTS TO SOUTH WALL OF MTR BUILDING. EARTH BERM SHIELDING PLUG STORAGE BUILDING IS AT RIGHT OF VIEW. INL NEGATIVE NO. 9913. Unknown Photographer, 2/23/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

136

Aladdin upgrade design study: shielding  

SciTech Connect

The object of this shielding is to examine all aspects of Aladdin operation to ensure that adequate shielding is provided to meet the design objectives. To do this, we will look at shielding necessary for radiation produced during the injection process, during normal loss of the stored beam and during accidental loss of the stored beam. It will therefore be necessary to specify shielding not only at the ring, but also along the injection line and the optical beam lines. We will also give special attention to the occupation of the accelerator Vault during injection as this may be a desirable design option. In effect, two shielding plans will be presented, permitting estimates of cost and space requirements for both.

Swanson, W.P.; DeLuca, P.M. Jr.; Otte, R.A.; Schilthelm, S.W.

1985-04-23

137

NEUTRON SHIELDING STRUCTURE  

DOEpatents

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, B/sub 4/C, B/sub 2/O/ sub 3/, CaB/sub 6/, Li/sub 2/CO3, LiOH, LiBO/sub 2/, Li/s ub 2/O. The facing sheets are constructed of a neutron moderating material, so that fast neutrons will be moderated while traversing the facing sheets, and ultimately be absorbed by the absorber powder in the honeycomb. Beryllium is a preferred moderator material for use in the facing sheets. The advantage of the structure is that it combines the rigidity and light weight of a honeycomb construction with the neutron absorption properties of boron and lithium. (AEC)

Mattingly, J.T.

1962-09-25

138

Shielding and fragmentation studies.  

PubMed

Radiation dosimetry for manned spaced missions depends on the ability to adequately describe the process of high-energy ion transport through many materials. Since the types of possible nuclear interactions are many and complex, transport models are used which depend upon a reliable source of experimental data. To expand the heavy ion database used in the models we have been measuring charge-changing cross sections and fragment production cross sections from heavy-ion interactions in various elementa targets. These include materials flown on space missions such as carbon and aluminium, as well as those important in radiation dosimetry such as hydrogen, nitrogen and water. Measuring heavy-ion fragmentation through these targets also gives us the ability to determine the effectiveness of new materials proposed for shielding such as graphite composites and polyethylene hybrids. Measurement without a target present gives an indication of the level of contamination of the primary beam, which is also important in radiobiology experiments. PMID:16604611

Zeitlin, C; Guetersloh, S; Heilbronn, L; Miller, J

2005-01-01

139

Zone 4 Study: Shielded Lift Truck Refurbishment/Replacement  

SciTech Connect

The Zone 4 Stage Right Shielded Lift Trucks (SLT's) will likely need refurbishment or replacement within the next two to five years, due to wear. This document discusses the options to provide a long term and reliable means of satisfying Zone 4 material movement and inventory requirements.

AMAI, WENDY A.; JONES, JAMES F.; LENNOX, R. CHARLEENE; SIMON, RONALD W.; JONES, JAMES F

2002-09-01

140

Isotopic evolution of Hawaiian shield basalts over 4.5 million years and implications for plume structure  

NASA Astrophysics Data System (ADS)

Improved analytical precision for radiogenic isotopes (down to ~100 ppm for Pb and to <50 ppm for Sr, Nd and Hf), combined with statistical data treatment, allow for detailed investigations into the geochemical variations of basalts related to mantle plumes. For the main Hawaiian Islands, representing 4.5 myr of volcanism, we compiled high-precision Pb isotopic data (MC-ICP-MS or DS, TS TIMS) for 845 samples, integrated with Sr, Nd and Hf isotopic data on 500-600 samples for shield stage (67%), post-shield/late shield (22%) and rejuvenated lavas (10%). All data were normalized to the same standard values to avoid inter-laboratory biases and 30% of the analyses were determined at UBC. The Kea trend volcanoes have higher 206Pb/204Pb and 208Pb/204Pb, higher epsilon Nd, epsilon Hf, and lower 87Sr/86Sr than Loa trend volcanoes. This dichotomy does not stop at O`ahu as Loa characteristics are identified in the ~4.5 Ma Kaua`i lavas. Pb isotopes present the sharpest boundary between the trends, although some volcanoes (Kohala, Mahukona and Kaua`i) cross-over indicating that the Kea-Loa division disappears during some intervals of volcanism. Within each trend, Pb isotopic ratios increase with time and become more radiogenic for younger volcanoes. Principal component analysis of ~600 shield lavas indicates that two components govern over 99% of the Pb isotope variability during the shield building stage. The strength of the Loa-type signal varies significantly with time. The strongest signal appears near the end of the shield stage (Ko`olau, Lana`i) and is associated with relatively small volumes of lavas. There is usually a correlation of the Loa-type features with the SiO2 content of the lavas, although not systematically. Loa-trend volcanoes show larger isotopic variations (>1.5 times those of Kea-trend volcanoes) and there is a relationship between the value of the isotopic ratio and its variance. This means that the Ko`olau-Lana`i-type component is much more heterogeneous and probably younger (shorter residence time in the mantle). Hawaiian post-shield and rejuvenated lavas have more Kea-like geochemical characteristics than the underlying shield lavas with only two exceptions (Mahukona and Kohala); their isotopic compositions extend towards more depleted values that depart from the shield mixing trends and that do not intersect MORB-type compositions. We infer that (1) the Kea component is always present in the Hawaii mantle plume (including in the Hawaiian-Emperor seamount chain), (2) the proportion of the Loa component is highly variable in basalts all along the islands, (3) the distribution and variance of the Ko`olau-Lana`i enriched component indicate that the sediment-like component in the plume source does not need to be very old, and (4) the Loa component is preferentially sampled on the SW side of the chain, without much dilution from the other side.

Weis, D. A.; Garcia, M. O.; Depaolo, D. J.; Scoates, J. S.

2009-12-01

141

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)

1997-03-01

142

Arabian Shield ophiolites and Late Proterozoic microplate accretion  

NASA Astrophysics Data System (ADS)

Fragments of Late Proterozoic ocean crust and mantle (ophiolites) occur within six major fault zones that mark sutures between crustal blocks (microplates) that were accreted between about 630 and 715 Ma to form the Arabian Shield. We report new U-Pb zircon ages for ophiolitic gabbro, diorite, and plagiogranite that range from 840 to 700 Ma and establish these complexes among the oldest proven ophiolites. By dating the ophiolitic rocks we are able to monitor the magmatic ages of sea-floor spreading events during accretion of the Arabian Shield. Comparison of the ophiolitic dates with the ages of the adjacent crustal blocks provides a more complete basis for plate-tectonics reconstruction of the shield than has previously been possible. Our new zircon ages confirm earlier Sm-Nd mineral isochrons for ophiolites of the northwestern Arabian Shield, show that the ophiolites are among the oldest oceanic rocks in each terrane, support near- or within-arc tectonic settings for the ophiolites, suggest that the Bir Umq suture extends north along the Nabitah mobile belt into the northern shield, and suggest that older (>1250 Ma) continental crustal material is locally present in the dominantly “oceanic” western shield. We suggest that Indonesia and Alaska provide Phanerozoic analogues for stages in the accretion history. Note: Additional material for this article is Supplementary Data 8715, available on request from the GSA Documents Secretary (see footnote 1).

Pallister, John S.; Stacey, John S.; Fischer, Lynn B.; Premo, Wayne R.

1987-04-01

143

Evolution of the Hawaiian Mantle Plume: Shield and Rejuvenescent Magmatism at Middle Bank, the Youngest Sunken Hawaiian Volcano  

NASA Astrophysics Data System (ADS)

Post-shield volcanism provides unique insight into the structure of mantle plumes and the magmatic processes responsible for the evolution of ocean islands. Middle Bank is the closest seamount to the main Hawaiian archipelago, thus providing a perspective into the processes related to the dying phase of a Hawaiian volcano. We conducted a detailed survey of the volcano in 2007 using multibeam sonar coupled with Jason2 ROV imaging and sampling. According to plate tectonic models, Middle Bank volcano should be about 9.6 Ma, if it formed near the present location of Kilauea. Middle Bank is 100 km in diameter and rises nearly 5000 m from base level. Its morphology is dominated by three major rift zones that emanate to the east, west, and south from the beveled summit platform. The rifts are separated by talus fans, and the volcano is surrounded by dozens of satellite cones. Many of the satellite cones are covered by remarkably unsedimented lavas that were erupted in the submarine environment, which we interpret as a rejuvenated stage of volcanism. Most of the sampled rocks are strongly alkaline and range from basanite to hawaiite and trachyte. Samples from two sites are tholeiitic, which is consistent with them forming during the shield stage of volcanism. If so, then most of the late history of volcanism, from shield building to rejuvenated volcanism is preserved at Middle Bank. The alkaline basalts and basanites have La/Sm and La/Yb ratios that are higher than the tholeiites, and all of the rocks are strongly LREE enriched. Major and trace element compositions of hawaiites and trachytes are consistent with large amounts of crystal fractionation, which especially affected magmas erupted on the outer flanks of the volcano. The tholeiites have Sr/Nb and Zr/Nb that suggest that the Middle Bank shield is akin to the modern-day "Kea" trend geochemically. Thus, Middle Bank has preserved the archetypical tholeiitic-shield to alkaline-rejuvenated evolutionary stages that characterize the subaerial Hawaiian volcanoes.

Geist, D.; Garcia, M.; Ito, G.; Harpp, K.; Weis, D.

2008-12-01

144

Lunar Surface Reactor Shielding Study  

SciTech Connect

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; McAlpine, William [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Lipinski, Ronald [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

2006-01-20

145

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

146

Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes  

NASA Astrophysics Data System (ADS)

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; Kilinçarslan, ?emsettin; Mavi, Betül; Güno?lu, Kadir; Akkurt, Iskender; Akka?, Ay?e

2011-12-01

147

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

148

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

149

NEUTRON ABSORPTION AND SHIELDING DEVICE  

DOEpatents

A neutron absorption and shielding device is described which is adapted for mounting in a radiation shielding wall surrounding a radioactive area through which instrumentation leads and the like may safely pass without permitting gamma or neutron radiation to pass to the exterior. The shielding device comprises a container having at least one nonrectilinear tube or passageway means extending therethrough, which is adapted to contain instrumentation leads or the like, a layer of a substance capable of absorbing gamma rays, and a solid resinous composition adapted to attenuate fast-moving neutrons and capture slow- moving or thermal neutrons.

Axelrad, I.R.

1960-06-21

150

Project BioShield. 2003.  

National Technical Information Service (NTIS)

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...

F. Gottron

2003-01-01

151

Radiation shielding for neutron guides  

NASA Astrophysics Data System (ADS)

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

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

2006-11-01

152

Ophthalmomyiasis during Operation Desert Shield.  

PubMed

A case of fly larva infestation of the eye (ophthalmomyiasis) is reported in an American soldier serving in Operation Desert Shield. Background information, prognosis, and treatment are discussed. PMID:1956540

Torok, P G; Davis, D L; Roley, E

1991-08-01

153

Shielding electronics behind composite structures  

SciTech Connect

The increasing use of composite structures and composite electronics boxes in space can result in a several-fold increase in electronics radiation total dose, as compared to using aluminum structures and aluminum electronics boxes. There are also desires to use Multi-Function Structures (MFS), where electronics are integral with composite structures (no electronics boxes). MFS approaches can result in an order of magnitude increase in radiation dose to electronics over conventional aluminum structures and boxes. The designer must either use rad-hard parts which are becoming more difficult to obtain since the end of the Cold War, increase spot shielding, use RADPAK{trademark} solutions, or add shielding to composite boxes and structures. With the increasing use of low hardness commercial parts to reduce costs, a brute force solution of adding shielding to composite boxes is frequently the lowest cost solution. Analyses, test data, and a flight experiment are described to assess these shielding options.

Spieth, B.D. [ITN Energy Systems, Wheat Ridge, CO (United States); Qassim, K.S.; Pittman, R.N. [Air Force Research Lab., Kirtland AFB, NM (United States); Russell, D.A. [Boeing Information, Space and Defense Systems, Seattle, WA (United States)

1998-12-01

154

Shields to Reduce Spray Drift  

Microsoft Academic Search

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

HE Ozkan; A Miralles; C Sinfort; H Zhu

1997-01-01

155

Enhancement of EMP Shielding by Ferromagnetic Saturation  

Microsoft Academic Search

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

R. R. Ferber; F. J. Young

1970-01-01

156

Shielding techniques for communication cable - An update  

Microsoft Academic Search

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

T. R. Scott; T. R. Russell

1984-01-01

157

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

158

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

159

New shielding materials for clinical electron beams  

Microsoft Academic Search

Since lead has recently been recognized as a source of environmental pollution, we have investigated new electron shielding materials that do not contain lead. We compared the shielding thicknesses of a hard plate and a sheet composed of the new materials with that of lead for electron beams. The shielding thickness was evaluated as the thickness required for shielding primary

Minoru Tajiri; Yuji Tokiya; Jun Uenishi; Masayoshi Sunaoka; Kazuhiro Watanabe

2006-01-01

160

Magnetic shielding for interplanetary spacecraft  

SciTech Connect

The protection of spacecraft crews from the radiation produced by high energy electrons, protons and heavier ions in the space environment is a major health concern on long duration missions. Conventional approaches to radiation shielding in space have relied on thicker spacecraft walls to stop the high energy charged particles and to absorb the resulting gamma and bremsstrahlung photons. The shielding concept described here uses superconducting magnets to deflect charged particles before they collide with the spacecraft, thus avoiding the production of secondary particles. A number of spacecraft configurations and sizes have been analyzed, ranging from a small ``storm cellar`` for use during solar flares to continuous shielding for space stations having a crew of 15--25. The effectiveness of the magnetic shielding has been analyzed using a Monte Carlo program with incident proton energies from 0.5 to 1000 MeV. Typically the shield deflects 35--99 percent of the incident particles, depending, of course on particle energy and magnetic field strength. Further evaluation studies have been performed to assess weight comparisons between magnetic and conventional shielding; to determine magnet current distributions which minimize the magnetic field within the spacecraft itself; and to assess the potential role of ceramic superconductors. 2 figs., 8 tabs.

Herring, J.S.; Merrill, B.J.

1991-12-01

161

Magnetic shielding for interplanetary spacecraft  

SciTech Connect

The protection of spacecraft crews from the radiation produced by high energy electrons, protons and heavier ions in the space environment is a major health concern on long duration missions. Conventional approaches to radiation shielding in space have relied on thicker spacecraft walls to stop the high energy charged particles and to absorb the resulting gamma and bremsstrahlung photons. The shielding concept described here uses superconducting magnets to deflect charged particles before they collide with the spacecraft, thus avoiding the production of secondary particles. A number of spacecraft configurations and sizes have been analyzed, ranging from a small storm cellar'' for use during solar flares to continuous shielding for space stations having a crew of 15--25. The effectiveness of the magnetic shielding has been analyzed using a Monte Carlo program with incident proton energies from 0.5 to 1000 MeV. Typically the shield deflects 35--99 percent of the incident particles, depending, of course on particle energy and magnetic field strength. Further evaluation studies have been performed to assess weight comparisons between magnetic and conventional shielding; to determine magnet current distributions which minimize the magnetic field within the spacecraft itself; and to assess the potential role of ceramic superconductors. 2 figs., 8 tabs.

Herring, J.S.; Merrill, B.J.

1991-01-01

162

Shielding requirements in helical tomotherapy  

NASA Astrophysics Data System (ADS)

Helical tomotherapy is a relatively new intensity-modulated radiation therapy (IMRT) treatment for which room shielding has to be reassessed for the following reasons. The beam-on-time needed to deliver a given target dose is increased and leads to a weekly workload of typically one order of magnitude higher than that for conventional radiation therapy. The special configuration of tomotherapy units does not allow the use of standard shielding calculation methods. A conventional linear accelerator must be shielded for primary, leakage and scatter photon radiations. For tomotherapy, primary radiation is no longer the main shielding issue since a beam stop is mounted on the gantry directly opposite the source. On the other hand, due to the longer irradiation time, the accelerator head leakage becomes a major concern. An analytical model based on geometric considerations has been developed to determine leakage radiation levels throughout the room for continuous gantry rotation. Compared to leakage radiation, scatter radiation is a minor contribution. Since tomotherapy units operate at a nominal energy of 6 MV, neutron production is negligible. This work proposes a synthetic and conservative model for calculating shielding requirements for the Hi-Art II TomoTherapy unit. Finally, the required concrete shielding thickness is given for different positions of interest.

Baechler, S.; Bochud, F. O.; Verellen, D.; Moeckli, R.

2007-08-01

163

Numerical Approach for Computation of Electromagnetic Shielding  

NASA Astrophysics Data System (ADS)

Disturbing magnetic field (so-called magnetic smog) can be in certain areas suppressed by shielding jacket. Disturbing field is possible to be "lead away" from the shielded area with the use of jacket made of materials with high magnetic permeability (so-called passive shielding, or flux-entrapment shielding). If the disturbing field is time-variable, eddy currents are induced into electrically conductive jacket. Magnetic field generated by these eddy currents suppress the disturbing field (this is called active shielding, or lossy magnetic shielding). Both of these principles can be applied altogether (this is called combined shielding). Presented paper states numerical approach to shielding jacket design and is an introduction to following solution of a real problem of magnetic shielding when the disturbing magnetic field is space-time complicated. Effective design of the magnetic shielding should then be formulated as an optimization task.

Mayer, Daniel; Ulrych, Bohuš

2013-06-01

164

Neutronic reactor thermal shield  

DOEpatents

1. The combination with a plurality of parallel horizontal members arranged in horizontal and vertical rows, the spacing of the members in all horizontal rows being equal throughout, the spacing of the members in all vertical rows being equal throughout; of a shield for a nuclear reactor comprising two layers of rectangular blocks through which the members pass generally perpendicularly to the layers, each block in each layer having for one of the members an opening equally spaced from vertical sides of the block and located closer to the top of the block than the bottom thereof, whereby gravity tends to make each block rotate about the associated member to a position in which the vertical sides of the block are truly vertical, the openings in all the blocks of one layer having one equal spacing from the tops of the blocks, the openings in all the blocks of the other layer having one equal spacing from the tops of the blocks, which spacing is different from the corresponding spacing in the said one layer, all the blocks of both layers having the same vertical dimension or length, the blocks of both layers consisting of relatively wide blocks and relatively narrow blocks, all the narrow blocks having the same horizontal dimension or width which is less than the horizontal dimension or width of the wide blocks, which is the same throughout, each layer consisting of vertical rows of narrow blocks and wide blocks alternating with one another, each vertical row of narrow blocks of each layer being covered by a vertical row of wide blocks of the other layer which wide blocks receive the same vertical row of members as the said each vertical row of narrow blocks, whereby the rectangular perimeters of each block of each layer is completely out of register with that of each block in the other layer.

Lowe, Paul E. (Blue Ash, OH)

1976-06-15

165

Preliminary shielding assessment for the 100 MeV proton linac (KOMAC).  

PubMed

The Proton Engineering Frontier Project is building the Korea Multipurpose Accelerator Complex facilities from 2002 to 2012, which consists of a high-current 100 MeV proton linear accelerator and various beam-lines. This paper provides a preliminary estimate of the shielding required for the 20 mA proton linac and the beam-dump. For an accurate information on secondary neutron production from the guiding magnet and primary heat sink of the beam dump, proton-induced 63Cu and 65Cu cross section data were evaluated and applied to shielding calculations. The required thickness of the concrete was assessed by a simple line-of-sight model for the lateral shielding of the beam-line and the full shielding of the beam dump. Monte Carlo simulations were also performed using the MCNPX code to obtain the source term and attenuation coefficients for the three-dimensional lateral shielding model of the beam-line. PMID:16381787

Lee, Young-Ouk; Cho, Y S; Chang, J

2005-01-01

166

Finite-element modeling of magnetic shielding for SCUBA-2  

NASA Astrophysics Data System (ADS)

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

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

2006-07-01

167

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

168

Radiation Shielding Materials and Containers Incorporating Same  

SciTech Connect

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

169

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

NASA Astrophysics Data System (ADS)

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

Sherrod, David R.; Murai, Takashi; Tagami, Takahiro

2007-04-01

170

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

USGS Publications Warehouse

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

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

2007-01-01

171

Depth & Shielding Requirements for mini-CLEAN  

NASA Astrophysics Data System (ADS)

Neutron-induced nuclear recoil represents an irreducible background in detectors aimed at the direct detection of WIMP dark matter. Muon-induced neutrons can be adequately suppressed by staging experiments sufficiently deep underground, however, it is also critical to suppress neutron production via (alpha, n) interactions due to naturally occurring radioactivity in detector construction materials. We present the results of simulations for the mini-CLEAN detector under development to search for WIMP dark matter using 100 kg of liquid argon or liquid neon as the target material. We show that neutron backgrounds can be sufficiently suppressed in a conceptually simple detector using the coincidence between the prompt nuclear recoil signal and the delayed neutron capture gamma ray. The shielding of (?,n) neutrons that are produced in rock as a function of thickness of polyethylene is modeled.

Mei, Dong-Ming; Hime, Andrew

2006-10-01

172

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

173

Target station shielding issues at the spallation neutron source.  

PubMed

Recent spallation neutron source shielding activities in support of the neutron beam shutters and the hot cell walls are presented. Existing neutron beam shutters can be replaced with concrete at low power or with concrete and steel at approximately 500 kW of beam power. Potential voids in the hot cell walls are analysed to determine the impact on dose rates as a function of void size. A change in the type of shielding work is noted as the project moved from the early design stages as a 'green field' site to the current stage as a construction project nearing completion, where issues to be addressed are approaching retrofit-type analyses. PMID:16381707

Ferguson, P D; Gallmeier, F X; Iverson, E B; Popova, I I

2005-01-01

174

Reactor and shielding design implications of clustering nuclear thermal rockets  

Microsoft Academic Search

This paper examines design considerations in the context of engine-out accidents in clustered nuclear-thermal rocket stages, and an accident-management protocol is devised. Safety and performance issues are considered in the light of designs for the reactor and shielding elements of ROVER\\/NERVA-type engines. The engine-out management process involves: phase one, in which sufficient propulsive power is guaranteed for mission completion; and

John J. Buksa; Michael G. Houts

1992-01-01

175

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

176

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)

1997-12-01

177

Photo Induced-EMF Sensor Shield.  

National Technical Information Service (NTIS)

A photo-EMF detector including a shield to prevent a portion of the detector from illumination. The shield prevents the generation of unwanted noise-currents, thus increasing the performance of the photo-EMF detector.

G. J. Dunning M. Sokolich D. Vogel D. M. Pepper

2004-01-01

178

Shielding benchmark tests of JENDL-3.  

National Technical Information Service (NTIS)

The integral test of neutron cross sections for major shielding materials in JENDL-3 has been performed by analyzing various shielding benchmark experiments. For the fission-like neutron source problem, the following experiments are analyzed: (1) ORNL Bro...

M. Kawai A. Hasegawa K. Ueki N. Yamano K. Sasaki

1994-01-01

179

Single bumper shields based on Vectran fibers  

NASA Astrophysics Data System (ADS)

High strength fiber is a potential material for shielding from a viewpoint of strength, lightweight and flexibility. We developed a single bumper shield based on Vectran fibers, that stopped a polycarbonate projectile with 14 mm in diameter, 1 g in weight and 6.45 km/s in velocity. The thickness of this shield was 7 mm. As compared with the mesh stuffed Whipple bumper shield installed on the Japanese Experiment Module, the areal density was half and the thickness was approximately one sixteenth. The aim of our hypervelocity impact experiments was to develop a thin bumper material consisting of only Vectran fibers and to research a deployable shielding system for debris protection using the fiber material. The results indicated that the new thin shield with 7 mm in thickness has a good protection capability. The new single bumper shield may provide the basic technology for reinforcing the protection capability and reducing the weight of the shield drastically.

Tanaka, M.; Moritaka, Y.

2004-01-01

180

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

181

Magnetic Shielding for High Fields.  

National Technical Information Service (NTIS)

During the program a code was developed to predict the attenuation in a multilayer, non-linear system. This program allows modeling of shielding effectiveness for the complex case of high conductivity and high permeability layers in which the high permeab...

W. J. Biter

1996-01-01

182

Gamma-Ray Shielding Studies.  

National Technical Information Service (NTIS)

A monoenergetic beam of gamma rays was used to study the deep penetration of 10-MeV gamma radiation in aluminum. Recently a positron annihilation system was developed at General Atomic for the purpose of making shielding measurements in the energy range f...

J. A. Lonergan E. A. Beaver J. Parez D. F. Herring

1967-01-01

183

Calibration of Shielded Net Radiometers  

Microsoft Academic Search

Net radiation is an important term because of its use in water bal- ance and other studies. Faulty data results from net radiometers that are not calibrated properly. Using the total shading method to cali- brate shielded net radiometers (NRs) results in faulty calibration coef- ficients because large negative net radiation is included in the results. The proposed partial shading

Leo J. Fritschen; Charles L. Fritschen

2007-01-01

184

Atomic polarizabilities and shielding factors  

Microsoft Academic Search

A detailed discussion is given of the methods of calculating atomic polarizabilities and shielding factors and the relationships between them are demonstrated. The formulation of the uncoupled Hartree-Fock approximation is presented and it is shown that the methods are all approximate versions of it. A more accurate procedure, the coupled Hartree-Fock approximation, is described. Comprehensive tables of dipole and quadrupole

A. Dalgarno

1962-01-01

185

Decontaminating lead bricks and shielding  

Microsoft Academic Search

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and

Lussiez

1993-01-01

186

Decontaminating lead bricks and shielding  

Microsoft Academic Search

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and

Lussiez

1994-01-01

187

Shielding and grounding in large detectors  

SciTech Connect

Prevention of electromagnetic interference (EMI), or ``noise pickup,`` is an important design aspect in large detectors in accelerator environments. Shielding effectiveness as a function of shield thickness and conductivity vs the type and frequency of the interference field is described. Noise induced in transmission lines by ground loop driven currents in the shield is evaluated and the importance of low shield resistance is emphasized. Some measures for prevention of ground loops and isolation of detector-readout systems are discussed.

Radeka, V.

1998-09-01

188

Stand-off shields for hypervelocity particles  

SciTech Connect

Stand-off hypervelocity particle shields offer potential weight savings of an order of magnitude or more over conventional homogeneous armors. Based on an earlier complete model for the design and optimization of a stand-of shield system, a more restricted model appropriate for retrofit shields is described. Procedures to minimize the shield mass are provided, and scaling laws for many of the important parameter relationships are illustrated. 6 refs., 5 figs.

Lawrence, R.J.

1989-01-01

189

Metallogeny of gold in relation to the evolution of the Nubian Shield in Egypt  

Microsoft Academic Search

Gold mineralization in the Eastern Desert of Egypt is confined, almost completely, to the basement rocks of the Nubian Shield that was cratonized during the Panafrican orogeny.Island-arc, orogenic and post-orogenic stages are indicated for the tectonic-magmatic evolution of the Nubian Shield in Late Proterozoic times. Different styles of gold mineralization recognised in the Eastern Desert are inferred to have developed

Nagy Shawky Botros

2002-01-01

190

MATERIAL REQUIREMENTS FOR SHIELDING AGAINST SPACE RADIATIONS  

Microsoft Academic Search

A brief but general discussion of the material requirements for ; shielding against space radiations is presented. Emphasis is placed on ; describing the salient features of the space radiation attenuation problem in ; order to deduce the materials that will most likely produce minimum-weight ; shields. The shielding characteristics of the materials are described as a ; function of

Zerby

1963-01-01

191

Electromagnetic shielding of high-voltage cables  

NASA Astrophysics Data System (ADS)

The electromagnetic shielding of high-voltage (HV) cables has been studied both by numerical computations and by experiments performed in real-life practical situations. Two shield topologies have been considered, i.e. open- versus closed-shield configurations. The open-shield configuration consists of placing horizontally plates on the ground. The closed-shield configuration consists of a formed cable conduct base in which the HV cable is placed, and on which a cover is mounted. HV cables (150 kV) were studied in both experimental trials. With respect to the considered materials in the experiments, the ferromagnetic hot-rolled low-carbon material Magnetil® is used (ferromagnetic material), and its behaviour is compared to the shielding based on aluminium (conductive non-magnetic material). Briefly, the following average shielding factors (SF) are obtained with open-shield configurations: SF around 2 when using Magnetil®, SF around 4 when using aluminium. In closed-shielding configurations, a much more performant shielding behaviour is experimentally obtained, namely SF around 20 when using Magnetil®, while SF around 8 when using aluminium. The optimum shielding behaviour is thus obtained by a ferromagnetic closed shield.

de Wulf, M.; Wouters, P.; Sergeant, P.; Dupré, L.; Hoferlin, E.; Jacobs, S.; Harlet, P.

2007-09-01

192

Symmetrical Multifoil Shields for reducing Spray Drift  

Microsoft Academic Search

In this study, two symmetrical multi-foil shields were designed to minimise spray drift in both upwind and downwind travel directions. One shield was a symmetrical double foil that induced direct air assist (an air jet acting directly on the spray droplets), while the other shield was a symmetrical triple foil that induced both direct air assist and an air curtain

M. M Sidahmed; H. H Awadalla; M. A Haidar

2004-01-01

193

ITER reactor building design study  

Microsoft Academic Search

The International Thermonuclear Experimental Reactor (ITER) is at the midpoint of a two-year conceptual design. The ITER reactor building is a reinforced concrete structure that houses the tokamak and associated equipment and systems and forms a barrier between the tokamak and the external environment. It provides radiation shielding and controls the release of radioactive materials to the environment during both

S. L. Thomson; J. D. Blevins; M. W. Delisle

1989-01-01

194

Analysis of Decision Conferences (DC): The Impact of the Group's Cognitive Pressures in Problem Recognition Stage on Their Problem Formulation (Model Building)....  

National Technical Information Service (NTIS)

The main purpose of this research was to determine whether or not, and how the degree of cognitive pressure in problem recognition stage can affect the groups decision-making processes. The empirical basis for the study consists of records of groups' prob...

K. J. Chun L. D. Phillips P. C. Humphreys

1989-01-01

195

Active magnetic compensation composed of shielding panels.  

PubMed

Magnetically shielded rooms (MSRs) with materials of high permeability and active shield systems have been used to shield magnetic noise for biomagnetic measurements up to now. However, these techniques have various disadvantages. Therefore, we have developed a new shielding system composed of shielding panels using an active compensation technique. In this study, we evaluated the shielding performance of several unit panels attached together. Numerical and experimental approaches indicated that the shielding factor of a cubic model composed of 24 panels was 17 for uniform fields, and 7 for disturbances due to car movement. Furthermore, the compensation space is larger than that of an ordinary active system using large coils rather than panels. Moreover, the new active compensation system has the important advantage that panels of any shape can be assembled for occasional use because the unit panels are small and light. PMID:16012696

Kato, K; Yamazaki, K; Sato, T; Haga, A; Okitsu, T; Muramatsu, K; Ueda, T; Kobayashi, K; Yoshizawa, M

2004-11-30

196

Stage Model for Knowledge Management  

Microsoft Academic Search

This study develops an integrated management framework for building organizational capabilities of knowledge management (KM). The framework consists of four major management objects: organizational knowledge, knowledge worker, knowledge management process, and information technology. Based on the framework, this study proposes a stage model of organizational knowledge management encompassing Initiation, Propagation, Integration, and Networking stages. Each of the four stages is

Jang-hwan Lee; Young-gul Kim; Sung-ho Yu

2001-01-01

197

Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors  

SciTech Connect

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

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

2011-09-21

198

Shielding calculations for Inshas cyclotron  

NASA Astrophysics Data System (ADS)

Methods used in shielding calculations for the cyclotron vault and experimental rooms of Egypt's first cyclotron laboratory to be erected at the premises of the Nuclear Research Center, Atomic Energy Authority (Inshas) are discussed. Use is made of the removal diffusion theory and of the techniques presented in NCRP-51, Wall and ceiling dimensions are estimated based on radiation protection norms given in the ICRP-60 as issued in 1991.

Comsan, M. N. H.

1996-05-01

199

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; Rashid, A. B. M. Harun

2013-09-01

200

Heat pipe thermionic reactor shield optimization studies  

NASA Astrophysics Data System (ADS)

Shield optimization studies were conducted for a thermionic reactor, that uses heat pipes for both reactor heat removal and radiator. The radiator was placed on the opposite side of the payload to more efficiency reject the heat without affecting the LiH shadow shield. Neutron scattering off the radiator was an important consideration. The shield that was added to reduce the neutron scattering by itself became a source for scattering. By proper shield material selection, the radiator and radiator shield scattering contribution was reduced. A direct shield material selection trade study was performed, and tungsten was selected for the gamma ray shield. The direct shield mass was then optimized with respect to separation distance, using both the mass of the boom and electrical cables. A very important conclusion was that the optimum system mass depends on the boom structural criteria that is used. At a separation distance of 5 m the shield mass was calculated to be 1,445 kg. At 10 m, the shield mass drops to 700 kg; however, the additional electrical cable mass was 73 kg and the additional boom mass was 335 kg (or 67 kg/m) for a total mass of 1,108 kg. The boom minimum resonant structural frequency was 10 Hz.

Keshishan, Vahé; Dix, Terry E.

1992-01-01

201

Heat-shield design for glovebox applications.  

SciTech Connect

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

Frigo, A. A.

1998-07-10

202

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

203

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

204

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

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

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

205

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

206

A&M. Shielded locomotive (TAN807). Parked and inactive on track west ...  

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

A&M. Shielded locomotive (TAN-807). Parked and inactive on track west of A&M building. Camera facing northeast. Date: March 2004. INEEL negative no. HD-39-10-1 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

207

Thermal shield bowing in long superconducting magnets  

SciTech Connect

One of the interesting problems associated with building long magnets for the SSC (Superconducting Super Collider) is predicting and controlling the dynamic response of the cryostat tubes during cooldown. Thermal bowing occurs in any of these tubes that are asymmetric in shape or which are not cooled uniformly. Understanding the bowing behavior is important for two reasons. First, one needs to know the magnitude of the induced displacements so that potential interferences in the entire magnet assembly can be located. Second, the bowing phenomenon introduces structural loads on the supports which need to be folded into the design of those supports. It is desirable, due to cost and time constraints, to develop an analytical model which accurately predicts loads and displacements rather than relying on a physical model of each candidate cryostat tube design. This report describes a procedure and an analytical model to predict this dynamic behavior on the thermal radiation shield for Fermilab's proposed SSC magnet design. The results are compared with test data obtained on a physical model fabricated and tested in an effort to verify the analytical approach.

Nicol, T.H.; Roman, M.; Fulton, S.

1985-09-01

208

VAPOR SHIELD FOR INDUCTION FURNACE  

DOEpatents

This patent relates to a water-cooled vapor shield for an inductlon furnace that will condense metallic vapors arising from the crucible and thus prevent their condensation on or near the induction coils, thereby eliminating possible corrosion or shorting out of the coils. This is accomplished by placing, about the top, of the crucible a disk, apron, and cooling jacket that separates the area of the coils from the interior of the cruclbIe and provides a cooled surface upon whlch the vapors may condense.

Reese, S.L.; Samoriga, S.A.

1958-03-11

209

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.

210

Shielding for thermoacoustic tomography with RF excitation  

NASA Astrophysics Data System (ADS)

Radiofrequency (RF) pulses used to generate thermoacoustic computerized tomography (TCT) signal couple directly into the pulser-receiver and oscilloscope, swamping true TCT signal. We use a standard RF enclosure housing both RF amplifier and object being imaged. This is similar to RF shielding of magnetic resonance imaging (MRI) suites and protects electronics outside from stray RF. Unlike MRI, TCT receivers are ultrasound transducers, which must also be shielded from RF. A transducer housing that simultaneously shields RF and permits acoustic transmission was developed specifically for TCT. We compare TCT signals measured with and without RF shielding.

Mitchell, M.; Becker, G.; Dey, P.; Generotzky, J.; Patch, S. K.

2008-03-01

211

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

212

Accelerator magnet designs using superconducting magnetic shields  

SciTech Connect

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

Brown, B.C.

1990-10-01

213

Preliminary design study of solar probe heat shields  

NASA Astrophysics Data System (ADS)

The requirements, constraints, design guidelines, and expected performances of heat-shield systems for a solar probe are analyzed. A multiple-stage, asymmetric, right-angle radiation cascade configuration is used as the basis for comparison. Output-to-input radiative flux ratios are first calculated for a system employing gray surfaces. Assuming that the temperature of the inner surface of the payload bus is allowed to reach 400 K, it is shown that four- and five-stage cascade systems employing graphite can approach, respectively, to within about 5.5 and 4 solar radii of the sun. The systems using slip-cast silica and tungsten are then analyzed accounting for the degradation of surface-optical performance caused by the solar wind. It is shown that two- and three-stage silica-tungsten systems can approach, respectively, to within 4 and 3 solar radii of the sun.

Park, C.

1981-01-01

214

Simulation analysis for the materials shielding effectiveness of EMP  

Microsoft Academic Search

The theory of shielding is introduced, and the simulation model is built. The software based on the CST is applied to simulate and analyze the pulse waveform. The shielding effectiveness of different pulse width is computed. Comparing the pulse shielding effectiveness with continuous wave shielding effectiveness, there is consistent result approximately. And the shielding effectiveness based on the frequency function

Long Zhang; Xiaofeng Hu; Xinfu Lu; Genchun Zhu; Yongqiang Zhang

2011-01-01

215

Magnetic Shielded Enclosure Design in the DC and VLF Region  

Microsoft Academic Search

A review of magnetic, shielding concepts and equations as applied to ideal shield configurations has provided a basis for the analysis of the shielding effectiveness of practical shielded enclosures to dc and VLF magnetic fields. The permeability of the shield material is considered as a function of the induction, and a significantly improved method of estimating the induction and permeability

Alan Thomas; ALFRED ECKERSLEY

1968-01-01

216

Decontaminating lead bricks and shielding  

SciTech Connect

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

Lussiez, G.W.

1993-05-01

217

Decontaminating lead bricks and shielding  

SciTech Connect

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

Lussiez, G.

1994-02-01

218

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

Microsoft Academic Search

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

David P. Conover; Senior Mine Engineer

219

Coffer dam for temporary shielding of reactor vessel internals  

SciTech Connect

This patent describes a method for shielding stored internals' radiation in preparation for annealing a reactor vessel in a containment building. It comprises removing nuclear fuel from the reactor vessel; removing and storing upper and lower core internal underwater in a refueling canal; introducing segments individually through a hatch in the containment building; connecting the segments to each other in sealing relation with sealing means between the segments to form a coffer dam; fixedly connecting the coffer dam to an upper flange of the reactor vessel in sealing relation; placing an annealing apparatus in the reactor vessel; pumping water form the reactor vessel and coffer dam; annealing; filling the reactor vessel with water; removing the annealing apparatus.

Bauer, F.I.; Mavretish, R.S.; Grimm, N.P.

1991-08-06

220

Neutron shielding studies of the RTBT line at the SNS  

NASA Astrophysics Data System (ADS)

The SNS is an accelerator based neutron source in Oak Ridge, Tennessee. This unique facility provides the most intense pulsed neutron beams in the world, which are produced by bombarding a mercury target with energetic protons from a large accelerator complex. A high intense pulsed proton beam traveling through the RTBT (Ring to Target Beam Transport) line produces a high neutron background outside the target building. Detailed analysis of this background must clearly be understood for a potential neutrino detector that may be built outside the target building. We present here preliminary results of the neutron background using the most recent Monte Carlo particle transport codes FLUKA and MCNP. These results can be used as a reference for the neutron shielding studies.

Ranawaka, Thiloshana; Empl, Anton; Hungerford, Ed

2010-03-01

221

Nuclear data relevant to shield design of FMIT facility  

SciTech Connect

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

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

1980-04-01

222

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

223

EMP coupling to coaxial shielded cables  

Microsoft Academic Search

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

M. D'Amore; M. Feliziani

1988-01-01

224

Project Desert Shield-Preschool Style.  

ERIC Educational Resources Information Center

Describes Project Desert Shield, a curriculum that preschool children and teachers at a U.S. military base in Germany developed to embrace and constructively deal with the interests and concerns of the children about Operation Desert Shield/Desert Storm through dramatic play. (Author/BB)

Suskind, Diane

1993-01-01

225

Shielding effectiveness of superconductive particles in plastics  

SciTech Connect

The ability to cool superconductors with liquid nitrogen instead of liquid helium has opened the door to a wide range of research. The well known Meissner effect, which states superconductors are perfectly diamagnetic, suggests shielding applications. One of the drawbacks to the new ceramic superconductors is the brittleness of the finished material. Because of this drawback, any application which required flexibility (e.g., wire and cable) would be impractical. Therefore, this paper presents the results of a preliminary investigation into the shielding effectiveness of YBa/sub 2/Cu/sub 3/O/sub 7-x/ both as a composite and as a monolithic material. Shielding effectiveness was measured using two separate test methods. One tested the magnetic (near field) shielding, and the other tested the electromagnetic (far field) shielding. No shielding was seen in the near field measurements on the composite samples, and only one heavily loaded sample showed some shielding in the far field. The monolithic samples showed a large amount of magnetic shielding. 5 refs., 5 figs.

Pienkowski, T.; Kincaid, J.; Lanagan, M.T.; Poeppel, R.B.; Dusek, J.T.; Shi, D.; Goretta, K.C.

1988-09-01

226

US Missile Shield Plan Heightens European Insecurities  

Microsoft Academic Search

European Missile Shield The US Missile Defence Agency (MDA) – without recourse to NATO – is engaged in bilateral negotiations with Poland and the Czech Republic to site missile-shield silos and X-Band radar facilities in central Europe. The US intends to site 10 long-range interceptor missiles at one weapon silo - approximately the size of a football pitch - in

Tom Clonan

2008-01-01

227

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2010 CFR

...10 Energy 1 2009-01-01 2009-01-01 false Shielding. 36.25 Section 36.25 Energy NUCLEAR REGULATORY...Design and Performance Requirements for Irradiators § 36.25 Shielding. (a) The radiation dose rate in areas that...

2009-01-01

228

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2010 CFR

...10 Energy 1 2010-01-01 2010-01-01 false Shielding. 36.25 Section 36.25 Energy NUCLEAR REGULATORY...Design and Performance Requirements for Irradiators § 36.25 Shielding. (a) The radiation dose rate in areas that...

2010-01-01

229

10 CFR 36.25 - Shielding.  

Code of Federal Regulations, 2013 CFR

...10 Energy 1 2013-01-01 2013-01-01 false Shielding. 36.25 Section 36.25 Energy NUCLEAR REGULATORY...Design and Performance Requirements for Irradiators § 36.25 Shielding. (a) The radiation dose rate in areas that...

2013-01-01

230

CASTABLE MATERIALS FOR NEUTRON SHIELDS. PART 2  

Microsoft Academic Search

The development of elastomeric materials for neutron shields is ; discussed. Numerous liquid natural, butyl, and polybutadiene rubbers, together ; with a specially synthesized boron modified, acrylic acid terpolymer were ; evaluated to determine their curing characteristics and properties pertaintng to ; neutron shields. It was determined that a polybutene extended butyl rubber ; filled with polyethylene and vulcanized using

W. M. Veroeven; J. W. McGarvey

1962-01-01

231

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

232

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

Microsoft Academic Search

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

David Bristow; Christopher A. Kennedy

2010-01-01

233

Cross-Dipole Bandpass Frequency Selective Surface for Energy-Saving Glass Used in Buildings  

Microsoft Academic Search

Energy-saving glass is becoming very popular in building design due to their effective shielding of building interior against heat entering the building with infrared (IR) waves. This is obtained by depositing a thin layer of metallic-oxide on the glass surface using special sputtering processes. This layer attenuates IR waves and hence keeps buildings cooler in summer and warmer in winter.

Ghaffer I. Kiani; Lars G. Olsson; Anders Karlsson; Karu P. Esselle; Martin Nilsson

2011-01-01

234

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

235

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

236

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

237

Shielding measurements for 230-Mev protons  

SciTech Connect

Energetic neutrons, produced as protons interact with matter, dominate the radiation shielding environment for proton accelerators. Because of the scarcity of data describing the shielding required to protect personnel from these neutrons, absorbed dose and dose-equivalent values are measured as a function of depth in a thick concrete shield at neutron emission angles of 0, 22, 45, and 90 deg for 230-MeV protons incident upon stopping-length aluminum, iron, and lead targets. Neutron attenuation lengths vary sharply with angle but are independent of the target material. Comparing results with prior shielding calculations, the High-Energy Transport Code overestimates neutron production and attenuation lengths in the forward direction. Analytical methods compare favorably in the forward direction but overestimate the production and attenuation lengths at large angles. The results presented are useful for determining the shielding requirements for proton radiotherapy facilities and as a benchmark for future calculations.

Siebers, J.V.; DeLuca, P.M. Jr.; Pearson, D.W. (Univ. of Wisconsin, Madison (United States). Dept. of Medical Physics); Coutrakon, G. (Loma Linda Univ., CA (United States). Medical Center)

1993-09-01

238

Practical radiation shielding for biomedical research  

SciTech Connect

This paper reports on calculations which exist for estimating shielding required for radioactivity; however, they are often not applicable for the radionuclides and activities common in biomedical research. A variety of commercially available Lucite shields are being marketed to the biomedical community. Their advertisements may lead laboratory workers to expect better radiation protection than these shields can provide or to assume erroneously that very weak beta emitters require extensive shielding. The authors have conducted a series of shielding experiments designed to simulate exposures from the amounts of {sup 32}P, {sup 51}Cr and {sup 125}I typically used in biomedical laboratories. For most routine work, {ge}0.64 cm of Lucite covered with various thicknesses of lead will reduce whole-body occupational exposure rates of {lt} 1mR/hr at the point of contact.

Klein, R.C.; Reginatto, M.; Party, E.; Gershey, E.L. (Rockefeller Univ., New York, NY (United States))

1990-06-01

239

ISABELLE shielding criteria and design.  

PubMed

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

Gollon, P J; Casey, W R

1984-01-01

240

Background simulations and shielding calculations  

SciTech Connect

Key improvements in the sensitivity of the underground particle astrophysics experiments can only be achieved if the radiation causing background events in detectors is well understood and proper measures are taken to suppress it. The background radiation arising from radioactivity and cosmic-ray muons is discussed here together with the methods of its suppression. Different shielding designs are considered to attenuate gamma-rays and neutrons coming from radioactivity in rock and lab walls. Purity of materials used in detector construction is analysed and the background event rates due to the presence of radioactive isotopes in detector components are discussed. Event rates in detectors caused by muon-induced neutrons with and without active veto systems are presented leading to the requirements for the depth of an underground laboratory and the efficiency of the veto system.

Kudryavtsev, Vitaly A. [Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH (United Kingdom)

2011-04-27

241

Subglacial to Emergent Volcanism at Shield Nunatak, Mt. Melbourne Volcanic Field, Antarctica  

Microsoft Academic Search

Summary: Sections through Shield Nunatak vo1cano, an alkali basaltic subglacial table-mountain from the Mt. Melbourne Volcanic Field, are descrlbed. Resting on a base of older lava flows and a fossile tillite iayer, the volcano is formed mainly by massive ash and lapilli (mass flow) deposits while pillow lavas are absent. The recurrent stage of emergence from subglacial to subaerial conditions

G. Wörner; L. Viereck

242

Collaborative Stage  

Cancer.gov

Required SEER Site-Specific Factors for Collaborative Stage - This tool highlights the site-specific factors (SSF) required for staging, obsolete SSF’s, clinically significant SSFs, as well as those not required.

243

Stage design  

DOEpatents

A method is described of cycling gases through a plurality of diffusion stages comprising the steps of admitting the diffused gases from a first diffusion stage into an axial compressor, simultaneously admitting the undiffused gases from a second diffusion stage into an intermediate pressure zone of said compressor corresponding in pressure to the pressure of said undiffused gases, and then admitting the resulting compressed mixture of diffused and undiffused gases into a third diffusion stage.

Shacter, J.

1975-12-01

244

Störmer theory applied to magnetic spacecraft shielding  

NASA Astrophysics Data System (ADS)

The existence of a toroidal region from which charged particles are excluded was demonstrated by Störmer (1955) for a dipole magnetic field geometry. Using a standard numerical code to trace the trajectories of particles in a magnetic field, we find excellent agreement with the predicted region for a variety of particle energies and masses. The ability of magnetic fields to shield certain regions from energetic particles, such as galactic cosmic rays (GCRs), has led to the suggestion that certain magnetic field configurations could be used to shield the occupants of a spacecraft from the harmful effects of GCRs during interplanetary space travel. In particular, systems involving a deployed superconducting coil of wire that extends well beyond the dimensions of the spacecraft have been proposed as a viable solution to shielding GCRs. The correct use of the analysis by Störmer (1955) requires that the radius of such a coil be much smaller than the dimension of the region being shielded. Alternatively, it is shown that the energy of the particles shielded from a given region decreases as the radius of a coil with a constant magnetic moment increases. The reality is that large magnetic fields, and thus currents, are necessary to adequately shield GCRs, neither of which are provided by deployed magnetic shields.

Shepherd, S. G.; Kress, B. T.

2007-04-01

245

Determination of shielding requirements for mammography.  

PubMed

Shielding requirements for mammography when considerations are to be given to attenuation by compression paddle, breast tissue, grid and image receptor (intervening materials) has been investigated. By matching of the attenuation and hardening properties, comparisons are made between shielding afforded by breast tissue materials (water, Lucite and 50%-50% adipose-glandular tissue) and some materials considered for shielding diagnostic x-ray beams, namely lead, steel and gypsum wallboard. Results show that significant differences exist between the thickness required to produce equal attenuation and that required to produce equal hardening of a given incident beam. While attenuation equivalent thickness produces equal exposure, it does not produce equal hardening. For shielding purposes, equivalence in exposure reduction without equivalence in penetrating power of an emerging beam does not amount to equivalence in shielding affordable by two different materials. Presented are models and results of sample calculations of additional shielding requirements apart from that provided by intervening materials. The shielding requirements for the integrated beam emerging from intervening materials are different from those for the integrated beam emerging from materials (lead/steel/gypsum wallboard) with attenuation equivalent thicknesses of these intervening materials. PMID:15191311

Okunade, Akintunde Akangbe; Ademoroti, Olalekan Albert

2004-05-01

246

Integral law modeling of magnetic shields  

NASA Astrophysics Data System (ADS)

A computational tool for designing magnetic field shields is described. The tool handles electrically conducting and magnetically permeable rectangular shields. Multiple rectangular shield sub-units with orientations parallel to the three coordinate planes may be simply joined to form more complex shields. The shield geometry is discretized into rectangular elements and a current distribution is assumed for each. A system of equations consisting of the integral forms of Faraday's Law and conservation of current for electrically conducting materials, and magnetic field boundary equations at nodal points for magnetically permeable materials is built. The system of equations is simultaneously solved for values of free volume currents and magnetization surface currents at discretization points on the shield geometry. These values-taken with the assumed distribution of currents-are used to compute fields which are superimposed with the source fields at any point in space to predict the altered field levels. Results are compared with Ansoft Corporation's finite element 2D and 3D solvers, other shielding formulations, and experimentally measured data.

Gerrans, Neil Thomas

247

Integrated shielding systems for manned interplanetary spaceflight  

NASA Astrophysics Data System (ADS)

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

George, Jeffrey A.

1992-01-01

248

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

2012-08-29

249

Low background shielding of HPGe detector.  

PubMed

National Radiation Protection Institute in Prague is equipped with 14 HPGe detectors with relative efficiency up to 150%. Steel shielding with one of these detectors (relative efficiency 100%) was chosen to be rebuilt to decrease minimum detectable activity (MDA). Additional lead and copper shielding was built up inside the original steel shielding to reduce the volume of the inner space and filled with nitrogen by means of evaporating liquid nitrogen. MDA values decreased for Compton background up to 0.67 of original value. PMID:19243960

Trnková, L; Rulík, P

2009-01-29

250

Planetary surface reactor shielding using indigenous materials  

SciTech Connect

The exploration and development of Mars will require abundant surface power. Nuclear reactors are a low-cost, low-mass means of providing that power. A significant fraction of the nuclear power system mass is radiation shielding necessary for protecting humans and/or equipment from radiation emitted by the reactor. For planetary surface missions, it may be desirable to provide some or all of the required shielding from indigenous materials. This paper examines shielding options that utilize either purely indigenous materials or a combination of indigenous and nonindigenous materials.

Houts, Michael G.; Poston, David I.; Trellue, Holly R. [Nuclear Systems Design and Analysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Baca, Justin A.; Lipinski, Ronald J. [Nuclear Technology and Research, Sandia National Laboratories, Albuquerque, New Mexico 87185-1146 (United States)

1999-01-22

251

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

252

REPOSITORY RADIATION SHIELDING DESIGN GUIDE  

SciTech Connect

The scope of this document includes radiation safety considerations used in the design of facilities for the Yucca Mountain Site Characterization Project (YMP). The purpose of the Repository Radiation Shielding Design Guide is to document the approach used in the radiological design of the Mined Geologic Disposal System (MGDS) surface and subsurface facilities for the protection of workers, the public, and the environment. This document is intended to ensure that a common methodology is used by all groups that may be involved with Radiological Design. This document will also assist in ensuring the long term survivability of the information basis used for radiological safety design and will assist in satisfying the documentation requirements of the licensing body, the Nuclear Regulatory Commission (NRC). This design guide provides referenceable information that is current and maintained under the YMP Quality Assurance (QA) Program. Furthermore, this approach is consistent with maintaining continuity in spite of a changing design environment. This approach also serves to ensure common inter-disciplinary interpretation and application of data.

M. Haas; E.M. Fortsch

1997-09-12

253

NMR Shielding and the Periodic Table  

NASA Astrophysics Data System (ADS)

The object of this article is to find periodic, structurally significant observables that can be correlated to the nuclear shielding or alternatively to investigate whether chemical shift can be used to intensify the periodic disposition of valence electrons.

Gerothanassis, I. P.; Kalodimos, C. G.

1996-08-01

254

NMR Shielding and the Periodic Table  

Microsoft Academic Search

The object of this article is to find periodic, structurally significant observables that can be correlated to the nuclear shielding or alternatively to investigate whether chemical shift can be used to intensify the periodic disposition of valence electrons.

I. P. Gerothanassis; C. G. Kalodimos

1996-01-01

255

SP-100 low mass shield design  

SciTech Connect

The shielding considerations for an unmanned space reactor system are somewhat different from those for a terrestrial reactor. An unmanned operation in space implies that only a shadow shield, rather than a 4..pi.. one, is required to protect payload hardware that typically can tolerate 10/sup 4/ to 10/sup 6/ times more radiation than can a human crew. On the other hand, the system mass, of which the radiation shield can be a significant fraction, is a severe constraint for space reactors and not normally a problem with terrestrial ones. The object of this paper is to briefly summarize advancements made on various aspects of low mass shield design for space reactors, including materials and their arrangements, geometric factors and their potential impact on system design optimization, and proposed new configuration concepts for further mass reduction.

Carlson, D.E.

1985-01-01

256

Charge, a Space Radiation Shielding Code.  

National Technical Information Service (NTIS)

The report describes CHARGE, a FORTRAN program for the analysis of primary proton and electron passage through plane or spherical shields containing up to 100 regions, and the attendant generation and transmission of electron-induced X-rays (bremsstrahlun...

J. R. Lilley W. R. Yucker

1965-01-01

257

Shielding and Grounding Topology for Interference Control.  

National Technical Information Service (NTIS)

The topological approach to shielding and grounding is a rational and systematic method of providing the high degree of isolation required between external conductors exposed to lightning or other harsh environments and small-signal circuits susceptible t...

E. F. Vance

1977-01-01

258

Printed Wiring Board for Shielding Electromagnetic Waves.  

National Technical Information Service (NTIS)

Recently, undesired radiation of electromagnetic waves from electronic devices has become a serious problem as the signal speed is increased. For the conventional measures, circuit pattern design, selection of components, shielding, grounding and wiring h...

H. Haniu S. Kubota T. Takatsuji H. Higuchi M. Takamatsu

1989-01-01

259

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

260

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

261

The Clinical Testing of Male Gonad Shields.  

National Technical Information Service (NTIS)

Two types of male gonad shields, designed for use with support garments, were tested in a number of hospitals and clinics throughout the United States. The clinical evaluation consisted of: (1) Measuring dose reduction with thermoluminescent dosimeters; a...

W. W. Church B. M. Burnett

1975-01-01

262

Low Cost Fabrication of Ablative Heat Shields.  

National Technical Information Service (NTIS)

A material and process study was performed using subscale panels in an attempt to reduce the cost of fabricating ablative heat shield panels. Although no improvements were made in the material formulation, a significant improvement was obtained in the pro...

A. M. Cecka W. C. Schofield

1972-01-01

263

Experimental results of neutron fluence outside an iron shield in the forward direction  

SciTech Connect

Analyses of both lateral shielding measurements and Monte Carlo calculations for beam stop geometry for incident hadrons at energies between 10 GeV and 10 TeV suggests that the dose equivalent can be represented by the expression H = H{sub 0}(E)e{sup -r/{lambda}}/r{sup 2} where H, is the source term, r is the radial distance to the point of interest in the shield, and {lambda} is the effective interaction length, or absorption mean free path. However, unlike the lateral shielding case, there is no similarly simple analytical expression that can be used to describe the on-axis longitudinal cascade development. In this study the results from the measurement in the forward direction of neutron fluence spectra (and the derived quantity dose equivalent) for 25 to 150 GeV pions incident on an iron beam stop as a function of thickness of iron are presented. The observed dependence of both fluence and dose equivalent on shield thickness and hadron energy was then quantified in terms of an expression in which a build up factor as well as an attenuation term was included. On the basis of this analysis the conversion factor from fluence to dose equivalent was also determined for these forward going neutrons. This work represents the first systematic study at an high energy accelerator of the depth dependence of neutron fluence in longitudinal shielding.

Torres, M.M.C. [Argonne National Lab., IL (United States); Elwyn, A.J. [Fermi National Accelerator Lab., Batavia, IL (United States); Fein, D.; James, E.; Johns, K. [Arizona Univ., Tucson, AZ (United States); Davis, W. [Ball State Univ., Muncie, IN (United States); Ciampa, D.P. [Minnesota Univ., Minneapolis, MN (United States); Mierkiewicz, E. [Northern Illinois Univ., De Kalb, IL (United States)

1996-09-01

264

Propagation of broadcast signals into buildings at 762 MHz  

Microsoft Academic Search

The paper describes measurements of indoor reception of a 7 MHz OFDM signal transmitted at a center frequency of 762 MHz. The channel impulse response and the selectivity characteristics in the frequency domain and the spatial domain are measured. Furthermore, an indication is given of the effect of building attenuation. Building penetration loss is due to attenuation or shielding of

P. de Bot; A. Wijlaars; H. Vermeer; H. Kollenbrander

1994-01-01

265

CDF forward shielding for Run II  

SciTech Connect

Detailed calculations of the accelerator related background in the CDF forward muon spectrometer have been performed with the MARS13 code and a newly developed C++ code for particle tracking in accelerator lattices. Calculated space distributions of background hits are in a good agreement with data taken in Run I. Several shielding configurations in the CDF hall and Tevatron tunnel have been studied. The optimal one provides a 30-fold shielding efficiency compatible with CDF Run II requirements.

Krivosheev, O.E.; Mokhov, N.V.

1998-03-16

266

Earth pressure balance control for EPB shield  

Microsoft Academic Search

This paper mainly deals with the critical technology of earth pressure balance (EPB) control in shield tunneling. On the assumption\\u000a that the conditioned soil in the working chamber of the shield is plasticized, a theoretical principle for EPB control is\\u000a proposed. Dynamic equilibrium of intake volume and discharge volume generated by thrust and discharge is modeled theoretically\\u000a to simulate the

HuaYong Yang; Hu Shi; GuoFang Gong; GuoLiang Hu

2009-01-01

267

Subsea wellhead shielding and shock mitigating system  

Microsoft Academic Search

An apparatus is described for shielding subsea well-heads from shock loads due to accidental impact due to the landing of retrieval gear. The apparatus shields the well-head from vertical impact loads by means of a generally conical outer structure and utilizes a shock-absorbing material between a portion of the outer structure and the wellhead to minimize lateral impact loads. The

G. B. Forbes; R. W. Van Houten

1976-01-01

268

Effectiveness of IC shielded packages against space radiation  

Microsoft Academic Search

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

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

1997-01-01

269

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

270

Advancements in FBR shielding - Ten years in Japan  

SciTech Connect

Research and development in the area of fast breeder reactor (FBR) shielding in Japan was fully under way in April 1987 when criticality of the JOYO experimental FBR was first attained. The main activities performed and results obtained during more than 10 yr of FBR shielding research are presented. The paper describes shielding research in Joyo; Monju shielding design and related research; research activities for future FBRs; and evaluation of Monju shielding designs.

Ohtani, Nobuo; Suzuki, Soju

1990-01-01

271

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

272

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

Microsoft Academic Search

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

X. Li; D. Xie; J. Wang

2007-01-01

273

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

274

Analytical shielding calculations for a proton therapy facility.  

PubMed

The University of Pennsylvania is building a proton therapy facility in collaboration with Walter Reed Army Medical Center. The proposed facility has four gantry rooms, a fixed beam room and a research room, and will use a cyclotron as the source of protons. In this study, neutron shielding considerations for the proposed proton therapy facility were investigated using analytical techniques and Monte Carlo simulated neutron spectra. Neutron spectra calculations were done using the GEANT4 (v6.2) simulation code for various materials: water, carbon, iron, nickel and tantalum to estimate the neutron production at proton beam energies of 100, 175 and 250 MeV. Dose equivalent calculations were performed using analytical methods at various critical points within the facility, by folding the GEANT4 produced neutron spectra with dose equivalent rate data from the National Council on Radiation Protection and Measurements (NCRP) Report #144. PMID:18487617

Avery, Stephen; Ainsley, Chris; Maughan, Richard; McDonough, James

2008-05-16

275

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

276

Correlation between shielding effectiveness measurements and alternative methods for the characterization of shielding materials  

Microsoft Academic Search

The correlation between different methods for the characterization of shielding materials is discussed. It is found that a good agreement is obtained using basic methods, such as a four-point resistance measurement, or standard shielding effectiveness methods and using other methods allowing a quick control in the field during injection moulding process

J. A. Catrysse; M. de Goeije; W. Steenbakkers; L. Anaf

1993-01-01

277

LPT. Shield test facility (TAN645 and 646). Calibration lab shield ...  

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

LPT. Shield test facility (TAN-645 and -646). Calibration lab shield door. Ralph M. Parsons 1229-17 ANP/GE-6-645-MS-1. April 1957. Approved by INEEL Classification Office for public release. INEEL index code no. 037-0645-40-693-107369 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

278

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

279

Recycled oceanic crust in the Hawaiian Plume: evidence from temporal geochemical variations within the Koolau Shield  

NASA Astrophysics Data System (ADS)

The subaerial surface of Koolau volcano is composed of lavas that define the distinctive endmember composition for Hawaiian shield lavas, known as the Koolau component, now designated as the Makapuu-stage. The geochemical characteristics of lavas recovered by the Koolau Scientific Drilling Project (KSDP) show that this distinctive composition forms a <300-m thick veneer. Below this veneer, from ~300m to 470 m below sea level, Koolau shield lavas transition to a composition similar to Mauna Loa lavas, now designated as the Kalihi-stage. This transition was gradual, occurring over >80 ka; therefore it was not caused by an abrupt event, such as a landslide. Among all Koolau shield lavas, there are correlations between radiogenic isotopic ratios of Sr, Nd and Pb and compositional characteristics, such as SiO2 content (adjusted to be in equilibrium with Fo90 olivine), Sr/Nb, La/Nb and Th/La. These long-term compositional and isotopic trends show that as the shield aged, there was an increasing role for an ancient recycled marine sediment component (<3% of the source) accompanied by up to 20% SiO2-rich dacitic melt. This melt was generated by partial melting of garnet pyroxenite, probably kilometers in size, that formed from recycled basaltic oceanic crust. In detail, time series analyses of depth profiles of Al2O3/CaO, Sr/Nb, La/Nb and Th/La in the KSDP drill core show correlations among these ratios indicating that recycled oceanic crust contributed episodically, ~29 ka period, to the magma source during the prolonged transition from Kalihi- to Makapuu-stage lava compositions. The long-term geochemical trends show that recycled oceanic crust was increasingly important as the Koolau shield moved away from the plume and encountered lower temperature.

Huang, Shichun; Frey, Frederick A.

2005-07-01

280

Hydrogen Induced Cracking of Drip Shield  

SciTech Connect

One potential failure mechanism for titanium and its alloys under repository conditions is via the absorption of atomic hydrogen in the metal crystal lattice. The resulting decreased ductility and fracture toughness may lead to brittle mechanical fracture called hydrogen-induced cracking (HIC) or hydrogen embrittlement. For the current design of the engineered barrier without backfill, HIC may be a problem since the titanium drip shield can be galvanically coupled to rock bolts (or wire mesh), which may fall onto the drip shield, thereby creating conditions for hydrogen production by electrochemical reaction. The purpose of this scientific analysis and modeling activity is to evaluate whether the drip shield will fail by HIC or not under repository conditions within 10,000 years of emplacement. This Analysis and Model Report (AMR) addresses features, events, and processes related to hydrogen induced cracking of the drip shield. REV 00 of this AMR served as a feed to ''Waste Package Degradation Process Model Report'' and was developed in accordance with the activity section ''Hydrogen Induced Cracking of Drip Shield'' of the development plan entitled ''Analysis and Model Reports to Support Waste Package PMR'' (CRWMS M&O 1999a). This AMR, prepared according to ''Technical Work Plan for: Waste Package Materials Data Analyses and Modeling'' (BSC 2002), is to feed the License Application.

G. De

2003-02-24

281

Large shield volcanoes on the Moon  

NASA Astrophysics Data System (ADS)

volcanic style of the Moon has long been understood to consist almost exclusively of flood basalts erupted from fissures along with minor pyroclastic activity; large central vent shield volcanoes that characterize basaltic volcanism on the other terrestrial planets appeared to be absent. Small (few kilometers diameter) central vent constructs have long been recognized in the lunar maria and often are found clustered in fields throughout the lunar maria. New global topographic data from the LOLA and LROC instruments on LRO reveal that almost all of these volcanic complexes on the Moon occur on large, regional topographic rises in the lunar maria, tens to hundreds of kilometers in extent and between several hundred to several thousand meters high. We propose that these topographic swells are shield volcanoes and are the lunar equivalents of the large basaltic shields found on the Earth, Venus, and Mars. The newly recognized lunar shields are found peripheral to the large, deeply flooded impact basins Imbrium and Serenitatis, suggesting a genetic relation to those features. Loading of the lithosphere by these basalt-filled basins may be responsible for inducing a combination of flexural and membrane stress, inducing a pressure distribution on vertically oriented dikes favorable to magma ascent. This condition would occur in a zone annular to the large circular loads produced by the basins, where the shield volcanoes occur.

Spudis, Paul D.; McGovern, Patrick J.; Kiefer, Walter S.

2013-05-01

282

MEANS FOR SHIELDING AND COOLING REACTORS  

DOEpatents

Reactors of the water-cooled type and a means for shielding such a rcactor to protect operating personnel from harmful radiation are discussed. In this reactor coolant tubes which contain the fissionable material extend vertically through a mass of moderator. Liquid coolant enters through the bottom of the coolant tubes and passes upwardly over the fissionable material. A shield tank is disposed over the top of the reactor and communicates through its bottom with the upper end of the coolant tubes. A hydrocarbon shielding fluid floats on the coolant within the shield tank. With this arrangements the upper face of the reactor can be opened to the atmosphere through the two superimposed liquid layers. A principal feature of the invention is that in the event radioactive fission products enter thc coolant stream. imposed layer of hydrocarbon reduces the intense radioactivity introduced into the layer over the reactors and permits removal of the offending fuel material by personnel shielded by the uncontaminated hydrocarbon layer.

Wigner, E.P.; Ohlinger, L.A.; Young, G.J.; Weinberg, A.M.

1959-02-10

283

Cosmic Ray Interactions in Shielding Materials  

SciTech Connect

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

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

2011-09-08

284

Advances in space radiation shielding codes.  

PubMed

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. PMID:12793737

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

2002-12-01

285

Neutron Detector Shielding Using Boron and Water  

NASA Astrophysics Data System (ADS)

There has always been a need to develop better shielding for particle detectors from background radiation. With the development of DUSEL (Deep Underground Science and Engineering Laboratory at Homestake), new opportunities exist to make measurements away from the surface cosmic radiation. Doing measurements underground, coupled with better shielding, allows measurements of reactions that are too weak to observe otherwise. Underground, we can take advantage of thousands of meters of rock to shield detectors from cosmic background radiation. Even this rock can be insufficient, as a naturally occurring radioisotopes found in the rock can yield many kinds of radiation, such as gamma rays, beta rays, alpha particles, neutrons, and other fission products. We are designing and testing a shield made for our proportional neutron detectors made of boron and water. Water is used to slow down, or thermalize, the neutrons. Boron is in turn used to capture the incoming neutrons, due to its large neutron capture cross section. This shield was tested and the data has been analyzed, showing that we can achieve a factor of 63 reduction in the number of neutrons detected. We will also scale down this design so that it can provide background protection to detectors in the Nuclear Structure Laboratory at the University of Notre Dame.

Jung, Frederick; Best, Andreas; Aprahamian, Ani; Wiescher, Michael

2010-11-01

286

LPT. Plot plan and site layout. Includes shield test pool/EBOR ...  

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

LPT. Plot plan and site layout. Includes shield test pool/EBOR facility. (TAN-645 and -646) low power test building (TAN-640 and -641), water storage tanks, guard house (TAN-642), pump house (TAN-644), driveways, well, chlorination building (TAN-643), septic system. Ralph M. Parsons 1229-12 ANP/GE-7-102. November 1956. Approved by INEEL Classification Office for public release. INEEL index code no. 038-0102-00-693-107261 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

287

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

SciTech Connect

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

Mattus, Catherine H.; Dole, Leslie R.

2003-02-27

288

Facility Focus: Science Buildings.  

ERIC Educational Resources Information Center

|Describes three college science buildings that support student- centered learning in their science programs. How the schools created facility spaces that were interactive but quiet, merged multi- disciplinary sciences into the facility design, and encouraged departmental collaboration in the planning stage are addressed. (GR)|

College Planning & Management, 2000

2000-01-01

289

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

290

Static Structural Analysis for a Neutron Shielding Block in ITER  

NASA Astrophysics Data System (ADS)

The ITER neutron shielding blocks are located between the outer shell and the inner shell of the vacuum vessel to provide neutron shielding. Considering the combined loads acting on the shielding blocks during ITER plasma operation, the structure of the shielding blocks must be evaluated. Using the finite element method with ANSYS analysis software, static structural analysis is performed, including elastic analysis and limit analysis for one typical shielding block. The evaluated results based on RCC-MR code show that the structure of this shielding block can meet the design requirement.

Hao, Junchuan; Song, Yuntao; Wang, Xiaoyu; Ioki, K.; Du, Shuangsong; Ji, Xiang; Feng, Changle; Xu, Yang

2013-02-01

291

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

292

The Interaction of Debye-Shielded Particles  

SciTech Connect

Macroscopic particles or solid surfaces in contact with a typical low-temperature plasma immediately charge negatively and surround themselves with an electron-depleted region of positive charge. This Debye shielding effect is involved in the Debye-Huckel theory in liquids and plasma sheath formation in the gas phase. In this report, the interaction between such screened particles is found by using the same basic approximation that is used in constructing the Debye shielding potential itself. The results demonstrate that a significant attraction exists between the particles, and, if conditions are right, this attractive force can contribute to the generation of particulate plasma crystals.

Buss, Richard J.; Riley, Merle E.

1999-04-01

293

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

294

Radiation shielding issues on the FMIT  

SciTech Connect

The Fusion Materials Irradiation Test Facility (FMIT) is being built to study neutron radiation effects in candidate fusion reactor materials. The FMIT will yield high fluence data in a fusion-like neutron radiation environment produced by the interaction of a 0.1A, 35 MeV deuteron beam with a flowing lithium target. The design of the facility as a whole is driven by a high availability requirement. The variety of radiation environments in the facility requires the use of diverse and extensive shielding. Shielding design throughout the FMIT must accommodate the need for maintenance and operations access while providing adequate personnel and equipment protection.

Burke, R.J.; Davis, A.A.; Huang, S.; Morford, R.J.

1981-05-01

295

Numerical simulation of space debris impacts on the Whipple shield  

NASA Astrophysics Data System (ADS)

The authors carried out three series of experimental tests of the first bumper perforation and main wall cratering processes directly caused by three types of projectiles with about 2, 4 and 7 km s -1 impact velocities but comparable initial kinetic energies, by using three different accelerators (one-stage powder gun, two-stage light-gas gun and rail gun), for the purpose of investigating space debris hypervelocity impacts onto single-walled Whipple bumper shields [1]. In the present study, after reviewing the numerical simulation method of hydrocode for both Eulerian and Lagrangian descriptions, a number of parametric numerical simulation analyses using multiple material Eulerian methods were performed in order to optimize the material properties of bumper and main wall materials through comparison with experimental results of single target impacts by the projectiles. In particular, the material data on the dynamic fracture phenomena are discussed in detail in the first part. Then a couple of numerical calculations using the interactive Lagrangian rezoning method to simulate the overall impact process against the single walled Whipple shield were performed and compared with the corresponding experimental results. Both results indicated fairly good agreement with each other. Moreover, it was demonstrated that the present method is helpful and efficient in understanding the impact phenomena and fracture mechanism in the space debris hypervelocity impact problem. Finally the multiple material Eulerian method was applied to the same problems modeled by the interactive Lagrangian rezoning method used previously, because the former is much easier to use for almost all users, although it is more diffusive and unclear of material boundaries than the latter. Those two kinds of numerical results also indicated fairly good agreements with each other.

Katayama, M.; Toda, S.; Kibe, S.

1997-06-01

296

Nodal staging  

PubMed Central

Abstract Lymph node metastases are a poor prognostic indicator in many tumours and therefore accurate identification during staging is important prior to commencing treatment. The presence of lymph node metastases can significantly alter patient management and therefore accurate diagnosis of the presence and extent of nodal disease can help optimise patient management. In this review, the radiologic features that aid in the differentiation of malignant and benign lymph nodes are discussed. The keys to successful interpretation on cross-sectional computed tomography (CT) and magnetic resonance imaging of nodal metastases are highlighted. The clinical role of positron emission tomography-CT imaging for nodal staging is discussed and emerging imaging techniques that may further improve nodal staging accuracy are surveyed.

Koh, Dow-Mu

2009-01-01

297

Shield Optimization in Simple Geometry for the Gateway Concept.  

National Technical Information Service (NTIS)

The great cost of added radiation shielding is a potential limiting factor in many deep space missions. For this enabling technology, we are developing tools for optimized shield design over multi-segmented missions involving multiple work and living area...

R. K. Tripathi L. C. Simonsen J. E. Nealy

2003-01-01

298

Summary of Prometheus Radiation Shielding Nuclear Design Analysis  

SciTech Connect

This report transmits a summary of radiation shielding nuclear design studies performed to support the Prometheus project. Together, the enclosures and references associated with this document describe NRPCT (KAPL & Bettis) shielding nuclear design analyses done for the project.

J. Stephens

2006-01-13

299

High-Density Braid Cable Shields. Final Report.  

National Technical Information Service (NTIS)

Development and improvement of electromagnetic radiation (EMR) shielding was undertaken. The study included cable braiding equipment, induction soldering, shield effectiveness and quality testing, and nondestructive defect locating equipment. (ERA citatio...

E. Belarde

1978-01-01

300

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

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

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

301

Shielding of Manned Space Vehicles Against Protons and alpha Particles.  

National Technical Information Service (NTIS)

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 ...

R. G. Alsmiller R. T. Santoro J. Barish H. C. Claiborne

1972-01-01

302

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral...and Operational Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2009-07-01

303

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral...and Operational Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2010-07-01

304

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral...and Operational Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2009-07-01

305

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral...and Operational Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2010-07-01

306

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

307

Neutron shielding material based on colemanite and epoxy resin.  

PubMed

In recent years, there has been a need for compact shielding design such as self-shielding of a PET cyclotron or upgradation of radiation machinery in existing facilities. In these cases, high performance shielding materials are needed. Concrete or polyethylene have been used for a neutron shield. However, for compact shielding, they fall short in terms of performance or durability. Therefore, a new type of neutron shielding material based on epoxy resin and colemanite has been developed. Slab attenuation experiments up to 40 cm for the new shielding material were carried out using a 252Cf neutron source. Measurement was carried out using a REM-counter, and compared with calculation. The results show that the shielding performance is better than concrete and polyethylene mixed with 10 wt% boron oxide. From the result, we confirmed that the performance of the new material is suitable for practical use. PMID:16381724

Okuno, Koichi

2005-01-01

308

Impact damage on shielded gas-filled vessels  

NASA Astrophysics Data System (ADS)

This paper gives a summary of the findings from impacts on shielded gas-filled cylindrical aluminium alloy (A12219 T851) and titanium alloy (Ti6A14V) pressure vessels that were performed at the Ernst-Mach-Institute in the frame of an ESA contract. The effect of impacts on shielded vessels with projectiles that have a kinetic energy close to the ballistic limit of the combined system of shield and vessel's front wall was investigated. The shields were single Al-bumper plates, unreinforced MLI and MLI reinforced with 2 layers of Betacloth. The threshold diameters that cause leakage from the vessel's front wall were determined experimentally as a function of shield material and shield spacing. For Al-shielded Al- and Ti-vessels, a safety design factor to avoid leakage is presented based on existing Whipple shield equations.

Schäfer, F.; Schneider, E.; Lambert, M.

2001-10-01

309

Gravity Scaling of a Power Reactor Water Shield.  

National Technical Information Service (NTIS)

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 ...

J. B. Pearson R. S. Reid

2008-01-01

310

Design and evaluation of an inexpensive radiation shield for ...  

Treesearch

Jul 21, 2013 ... This paper describes a low-cost (~3 USD) radiation shield (radshield) ... When compared with observations from a high-quality temperature sensor ... Keywords: solar radiation shield, air temperature, microclimate, topoclimate.

311

Martian regolith as space radiation shielding.  

PubMed

In current Mars scenario descriptions, an entire mission is estimated to take 500-1000 days round trip with a 100-600 day stay time on the surface. To maintain radiation dose levels below permissible limits, dose estimates must be determined for the entire mission length. With extended crew durations anticipated on Mars, the characterization of the radiation environment on the surface becomes a critical aspect of mission planning. The most harmful free-space radiation is due to high energy galactic cosmic rays (GCR) and solar flare protons. The carbon dioxide atmosphere of Mars has been estimated to provide a sufficient amount of shielding from these radiative fluxes to help maintain incurred doses below permissible limits. However, Mars exploration crews are likely to incur a substantial dose while in transit to Mars that will reduce the allowable dose that can be received while on the surface. Therefore, additional shielding may be necessary to maintain short-term dose levels below limits or to help maintain career dose levels as low as possible. By utilizing local resources, such as Martian regolith, shielding materials can be provided without excessive launch weight requirements from Earth. The scope of this synopsis and of Ref. 3 focuses on presenting our estimates of surface radiation doses received due to the transport and attenuation of galactic cosmic rays and February 1956 solar flare protons through the Martian atmosphere and through additional shielding provided by Martian regolith. PMID:11537624

Simonsen, L C; Nealy, J E; Townsend, L W; Wilson, J W

312

Corrosion protection and EMP/EMI shielding  

SciTech Connect

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

Brahney, J.H.

1990-06-01

313

Integrated first-wall\\/blanket\\/shield concept  

Microsoft Academic Search

An integrated first-wall\\/blanket\\/shield concept has evolved from the desire to improve the attractiveness and reduce the capital cost of fusion reactors. Design simplicity, improved safety, high performance, and reactor modularization are the key design factors in developing this concept. The main features and analysis of the concept are the subject of this paper.

Gohar

1986-01-01

314

Modelling eddy currents in thin shields  

Microsoft Academic Search

Purpose – The purpose of this paper is to present a simplified rigorous mathematical formulation of the problem of electric currents induced in thin shields with holes yielding more efficient numerical computations with respect to available methods. Design\\/methodology\\/approach – A surface integral equation satisfied by the current density was constructed, which is, subsequently, represented at any point by linear combinations

Florea I. Hantila; Ioan R. Ciric; Augustin Moraru; Mihai Maricaru

2009-01-01

315

Shielding of augmented tendon-tendon repair  

Microsoft Academic Search

Strength and function of autogenic and xenogenic reconstruction of digital extensor tendons was examined in an ovine model. In this study, tendon-graft junctions were formed by either suture augmented with a woven polyester tube (A), or augmented and shielded from surrounding tissues by chemically-treated bovine pericardium (S). By 12 wk, both A and S sheep had returned to full range

G. J. Rogers; B. K. Milthorpe; K. Schindhelm; C. R. Howlett; S. Roe

1995-01-01

316

Lunar soil as shielding against space radiation  

Microsoft Academic Search

We have measured the radiation transport and dose reduction properties of lunar soil with respect to selected heavy ion beams with charges and energies comparable to some components of the galactic cosmic radiation (GCR), using soil samples returned by the Apollo missions and several types of synthetic soil glasses and lunar soil simulants. The suitability for shielding studies of synthetic

J. Miller; L. Taylor; C. Zeitlin; L. Heilbronn; S. Guetersloh; M. DiGiuseppe; Y. Iwata; T. Murakami

2009-01-01

317

Radiation resistance of radiation shield rubber.  

National Technical Information Service (NTIS)

The radiation shield rubber of ethylene-propylene copolymer (EPDM) and of chlorinated polyethylene (CM) mixed with a large amount of powder or foil lead were irradiated under vacuum or in oxygen atmosphere by Co-60 gamma rays for an evaluation of the radi...

A. Kasai N. Yamaguchi T. Watanabe T. Seguchi M. Nishii

1990-01-01

318

Shielding efficiency measurements under pulsed electromagnetic fields  

Microsoft Academic Search

The paper describes a method of using the transfer function of a given system to calculate the shielding efficiency (SE) of a protective screen with the help of measurements conducted in the time domain. A high voltage electromagnetic pulse simulator (EMPS) creates the required pulse fields. The radiated field in the working zone of the simulator is measured by a

V. Venkateswarlu; Y. Narayana Rao

1995-01-01

319

Electromagnetic Interference and Shielding: An Introduction. (Revised).  

National Technical Information Service (NTIS)

The basic equations of the electromagnetc field are summarized as far as they are needed in the theory of ElectroMagnetic Interference and Shielding. Through the analysis of the radiation from small current-carrying wires ('electric dipole') and small cur...

A. T. de Hoop D. Quak

1993-01-01

320

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

321

Origin of NMR shielding in fluorides  

NASA Astrophysics Data System (ADS)

In this work, we analyze in detail the relation between electronic structure and fluorine nuclear magnetic resonance (NMR) shielding in a series of solid state alkali fluorides (LiF, NaF, KF, RbF, and CsF). For that purpose, we use solid-state NMR calculations implemented in the density functional theory full potential wien2k code (APW+lo). Both measurements and calculations show that the NMR shielding varies across the series by approximately 200 ppm. We focus our discussion on an explanation of the origin of the observed trend, and we show that the variation is mainly determined by contributions from “semicore” metal-p and valence F-p bands. More specifically, the trend in fluorine shielding can be related to the small but significant change in the hybridization of these states. A second important ingredient determining the value of the shielding is the presence and position of metal-d states in the unoccupied part of the Kohn-Sham bands. Although the present analysis has been demonstrated for the 19F nucleus in alkali fluorides, the main results are more general and can explain similar trends observed in other solids and for other nuclei.

Laskowski, Robert; Blaha, Peter

2012-06-01

322

SCALE radiation shielding V and V package  

SciTech Connect

Verification and validation (V and V) are essential elements of software quality assurance (QA) for computer codes that are used for scientific calculations. The sponsors of the SCALE code system have required a QA plan and a V and V plan. For purposes of validating and verifying the SCALE shielding codes, a set of problems has been assembled and tested.

Emmett, M.B.; Bowman, S.M.; Broadhead, B.L.

1997-12-01

323

Seismic Properties of the Central Indian Shield  

Microsoft Academic Search

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

Limei Zhou; Wang-Ping Chen; Serdar Ozalaybey

2000-01-01

324

Electronically shielded solid state charged particle detector  

Microsoft Academic Search

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

David K. Balmer; Thomas W. Haverty; Carl W. Nordin; William H. Tyree

1996-01-01

325

Transient electron shield currents in vacuum arcs  

Microsoft Academic Search

It is shown that a conducting shield, as a third electrode in a vacuum arc plasma, can temporarily act as an auxiliary anode. This is due to an inductive shift of arc plasma potential caused by a sufficiently rapid decrease of arc current. Using current injection experiments, the existence of cathode spot activity after circuit current zero is demonstrated and

R. P. P. Smeets

1986-01-01

326

The accuracy of NOVICE electron shielding calculations  

Microsoft Academic Search

NOVICE Monte Carlo calculations of electron transport are compared with SHIELDOSE and ITS calculations and with experimental data for an empty electronics box. The accuracy of NOVICE solid angle sectoring methods relative to Monte Carlo methods is discussed for simple shield geometries

Thomas M. Jordan

1991-01-01

327

Electronically shielded solid state charged particle detector  

Microsoft Academic Search

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

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

1995-01-01

328

Electron Shielding in n-InSb  

Microsoft Academic Search

The effect on bound electrons in donor levels by conduction-band electrons in n-InSb is investigated using a self-consistent calculation. Results of the calculations show that no bound state exists for impurity concentrations greater than 6×1013 cm-3. This shielding appears to be the predominant effect leading to the lack of impurity-binding energy.

S. P. Li; W. F. Love; S. C. Miller

1967-01-01

329

Subsurface Shielding Source Term Specification Calculation  

SciTech Connect

The purpose of this calculation is to establish appropriate and defensible waste-package radiation source terms for use in repository subsurface shielding design. This calculation supports the shielding design for the waste emplacement and retrieval system, and subsurface facility system. The objective is to identify the limiting waste package and specify its associated source terms including source strengths and energy spectra. Consistent with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001, p. 15), the scope of work includes the following: (1) Review source terms generated by the Waste Package Department (WPD) for various waste forms and waste package types, and compile them for shielding-specific applications. (2) Determine acceptable waste package specific source terms for use in subsurface shielding design, using a reasonable and defensible methodology that is not unduly conservative. This calculation is associated with the engineering and design activity for the waste emplacement and retrieval system, and subsurface facility system. The technical work plan for this calculation is provided in CRWMS M&O 2001. Development and performance of this calculation conforms to the procedure, AP-3.12Q, Calculations.

S.Su

2001-04-12

330

Spallation Neutron Source Radiation Shielding Issues  

Microsoft Academic Search

This paper summarizes results of Spallation Neutron Source calculations to estimate radiation hazards and shielding requirements for activated Mercury, target components, target cooling water, and ⁷Be plateout. Dose rates in the accelerator tunnel from activation of magnets and concrete were investigated. The impact of gaps and other streaming paths on the radiation environment inside the test cell during operation and

Y. Y. Azmy; J. M. Barnes; J. D. Drischler; J. O. Johnston; R. A. Lillie; G. S. McNeilly; R. T. Santoro

1999-01-01

331

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

332

Thermal analysis of JET cryopump nitrogen shield  

Microsoft Academic Search

This work was performed under the collaborative program between DIII-D ADP cryopump and JET pumped divertor. The purpose of the analysis was to reduce the uncertainty in the JET cryopump design by using thermal hydraulic methods developed at GA for DIII-D cryopump. The reference design of JET cryopump nitrogen shield consists of a parallel flow arrangement. This arrangement was selected

Baxi

1991-01-01

333

Cost and Financing of Operation Desert Shield.  

National Technical Information Service (NTIS)

The total U.S. cost of Operation Desert Shield without any hostilities could exceed $130 billion in fiscal year 1991, assuming the forces now in place remain there throughout the fiscal year. This cost consists of three components. One is the baseline cos...

1991-01-01

334

Broadband Seismic Characterization of the Arabian Shield.  

National Technical Information Service (NTIS)

From November 1995 to March 1997 a total of nine broadband temporary stations were deployed across the Saudi Arabian shield. These stations consisted of STS-2 seismometers that recorded continuously at 40 sps on Refraction Technology RT72A-07 dataloggers....

F. L. Vernon J. Berger

1998-01-01

335

Internally shielded beam transport and support system  

Microsoft Academic Search

Due to environmental concerns, the Advanced Photon Source has a policy that disallows any exposed lead within the facility. This creates a real problem for the beam transport system, not so much for the pipe but for the flexible coupling (bellows) sections. A complete internally shielded x-ray transport system, consisting of long transport lines joined by flexible coupling sections, has

W. Schildkamp; H. Brewer

1996-01-01

336

Protective Eye Shield Against Small Fragments.  

National Technical Information Service (NTIS)

Casualty reports from Southeast Asia indicate a need for a small fragment protective eye shield which will not interfere with the normal duties of the user. Commercially available eye goggles which are in accordance with Federal Specification FSN 4240-052...

R. J. Hassett S. L. Hanlein J. E. Goeller

1970-01-01

337

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

338

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

339

Internally shielded beam transport and support system  

SciTech Connect

Due to environmental concerns, the Advanced Photon Source has a policy that disallows any exposed lead within the facility. This creates a real problem for the beam transport system, not so much for the pipe but for the flexible coupling (bellows) sections. A complete internally shielded x-ray transport system, consisting of long transport lines joined by flexible coupling sections, has been designed for CARS sector 14 to operate either at high vacuum or as a helium flight tube. It can effectively shield against air scattering of wiggler or undulator white beam with proper placement of apertures, collimators, and masks for direct beam control. The system makes use of male- and female-style fittings that create a labyrinth allowing for continuous shielding through the flexible coupling sections. These parts are precision machined from a ternary hypereutectic lead alloy (cast under 15 inches of head pressure to assure a pinhole-free casting) then pressed into either end (rotatable vacuum flanges) of the bellows assembly. The transport pipe itself consists of a four part construction using a stepped transition ring (Z-ring) to connect an inner tube to the vacuum flange and also to a protective and supportive outer tube. The inner tube is wrapped with 1/16{double_prime} pure lead sheet to a predetermined thickness following the shape of the stepped transition ring for continuous shielding. This design has been prototyped and radiation tested. {copyright} {ital 1996 American Institute of Physics.}

Schildkamp, W.; Brewer, H. [Consortium for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 (United States)

1996-09-01

340

Electromagnetic shielding effectiveness of composite material  

Microsoft Academic Search

The purpose of this paper is to present an engineering study of the electromagnetic shielding effectiveness of composite materials used in space applications. The objective of the study is to identify and quantify the important electrical characteristics of composite materials proposed as substitutes for conventional metal-based structural elements of spacecraft. Current design practices utilized by various developers of spacecraft, particularly

Patrick J. Serna; Gary H. Liechty

1999-01-01

341

Hot cell shield plug extraction apparatus  

DOEpatents

A hot cell installation for the handling of highly radioactive material may comprise a dozen or more interconnected high density concrete vaults, the concrete vault walls having a thickness of approximately three feet. Typically, hot cells are constructed in rows so as to share as many shielding walls as possible. A typical overall length of a row of cells might be 70 yards. A secondary mechanism exists for placing certain objects into a cell. A typical hot cell has been constructed with 8 inch diameter holes through the exterior shielded walls in the vicinity of, and usually above, the viewing windows. It became evident that if the hot cell plugs could be removed and replaced conveniently significant savings in time and personnel exposure could be realized by using these 8 inch holes as entry ports. Fifteen inch cylindrical steel plugs with a diameter of eight inches weigh about two hundred pounds. The shield plug swing mechanism comprises a steel shielding plug mounted on a retraction device that enables the plug to be pulled out of the wall and supports the weight of the pulled out plug. The retraction device is mounted on a hinge, which allows the plug to be swung out of the way so that an operator can insert material into or remove it from the interior of the hot cell and then replace the plug quickly. The hinge mounting transmits the load of the retracted plug to the concrete wall.

Knapp, P.A.; Manhart, L.K.

1994-12-31

342

Impact of a flattening filter free linear accelerator on structural shielding design.  

PubMed

PURPOSE: The present study aimed to assess the effects of a flattening filter free medical accelerator on structural shielding demands of a treatment vault of a medical linear accelerator. We tried to answer the question, to what extent the required thickness of the shielding barriers can be reduced if instead of the standard flattened photon beams unflattened ones are used. MATERIAL AND METHODS: We chose both an experimental as well as a theoretical approach. On the one hand we measured photon dose rates at protected places outside the treatment room and compared the obtained results for flattened and unflattened beams. On the other hand we complied with international guidelines for adequate treatment vault design and calculated the shielding barriers according to the therein given specifications. Measurements were performed with an Elekta Precise™ linac providing nominal photon energies of 6 and 10 MV. This machine underwent already earlier some modifications in order to be able to operate both with and without a flattening filter. Photon dose rates were measured with a LB133-1 dose rate meter manufactured by Berthold. To calculate the thickness of shielding barriers we referred to the Austrian standard ÖNORM S 5216 and to the US American NCRP Report No. 151. RESULTS: We determined a substantial photon dose rate reduction for all measurement points and photon energies. For unflattened 6 MV beams a reduction factor ranging from 1.4 to 1.8 was identified. The corresponding values for unflattened 10 MV beams were 2.1 and 3.2. The performed shielding calculations indicated the same tendency: For all relevant radiation components we found a reduction in shielding thickness when unflattened beams were used. The required thickness of primary barriers was reduced up to 8.0%, the thickness of secondary barriers up to 11.4%, respectively. CONCLUSIONS: For an adequate dimensioning of treatment vault shielding barriers it is by no means irrelevant if the accommodated linac operates with or without a flattening filter. The lower consumption of shielding space and material for new treatment vaults housing a FFF machine may reduce building costs, whereas for existing vaults one might benefit in terms of increased weekly workload. Also a more frequent use of monitor unit intense treatment techniques as well as aiming at reduced occupational exposure for staff is conceivable. PMID:23763984

Jank, Julia; Kragl, Gabriele; Georg, Dietmar

2013-06-10

343

Building a Process-Savvy Organization  

ERIC Educational Resources Information Center

Process improvement and organizational development go hand-in-hand. Building out your organizational process infrastructure will provide the tools necessary to build and maintain effective processes. It takes time, effort, and persistence to get through the initial stages, but the foundational steps of process awareness set the stage for later…

Jordan, Tom

2007-01-01

344

A lightweight composite shielding material for electromagnetic gun launchers  

Microsoft Academic Search

There is a need for the development of a lightweight electromagnetic shield that can be easily installed and maintained to provide high-performance shielding for electric gun barrels. In the past few years, there have been advancements in the development of lightweight material, which could be quite useful in the electric gun technology. Material is TI-Shield, manufactured by instruments, Inc. TI-Shield

Warren Williams; Kobi O'Malley

1997-01-01

345

Binary Stage.  

National Technical Information Service (NTIS)

The fluid amplifier is utilized in a computing system. The pure fluid binary counting stage comprises a pair of pure fluid amplifiers coupled together through a delay and energy storage system such that one of the fluid through a delay and energy storage ...

R. E. Bowles

1965-01-01

346

Staging tourism  

Microsoft Academic Search

Metaphorically, tourists can be considered to enact a range of performances on distinct stages. Their enactions are distinguished according to various factors, including their competence, reflexivity, the extent to which they are directed and regulated, or participate in group or solo performances. Providing examples from research carried out at the Taj Mahal in India, particular attention is directed to the

Tim Edensor

2000-01-01

347

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

348

STATE OF DEVELOPMENT IN THE RANGE OF REACTOR SHIELDING. II. THEORY AND PRACTICE  

Microsoft Academic Search

In this second part of the article on reactor shielding, neutron ; shielding is first discussed. Then safety shielding is considered. A brief ; survey on radiation detection instruments used for examination of shielding is ; given. 16 references. (tr-auth);

van Ammers; Ir. H

1960-01-01

349

Shielding performances of ITO transparent windows: Theoretical and experimental characterization  

Microsoft Academic Search

The shielding performance of indium-titanium-oxide (ITO) thin film depends on the characteristics of the impinging electromagnetic field, on the geometry of the shield, and on the frequency range. In this paper, a complete experimental characterization of the shielding effectiveness of ITO transparent windows is performed by using three different approaches. The obtained results are compared in order to define the

Sandra Greco; Maria Sabrina Sarto; Alessio Tamburrano

2008-01-01

350

Space radiation shielding strategies and requirements for deep space missions  

Microsoft Academic Search

Methods for estimating crew exposure to radiation and for evaluating shield requirements for spacecraft equipment and crew are examined. The development status for deterministic space radiation transport computer codes and models of their nuclear interaction inputs, which are useful for estimating the composition and thickness of shield materials, is discussed. The relation between shield thickness and exposures is studied. Estimates

Lawrence W. Townsend; John W. Wilson; John E. Nealy

1989-01-01

351

EBT-P Gamma-Ray-Shielding Analysis.  

National Technical Information Service (NTIS)

First, a one-dimensional scoping study was performed for the gamma-ray shield of the ELMO Bumpy Torus proof-of-principle device to define appropriate shielding material and determine the required shielding thickness. The dose-equivalent results are analyz...

Y. Gohar

1983-01-01

352

EBT-P Gamma-Ray Shielding System.  

National Technical Information Service (NTIS)

An elaborate study was carried out for the coil and biological shield of the ELMO Bumpy Torus proof-of-principle (EBT-P) device. A three-dimensional scoping study for the coil shield was performed for four different shielding options to define the heat lo...

Y. Gohar

1981-01-01

353

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

354

Analytical formulation for the shielding effectiveness of enclosures with apertures  

Microsoft Academic Search

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

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

1998-01-01

355

Gravity Scaling of a Power Reactor Water Shield  

Microsoft Academic Search

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

Robert S. Reid; J. Boise Pearson

2008-01-01

356

Development of Radiation Transport Codes for Shielding Analysis  

Microsoft Academic Search

A variety of discrete ordinates codes have been developed during the past ten years for radiation shielding calculations in rather complicated geometries and also for transport calculations of Bremsstrahlung photons.For more efficient shielding analyses albedo transport codes have been developed and utilized for practical shielding calculations. Point-energy Monte Carlo codes have come to be available during this period for checking

Kiyoshi TAKEUCHI

1989-01-01

357

The SRB heat shield: Aeroelastic stability during reentry  

Microsoft Academic Search

Wind tunnel tests of a 3% scale model of the aft portion of the SRB equipped with partially scaled heat shields were conducted for the purpose of measuring fluctuating pressure levels in the aft skirt region. During these tests, the heat shields were observed to oscillate violently, the oscillations in some instances causing the heat shields to fail. High speed

C. S. Ventres; E. H. Dowell

1977-01-01

358

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.

Wiberg, Leanne; History, National M.

2000-01-01

359

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

360

SHIELDING PROPERTIES OF A SIR MARK A CONTROL ROD DRIVE MECHANISM SHIELDING LABORATORY EXPERIMENT NO. 1 (SL1)  

Microsoft Academic Search

Shielding Laboratory Experimert SL-l is described and the results are ; reported. In this experiment the neutron and gamma ray shielding properties of a ; control rod drive mechanism were determined. Measurements were made for fast ; neutrons, epithermal neutrons, thermal neutrons, and gamma rays. This ; information will be used in evaluating the shielding effectiveness of the ; mechanism.

1954-01-01

361

Shielding of Electronic Systems against Transient Electromagnetic Interferences  

NASA Astrophysics Data System (ADS)

In order to protect electronic systems against the effects of transient electromagnetic interferences, shields made of electrically conductive material can be used. The subject of this paper is an electrically conductive textile. When applying the shield, a reliable measure is needed in order to determine the effectiveness of the shield to protect against electromagnetic pulses. For this purpose, a time domain measurement technique is presented using double exponential pulses. With these pulses, the susceptibility of an operating electronic device with and without the shield is determined. As a criterion of quality of a shield, the breakdown failure rate found in both cases is compared.

Herlemann, H.; Korte, S.; Camp, M.; Garbe, H.; Koch, M.; Sabath, F.

2005-05-01

362

Design of radiation shielding for the proton therapy facility at the National Cancer Center in Korea.  

PubMed

The design of radiation shielding was evaluated for a proton therapy facility being established at the National Cancer Center in Korea. The proton beam energy from a 230 MeV cyclotron is varied for therapy using a graphite target. This energy variation process produces high radiation and thus thick shielding walls surround the region. The evaluation was first carried out using analytical expressions at selected locations. Further detailed evaluations have been performed using the Monte Carlo method. Dose equivalent values were calculated to be compared with analytical results. The analytical method generally yielded more conservative values. With consideration of adequate occupancy factors annual dose equivalent rates are kept <1 mSv y(-1) in all areas. Construction of the building is expected to be completed near the end of 2004 and the installation of therapy equipment will begin a few months later. PMID:16381727

Kim, Jong-Won; Kwon, Jeong-Wan; Lee, Jaiki

2005-01-01

363

Building structures  

US Patent & Trademark Office Database

A building structure offset uses hexagon structures assembled in an offset layering architecture to construct walls, floors and roofs. Hexagon building structures include interior panels adhered to both sides of a foam core. The structures also include radial cutouts the corners for offset layering assembly with another structure. Peg retainers selectively secure the hexagon building structures together. Fastening holes provide fastener locations for screwing or bolting through the layers of the hexagon structures. The holes align with an offset layer of hexagons when assembled in the axial direction. Conduit holes are selectively located depending on the fastening technique selected. The system includes five derivatives of hexagon building structures and a header, providing square, triangular, and curved geometries when assembled. Since hexagon buildings are built from hexagon building structures without customization, hexagon buildings can be rebuilt, modified, or recycled using the same materials.

Zornes; David A. (Redmond, WA)

2003-10-14

364

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…

American Inst. of Architects, Washington, DC.

365

Superconducting magnetic shields for neutral beam injectors. Final report  

SciTech Connect

Large high energy deuterium neutral beams which must be made from negative ions require extensive magnetic shielding against the intense fringe fields surrounding a magnetic fusion power plant. The feasibility of shielding by multilayer sheets of copper-superconducting laminated material was investigated. It was found that, if necessary fabrication techniques are developed, intrinsically stable type II superconductors will be able to shield against the magnetic fields of the fusion reactors. Among the immediate benefits of this research is better magnetic shields for neutral beam injectors in support of DOE's fusion program. Another application may be in the space vehicles, where difficulties in transporting heavy ..mu..-metal sections may make a comparatively light superconducting shield attractive. Also, as high-field superconducting magnets find widespread applications, the need for high-intensity magnetic shielding will increase. As a result, the commercial market for the magnetic shields should expand along with the market for superconducting magnets.

Not Available

1985-04-01

366

Magnetic shielding for the Fermilab Vertical Cavity Test Facility  

SciTech Connect

A superconducting RF cavity has to be shielded from magnetic fields present during cool down below the critical temperature to avoid freezing in the magnetic flux at localized impurities, thereby degrading the cavity intrinsic quality factor Q{sub 0}. The magnetic shielding designed for the Fermilab vertical cavity test facility (VCTF), a facility for CW RF vertical testing of bare ILC 1.3 GHz 9-cell SRF cavities, was recently completed. For the magnetic shielding design, we used two cylindrical layers: a room temperature 'outer' shield of Amumetal (80% Ni alloy), and a 2K 'inner' shield of Cryoperm 10. The magnetic and mechanical design of the magnetic shielding and measurement of the remanent magnetic field inside the shielding are described.

Ginsburg, Camille M.; Reid, Clark; Sergatskov, Dmitri A.; /Fermilab

2008-09-01

367

Phase shielding soliton in parametrically driven systems.  

PubMed

Parametrically driven extended systems exhibit dissipative localized states. Analytical solutions of these states are characterized by a uniform phase and a bell-shaped modulus. Recently, a type of dissipative localized state with a nonuniform phase structure has been reported: the phase shielding solitons. Using the parametrically driven and damped nonlinear Schrödinger equation, we investigate the main properties of this kind of solution in one and two dimensions and develop an analytical description for its structure and dynamics. Numerical simulations are consistent with our analytical results, showing good agreement. A numerical exploration conducted in an anisotropic ferromagnetic system in one and two dimensions indicates the presence of phase shielding solitons. The structure of these dissipative solitons is well described also by our analytical results. The presence of corrective higher-order terms is relevant in the description of the observed phase dynamical behavior. PMID:23767606

Clerc, Marcel G; Garcia-Ñustes, Mónica A; Zárate, Yair; Coulibaly, Saliya

2013-05-24

368

Phase shielding soliton in parametrically driven systems  

NASA Astrophysics Data System (ADS)

Parametrically driven extended systems exhibit dissipative localized states. Analytical solutions of these states are characterized by a uniform phase and a bell-shaped modulus. Recently, a type of dissipative localized state with a nonuniform phase structure has been reported: the phase shielding solitons. Using the parametrically driven and damped nonlinear Schrödinger equation, we investigate the main properties of this kind of solution in one and two dimensions and develop an analytical description for its structure and dynamics. Numerical simulations are consistent with our analytical results, showing good agreement. A numerical exploration conducted in an anisotropic ferromagnetic system in one and two dimensions indicates the presence of phase shielding solitons. The structure of these dissipative solitons is well described also by our analytical results. The presence of corrective higher-order terms is relevant in the description of the observed phase dynamical behavior.

Clerc, Marcel G.; Garcia-Ñustes, Mónica A.; Zárate, Yair; Coulibaly, Saliya

2013-05-01

369

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

370

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

371

An integrated model for earthquake risk assessment of buildings  

Microsoft Academic Search

This study is devoted to the formulation and construction of an integrated model for earthquake risk assessment of buildings in seismic regions. The model developed has five stages: i) characterization of ground motion, ii) construction of the building model, iii) evaluation of the inelastic building response, iv) structural damage assessment, and v) risk evaluation. Stages iii) and iv) are emphasized

T. Fischer; M. Alvarez; J. C. De la Llera; R. Riddell

2002-01-01

372

Spallation Neutron Source Radiation Shielding Issues  

SciTech Connect

This paper summarizes results of Spallation Neutron Source calculations to estimate radiation hazards and shielding requirements for activated Mercury, target components, target cooling water, and {sup 7}Be plateout. Dose rates in the accelerator tunnel from activation of magnets and concrete were investigated. The impact of gaps and other streaming paths on the radiation environment inside the test cell during operation and after shutdown were also assessed.

Azmy, Y.Y.; Barnes, J.M.; Drischler, J.D.; Johnston, J.O.; Lillie, R.A.; McNeilly, G.S.; Santoro, R.T.

1999-11-14

373

The impedance of rf-shielding wires  

SciTech Connect

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

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

1999-03-29

374

Heavy Metal Pad Shielding during Fluoroscopic Interventions  

PubMed Central

Significant direct and scatter radiation doses to patient and physician may result from routine interventional radiology practice. A lead-free disposable tungsten antimony shielding pad was tested in phantom patients during simulated diagnostic angiography procedures. Although the exact risk of low doses of ionizing radiation is unknown, dramatic dose reductions can be seen with routine use of this simple, sterile pad made from lightweighttungsten antimony material.

Dromi, Sergio; Wood, Bradford J.; Oberoi, Jay; Neeman, Ziv

2008-01-01

375

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

376

Shielded serpentine traveling wave tube deflection structure  

DOEpatents

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

Hudson, C.L.; Spector, J.

1994-12-27

377

Ablation Radiation Shields for Nuclear Fusion Rockets  

NASA Astrophysics Data System (ADS)

Pulse nuclear propulsion has been the subject of extensive studies since the 1960's. Early concepts examined external pulse propulsion where small critical mass nuclear devices are ejected from the rear of the rocket. A pusher plate absorbs some of the energy form the detonation, which ablates the plate and provides thrust for the rocket. It is also possible to have the device detonate in an enclosed chamber (i.e., internal pulse propulsion). Again, in this case, ablation is the primary method for applying the thrust. Ablation can not only provide thrust but it can also aid in the dissipation of the heat in a neutron radiation shield. Since high-energy neutrons will be abundant in deuterium-tritium fusion reactions, fusion rockets that use this reaction usually are designed with a radiator to dissipate the heat from the shield. These radiators usually require a considerable mass. Carbon and tungsten ablative shields may be considerably more effective. Ablation and radiation are compared as mechanisms to dissipate the heat. Although ablation is shown to provide a considerable mass saving heat loses at the surfaces will create thermal gradients that will adversely effect the ablation rate, and may significantly increase the mass loss.

Coreano, Luis; Cassenti, Brice N.

2003-01-01

378

Fusion neutronics-streaming, shielding, heating, activation  

NASA Astrophysics Data System (ADS)

The International Thermonuclear Experimental Reactor (ITER) represents an important step towards a fusion power plant. Controlled fusion will be realized in a d-t-plasma magnetically confined by a Tokamak configuration. The first wall of the plasma chamber, blanket and vacuum vessel of ITER form a compact assembly for converting the kinetic energy of fusion neutrons into heat while simultaneously shielding the superconducting coils efficiently against neutron and accompanying photon radiation. This shielding system can be investigated with neutrons generated by low-energy accelerators. We report on experiments concerning shielding and streaming properties of a mock-up where energy spectra of both neutrons and protons were measured. They are compared with predictions of Monte Carlo calculations (code MCNP-4A) using various data libraries. The agreement justified the use of measured spectra as basis to calculate design parameters such as neutron and photon heating, radiation damage, gas production, and activation. Some of these parameters were also directly measured. The results validate the ITER design. .

Freiesleben, H.; Richter, D.; Seidel, K.; Unholzer, S.

2001-07-01

379

Thermal analysis of JET cryopump nitrogen shield  

SciTech Connect

This work was performed under the collaborative program between DIII-D ADP cryopump and JET pumped divertor. The purpose of the analysis was to reduce the uncertainty in the JET cryopump design by using thermal hydraulic methods developed at GA for DIII-D cryopump. The reference design of JET cryopump nitrogen shield consists of a parallel flow arrangement. This arrangement was selected due to concern about conduction between warm and cold parts of the shield during cool down transients. Such a parallel flow arrangement in two phase flow may be unstable. Hence, an analysis was undertaken to investigate the conduction effects in the shield for this and other flow arrangements. Thermal analysis was done by a finite element program developed at GA. In this analysis, three flow arrangements were developed for cool down from 300{degree}K to about 80{degree}K. In order to simplify the analysis, coolant was assumed to be a N{sub 2}gas at an inlet temperature of 80{degree}K.

Baxi, C.B.

1991-02-01

380

Shielding effects in 1-D transformation kinetics  

NASA Astrophysics Data System (ADS)

A new derivation is presented for the fraction of material transformed as a function of time,X (t), for 1-D phase transformations which occur via nucleation and growth and which produce anisotropic particles. The derivation, which is coached in terms of agressor and blocker particles, accounts for shielding effects and is more easily generalizable to more complex situations than a previous derivation for X(t) for this problem. Since this 1-D problem is equivalent to the 2-D case in the limit of low seeding density, the accuracy of our resulting formula for X(t) is assessed by illustrative calculations using elliptically shaped particles. It is found that the derived expression is nearly precise. In addition, we examine the influence of particle growth rate anisotropy and particle shape on the importance of shielding effects. We conclude that for growth rate anisotropies (ratio of major to minor axis growth rates) smaller than 5, shielding effects are not very significant. Also, particle shape appears to have a small effect on transformation kinetics.

Birnie, Dunbar P.; Weinberg, Michael C.

1996-02-01

381

Combined therapy for vernal shield ulcer.  

PubMed

A 22-year-old male patient presented with complaints of pain and redness in the right eye. Slitlamp examination revealed giant papillae on both tarsal conjunctivae, bilateral punctate corneal epitheliopathy and a 2.9 x 2.9 mm epithelial defect in the right eye. The diagnosis was bilateral vernal keratoconjunctivitis with shield ulcer in the right eye. Treatment was commenced with prednisolone (1%) eye drops four times daily and sodium hyaluronate (0.1%) eye drops eight times daily. After one week, the patient had improved symptomatically but the epithelial defect remained unchanged. Topical cyclosporine (0.05%) applied eight times per day was added to the regimen of topical corticosteroid and artificial tears. Three weeks after commencing combined therapy, the shield ulcer had healed completely, leaving a corneal opacity that negatively stained with fluorescein. The patient was followed for five months and no recurrence of ulcer was noted, despite the discontinuation of topical cyclosporine and prednisolone. Simultaneous institution of topical corticosteroid, artificial tears and topical cyclosporine seems to augment the therapeutic efficacy of each other and may be a promising regime in the management of shield ulcer. PMID:18045257

Kumar, Sunil

2008-01-01

382

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

383

Beta radiation shielding with lead and plastic: effect on bremsstrahlung radiation when switching the shielding order.  

PubMed

Lead and plastic are commonly used to shield beta radiation. Radiation protection literature is ubiquitous in advising the placement of plastic first to absorb all the beta particles before any lead shielding is used. This advice is based on the well established theory that radiative losses (bremsstrahlung production) are more prevalent in higher atomic number (Z) materials than in low Z materials. Using 32P beta radiation, we measured bremsstrahlung photons transmitted through lead and plastic (Lucite) shielding in different test configurations to determine the relative efficacy of lead alone, plastic alone, and the positional order of lead and plastic. With the source (32P) and detector held at a constant separation distance, we inserted lead and/or plastic absorbers and measured the reduction in bremsstrahlung radiation level measured by the detector. With these test conditions, analysis of measured bremsstrahlung radiation in various thicknesses and configurations of lead and plastic shielding shows the following: placing plastic first vs. lead first reduces the transmitted radiation level only marginally (10% to 40%); 2 mm of additional lead is sufficient to correct the "mistake" of placing the lead first; and for equal thicknesses or weights of lead and plastic, lead is a more efficient radiation shield than plastic. PMID:17228183

Van Pelt, Wesley R; Drzyzga, Michael

2007-02-01

384

Intelligent buildings  

SciTech Connect

The use and development of integrated sensor based systems in building design could turn the concept of an intelligent building from dream to reality over the next few years. To the user, an intelligent building offers economic and efficient environmental systems - heating, lighting and air conditioning; increased safety - with fire and security monitoring; improved business potential - with integrated data communication systems. To the manufacturer, intelligent buildings offer a lucrative market, particularly if they are able to exploit both the commercial and consumer markets. This book provides architects, building developers, system suppliers, engineers and academic researchers with an overview of the intelligent building market. The book brings together previously published papers as well as new material and examines the economics of sensor based systems. It explores the latest technological development and discusses the problems and the pitfalls. Emphasis is placed on practical case study material, covering a broad range of end users.

McClelland, S.

1989-01-01

385

[Protective action of radioprotectors and shielding against high-energy protons in experiments with rats].  

PubMed

Experiments with male rats were staged to study effectiveness of radioprotectors of two classes of chemical compounds (aminothiols--cystamine and indolyl alkylamines--mexamine and indralin) against high-energy protons (120 MeV) at a minimal absolutely lethal dose (10 Gy) and more than lethal doses (11.0-14.0 Gy). The best protective effect was provided by intraabdominal indralin at a dose of 75 mg/kg. However, this protective effect of indralin weakens with a dose rise and fades away with the dose rising to the absolutely lethal or more than lethal level (14.0 Gy). Investigations of the effectiveness of shielding different segments of the rat's body from high-energy protons (120 MeV) at more than lethal doses showed a substantial reduction and then full loss of the shielding protective action. Evaluation of the effectiveness of combined protection (radioprotectors plus shielding) against high-energy protons at more than lethal doses led to the conclusion about an additive (at 1.0-13.0 Gy) or potentiative (at 14.0 Gy) effect. For instance, indralin (75 mg/kg) and shielding of the abdomen increased rat's survivability to 89.7% after exposure at 11.0-13.0 Gy and to 87.5% after exposure at 14.0 Gy. It should be kept in mind that the radioprotective action of this combination was also observed during exposure to more than lethal doses when the protective effect of shielding and chemical compounds is minimal or lost altogether. PMID:18714729

Shashkov, V S; Karsanova, S K; Iasnetsov, V V

386

Shielding aspects of D- sup 3 He fusion power reactors  

SciTech Connect

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

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

1992-08-01

387

Beam loss, residual radiation, and collimation and shielding in the Fermilab booster  

SciTech Connect

During its 30 years of operation, the Fermilab Booster has served only as an injector for the relatively low repetition rate proton accelerator complex. With the construction of an 8 GeV target station for the 5 Hz MiniBooNE neutrino beam and rapid multi-batch injection into the Main Injector for the NuMI experiment, the demand for Booster protons will increase dramatically over the next few years. This implies serious constraints on beam losses in the machine. A collimation system and shielding design based on realistic Monte Carlo simulations are presented. A two-stage beam collimation system with local shielding has been designed. It provides adequate protection of the Booster components and environment by localizing operational losses. This loss control is a key to the entire future Fermilab high energy physics program.

Alexandr I. Drozhdin et al.

2001-07-20

388

Two-stage free electron laser research  

NASA Astrophysics Data System (ADS)

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

Segall, S. B.

1984-10-01

389

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.

390

Assessment of Cosmic Background Attenuation at Building 3425 (Underground Laboratory)  

Microsoft Academic Search

Specifications for the Underground Facility (building 3425) in the Radiation Detection and Nuclear Sciences complex presently under construction at Pacific Northwest National Laboratory mandate a 30 meters water equivalent shielding for cosmic background attenuation at the 30-foot underground depth of the laboratory. A set thickness of a specified fill material was determined; however a smaller thickness of a higher density

Richard T. Kouzes; James D. Borgardt; Azaree T. Lintereur; Mark E. Panisko

2009-01-01

391

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

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

392

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

393

HOT CELL BUILDING, TRA632. FIRST FLOOR PLAN. PLOT PLAN SHOWS ...  

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

HOT CELL BUILDING, TRA-632. FIRST FLOOR PLAN. PLOT PLAN SHOWS RELATIONSHIP TO PLUG STORAGE BUILDING. ONE HOT CELL ENCLOSED IN CONCRETE SHIELDING. IDAHO OPERATIONS OFFICE MTR-632-IDO-1, 11/1952. INL INDEX NO. 531-0632-00-396-110560, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

394

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

395

PROCESS WATER BUILDING, TRA605. FORMS AR SET TO CREATE THREE ...  

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

PROCESS WATER BUILDING, TRA-605. FORMS AR SET TO CREATE THREE SHIELDED CELLS FOR THE PUMPS THAT WILL BE IN WEST HALF OF THE BUILDING. PUMPS WILL LIFT WATER TO WORKING RESERVOIR. CAMERA FACES NORTHEAST. INL NEGATIVE NO. 1465. Unknown Photographer, 2/13/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

396

Building digest - general building aspects  

SciTech Connect

Thirteen bulletins are compiled covering Flush Doors; Wood Seasoning; Proportioning of Fly Ash Concrete Mix; The Yield of Mortar and Concrete Mix; Solar Water Heater - Domestic Type; Units for Living; Plastics and their Applications in Buildings; Hardboard and Particle Board; Woodwool Board; Material Constants in Building Works; Check-list for Taking Over Newly Constructed Buildings; Some Typical Enquiries and their Replies; and Energy Conservation in Buildings. These bulletins provide a comprehensive, step-by-step set of instructions on how to make and use the materials and techniques covered. Wood preservation and termite and rodent resistance of plastic pipes is also covered.

Damodaran, K.; George, J.; Rehsi, S.S.; Singh, S.; Sofat, G.C.

1981-01-01

397

Development of neutron shielding material using metathesis-polymer matrix  

NASA Astrophysics Data System (ADS)

A neutron shielding material using a metathesis-polymer matrix, which is a thermosetting resin, was developed. This shielding material has characteristics that can be controlled for different mixing ratios of neutron absorbers and for formation in the laboratory. Additionally, the elastic modulus can be changed at the hardening process, from a flexible elastoma to a mechanically tough solid. Experiments were performed at the Kyoto University Research Reactor in order to determine the important characteristics of this metathesis-polymer shielding material, such as neutron shielding performance, secondary gamma-ray generation and activation. The metathesis-polymer shielding material was shown to be practical and as effective as the other available shielding materials, which mainly consist of thermoplastic resin.

Sakurai, Yoshinori; Sasaki, Akira; Kobayashi, Tooru

2004-04-01

398

Shielding Design of the Spallation Neutron Source (SNS)  

SciTech Connect

The shielding design is important for the construction of an intense high-energy accelerator facility like the proposed Spallation Neutron Source (SNS) due to its impact on conventional facility design, maintenance operations, and since the cost for the radiation shielding shares a considerable part of the total facility costs. A calculational strategy utilizing coupled high energy Monte Carlo calculations and multi-dimensional discrete ordinates calculations, along with semi-empirical calculations, was implemented to perform the conceptual design shielding assessment of the proposed SNS. Biological shields have been designed and assessed for the proton beam transport system and associated beam dumps, the target station, and the target service cell and general remote maintenance cell. Shielding requirements have been assessed with respect to weight, space, and dose-rate constraints for operating, shutdown, and accident conditions. A discussion of the proposed facility design, conceptual design shielding requirements, calculational strategy, source terms, preliminary results and conclusions, and recommendations for additional analyses are presented.

Johnson, J.O.

1998-09-17

399

The Spallation Neutron Source (SNS) conceptual design shielding analysis  

SciTech Connect

The shielding design is important for the construction of an intense high-energy accelerator facility like the proposed Spallation Neutron Source (SNS) due to its impact on conventional facility design, maintenance operations, and since the cost for the radiation shielding shares a considerable part of the total facility costs. A calculational strategy utilizing coupled high energy Monte Carlo calculations and multi-dimensional discrete ordinates calculations, along with semi-empirical calculations, was implemented to perform the conceptual design shielding assessment of the proposed SNS. Biological shields have been designed and assessed for the proton beam transport system and associated beam dumps, the target station, and the target service cell and general remote maintenance cell. Shielding requirements have been assessed with respect to weight, space, and dose-rate constraints for operating, shutdown, and accident conditions. A discussion of the proposed facility design, conceptual design shielding requirements calculational strategy, source terms, preliminary results and conclusions, and recommendations for additional analyses are presented.

Johnson, J.O.; Odano, N.; Lillie, R.A.

1998-03-01

400

Thermal shielding of an emerging active region  

NASA Astrophysics Data System (ADS)

Context. The interaction between emerging active regions and the pre-existing coronal magnetic field is important for better understanding the mechanisms of storage and release of magnetic energy from the convection zone to the high corona. Aims: We describe the first steps of an emerging active region within a pre-existing quiet-Sun corona in terms of the thermal and magnetic structure. Methods: We used unprecedented spatial, temporal and spectral coverage from the Atmospheric Imager Assembly (AIA) and from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). Results: Starting on 30 May 2010 at 17:00 UT, we followed the emerging active region AR11076 within a quiet-Sun region for 8 h. Using several SDO/AIA filters that cover temperatures from 50 000 K to 10 MK, we show that the emerging process is characterised by a thermal shield at the interface between the emerging flux and pre-existing quiet-Sun corona. Conclusions: The active region 11076 is a peculiar example of an emerging active region because (i) the polarities emerge in a photospheric quiet-Sun region near a supergranular-like distribution, and (ii) the polarities that form the bipolar emerging structure do not rotate with respect to each other, which indicates a slight twist in the emerging flux bundle. There is a thermal shield at the interface between the emerging active region and the pre-existing quiet-Sun region. The thermal shielding structure deduced from all SDO/AIA channels is strongly asymmetric between the two polarities of the active region, suggesting that the heating mechanism for one polarity is probably magnetic reconnection, whilst it is caused by increasing magnetic pressure for the opposite polarity. Appendix A and two movies are available in electronic form at http://www.aanda.org

Régnier, S.

2012-08-01

401

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.

402

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

403

Radiation shield design for LMFBR spent-fuel shipping casks  

Microsoft Academic Search

Previous analyses have examined a limited number of the alternatives available for designing an LMFBR spent-fuel shipping cask (SFSC) using a non-volatile neutron shield; i.e., a neutron shield which will not be lost in an accident involving a fire. The present study extends the scope of these hypothetical designs to include combinations of volatile and non-volatile neutron shield materials.

Dupree

1977-01-01

404

FWBS Program element II: Blanket and shield testing  

Microsoft Academic Search

The First Wall\\/Blanket\\/Shield (FWBS) Program has the goal to provide the development and testing of FWBS systems for magnetic fusion reactors. Program Element II of this program is to develop the thermal-hydraulic and thermomechanical data base for blanket and shield components. The critical blanket\\/shield data needs were identified, alternate techniques to simulate fusion neutron bulk heating were evaluated, and a

K. R. Schultz; A. R. Veca

1983-01-01

405

Longwall shield design: is bigger better?  

SciTech Connect

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

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

2008-05-15

406

Shielding design at Fermilab: Calculations and measurements  

SciTech Connect

The development of the Fermilab accelerator complex during the past two decades from its concept as the ''200 BeV accelerator'' to that of the present tevatron, designed to operate at energies as high as 1 TeV, has required a coincidental refinement and development in methods of shielding design. In this paper I describe these methods as used by the radiation protection staff of Fermilab. This description will review experimental measurements which substantiate these techniques in realistic situations. Along the way, observations will be stated which likely are applicable to other protron accelerators in the multi-hundred GeV energy region, including larger ones yet to be constructed.

Cossairt, J.D.

1986-11-01

407

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

408

Shielded serpentine traveling wave tube deflection structure  

DOEpatents

A shielded serpentine slow wave deflection structure (10) having a serpene signal conductor (12) within a channel groove (46). The channel groove (46) is formed by a serpentine channel (20) in a trough plate (18) and a ground plane (14). The serpentine signal conductor (12) is supported at its ends by coaxial feed through connectors 28. A beam interaction trough (22) intersects the channel groove (46) to form a plurality of beam interaction regions (56) wherein an electron beam (54) may be deflected relative to the serpentine signal conductor (12).

Hudson, Charles L. (Santa Barbara, CA); Spector, Jerome (Berkeley, CA)

1994-01-01

409

Superconducting shields and manufactured ceramic wares of complex configuration  

NASA Astrophysics Data System (ADS)

A technology has been developed for fabrication of magnetic shields and other high technological wares of superconducting yttrium-barium-copper ceramic by hot casting under pressure. The method enables to form wares of complex configurations and different sizes without any additional machining. The method of hot casting under pressure allows to obtain superconducting shields with a fair homogeneity of the critical field over the shielding length. At working temperature 77, 4K the shields have a threshold screening field Hc* about 1.5 mT, high screening factor (S>104) and low intrinsic noise level (<10-6mT).

Fedorov, Vladimir E.; Pletnev, Peter M.; Korpachev, Michael G.; Korpacheva, Anastasiya I.; Mazhara, Anatoly P.; Dikovskij, Valery Ja.; Gindulina, Venera Z.; Potapova, Olga G.

1991-12-01

410

Radiation protection and shielding standards for the 1980s  

SciTech Connect

The American Nuclear Society (ANS) is a standards-writing organization member of the American National Standards Institute (ANSI). The ANS Standards Committee has a subcommittee denoted ANS-6, Radiation Protection and Shielding, whose charge is to develop standards for radiation protection and shield design, to provide shielding information to other standards-writing groups, and to develop standard reference shielding data and test problems. This paper is a progress report of this subcommittee. Significant progress has been made since the last comprehensive report to the Society.

Trubey, D.K.

1982-01-01

411

Implications of Shield's inverse deformation theorem for compressible finite elasticity  

NASA Astrophysics Data System (ADS)

Some properties of the Shield transformation on elastic strain energy functions are established. It is reflexive, it preserves objectivity and material symmetry for isotropic materials, and it also preserves infinitesimal strain response, ellipticity and Hadamard stability, and the Baker Ericksen condition. Two new classes of strain energies for compressible isotropic materials are introduced, one of them being the image under the Shield transformation of the class of harmonic strain energies. In view of Shield’s Inverse Deformation Theorem, these new classes of strain energies will allow solution in closed form of a variety of problems in finite elastostatics.

Carroll, M. M.; Rooney, F. J.

2005-11-01

412

Building Skills to Build Communities  

ERIC Educational Resources Information Center

|Communities are at the heart of the government's vision for the Big Society. And it's the author's strongly held view that skills should be at the heart of each and every one of those communities. If one grows the skills of an individual then the community will flourish. There is a job to be done in building skills to build communities--skilled…

Russell, Geoff

2011-01-01

413

Intelligent Buildings  

SciTech Connect

The topic of "intelligent buildings" (IBs) emerged in the early 1980s. Since, the term has been used to represent a variety of related, yet differing topics, each with a slightly different focus and purpose. Wiring and networking-infrastructure companies emphasize the cabling requirements for communication in intelligent buildings and the need to accommodate future needs for higher-speed broadband. Lucent (Lucent 2000) for example, defines an IB as "...one with a completely integrated wiring architecture. A single cabling system that handles all information traffic - voice, data, video, even the big building management systems."

Brambley, Michael R.; Armstrong, Peter R.; Kintner-Meyer, Michael CW; Pratt, Robert G.; Katipamula, Srinivas

2001-01-01

414

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

415

SHIELDING REQUIREMENTS FOR NSLS-II.  

SciTech Connect

Brookhaven National Laboratory is in the process of designing a new Electron Synchrotron for scientific research using synchrotron radiation. This facility, called the 'National Synchrotron Light Source II' (NSLS-II), will provide x-ray radiation of ultra-high brightness and exceptional spatial and energy resolution. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. The project scope includes the design, construction, installation, and commissioning of the following accelerators: a 200 MeV linac, a booster accelerator operating from 200 MeV to 3.0 GeV, and the storage ring which stores a maximum of 500 mA current of electrons at an energy of 3.0 GeV. It is planned to operate the facility primarily in a top-off mode, thereby maintaining the maximum variation in stored beam current to < 1%. Because of the very demanding requirements for beam emittance and synchrotron radiation brilliance, the beam life-time is expected to be low, on the order of 2-3 hours. Analysis of the bulk shielding for operating this facility and the input parameters used for this analysis are discussed in this paper. The characteristics of each of the accelerators and their operating modes are summarized with the input assumptions for the bulk shielding analysis.

JOB,P.K.; CASEY, W.R.

2008-01-02

416

Optimization of Shielded Scintillator for Neutron Detection  

NASA Astrophysics Data System (ADS)

The High Energy Density Physics group is interested in the basic science of creating a neutron and gamma ray source. The neutrons and gamma rays are produced by accelerating ions via a laser into a target and creating fusion neutrons and gamma rays. A scintillator and photomultiplier tube will be used to detect these neutrons. Neutrons and photons produce ionizing radiation in the scintillator which then activates metastable states. These metastable states have both short and long decay rates. The initial photon count is orders of magnitude higher than the neutron count and poses problems for accurately detecting the neutrons due to the long decay state that is activated by the photons. The effects of adding lead shielding on the temporal response and signal level of the neutron detector will be studied in an effort to minimize the photon count without significant reduction to the temporal resolution of the detector. MCNP5 will be used to find the temporal response and energy deposition into the scintillator by adding lead shielding. Results from the simulations will be shown. Optimization of our scintillator neutron detection system is needed to resolve the neutron energies and neutron count of a novel neutron and gamma ray source.

Belancourt, Patrick; Morrison, John; Akli, Kramer; Freeman, Richard

2011-11-01

417

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

418

Active Neutron Veto Shield Design for SuperCDMS-SNOLAB  

NASA Astrophysics Data System (ADS)

Protection against neutron backgrounds is one of the key issues for the next generation SuperCDMS direct dark matter detection experiment that aims at exploring the 10-46 cm^2 cross section region for spin-independent interactions of Weakly Interacting Massive Particles (WIMPs) with nucleons. Estimation of the background from radioactive processes is a crucial task for the current experiment stage and for designing future large-scale detectors. An active neutron veto would make the next generation of dark matter experiment more robust, improving the credibility of a dark matter detection claim based on the observation of a few recoil events. SuperCDMS is investigating the feasibility of adding a liquid scintillator active neutron veto, loaded with high neutron capture cross section isotopes, to the SuperCDMS SNOLAB shield design. This system not only will allow us to reject neutron-induced backgrounds, but also will provide an in-situ measurement of the neutron flux near the detector. I will report the status of ongoing studies related to the design and construction of such a veto.

Qiu, Hang

2013-04-01

419

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.

Deas, Joseph B.; Hunter, Martha S.

2012-01-01

420

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.

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

421

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

422

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

423

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

424

LOFT. Containment and service building (TAN650). Section through north/south axis. ...  

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

LOFT. Containment and service building (TAN-650). Section through north/south axis. Shows basement and four additional levels of pre-amp tower, shielded roadway, chambers below reactor floor, railroad door, sumps, shielding. Section C shows basement sumps and chambers below reactor floor. Kaiser engineers 6413-11-STEP/LOFT-650-A-5. Date: October 1964. INEEL index code no. 036-650-00-486-122217 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

425

Radiation shielding for 250 MeV protons  

SciTech Connect

This paper is targetted at personnel who have the responsibility of designing the radiation shielding against neutron fluences created when protons interact with matter. Shielding of walls and roofs are discussed, as well as neutron dose leakage through labyrinths. Experimental data on neutron flux attenuation are considered, as well as some calculations using the intranuclear cascade calculations and parameterizations.

Awschalom, M.

1987-04-01

426

Electromagnetic shielding of plastic material in laser diode modules  

Microsoft Academic Search

Electromagnetic shielding of plastic materials in laser modules was studied experimentally and theoretically. The conductive carbon fiber fillers into plastics to produce electrically conductive composites were proposed for the evaluation of electromagnetic interference (EMI) shielding effectiveness (SE). The different volume fractions of conductive carbon fiber fillers ranging from 5, 10, 20, and 30% were used. The SE of conductive plastics

S. K. Chiu; J. Y. Cheng; W. S. Jou; G. J. Jong; S. C. Wang; C. M. Wang; C. S. Lin; T. L. Wu; W. H. Cheng

2001-01-01

427

Cooling structure for EMC shielded high frequency electronics  

Microsoft Academic Search

Cooling of electronics is normally achieved using air passing through apertures in the enclosure; as a result the shielding effectiveness of the shielded enclosure is reduced. In this paper, the design of a new cooling structure and its evaluation in a wind tunnel is presented. The developed design presented here is a double heat sink in extruded aluminum. Into one

W. Peter Siebert

2006-01-01

428

A STUDY OF SPACE RADIATION SHIELDING PROBLEMS FOR MANNED VEHICLES  

Microsoft Academic Search

The resolution of the problem of protecting space vehicle crews from ; charged particles of either solar-flare or trapped-radiation origin will probably ; depend on shielding. The basic problem is concerned with determining ; quantitatively the attenuation requirement of the incident radiation and ; selecting an appropriate material to provide this shielding. The hazards of ; space radiation, the methods

R. K. Wilson; R. A. Miller; R. L. Kloster

1962-01-01

429

The Space Radiation: Nature, Biological Effects and Shielding  

Microsoft Academic Search

The latest findings in origin, biological effects and shielding of the space ionizing radiation (SIR) are reviewed. It is stressed that after the impending implementation of artificial gravity, SIR could become the most serious concern for deep space travelers. SIR is more effective in induction of the genome- and cell-associated damages, compared with the conventional radioactive sources. The shielding of

Kh. Muradian

2002-01-01

430

Degradation of thermal shield materials in the space radiation environment  

Microsoft Academic Search

Changes in temperature distribution data of Experimental Technology Satellite 4 after its 3 months mission term are discussed. Analysis of the data suggested that the thermal shields loose their function in the space radiation environment. The effect of energetic particles on the shield materials was investigated. Electron beams of 500 keV and proton beams of 900 keV were irradiated on

S. Shimoji; H. Kimura; M. Koitabashi; T. Imamura; R. Kasai; M. Matsushita

1983-01-01

431

Description of transport codes for space radiation shielding.  

PubMed

Exposure to ionizing radiation in the space environment is one of the hazards faced by crews in space missions. As space radiations traverse spacecraft, habitat shielding, or tissues, their energies and compositions are altered by interactions with the shielding. Modifications to the radiation fields arise from atomic interactions of charged particles with orbital electrons and nuclear interactions leading to projectile and target fragmentation, including secondary particles such as neutrons, protons, mesons, and nuclear recoils. The transport of space radiation through shielding can be simulated using Monte Carlo techniques or deterministic solutions of the Boltzmann equation. To determine shielding requirements and to resolve radiation constraints for future human missions, the shielding evaluation of a spacecraft concept is required as an early step in the design process. To do this requires (1) accurate knowledge of space environmental models to define the boundary condition for transport calculations, (2) transport codes with detailed shielding and body geometry models to determine particle transmission into areas of internal shielding and at each critical body organ, and (3) the assessment of organ dosimetric quantities and biological risks by applying the corresponding response models for space radiation against the particle spectra that have been accurately determined from the transport code. This paper reviews current transport codes and analyzes their accuracy through comparison to laboratory and spaceflight data. This paper also introduces a probabilistic risk assessment approach for the evaluation of radiation shielding. PMID:23032892

Kim, Myung-Hee Y; Wilson, John W; Cucinotta, Francis A

2012-11-01

432

IET. Periscope shielding and installation details. Shows range of scanning ...  

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

IET. Periscope shielding and installation details. Shows range of scanning head, removable concrete cap, concrete shielding. Ralph M. Parsons 902-4-ANP-620-A 324. Date: February 1954. Approved by INEEL Classification Office for public release. INEEL Index code no. 035-0620-00-693-106909 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

433

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

434

Impact of the retained heat shield concept on science instruments  

Microsoft Academic Search

Associated interface problems between the mass spectrometer and the actual probe design are considered along with the problem of producing a clean sample to the gas detection instrument. Of particular interest is the penetration of the heat shield by the mass spectrometer sampling tube, because it must be demonstrated that the sampling tube can penetrate the heat shield and that

W. C. Kessler

1974-01-01

435

Late Proterozoic extensional collapse in the Arabian-Nubian Shield  

Microsoft Academic Search

A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid area and as a result, they are interpreted as extensional metamorphic core complexes. The presence

B. B. Blasband; S. H. White; P. Brooijmans; H. de Boorder; W. Visser

2000-01-01

436

Estimation of Electric Parameters of Thin Electromagnetic Shielding Materials  

Microsoft Academic Search

It is important to know the electric parameters of the shielding material for numerical analysis. The purpose of this report is to estimate electric parameters of thin shielding materials. Electromagnetic field in the vicinity of a horizontal multi-layered material with a magnetic dipole source is calculated numerically by a Sommerfeld integral. On the basis of this calculation, we develop a

Isamu Nagano; Yoshiyuki Yoshimura; Satoshi Yagitani; Hiroaki Yokomoto; Toshihide Tosaka; Toshihiro Nakayabu

2003-01-01

437

Electromagnetic interference shielding effectiveness of carbon nanofiber\\/LCP composites  

Microsoft Academic Search

Vapor grown carbon nanofiber reinforced liquid crystal polymer (LCP) composites were studied. The surface resistivity of LCP was lowered more than 11 orders of magnitude by incorporating 5wt% of nanofibers. The electromagnetic interference shielding effectiveness (SE) at different frequencies was also studied. The composites were shown to exhibit up to 41dB of SE. The shielding mechanism of the system was

Shuying Yang; Karen Lozano; Azalia Lomeli; Heinrich D. Foltz; Robert Jones

2005-01-01

438

Relativistic One-Electron Calculations of Shielded Atomic Hyperfine Constants  

Microsoft Academic Search

Core shielding effects in atomic hyperfine structure are examined within the framework of relativistic electron theory in the Hartree-Fock-Slater approximation. Expressions are developed for shielding factors pertaining to electric and magnetic hyperfine constants of arbitrary order. Known values of the nuclear magnetic moments for alkali and halogen atoms are used to obtain theoretical predictions of the dipole hyperfine constant \\

M. J. Amoruso; W. R. Johnson

1971-01-01

439

Accurate calculation of shielding factor for high energy beam currents  

Microsoft Academic Search

The theoretical basis for neutral beam current drive was well developed nearly two decades ago. A key element of the net driven current is the shielding factor, which includes both classical (friction) and neoclassical (viscous) responses of the thermal plasma to the fast ion current. We review the strengths and limitations of existing formulations of the shielding factor in terms

W. A. Houlberg; S. P. Hirshman

2004-01-01

440

Large Perturbations in Electron Beams from Shielded and Immersed Guns†  

Microsoft Academic Search

Largo perturbations in cylindrical beams from magnetically shielded and immersed guns are calculated by numerical integration of the electron dynamic equations. Contours of a particular beam from both typos of electron guns are given, and the calculated contours in the shielded gun are compared with the experimental results obtained by Lawson. By the use of reduced variables, universal beam contours

T. S. CHEN

1958-01-01

441

The effectiveness of acoustic shielding for HSCT nozzle configurations  

Microsoft Academic Search

A comparison of the acoustic shielding effectiveness of round and rectangular nozzles is presented as a function of nozzle spacing for sonic flow from convergent nozzles. The flow simulates the exhaust from fully-mixed ejectors as might be encountered on the High Speed Civil Transport. These data are intended to offer comparative acoustic shielding guidelines to be used when selecting a

Richard W. Wlezien; Chris B. Rogers; Kingo J. Yamamoto; Belle Wang

1991-01-01

442

Self-sealing materials for space debris shield  

Microsoft Academic Search

To protect space structures from debris impact, the new types of shield using a self-sealing materials are suggested. A hole by debris impact on shield will be fixed with the self-sealing materials by melting, sealing and solidification. Time to seal impact hole was experimentally simulated. If time to seal impact hole was assumed to be about 5 s, viscosity of

M. Tochizawa; N. Inoue; M. Tanaka; Yoshitake Nishi

2004-01-01

443

Combining magnetic shielding and cryopumping for a neutral beam source  

Microsoft Academic Search

Neutral beam sources similar to the designs executed by LBL for TFTR and for Doublet III require a substantial hydrogen pumping speed and careful magnetic shielding in order to optimize neutral beam production. A design which satisfies each requirement separately results in a design where the performance of both the magnetic shield and the cryopump is compromised by the requirement

J. Tanabe; M. A. Green

1979-01-01

444

Military-Media Relations: First Impressions of Operation Desert Shield.  

National Technical Information Service (NTIS)

Military-media relations in Operation Desert Shield is analyzed by comparing how the media has been handled in recent military operations to Desert Shield. Past operations are reviewed to discern if the military is learning from these experiences so that ...

K. S. Plato

1991-01-01

445

Antimutagenicity of herbal detoxification formula Smoke Shield against environmental mutagens.  

PubMed

Smoke Shield is a formulation designed to reduce smoke related mutagenicity and toxicity in the population. Smoke Shield contains a dual extract of turmeric (Curcuma longa) obtained by supercritical CO2 gas extraction and post-supercritical hydroethanolic extraction together with extracts of green tea and other spices, whose presence synergistically increases the activity of turmeric. In the present study we have shown its antimutagenic activity to various environmental mutagens in vitro and in vivo. Smoke Shield was found to produce significant inhibition of mutagenicity to Salmonella typhimurium induced by sodium azide and 4-nitro-0-phenylenediamine (NPD) at a concentration of 2 mg/plate while inhibition to N-methyl-N-nitro N'nitrosoguanidine was less significant. Inhibition was also found to depend upon the strain which was used. Smoke Shield was found to be more effective against mutagens needing metabolic activation such as 2-Acetamidofluorene (2-AAF) and benzo[a]pyrene. Smoke Shield was also found to significantly inhibit the mutagenicity induced by tobacco extract to Salmonella typhimurium TA102. Smoke Shield was also found to inhibit the urinary mutagenicity of rats treated with the benzo[a]pyrene and tobacco extract. Moreover, Smoke Shield administration was found to inhibit the urinary mutagenicity in smokers. These results indicate that Smoke Shield could inhibit mutagenic response in vitro and in vivo produced by several kinds of mutagens present in our atmosphere. PMID:15149152

Kuttan, R; Kuttan, G; Joseph, S; Ajith, T A; Mohan, M; Srimal, R C

2004-03-01

446

Antimutagenicity of Herbal Detoxification Formula Smoke Shield Against Environmental Mutagens  

Microsoft Academic Search

Smoke Shield is a formulation designed to reduce smoke related mutagenicity and toxicity in the population. Smoke Shield contains a dual extract of turmeric (Curcuma longa) obtained by supercritical CO2 gas extraction and post-supercritical hydroethanolic extraction together with extracts of green tea and other spices, whose pres- ence synergistically increases the activity of turmeric. In the present study we have

R. Kuttan; G. Kuttan; S. Joseph; T. A. Ajith; M. Mohan; R. C. Srimal

447

Gravity Scaling of a Power Reactor Water Shield.  

National Technical Information Service (NTIS)

A similarity analysis on a water-based reactor shield examined the effect of gravity on free convection between a reactor shield inner and outer vessel boundaries. Two approaches established similarity between operation on the Earth and the Moon: 1) direc...

J. B. Pearson R. S. Reid

2007-01-01

448

Effects of Partial Shields on Transmission Lines at Low Frequencies  

Microsoft Academic Search

It is often desirable to estimate the degree of shielding achieved between two transmission lines crossing at some specified angle, when one of them is surrounded by a metallic tubing of finite length. A simple analysis that allows a rather accurate estimation of the shielding effectiveness of the tubing at low frequencies where the quasi-static assumption holds is presented. Based

Nabil Farhat; Yung-Ping Loh; Ralph Showers

1968-01-01

449

Shielding properties of lead and barium phosphate glasses  

NASA Astrophysics Data System (ADS)

P2O5-PbO-BaO glass system has been investigated to see its potential use as radiation shielding material by studying the effect of the content of each of its composing oxides. The results show that this glass system is suitable as radiation shielding material and has some advantages comparing to the existing commonly used radiation protection glasses.

Kharita, M. H.; Jabra, R.; Yousef, S.; Samaan, T.

2012-10-01

450

Shielding and energy transfer of transient electromagnetic fields  

Microsoft Academic Search

For the time-harmonic electromagnetic fields the shielding effectiveness of conducting and permeable materials is characterized by the relation of the field amplitudes or their quadratures arising at chosen locations in the absence of the electromagnetic shield to the ones arising in the presence of it. In theoretical treatises homogeneous electric or magnetic fields, plane fields of parallel conductors, homogeneous plane

G. Mrozynski; H. Pankratz; O. Erb

2002-01-01

451

An Efficient Algorithm for Shielding Electromagnetic Topological Diagram  

Microsoft Academic Search

An electromagnetic topology method used to analyze interactions between electronic systems and electromagnetic environment is presented. Combining electromagnetic topology model with the graph theory, an efficient algorithm is obtained. The algorithm can find out all the paths which have a lower shielding coefficient than the given threshold K in the shielding electromagnetic topological diagram.

Yongfeng Wang; Chengda Yu; Chaowei Zhang

2010-01-01

452

SUBLAYER SETS AND RELATIVE SHIELDING ORDER IN ELECTROMAGNETIC TOPOLOGY  

Microsoft Academic Search

This paper explores some aspects of qualitative electromagnetic topology for system design. Sublayers are partitioned into sets for separate treatment in the design process. The concept of relative shielding order between pairs of sublayers is introduced and constraints on this non-negative-integer parameter are explored. Special cases are considered, including that of uniform relative shielding order between pairs of a set

Carl E. Baum

1982-01-01

453

High Voltage Transmission Line Protection Using Shielding Method  

Microsoft Academic Search

This paper describes shielding method for lightning protection on high voltage transmission line and also how to protect lightning effects on the line. If the fault is present, additional power system will be damaged and minimizing system reliability. This shielding method used in transmission line bases the unequal lightning ground flash density all over the country. This paper is tend

Zar Ni Tun; Tun Naing

2009-01-01

454

Initial progress in the first wall, blanket, and shield Engineering Test Program for magnetically confined fusion-power reactors  

Microsoft Academic Search

The first wall\\/blanket\\/shield (FW\\/B\\/S) Engineering Test Program (ETP) progressed from the planning stage into implementation during July, 1981. The program, generic in nature, comprises four Test Program Elements (TPE's), the emphasis of which is on defining the performance parameters for the Fusion Engineering Device (FED) and the major fusion device to follow FED. These elements are: (1) nonnuclear thermal-hydraulic and

H. Herman; C. C. Baker; V. A. Maroni

1981-01-01

455

FAST CHOPPER BUILDING, TRA665. CAMERA FACING NORTH. NOTE BRICKEDIN WINDOW ...  

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

FAST CHOPPER BUILDING, TRA-665. CAMERA FACING NORTH. NOTE BRICKED-IN WINDOW ON RIGHT SIDE (BELOW PAINTED NUMERALS "665"). SLIDING METAL DOOR ON COVERED RAIL AT UPPER LEVEL. SHELTERED ENTRANCE TO STEEL SHIELDING DOOR. DOOR INTO MTR SERVICE BUILDING, TRA-635, STANDS OPEN. MTR BEHIND CHOPPER BUILDING. INL NEGATIVE NO. HD42-1. Mike Crane, Photographer, 3/2004 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

456

7 CFR 1755.406 - Shield or armor ground resistance measurements.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Shield or armor ground resistance measurements. 1755.406 Section...1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall be made on...

2010-01-01

457

7 CFR 1755.406 - Shield or armor ground resistance measurements.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Shield or armor ground resistance measurements. 1755.406 Section...1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall be made on...

2009-01-01

458

75 FR 57519 - Weather Shield Manufacturing, Medford, WI; Notice of Negative Determination Regarding Application...  

Federal Register 2010, 2011, 2012, 2013

...Training Administration [TA-W-72,673] Weather Shield Manufacturing, Medford, WI...applicable to workers and former workers of Weather Shield Manufacturing, Inc., Medford...production of doors and windows at various Weather Shield Manufacturing, Inc....

2010-09-21

459

76 FR 35026 - Weather Shield Manufacturing, Inc. Corporate Office, Medford, WI; Notice of Amended Negative...  

Federal Register 2010, 2011, 2012, 2013

...Training Administration TA-W-72,673 Weather Shield Manufacturing, Inc. Corporate...administrative record in Former Employees of Weather Shield Manufacturing, Inc. v. United...applicable to workers and former workers of Weather Shield Manufacturing, Inc.,...

2011-06-15

460

76 FR 70761 - Weather Shield Manufacturing, Inc. Corporate Office, Medford, WI; Notice of Negative...  

Federal Register 2010, 2011, 2012, 2013

...Training Administration [TA-W-72,673] Weather Shield Manufacturing, Inc. Corporate...administrative record in Former Employees of Weather Shield Manufacturing, Inc. v. United...applicable to workers and former workers of Weather Shield Manufacturing, Inc.,...

2011-11-15

461

75 FR 51851 - Weather Shield Manufacturing, Inc., Corporate Office, Medford, WI; Notice of Revised...  

Federal Register 2010, 2011, 2012, 2013

...Training Administration [TA-W-64,725] Weather Shield Manufacturing, Inc., Corporate...for further review, Former Employees of Weather Shield Manufacturing, Inc. v. United...December 17, 2008, former workers of Weather Shield Manufacturing, Inc....

2010-08-23

462

78 FR 775 - Weather Shield Manufacturing, Inc., Corporate Office, Medford, WI; Notice of Negative...  

Federal Register 2010, 2011, 2012, 2013

...Training Administration [TA-W-72,673] Weather Shield Manufacturing, Inc., Corporate...further investigation in Former Employees of Weather Shield Manufacturing, Inc. v. United...behalf of workers and former workers of the Weather Shield Manufacturing, Inc.,...

2013-01-04

463

78 FR 19148 - Shielding and Radiation Protection Review Effort and Licensing Conditions for Dry Storage...  

Federal Register 2010, 2011, 2012, 2013

...72 [NRC-2013-0051] Shielding and Radiation Protection Review Effort and Licensing...SFST-ISG-26A), Revision 0, ``Shielding and Radiation Protection Review Effort and Licensing...staff when reviewing the shielding and radiation protection portions of applications...

2013-03-29

464

Galactic and Solar Cosmic Ray Shielding in Deep Space  

NASA Astrophysics Data System (ADS)

An analysis of the radiation hazards in support of NASA deep space exploration activities is presented. The emphasis is on materials required for radiation protection shielding. Aluminum has been found to be a poor shield material when dose equivalent is used with exposure limits for low Earth orbit (LEO) as a guide for shield requirements. Because the radiation issues are cost related-the parasitic shield mass has high launch costs, the use of aluminum as a basic construction material is clearly not cost-effective and alternate materials need to be developed. In this context, polyethylene is examined as a potentially useful material and demonstrates important advantages as an alternative to aluminum construction. Although polyethylene is useful as a shield material, it may not meet other design criteria (strength, stability, thermal); other polymer materials must be examined.

Wilson, John W.; Cucinotta, Francis A.; Tai, H.; Simonsen, Lisa C.; Shinn, Judy L.; Thibeault, Shelia; Kim, M. Y.

1997-12-01

465

A proposed performance index for galactic cosmic ray shielding materials  

NASA Astrophysics Data System (ADS)

In past studies, the reductions in absorbed dose and dose equivalent due to choice of material composition have been used to indicate shield effectiveness against exposure to galactic cosmic rays. However, these quantities are highly inaccurate in assessing shield effectiveness for protection against the biological effects of long-term exposure to the galactic heavy ions. A new quantity for shield performance is defined that correlates well with cell killing and cell transformation behind various shield thicknesses and materials. In addition, a relative performance index is identified that is inversely related to biological injury for different materials at a fixed shield mass and is directly related to the ratio of the fourth- and the second-order linear energy transfer (LET) moments.

Wilson, John W.; Wood, J. S.; Shinn, Judy L.; Cucinotta, Francis A.; Nealy, John E.

1993-08-01

466

MCG measurement in the environment of active magnetic shield.  

PubMed

MCG (Magnetocardiography) measurement by a SQUID gradiometer was attempted with only active magnetic shielding (active shielding). A three-axis-canceling-coil active shielding system, where three 16-10-16 turns-coil sets were put in the orthogonal directions, produces a homogeneous magnetic field in a considerable volume surrounding the center. Fluxgate sensors were used as the reference sensors of the system. The system can reduce environmental magnetic noise at low frequencies of less than a few Hz, at 50 Hz and at 150 Hz. Reducing such disturbances stabilizes biomagnetic measurement conditions for SQUIDs in the absence of magnetically shielded rooms (MSR). After filtering and averaging the measured MCG data by a first-order SQUID gradiometer with only the active shielding during the daytime, the QRS complex and T wave was clearly presented. PMID:16012640

Yamazaki, K; Kato, K; Kobayashi, K; Igarashi, A; Sato, T; Haga, A; Kasai, N

2004-11-30

467

Shielding integral benchmark archive and database (SINBAD)  

SciTech Connect

The shielding integral benchmark archive and database (SINBAD) collection of experiments descriptions was initiated in the early 1990s. SINBAD is an international collaboration between the Organization for Economic Cooperation and Development's Nuclear Energy Agency Data Bank (OECD/NEADB) and the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory (ORNL). SINBAD was designed to compile experiments and corresponding computational models with the goal of preserving institutional knowledge and expertise that need to be handed down to future scientists. SINBAD can serve as a learning tool for university students and scientists who need to design experiments or gain expertise in modeling and simulation. The SINBAD database is currently divided into three categories - fission, fusion, and accelerator experiments. Many experiments are described and analyzed using deterministic or stochastic (Monte Carlo) radiation transport software. The nuclear cross sections also play an important role as they are necessary in performing computational analysis. (authors)

Kirk, B.L.; Grove, R.E. [Radiation Safety Information Computational Center RSICC, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6171 (United States); Kodeli, I. [Josef Stefan Inst., Jamova 39, 1000 Ljubljana (Slovenia); Gulliford, J.; Sartori, E. [OECD NEA Data Bank, Bd des Iles, 92130 Issy-les-Moulineaux (France)

2011-07-01

468

Shielding Integral Benchmark Archive and Database (SINBAD)  

SciTech Connect

The Shielding Integral Benchmark Archive and Database (SINBAD) collection of benchmarks was initiated in the early 1990 s. SINBAD is an international collaboration between the Organization for Economic Cooperation and Development s Nuclear Energy Agency Data Bank (OECD/NEADB) and the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory (ORNL). SINBAD is a major attempt to compile experiments and corresponding computational models with the goal of preserving institutional knowledge and expertise that need to be handed down to future scientists. SINBAD is also a learning tool for university students and scientists who need to design experiments or gain expertise in modeling and simulation. The SINBAD database is currently divided into three categories fission, fusion, and accelerator benchmarks. Where possible, each experiment is described and analyzed using deterministic or probabilistic (Monte Carlo) radiation transport software.

Kirk, Bernadette Lugue [ORNL; Grove, Robert E [ORNL; Kodeli, I. [International Atomic Energy Agency (IAEA); Sartori, Enrico [ORNL; Gulliford, J. [OECD Nuclear Energy Agency

2011-01-01

469

Fan-fold shielded electrical leads  

DOEpatents

Disclosed are fan-folded electrical leads made from copper cladded Kapton, for example, with the copper cladding on one side serving as a ground plane and the copper cladding on the other side being etched to form the leads. The Kapton is fan folded with the leads located at the bottom of the fan-folds. Electrical connections are made by partially opening the folds of the fan and soldering, for example, the connections directly to the ground plane and/or the lead. The fan folded arrangement produces a number of advantages, such as electrically shielding the leads from the environment, is totally non-magnetic, and has a very low thermal conductivity, while being easy to fabricate. 3 figs.

Rohatgi, R.R.; Cowan, T.E.

1996-06-11

470

Shielded radiation protection quantities beyond LEO  

NASA Astrophysics Data System (ADS)

The National Council on Radiation Protection and Measurements (NCRP) has recommended that the quantities used to evaluate health risk to astronauts due to radiation exposure be effective dose and gray-equivalent. The NCRP recommends that effective dose be the limiting quantity for prevention of stochastic effects. Effective dose is a measure of whole body exposure, a weighted average of dose equivalent to a number body tissues for which the NCRP has adopted tissue weighting factors recommended by the International Commission on Radiation Protection (ICRP). For deterministic effects, the NCRP has recommended that gray-equivalent be used. Gray-equivalent is evaluated for specific critical organs and is the weighted sum of absorbed dose from field components to that organ using the relative biological effectiveness (RBE) number for that field component. RBE numbers recommended by the NCRP are used. The NCRP has provided effective dose limits as well as limits for gray-equivalent to eyes, skin, and blood forming organs (BFO) for astronauts in low earth orbit (LEO). As yet, no such limits have been defined for astronaut operations beyond LEO. In this study, the radiation protection quantities, effective dose and gray-equivalent to the eyes, skin, and BFO, are calculated for several environments beyond LEO. The lunar surface and Martian environments are included. For each environment, these radiation protection quantities are calculated behind varying amounts of various types of shielding materials. The results are compared to the exposure limits for LEO, since limits have not yet been defined for interplanetary missions. The benefits of using shielding material containing hydrogen and choosing optimal mission times are discussed.

Clowdsley, M. S.; Wilson, J. W.; Kim, M. Y.; Anderson, B. M.; Nealy, J. E.

471

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

472

Shielding failure analysis of 132 kV transmission line shielded by surge arresters associated with multiple strokes lightning  

Microsoft Academic Search

Analysis of shielding failure is carried out to observe flashover of insulators parallel with phase conductors of a transmission line associated with a lightning strike on phase conductor. Peak current of different magnitude have been used to represent the multiple strokes lightning (MSL). This paper aims to simulate the worst case due to transmission shielding failure with three direct strikes

David Caulker; Hussein Ahmad; Zulkurnain Abdul Malek; Sallehhudin Yusof

2010-01-01

473

SUPPORT AND FLIGHTLINE BUILDINGS, LOOKING TOWARD SQUADRON OPERATIONS BUILDING (BUILDING ...  

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

SUPPORT AND FLIGHTLINE BUILDINGS, LOOKING TOWARD SQUADRON OPERATIONS BUILDING (BUILDING 2716)RIGHT, AIR FORCE COMMUNICATIONS SYSTEMS (AFCS) MAINTENANCE FACILITY (BUILDING 2714)CENTER AND BASE OPERATIONS (BUILDING 2712)LEFT. VIEW TO SOUTHEAST - Plattsburgh Air Force Base, U.S. Route 9, Plattsburgh, Clinton County, NY

474

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.

475

Building Tall  

NSDL National Science Digital Library

In this engineering activity (page 2 of PDF), young learners investigate how a wide base can make a building more stable. Learners use blocks or boxes of different sizes to construct stable towers. Learners will compare and contrast different structures, document their observations, experiment with different materials, and conduct stability tests. This activity is part of the Curious George "Under Construction" lesson plan and related to the show Curious George on PBS, specifically the episode "Curious George's Home for Pigeons." The lesson plan includes several activities that explore building engineering. Activities are connected to fiction and non-fiction books and include family extension projects.

Kids, Pbs

2006-01-01

476

2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND ...  

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

2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND GARDEN, VIEW TO SOUTHWEST - Sears Roebuck & Company Mail Order Plant, Bounded by Lexington & Grenshaw Streets, Kedzie Avenue & Independence Boulevard, Chicago, Cook County, IL

477

An evaluation of in-plane shields during thoracic CT.  

PubMed

The object of this study was to compare organ dose and image quality effects of using bismuth and barium vinyl in-plane shields with standard and low tube current thoracic CT protocols. A RANDO phantom was scanned using a 64-slice CT scanner and three different thoracic protocols. Thermoluminescent dosemeters were positioned in six locations to record surface and absorbed breast and lung doses. Image quality was assessed quantitatively using region of interest measurements. Scanning was repeated using bismuth and barium vinyl in-plane shields to cover the breasts and the results were compared with standard and reduced dose protocols. Dose reductions were most evident in the breast, skin and anterior lung when shielding was used, with mean reductions of 34, 33 and 10 % for bismuth and 23, 18 and 11 % for barium, respectively. Bismuth was associated with significant increases in both noise and CT attenuation values for all the three protocols, especially anteriorly and centrally. Barium shielding had a reduced impact on image quality. Reducing the overall tube current reduced doses in all the locations by 20-27 % with similar increases in noise as shielding, without impacting on attenuation values. Reducing the overall tube current best optimises dose with minimal image quality impact. In-plane shields increase noise and attenuation values, while reducing anterior organ doses primarily. Shielding remains a useful optimisation tool in CT and barium is an effective alternative to bismuth especially when image quality is of concern. PMID:23460031

Foley, S J; McEntee, M F; Rainford, L A

2013-03-03

478

Character Building.  

ERIC Educational Resources Information Center

|Examines violence prevention programs nationwide, which are not only changing student behavior but also laying the foundation of morality, honesty, respect, and accountability within U.S. students. Successful programs target specific populations, build individual skills, include parent effectiveness training, and encourage changes in peer group…

Dychkowski, Linda

2002-01-01

479

Laboratory Buildings.  

ERIC Educational Resources Information Center

The need for flexibility in science research facilities is discussed, with emphasis on the effect of that need on the design of laboratories. The relationship of office space, bench space, and special equipment areas, and the location and distribution of piping and air conditioning, are considered particularly important. This building type study…

Barnett, Jonathan

480

Building Trades.  

ERIC Educational Resources Information Center

This curriculum guide provides materials for a competency-based course in building trades at the secondary level. The curriculum design uses the curriculum infused model for the teaching of basic skills as part of vocational education and demonstrates the relationship of vocationally related skills to communication, mathematics, and science…

Gudzak, Raymond

481

Building Sustainability  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) provides this presentation for high school and community college instructors on developing curricula in the sustainable building industry. The document was part of a workshop held during ATEEC's Sustainable Energy Education and Training conference. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

2011-03-31

482

Building Trades.  

ERIC Educational Resources Information Center

|This curriculum guide provides materials for a competency-based course in building trades at the secondary level. The curriculum design uses the curriculum infused model for the teaching of basic skills as part of vocational education and demonstrates the relationship of vocationally related skills to communication, mathematics, and science…

Gudzak, Raymond

483

Experimental Study of ExoMars Sub- and Transonic Aerodynamics and Heat Shield Separation in HST  

NASA Astrophysics Data System (ADS)

In the framework of the ESA ExoMars project an experimental investigation has been conducted in the transonic DNW wind tunnel HST with two emphases. First the static aerodynamic behaviour of the complete descent module has been investigated in the sub- to transonic flow regime, duplicating reference flight trajectory conditions through the Martian atmosphere. Therefore force and moment coefficients have been derived by means of a six component internal balance with additional pressure signals to enable base pressure corrections. The second main objective was the aerodynamic characterization of the staging process between the capsule's heat shield and its back cover at corresponding trajectory flight conditions. For this attempt models were available for the capsule's single parts after separation, e.g. heat shield and back cover. These components have been investigated individually to characterize its behaviour after completion of the separation process as well as to gain reference data to compare to the behaviour during the actual staging process. This flight phase has been simulated in detail by thoroughly modifying the orientation of the separating models to each other. This was enabled by a modular distance between the separating components and modification of the angle of attack. Beside force and moment measurements on the heat shield, the back cover has been equipped with 12 static as well as 12 dynamic pressure sensors. This paper gives an overview of selected results gathered during this test campaign. The measured coefficients for the complete descent module as well as for the separating models are analyzed comparing typical capsule configuration behaviour. Depending on the distance between the separating models clear interferences are evident in both force and pressure signals.

Neeb, Gülhan, A.; Augenstein, E.

2011-08-01

484

Novel cryogen-free actively shielded superconducting magnets for maglev vehicles. Final report, August 1991-June 1992  

SciTech Connect

The report presents the results of a research effort into the design of a shielded superconducting magnet system for a maglev vehicle. The magnet design is based on a novel cryogen-free technology which allows operation without the use of any cryogenic fluids. This is accomplished by the use of a two-stage Gifford-McMahon (G-M) cryogenic refrigerator to provide cooling of the coil and a single cryostat thermal radiation shield by conduction. The design operating temperature of the magnet is 7.5 K, and that of the shield is 43 K. The magnet is wound with a tape form of niobium tin superconductor which allows operation at a module current density of 8100 A/sq cm at a flux density of 3.4 T at the 7.5 K temperature with a margin of 4.5 K to critical temperature. The magnet design is coupled with a linear synchronous motor and null-flux sidewall levitation system to provide a workable maglev system design. Costs for several components of the design, including coils and cryostat, shielding, and power conditioning apparatus are estimated.

Vermilyea, M.E.

1992-06-01

485

A magnetic shield\\/dual purpose mission  

Microsoft Academic Search

The objective of this work is to design, build, and fly a dual-purpose payload whose function is to produce a large volume, low intensity magnetic field and to test the concept of using such a magnetic field to protect manned spacecraft against particle radiation. An additional mission objective is to study the effect of this moving field on upper atmosphere

Seth Watkins; Jamil Albertelli; R. Braden Copeland; Eric Correll; Chris Dales; Dana Davis; Nechole Davis; Rob Duck; Sandi Feaster; Patrick Grant

1994-01-01

486

Thermal shield bowing in long superconducting magnets  

Microsoft Academic Search

One of the interesting problems associated with building long magnets for the SSC (Superconducting Super Collider) is predicting and controlling the dynamic response of the cryostat tubes during cooldown. Thermal bowing occurs in any of these tubes that are asymmetric in shape or which are not cooled uniformly. Understanding the bowing behavior is important for two reasons. First, one needs

T. H. Nicol; M. Roman; S. Fulton

1985-01-01

487

Electromagnetic Shielding of Oriented Carbon Fiber Composite Materials  

NASA Astrophysics Data System (ADS)

The paper analyses the electromagnetic shielding measurements of carbon fiber composite structure. In particular the shielding effectiveness is measured applying the nested reverberation chamber method in the frequency range of 3.5 GHz - 8.5 GHz. This method ensure a realistic electromagnetic excitation of the sample under test characterized by a random polarization and incoming direction. The paper also describes the material manufacturing procedure and gives important details about the sample mounting technique. Three material samples are considered which differ in carbon fiber orientation and stratification. Obtained results highlight the capability of such materials to behave as high-performance shields in the microwave region.

Micheli, D.; Laurenzi, S.; Mariani Primiani, V.; Moglie, F.; Gradoni, G.; Marchetti, M.

2012-05-01

488

Cable with overall shield for protection from lightning and faults  

SciTech Connect

Lightning can cause damage to electrical systems from direct and induced effects. A study was conducted to devise means to prevent or control the effects of lightning on instrument and control systems. The results indicate that the best approach is to use instrument cables with an overall shield grounded at both ends. The overshield functions as a magnetic shield because it generates a counter, or opposition, current which nearly cancels out the interfering current on the signal conductors. The overall shield is used in conjunction with protective devices and a single point ground system.

Bow, K.E. (Dow Chemical Co., Granville, OH (US)); Voltz, D.A. (Dow Chemical Co., Houston, TX (US))

1992-04-01

489

Self shielding in cylindrical fissile sources in the APNea system  

SciTech Connect

In order for a source of fissile material to be useful as a calibration instrument, it is necessary to know not only how much fissile material is in the source but also what the effective fissile content is. Because uranium and plutonium absorb thermal neutrons so Efficiently, material in the center of a sample is shielded from the external thermal flux by the surface layers of the material. Differential dieaway measurements in the APNea System of five different sets of cylindrical fissile sources show the various self shielding effects that are routinely encountered. A method for calculating the self shielding effect is presented and its predictions are compared with the experimental results.

Hensley, D.

1997-02-01

490

CONCEPTS FOR CAPACITIVELY RF-SHIELDED BELLOWS IN CRYOGENIC STRUCTURES.  

SciTech Connect

Bellows are frequently required in accelerators and colliders. Usually RF-shields with spring fingers are employed to screen the bellows. The lack of accessibility in cryogenic systems can be a problem and asks for alternate solutions