Science.gov

Sample records for specifications tower shielding

  1. The Tower Shielding Facility: Its glorious past

    SciTech Connect

    Muckenthaler, F.J.

    1997-05-07

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

  2. Loss of coolant analysis for the tower shielding reactor 2

    SciTech Connect

    Radcliff, T.D.; Williams, P.T.

    1990-06-01

    The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs.

  3. BNCT filter design studies for the ORNL Tower Shielding Facility

    SciTech Connect

    Ingersoll, D.T.; Slater, C.O.; Williams, L.R.

    1996-12-31

    Boron Neutron Capture Therapy (BNCT) in the United States has entered into a new phase with the initiation of clinical trials using neutron sources at the Brookhaven National Laboratory and the Massachusetts Institute of Technology. If these trials are successful at demonstrating the efficacy of BNCT as a viable treatment for glioblastoma multiforme, then there will be an immediate demand for several additional neutron sources in order to treat the several thousand patients currently diagnosed with glioblastomas in the U.S. each year. However, the requirements for an acceptable neutron source for BNCT are rather severe in terms of the need to provide a sufficient number of epithermal neutrons to a patient-accessible location in a reasonable time with minimal thermal-neutron, fast- neutron, and gamma-ray background. A recent study of potential neutron sources at Oak Ridge National Laboratory (ORNL) has been completed, which concludes that the Tower Shielding Facility (TSF), also appears very well suited for BNCT. The light-water-cooled reactor is contained in an aluminum pressure vessel and located in a large concrete `bunker` referred to as the Big Beam Shield (BBS). The BBS contains a 77-cm-diameter beam collimator, which permits access to a broad beam neutron flux exceeding 4 x 10[sup ll] Cm[sup -2]s[sup- 1] at the operational power of 1 MW. The collimated beam emerges horizontally onto an unenclosed test pad area on which shield mockups were assembled. The appropriate beam filter and collimator system can be easily constructed in the expansive area previously used for the large shield mockups. Additional engineering of the beam shutter mechanism and the construction of treatment support facilities will be needed but can be easily accommodated on the remote dedicated site. The filter design analysis is provided.

  4. Drag-shield drop tower residual acceleration optimisation

    NASA Astrophysics Data System (ADS)

    Figueroa, A.; Sorribes-Palmer, F.; Fernandez De Pierola, M.; Duran, J.

    2016-07-01

    Among the forces that appear in drop towers for microgravity experiments, aerodynamic drag plays a crucial role in the residual acceleration. Buoyancy can also be critical, especially at the first instances of the drop when the low speed of the experimental platform makes the aerodynamic drag small compared with buoyancy. In this paper the perturbation method is used to formulate an analytical model which has been validated experimentally. The experimental test was conduced by undergraduate students of aerospace engineering at the Institute of Microgravity ‘Ignacio Da Riva’ of the Technical University of Madrid (IDR/UPM) microgravity tower. The test helped students to understand the influence of the buoyancy on the residual acceleration of the experiment platform. The objective of the students was to understand the physical process during the drop, identify the main parameters involved in the residual acceleration and determine the most suitable configuration for the next drop tower proposed to be built at UPM.

  5. Performance specification for control tower display systems

    NASA Astrophysics Data System (ADS)

    Aleva, Denise L.; Meyer, Frederick M.

    2003-09-01

    Personnel in airport control towers monitor and direct the takeoff of outgoing aircraft, landing of incoming aircraft and all movements of aircraft on the ground. Although the primary source of information for the Local Controller, Assistant Local Controller and the Ground Controller is the real world viewed through the windows of the control tower, electronic displays are also used to provide situation awareness. Due to the criticality of the work to be performed by the controllers and the rather unique environment of the air traffic control tower, display hardware standards, which have been developed for general use, are not directly applicable. The Federal Aviation Administration (FAA) requested assistance of Air Force Research Laboratory Human Effectiveness Directorate in producing a document which can be adopted as a Tower Display Standard usable by display engineers, human factors practitioners and system integrators. Particular emphasis was placed on human factors issues applicable to the control tower environment and controller task demands.

  6. Subsurface Shielding Source Term Specification Calculation

    SciTech Connect

    S.Su

    2001-04-12

    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.

  7. 77 FR 67678 - Content Specifications and Shielding Evaluations for Type B Transportation Packages

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... COMMISSION Content Specifications and Shielding Evaluations for Type B Transportation Packages AGENCY... Regulatory Issue Summary (RIS) 2012-XX, ``Content Specifications and Shielding Evaluations for Type B... Plan for Transport Packages for Radioactive Material,'' for the review of content specifications...

  8. You're a What?: Tower Technician

    ERIC Educational Resources Information Center

    Vilorio, Dennis

    2012-01-01

    In this article, the author talks about the role and functions of a tower technician. A tower technician climbs up the face of telecommunications towers to remove, install, test, maintain, and repair a variety of equipment--from antennas to light bulbs. Tower technicians also build shelters and radiofrequency shields for electronic equipment, lay…

  9. Hydraulic design of a low-specific speed Francis runner for a hydraulic cooling tower

    NASA Astrophysics Data System (ADS)

    Ruan, H.; Luo, X. Q.; Liao, W. L.; Zhao, Y. P.

    2012-11-01

    The air blower in a cooling tower is normally driven by an electromotor, and the electric energy consumed by the electromotor is tremendous. The remaining energy at the outlet of the cooling cycle is considerable. This energy can be utilized to drive a hydraulic turbine and consequently to rotate the air blower. The purpose of this project is to recycle energy, lower energy consumption and reduce pollutant discharge. Firstly, a two-order polynomial is proposed to describe the blade setting angle distribution law along the meridional streamline in the streamline equation. The runner is designed by the point-to-point integration method with a specific blade setting angle distribution. Three different ultra-low-specificspeed Francis runners with different wrap angles are obtained in this method. Secondly, based on CFD numerical simulations, the effects of blade setting angle distribution on pressure coefficient distribution and relative efficiency have been analyzed. Finally, blade angles of inlet and outlet and control coefficients of blade setting angle distribution law are optimal variables, efficiency and minimum pressure are objective functions, adopting NSGA-II algorithm, a multi-objective optimization for ultra-low-specific speed Francis runner is carried out. The obtained results show that the optimal runner has higher efficiency and better cavitation performance.

  10. 21 CFR 1000.50 - Recommendation for the use of specific area gonad shielding on patients during medical diagnostic...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... shielding on patients during medical diagnostic x-ray procedures. 1000.50 Section 1000.50 Food and Drugs... shielding on patients during medical diagnostic x-ray procedures. Specific area gonad shielding covers an... that may cause genetic mutations during many medical x-ray procedures in which the gonads lie within...

  11. 21 CFR 1000.50 - Recommendation for the use of specific area gonad shielding on patients during medical diagnostic...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... shielding on patients during medical diagnostic x-ray procedures. 1000.50 Section 1000.50 Food and Drugs... shielding on patients during medical diagnostic x-ray procedures. Specific area gonad shielding covers an... that may cause genetic mutations during many medical x-ray procedures in which the gonads lie within...

  12. 21 CFR 1000.50 - Recommendation for the use of specific area gonad shielding on patients during medical diagnostic...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... shielding on patients during medical diagnostic x-ray procedures. 1000.50 Section 1000.50 Food and Drugs... shielding on patients during medical diagnostic x-ray procedures. Specific area gonad shielding covers an... that may cause genetic mutations during many medical x-ray procedures in which the gonads lie within...

  13. 21 CFR 1000.50 - Recommendation for the use of specific area gonad shielding on patients during medical diagnostic...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... shielding on patients during medical diagnostic x-ray procedures. 1000.50 Section 1000.50 Food and Drugs... shielding on patients during medical diagnostic x-ray procedures. Specific area gonad shielding covers an... that may cause genetic mutations during many medical x-ray procedures in which the gonads lie within...

  14. 21 CFR 1000.50 - Recommendation for the use of specific area gonad shielding on patients during medical diagnostic...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... shielding on patients during medical diagnostic x-ray procedures. 1000.50 Section 1000.50 Food and Drugs... shielding on patients during medical diagnostic x-ray procedures. Specific area gonad shielding covers an... that may cause genetic mutations during many medical x-ray procedures in which the gonads lie within...

  15. 78 FR 26090 - Content Specifications and Shielding Evaluations for Type B Transportation Packages

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... this RIS as a draft for public comment on November 13, 2012 (77 FR 67678), for a 45-day comment period... COMMISSION Content Specifications and Shielding Evaluations for Type B Transportation Packages AGENCY... Regulatory Commission (NRC) is issuing Regulatory Issue Summary (RIS) 2013-04, ``Content Specifications...

  16. Phthalonitrile-Based Carbon Foam with High Specific Mechanical Strength and Superior Electromagnetic Interference Shielding Performance.

    PubMed

    Zhang, Liying; Liu, Ming; Roy, Sunanda; Chu, Eng Kee; See, Kye Yak; Hu, Xiao

    2016-03-23

    Electromagnetic interference (EMI) performance materials are urgently needed to relieve the increasing stress over electromagnetic pollution problems arising from the growing demand for electronic and electrical devices. In this work, a novel ultralight (0.15 g/cm(3)) carbon foam was prepared by direct carbonization of phthalonitrile (PN)-based polymer foam aiming to simultaneously achieve high EMI shielding effectiveness (SE) and deliver effective weight reduction without detrimental reduction of the mechanical properties. The carbon foam prepared by this method had specific compressive strength of ∼6.0 MPa·cm(3)/g. High EMI SE of ∼51.2 dB was achieved, contributed by its intrinsic nitrogen-containing structure (3.3 wt% of nitrogen atoms). The primary EMI shielding mechanism of such carbon foam was determined to be absorption. Moreover, the carbon foams showed excellent specific EMI SE of 341.1 dB·cm(3)/g, which was at least 2 times higher than most of the reported material. The remarkable EMI shielding performance combined with high specific compressive strength indicated that the carbon foam could be considered as a low-density and high-performance EMI shielding material for use in areas where mechanical integrity is desired. PMID:26910405

  17. Convection towers

    DOEpatents

    Prueitt, Melvin L.

    1994-01-01

    Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode.

  18. Convection towers

    DOEpatents

    Prueitt, Melvin L.

    1996-01-01

    Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

  19. Convection towers

    DOEpatents

    Prueitt, Melvin L.

    1995-01-01

    Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

  20. Convection towers

    DOEpatents

    Prueitt, M.L.

    1996-01-16

    Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water. 6 figs.

  1. Convection towers

    DOEpatents

    Prueitt, M.L.

    1994-02-08

    Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode. 5 figures.

  2. Short Duration Reduced Gravity Drop Tower Design and Development

    NASA Astrophysics Data System (ADS)

    Osborne, B.; Welch, C.

    The industrial and commercial development of space-related activities is intimately linked to the ability to conduct reduced gravity research. Reduced gravity experimentation is important to many diverse fields of research in the understanding of fundamental and applied aspects of physical phenomena. Both terrestrial and extra-terrestrial experimental facilities are currently available to allow researchers access to reduced gravity environments. This paper discusses two drop tower designs, a 2.0 second facility built in Australia and a proposed 2.2 second facility in the United Kingdom. Both drop towers utilise a drag shield for isolating the falling experiment from the drag forces of the air during the test. The design and development of The University of Queensland's (Australia) 2.0 second drop tower, including its specifications and operational procedures is discussed first. Sensitive aspects of the design process are examined. Future plans are then presented for a new short duration (2.2 sec) ground-based reduced gravity drop tower. The new drop tower has been designed for Kingston University (United Kingdom) to support teaching and research in the field of reduced gravity physics. The design has been informed by the previous UQ drop tower design process and utilises a catapult mechanism to increase test time and also incorporates features to allow participants for a variety of backgrounds (from high school students through to university researchers) to learn and experiment in reduced gravity. Operational performance expectations for this new facility are also discussed.

  3. PEG shielded MMP sensitive CPPs for efficient and tumor specific gene delivery in vivo.

    PubMed

    Veiman, Kadi-Liis; Künnapuu, Kadri; Lehto, Tõnis; Kiisholts, Kristina; Pärn, Kalle; Langel, Ülo; Kurrikoff, Kaido

    2015-07-10

    Gene therapy has great potential to treat a range of different diseases, such as cancer. For that therapeutic gene can be inserted into a plasmid vector and delivered specifically to tumor cells. The most frequently used applications utilize lipoplex and polyplex approaches where DNA is non-covalently condensed into nanoparticles. However, lack of in vivo efficacy is the major concern that hinders translation of such gene therapeutic applications into clinics. In this work we introduce a novel method for in vivo delivery of plasmid DNA (pDNA) and efficient tumor-specific gene induction using intravenous (i.v) administration route. To achieve this, we utilize a cell penetrating peptide (CPP), PepFect14 (PF14), double functionalized with polyethylene glycol (PEG) and a matrix metalloprotease (MMP) substrate. We show that this delivery vector effectively forms nanoparticles, where the condensed CPP and pDNA are shielded by the PEG, in an MMP-reversible manner. Administration of the complexes results in efficient induction of gene expression specifically in tumors, avoiding normal tissues. This strategy is a potent gene delivery platform that can be used for tumor-specific induction of a therapeutic gene. PMID:25935707

  4. 6. Detail of northeast corner of Shell Interlocking Tower, showing ...

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

    6. Detail of northeast corner of Shell Interlocking Tower, showing ornamental east concrete beltcourse and tower shield with bronze numerals. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  5. Collapsible Towers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    NASA needed a means of orbiting a large radio telescope antenna. Astro Research Corporation developed a new structure that was strong, lightweight, folded into a small storage space, and could be erected by rotation. Later they adapted it to commercial use. Today the "Astromast" tower consists of tubular aluminum alloy and stainless steel members that deploy into small three-sided bays, each made rigid by six diagonal cables. All joints are flexible to permit folding and unfolding. Tower packs into container 5% of its height, can be erected without tools and is reusable. Tower has won "Design of the Year" award from Machine Design. Variations include portable emergency bridges and commercial scaffolding.

  6. Rapunzel's Tower

    ERIC Educational Resources Information Center

    Depp, Sheryl

    2007-01-01

    Children's literature often inspires the author's lessons, and reading to her primary students motivates their participation. In this article, the author presents and describes her lesson which is based on the book "Falling for Rapunzel" by Leah Wilcox. Students created a fairy tale tower in this lesson, which took place over three class periods.…

  7. Virtual Tower

    SciTech Connect

    Wayne, R.A.

    1997-08-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems.

  8. Meteoroid/Debris Shielding

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric L.

    2003-01-01

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

  9. 13. WEIGHING ROOM Fish were lifted up from tower by ...

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

    13. WEIGHING ROOM Fish were lifted up from tower by conveyor, controlled by buttons above the two sets of vertical electrical conduits. They entered the weighing room through the shielded window on the left (shielding missing from the window on the right), were weighed and then transported to the holding tanks. - Hovden Cannery, 886 Cannery Row, Monterey, Monterey County, CA

  10. Specifications for the development of BUGLE-93: An ENDF/B-VI multigroup cross section library for LWR shielding and pressure vessel dosimetry

    SciTech Connect

    White, J.E.; Wright, R.Q.; Roussin, R.W.; Ingersoll, D.T.

    1992-11-01

    This report discusses specifications which have been developed for a new multigroup cross section library based on ENDF/B-VI data for light water reactor shielding and reactor pressure vessel dosimetry applications. The resulting broad-group library and an intermediate fine-group library are defined by the specifications provided in this report. Processing ENDF/B-VI into multigroup format for use in radiation transport codes will provide radiation shielding analysts with the most currently available nuclear data. it is expected that the general nature of the specifications will be useful in other applications such as reactor physics.

  11. Cellular Phone Towers

    MedlinePlus

    ... the call. How are people exposed to the energy from cellular phone towers? As people use cell ... where people can be exposed to them. The energy from a cellular phone tower antenna, like that ...

  12. Towers for Offshore Wind Turbines

    NASA Astrophysics Data System (ADS)

    Kurian, V. J.; Narayanan, S. P.; Ganapathy, C.

    2010-06-01

    Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy from wind over the oceans and convert to electric energy. The advantages of offshore wind turbines as compared to land are that offshore winds flow at higher speed than onshore winds and the more available space. In some land based settings, for better efficiency, turbines are separated as much as 10 rotor diameters from each other. In offshore applications where only two wind directions are likely to predominate, the distances between the turbines arranged in a line can be shortened to as little as two or four rotor diameters. Today, more than a dozen offshore European wind facilities with turbine ratings of 450 kw to 3.6 MW exist offshore in very shallow waters of 5 to 12 m. Compared to onshore wind turbines, offshore wind turbines are bigger and the tower height in offshore are in the range of 60 to 80 m. The water depths in oceans where offshore turbines can be located are within 30 m. However as the distance from land increases, the costs of building and maintaining the turbines and transmitting the power back to shore also increase sharply. The objective of this paper is to review the parameters of design for the maximum efficiency of offshore wind turbines and to develop types offshore towers to support the wind turbines. The methodology of design of offshore towers to support the wind turbine would be given and the environmental loads for the design of the towers would be calculated for specific cases. The marine corrosion on the towers and the methods to control the corrosion also would be briefly presented. As the wind speeds tend to increase with distance from the shore, turbines build father

  13. Performance of solar shields

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.

    1975-01-01

    The loss of the micrometeoroid shield from the Orbital Workshop section of Skylab I, about 63 seconds after lift-off, proved to be the harbinger of a prodigious effort to quickly develop a workable substitute for the carefully tailored passive portion of the thermal-control system. The paper describes the intensive ten-day around-the-clock effort in which numerous potential thermal-shield materials were assessed, and during which period ten specific shield designs were developed and carried through various stages of development and test. Thermal-shield materials data are discussed, including optical, strength, fatigue, outgassing, tackiness, ultraviolet radiation, and material 'memory' properties.

  14. 500 kV shield wires; Sectionalize or ground everywhere

    SciTech Connect

    Tuominen, M.W. )

    1992-01-01

    The primary purpose of shield wires on transmission lines in lightning protection. Development of fiber-optic shied wires added communications capabilities. Schemes for adapting fiber-optic shield wires to sectionalized shield wire designs remain untested. It is a present policy to segment and insulate 500 kV shield wires. Computer modeling and supportive field measurements have revealed a characteristic distribution of grounded tower voltage versus distance for long lines. The intent of this paper is to report these results plus predict the outcome of grounding shield wires on transmission lines already in place. Shield wires are often called overhead ground wires and abbreviated OHGW.

  15. 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

  16. 43. TOP OF SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING ...

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

    43. TOP OF SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING EAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  17. 37. NORTH TOWER UPPER ZONE FROM SOUTH TOWER ROOF, LOOKING ...

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

    37. NORTH TOWER UPPER ZONE FROM SOUTH TOWER ROOF, LOOKING NORTH - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  18. 19. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST ...

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

    19. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  19. 47. NORTHWEST TOWER FROM SOUTH TOWER ROOF, LOOKING NORTH BY ...

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

    47. NORTHWEST TOWER FROM SOUTH TOWER ROOF, LOOKING NORTH BY NORTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  20. 36. FLAG TOWER CLOCK ZONE FROM SOUTH TOWER ROOF, LOOKING ...

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

    36. FLAG TOWER CLOCK ZONE FROM SOUTH TOWER ROOF, LOOKING NORTH - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  1. 40. CAMPANILE & SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING ...

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

    40. CAMPANILE & SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING EAST BY NORTHEAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  2. 18. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST ...

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

    18. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST BY WEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  3. Confusion at the Tower

    ERIC Educational Resources Information Center

    Li, Loretta F.

    2014-01-01

    This study will explore the omission of the Tower of Babel narrative from middle and secondary school world history, world studies, and world geography textbooks and will consider what might be learned from inclusion of the story in the curriculum. A total of 17 textbooks are analyzed. The Tower of Babel narrative is examined within the context of…

  4. Drop Tower Physics

    ERIC Educational Resources Information Center

    Dittrich, William A.

    2014-01-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

  5. Specific features of the planarian Dugesia tigrina regeneration and mollusk Helix albescens nociception under weak electromagnetic shielding

    NASA Astrophysics Data System (ADS)

    Temur'yants, N. A.; Demtsun, N. A.; Kostyuk, A. S.; Yarmolyuk, N. S.

    2012-12-01

    It has been demonstrated that weak electromagnetic shielding stimulates regeneration in the planarian Dugesia tigrina, the stimulating intensity being dependent on both the initial state of the animals, which is determined by season, and their functional asymmetry. As has been shown, the effect of a weak electromagnetic field induces phasic changes in the nociceptive sensitivity of the mollusk Helix albescens: an increase in the sensitivity to a thermal stimulus is replaced by the development of the hypalgesic effect.

  6. Wind tower service lift

    DOEpatents

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  7. Drop Tower Physics

    NASA Astrophysics Data System (ADS)

    Dittrich, William A. Toby

    2014-10-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in The Physics Teacher1 in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at the drop tower in Bremen, Germany. Using these drop towers, one can briefly investigate various physical systems operating in this near zero-g environment. The resulting "Drop Tower Physics" is a new and exciting way to challenge students with a physical example that requires solid knowledge of many basic physics principles, and it forces them to practice the scientific method. The question is, "How would a simple toy, like a pendulum, behave when it is suddenly exposed to a zero-g environment?" The student must then postulate a particular behavior, test the hypothesis against physical principles, and if the hypothesis conforms to these chosen physical laws, the student can formulate a final conclusion. At that point having access to a drop tower is very convenient, in that the student can then experimentally test his or her conclusion. The purpose of this discussion is to explain the response of these physical systems ("toys") when the transition is made to a zero-g environment and to provide video demonstrations of this behavior to support in-class discussions of Drop Tower Physics.

  8. Extensible Wind Towers

    NASA Astrophysics Data System (ADS)

    Sinagra, Marco; Tucciarelli, Tullio

    The diffusion of wind energy generators is restricted by their strong landscape impact. The PERIMA project is about the development of an extensible wind tower able to support a wind machine for several hundred kW at its optimal working height, up to more than 50 m. The wind tower has a telescopic structure, made by several tubes located inside each other with their axis in vertical direction. The lifting force is given by a jack-up system confined inside a shaft, drilled below the ground level. In the retracted tower configuration, at rest, tower tubes are hidden in the foundation of the telescopic structure, located below the ground surface, and the wind machine is the only emerging part of the system. The lifting system is based on a couple of oleodynamic cylinders that jack-up a central tube connected to the top of the tower by a spring, with a diameter smaller than the minimum tower diameter and with a length a bit greater than the length of the extended telescopic structure. The central tube works as plunger and lifts all telescopic elements. The constraint between the telescopic elements is ensured by special parts, which are kept in traction by the force of the spring and provide the resisting moment. The most evident benefit of the proposed system is attained with the use of a two-blade propeller, which can be kept horizontal in the retracted tower configuration.

  9. Tower Camera Handbook

    SciTech Connect

    Moudry, D

    2005-01-01

    The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.

  10. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS ...

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

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS SEVEN,EIGHT, NINE, TEN, AND BREAK OVER TOWER IN DISTANCE, LOOKING NORTH. TOWER SIX IS THE LAST BEFORE A DEEP CHASM, AS IS SEEN BY THE DISTANCE BETWEEN TOWERS SIX AND SEVEN. SEE CA-291-48 (CT) FOR IDENTICAL COLOR TRANSPARENCY. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  11. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS ...

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

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS SEVEN, EIGHT, NINE, TEN, AND BREAK OVER TOWER IN DISTANCE, LOOKING NORTH. TOWER SIX IS THE LAST BEFORE A DEEP CHASM, AS IS SEEN BY THE DISTANCE BETWEEN TOWERS SIX AND SEVEN. SEE CA-291-21 FOR IDENTICAL B&W NEGATIVE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  12. Aquarius: Tower Rollback

    NASA Video Gallery

    The mobile service tower at NASA's Launch Complex-2 at Vandenberg Air Force Base in California is being moved away from the ULA Delta II rocket with the Aquarius/SAC-D spacecraft atop, in preparati...

  13. Drop Tower Workshop

    NASA Technical Reports Server (NTRS)

    Urban, David

    2013-01-01

    Ground based microgravity facilities are an important proving ground for space experiments, ground-based research and space hardware risk mitigation. An overview of existing platforms will be discussed with an emphasis on drop tower capabilities. The potential for extension to partial gravity conditions will be discussed. Input will be solicited from attendees for their potential to use drop towers in the future and the need for enhanced capabilities (e.g. partial gravity)

  14. Modular shield

    DOEpatents

    Snyder, Keith W.

    2002-01-01

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

  15. Shielding considerations for satellite microelectronics

    SciTech Connect

    Fan, W.C.; Drumm, C.R.; Roeske, S.B.; Scrivner, G.J.

    1996-12-01

    Shielding for space microelectronics needs to provide an acceptable dose rate with minimum shield mass. The analysis presented here shows that the best approach is, in general, to use a graded-Z shield, with a high-Z layer sandwiched between two low-Z materials. A graded-Z shield is shown to reduce the electron dose rate by more than sixty percent over a single-material shield of the same areal density. For protons, the optimal shield would consist of a single, low-Z material layer. However, it is shown that a graded-Z shield is nearly as effective as a single-material shield, as long as a low-Z layer is located adjacent to the microelectronics. A specific shield design depends upon the details of the radiation environment, system model, design margins/levels, compatibility of shield materials, etc. Therefore, the authors present here general principles for designing effective shields and describe how the computer codes are used for this application.

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

    SciTech Connect

    Ingersoll, D.T. ); Ingersoll, J.K. )

    1992-11-01

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

  17. REACTOR SHIELD

    DOEpatents

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

    1959-02-17

    Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

  18. 69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER ...

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

    69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER UNDER CONSTRUCTION. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  19. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER TWO, WITH TOWERS ...

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

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER TWO, WITH TOWERS THREE,FOUR, FIVE AND SIX IN DISTANCE, LOOKING NORTHEAST. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  20. 8. GENERAL VIEW OF TOWER 32, LEFT, AND TOWER 31, ...

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

    8. GENERAL VIEW OF TOWER 32, LEFT, AND TOWER 31, RIGHT. VIEW LOOKING NORTH SHOWING AERIAL WIRE DESIGN WITH VERTICAL 'TOP HAT' WIRES IN CENTER. - Chollas Heights Naval Radio Transmitting Facility, 6410 Zero Road, San Diego, San Diego County, CA

  1. 3. VIEW NORTHWEST, height finder radar towers, and radar tower ...

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

    3. VIEW NORTHWEST, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  2. 46. OCTAGONAL & WEST TOWERS FROM SOUTH TOWER ROOF, LOOKING ...

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

    46. OCTAGONAL & WEST TOWERS FROM SOUTH TOWER ROOF, LOOKING NORTHWEST, WITH WEST WING ROOF - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  3. 42. SOUTHEAST TOWER & EAST WING ROOF FROM SOUTH TOWER ...

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

    42. SOUTHEAST TOWER & EAST WING ROOF FROM SOUTH TOWER ROOF, LOOKING EAST BY NORTHEAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  4. 41. SOUTHEAST TOWER & EAST WING FROM SOUTH TOWER ROOF, ...

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

    41. SOUTHEAST TOWER & EAST WING FROM SOUTH TOWER ROOF, LOOKING EAST BY NORTHEAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  5. View of the north tower porte cochere and flag tower, ...

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

    View of the north tower porte cochere and flag tower, looking southwest (duplicate of HABS No. DC-141-19) - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  6. 45. OCTAGONAL, WEST & NORTHWEST TOWERS FROM SOUTH TOWER ROOF, ...

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

    45. OCTAGONAL, WEST & NORTHWEST TOWERS FROM SOUTH TOWER ROOF, LOOKING WEST BY NORTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  7. Solar power towers

    SciTech Connect

    Not Available

    1998-04-01

    The high desert near Barstow, California, has witnessed the development of this country`s first two solar power towers. Solar One operated successfully from 1982 to 1988 and proved that power towers work efficiently to produce utility-scale power from sunlight. Solar Two was connected to the utility grid in 1996 and is operating today. Like its predecessor, Solar Two is rated at 10 megawatts. An upgrade of the Solar One plant, Solar Two demonstrates how solar energy can be stored in the form of heat in molten salt for power generation on demand. The experience gained with these two pilot power towers has established a foundation on which industry can develop its first commercial plants. These systems produce electricity on a large scale. They are unique among solar technologies because they can store energy efficiently and cost effectively. They can operate whenever the customer needs power, even after dark or during cloudy weather.

  8. Legionella in cooling towers.

    PubMed

    Witherell, L E; Novick, L F; Stone, K M; Duncan, R W; Orciari, L A; Kappel, S J; Jillson, D A

    1986-01-01

    Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test). PMID:10281778

  9. THE TOWER HOUSE, LOOKING WEST. The tower house provided a ...

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

    THE TOWER HOUSE, LOOKING WEST. The tower house provided a water tank on the second floor that gravity fed water to the Kineth house and farm buildings. The one-story addition to the west of the tower provided workshop space. The hog shed is seen on the left of the image and the concrete foundation of the upright silo is in the foreground on the right. - Kineth Farm, Tower House, 19162 State Route 20, Coupeville, Island County, WA

  10. Solar thermal power towers

    NASA Astrophysics Data System (ADS)

    Kreith, F.; Meyer, R. T.

    1984-07-01

    The solar thermal central receiver technology, known as solar power towers, is rapidly evolving to a state of near-term energy availability for electrical power generation and industrial process heat applications. The systems consist of field arrays of heliostat reflectors, a central receiver boiler, short term thermal storage devices, and either turbine-generators or heat exchangers. Fluid temperatures up to 550 C are currently achievable, and technology developments are underway to reach 1100 C. Six solar power towers are now under construction or in test operation in five countries around the world.

  11. 5. VIEW EAST, height finder radar towers, radar tower (unknown ...

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

    5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  12. Evaporation Tower With Prill Nozzles

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1984-01-01

    Tower more efficient than conventional evaporation equipment. Liquids such as milk and fruit juice concentrated by passing them through tiny nozzle to form droplets, then allowing droplets to fall through evacuated tower with cooled walls.

  13. Ivory Basements and Ivory Towers

    ERIC Educational Resources Information Center

    Fitzgerald, Tanya

    2012-01-01

    The metaphors of the ivory tower and ivory basement are used in this chapter to reflect how many women understand and experience the academy. The ivory tower signifies a place that is protected, a place of privilege and authority and a place removed from the outside world (and consequently the rigours of the market place). The ivory tower, by…

  14. The Ivory Tower Revisited

    ERIC Educational Resources Information Center

    Chantler, Abigail

    2016-01-01

    The corollary of the concept of the "ivory tower", as reflected in the writings of Plato and Newman amongst others, was, paradoxically, the vital importance of the university for wider society. Nevertheless from the mid-twentieth century, the esteem in which a "liberal" university education was held was diminished by rising…

  15. Cell Towers and Songbirds

    ERIC Educational Resources Information Center

    Klosterman, Michelle; Mesa, Jennifer; Milton, Katie

    2009-01-01

    This article describes how our common addiction to cell phones was used to launch a discussion about their use, impacts on the environment, and connections to issues of civic concern. By encouraging middle school science students to adopt the perspectives of special-interest groups debating communication tower restrictions designed to protect…

  16. COOLING TOWER PLUME MODEL

    EPA Science Inventory

    A review of recently reported cooling tower plume models yields none that is universally accepted. The entrainment and drag mechanisms and the effect of moisture on the plume trajectory are phenomena which are treated differently by various investigators. In order to better under...

  17. Talking Towers, Making Withs.

    ERIC Educational Resources Information Center

    Lemke, J. L.

    The notion of a linguistic "register" is useful in posing questions about how the ways language is used differ from one kind of human activity to another. This paper analyzes a videotaped segment of male grade 4/5 students (n=3) who are talking as they work to build a tower from plastic drinking straws and pins. Discussion of the analysis…

  18. Tower Mesonetwork Climatology and Interactive Display Tool

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the 45th Weather Squadron and Spaceflight Meteorology Group use data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria, and issue and verify forecasts for ground operations. Systematic biases in these parameters could adversely affect an analysis, forecast, or verification. Also, substantial geographical variations in temperature and wind speed can occur under specific wind directions. To address these concerns, the Applied Meteorology Unit (AMU) developed a climatology of temperatures and winds from the tower network, and identified the geographical variation and significant tower biases. The mesoclimate is largely driven by the complex land-water interfaces across KSC/CCAFS. Towers with close proximity to water typically had much warmer nocturnal temperatures and higher wind speeds throughout the year. The strongest nocturnal wind speeds occurred from October to March whereas the strongest mean daytime wind speeds occurred from February to May. These results of this project can be viewed by forecasters through an interactive graphical user interface developed by the AMU. The web-based interface includes graphical and map displays of mean, standard deviation, bias, and data availability for any combination of towers, variables, months, hours, and wind directions.

  19. Drop tower with no aerodynamic drag

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Jr.

    1981-01-01

    Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.

  20. Thermocouple shield

    SciTech Connect

    Ripley, Edward B.

    2009-11-24

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

  1. New student-designed research and demonstration drop tower

    NASA Astrophysics Data System (ADS)

    Bell, Donald; Weislogel, Mark

    A new drop tower has been designed and constructed at Portland State University. The ap-proach incorporates innovative features to increase throughput and microgravity quality in a highly public facility. Push button operation with full wireless CCTV coverage and passive magnetic deceleration provides quiet, safe operation from a single control station with low re-cycle time. A two-stage coaxial release mechanism decouples the payload from the drag shield to minimize disturbances to the experiment during release. This is especially important for fluids experiments that are highly sensitive to initial conditions. Performance of the new tower is presented including release, free fall, and deceleration accelerometer data. The two second tower is used for research and educational outreach. The research efforts focus on capillary flows and phenomena relevant to spacecraft fluid systems. The outreach efforts utilize partnerships with local primary, secondary and post-secondary institutions to promote the fields of science, technology, engineering and mathematics.

  2. Sound shield

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.

    1974-01-01

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

  4. Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  5. Wake shield

    NASA Technical Reports Server (NTRS)

    Bannister, Tommy; Karr, Gerald R.

    1987-01-01

    Progress on the modeling of the flow field around a wake shield using a recently obtained code based on the Monte Carlo method is discussed. The direct simulation Monte Carlo method is a method for solving the Boltzman Equation using an approximation to the collision integral term. The collision integrand is evaluated for randomly selected values of its arguments and the summation will approach the integral for large enough samples. The collision effects may be modeled for either hard sphere or various power law potentials. The convective side of the Boltzman equation is approximated over a time step using a simple trajectory calculation of molecules as they travel through the domain of interest.

  6. The Physics of Shot Towers

    NASA Astrophysics Data System (ADS)

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-04-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: How does the size of the lead shot depend on the height of the tower? In the process, we explain the basic technology underlying an important historical invention (the shot tower) and use simple physics (Newtonian mechanics and the thermodynamic laws of cooling) to model its operation.

  7. Evaluation of IR technology applied to cooling tower performance

    NASA Astrophysics Data System (ADS)

    MacNamara, Neal A.; Zayicek, Paul A.

    1999-03-01

    Infrared thermography (IR) is widely used by electric utilities as an integral part of their predictive maintenance program. IR is utilized for inspection of a variety of plant mechanical and electrical components. Additionally, IR can be used to provide thermal performance information for other key plant systems, including assessment of cooling towers. Cooling tower performance directly affects availability and heat rate in fossil and nuclear power plants. Optimal tower performance contributes to efficient turbine operation and maximum power output. It is estimated that up to half of the cooling towers installed have failed to meet their design performance specifications. As a result, any additional degradation of tower performance resulting from fouling, valve degradation, unbalanced flow, or a poor maintenance practice has a direct effect on generation output. We have collected infrared thermography images of mechanical draft cooling towers, as part of Evaluation of IR Technology Applied to Cooling Tower Performance. IR images have been analyzed to provide information regarding general performance conditions and identification of operational deficiencies related to thermal performance. Similarly, IR can be implemented for monitoring of tower flow balance activities and for post-maintenance surveillance. To date, IR images have been used to identify areas of general flow imbalance, flooding or limited flow in individual cells, missing or broken tower fill material, fan performance and other problems related to maintenance or operational issues. Additionally, an attempt is being made to use quantitative thermal data, provided by the IR image analysis software, in conjunction with condenser input/output site ambient information, to evaluate and compare individual tower cell performance.

  8. Towers of hybrid mesons

    SciTech Connect

    Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

    2009-05-01

    A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

  9. 2. Southern Light Tower and Northern Light Tower, view north, ...

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

    2. Southern Light Tower and Northern Light Tower, view north, south sides - Kennebec River Light Station, South side of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

  10. Drop Tower Facility at Queensland University of Technology

    NASA Astrophysics Data System (ADS)

    Plagens, Owen; Castillo, Martin; Steinberg, Theodore; Ong, Teng-Cheong

    The Queensland University of Technology (QUT) Drop Tower Facility is a {raise.17exscriptstyle˜}2.1 second, 21.3 m fall, dual capsule drop tower system. The dual capsule comprises of an uncoupled exterior hollow drag shield that experiences drag by the ambient atmosphere with the experimental capsule falling within the drag shield. The dual capsule system is lifted to the top of the drop tower via a mechanical crane and the dropping process is initiated by the cutting of a wire coupling the experimental package and suspending the drag shield. The internal experimental capsule reaches the bottom of the drag shield floor just prior to the deceleration stage at the air bag and during this time experience gravity levels of {raise.17exscriptstyle˜}10textsuperscript{-6} g. The deceleration system utilizes an inflatable airbag where experimental packages can be designed to experience a maximum deceleration of {raise.17exscriptstyle˜}10textsuperscript{18} g for {raise.17exscriptstyle˜}0.1 seconds. The drag shield can house experimental packages with a maximum diameter of 0.8 m and height of 0.9 m. The drag shield can also be used in foam mode, where the walls are lined with foam and small experiments can be dropped completely untethered. This mode is generally used for the study of microsatellite manipulation. Payloads can be powered by on-board power systems with power delivered to the experiment until free fall occurs. Experimental data that can be collected includes but is not limited to video, temperature, pressure, voltage/current from the power supply, and triggering mechanisms outputs which are simultaneously collected via data logging systems and high speed video recording systems. Academic and commercial projects are currently under investigation at the QUT Drop Tower Facility and collaboration is openly welcome at this facility. Current research includes the study of heterogeneously burning metals in oxygen which is aimed at fire safety applications and

  11. Effects of transmission towers on orchards and vineyards

    SciTech Connect

    Scott, W.S.

    1980-10-01

    Electric power transmission towers can pose problems for the farm operator in terms of the loss of productive area and interference with the movement of machinery. A study was conducted to evaluate the impact of transmission facilities on orchard and vineyard operations in Ontario, Canada. Economic losses to peach and grape crops were determined. Time loss varied greatly depending on the specific operation and tower location. Economic effects of transmission towers varied widely depending on location and orientation, and whether or not equipment can pass through the base area.

  12. A three-layer magnetic shielding for the MAIUS-1 mission on a sounding rocket.

    PubMed

    Kubelka-Lange, André; Herrmann, Sven; Grosse, Jens; Lämmerzahl, Claus; Rasel, Ernst M; Braxmaier, Claus

    2016-06-01

    Bose-Einstein-Condensates (BECs) can be used as a very sensitive tool for experiments on fundamental questions in physics like testing the equivalence principle using matter wave interferometry. Since the sensitivity of these experiments in ground-based environments is limited by the available free fall time, the QUANTUS project started to perform BEC interferometry experiments in micro-gravity. After successful campaigns in the drop tower, the next step is a space-borne experiment. The MAIUS-mission will be an atom-optical experiment that will show the feasibility of experiments with ultra-cold quantum gases in microgravity in a sounding rocket. The experiment will create a BEC of 10(5) (87)Rb-atoms in less than 5 s and will demonstrate application of basic atom interferometer techniques over a flight time of 6 min. The hardware is specifically designed to match the requirements of a sounding rocket mission. Special attention is thereby spent on the appropriate magnetic shielding from varying magnetic fields during the rocket flight, since the experiment procedures are very sensitive to external magnetic fields. A three-layer magnetic shielding provides a high shielding effectiveness factor of at least 1000 for an undisturbed operation of the experiment. The design of this magnetic shielding, the magnetic properties, simulations, and tests of its suitability for a sounding rocket flight are presented in this article. PMID:27370420

  13. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    SciTech Connect

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  14. 76 FR 490 - Marking Meteorological Evaluation Towers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ...-2251. FOR FURTHER INFORMATION CONTACT: Sheri Edgett-Barron, Obstruction Evaluation Services, Air... Federal Aviation Administration 14 CFR Part 77 Marking Meteorological Evaluation Towers AGENCY: Federal... to include guidance for Meteorological Evaluation Towers (METs). These towers are erected in...

  15. SSC environmental radiation shielding

    SciTech Connect

    Jackson, J.D.

    1987-07-01

    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.

  16. Corium shield

    DOEpatents

    McDonald, Douglas B.; Buchholz, Carol E.

    1994-01-01

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

  17. Power Tower Technology Roadmap and cost reduction plan.

    SciTech Connect

    Mancini, Thomas R.; Gary, Jesse A.; Kolb, Gregory J.; Ho, Clifford Kuofei

    2011-04-01

    Concentrating solar power (CSP) technologies continue to mature and are being deployed worldwide. Power towers will likely play an essential role in the future development of CSP due to their potential to provide dispatchable solar electricity at a low cost. This Power Tower Technology Roadmap has been developed by the U.S. Department of Energy (DOE) to describe the current technology, the improvement opportunities that exist for the technology, and the specific activities needed to reach the DOE programmatic target of providing competitively-priced electricity in the intermediate and baseload power markets by 2020. As a first step in developing this roadmap, a Power Tower Roadmap Workshop that included the tower industry, national laboratories, and DOE was held in March 2010. A number of technology improvement opportunities (TIOs) were identified at this workshop and separated into four categories associated with power tower subsystems: solar collector field, solar receiver, thermal energy storage, and power block/balance of plant. In this roadmap, the TIOs associated with power tower technologies are identified along with their respective impacts on the cost of delivered electricity. In addition, development timelines and estimated budgets to achieve cost reduction goals are presented. The roadmap does not present a single path for achieving these goals, but rather provides a process for evaluating a set of options from which DOE and industry can select to accelerate power tower R&D, cost reductions, and commercial deployment.

  18. Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

    NASA Technical Reports Server (NTRS)

    Rojdev, Kristina; Christiansen, Eric

    2013-01-01

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

  19. PBF Cooling Tower (PER720), and Auxiliary Building (PER624). Camera faces ...

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

    PBF Cooling Tower (PER-720), and Auxiliary Building (PER-624). Camera faces north to show south facades. Oblong vertical structure at left of center is weather shield for stairway. Date: August 2003. INEEL negative no. HD-35-10-4 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  20. Towers of Gravitational Theories

    NASA Astrophysics Data System (ADS)

    Goldberger, Walter D.; Rothstein, Ira Z.

    In this essay, we introduce a theoretical framework designed to describe black hole dynamics. The difficulties in understanding such dynamics stems from the proliferation of scales involved when one attempts to simultaneously describe all of the relevant dynamical degrees of freedom. These range from the modes that describe the black hole horizon, which are responsible for dissipative effects, to the long wavelength gravitational radiation that drains mechanical energy from macroscopic black hole bound states. We approach the problem from a Wilsonian point of view, by building a tower of theories of gravity each of which is valid at different scales. The methodology leads to multiple new results in diverse topics including phase transitions of Kaluza-Klein black holes and the interactions of spinning black hole in non-relativistic orbits. Moreover, our methods tie together speculative ideas regarding dualities for black hole horizons to real physical measurements in gravitational wave detectors.

  1. Towers of gravitational theories

    NASA Astrophysics Data System (ADS)

    Goldberger, Walter D.; Rothstein, Ira Z.

    2006-11-01

    In this essay we introduce a theoretical framework designed to describe black hole dynamics. The difficulties in understanding such dynamics stems from the proliferation of scales involved when one attempts to simultaneously describe all of the relevant dynamical degrees of freedom. These range from the modes that describe the black hole horizon, which are responsible for dissipative effects, to the long wavelength gravitational radiation that drains mechanical energy from macroscopic black hole bound states. We approach the problem from a Wilsonian point of view, by building a tower of theories of gravity each of which is valid at different scales. The methodology leads to multiple new results in diverse topics including phase transitions of Kaluza-Klein black holes and the interactions of spinning black hole in non-relativistic orbits. Moreover, our methods tie together speculative ideas regarding dualities for black hole horizons to real physical measurements in gravitational wave detectors.

  2. Historic American engineering record. Nevada national security site, Bren Tower Complex. Written historical and descriptive data and field records

    SciTech Connect

    Edwards, Susan R.; Goldenberg, Nancy

    2013-08-01

    The BREN (Bare Reactor Experiment, Nevada) Tower Complex is significant for its role in the history of nuclear testing, radiation dosimetry studies, and early field testing of the Strategic Missile Defense System designs. At the time it was built in 1962, the 1,527 ft (465 m) BREN Tower was the tallest structure west of the Mississippi River and exceeded the height of the Empire State Building by 55 ft (17 m). It remains the tallest ever erected specifically for scientific purposes and was designed and built to facilitate the experimental dosimetry studies necessary for the development of accurate radiation dose rates for the survivors of Hiroshima and Nagasaki. The tower was a key component of the Atomic Bomb Casualty Commission’s (ABCC) mission to predict the health effects of radiation exposure. Moved to its current location in 1966, the crucial dosimetry studies continued with Operation HENRE (High Energy Neutron Reactions Experiment). These experiments and the data they generated became the basis for a dosimetry system called the Tentative 1965 Dose or more commonly the T65D model. Used to estimate radiation doses received by individuals, the T65D model was applied until the mid-1980s when it was replaced by a new dosimetry system known as DS86 based on the Monte Carlo method of dose rate calculation. However, the BREN Tower data are still used for verification of the validity of the DS86 model. In addition to its importance in radiation heath effects research, the BREN Tower Complex is also significant for its role in the Brilliant Pebbles research project, a major component of the Strategic Defense Initiative popularly known as the “Star Wars” Initiative. Instigated under the Reagan Administration, the program’s purpose was to develop a system to shield the United States and allies from a ballistic missile attack. The centerpiece of the Strategic Defense System was space-based, kinetic-kill vehicles. In 1991, BREN Tower was used for the tether tests

  3. Magnetic shielding

    DOEpatents

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

    1985-02-12

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

  4. Magnetic shielding

    DOEpatents

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

    1987-10-06

    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.

  5. Magnetic shielding

    DOEpatents

    Kerns, John A.; Stone, Roger R.; Fabyan, Joseph

    1987-01-01

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

  6. Use of cooling tower blow down in ethanol fermentation.

    PubMed

    Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

    2010-01-01

    Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible. PMID:21076211

  7. PBF Cooling Tower. Hot deck of Cooling Tower with fan ...

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

    PBF Cooling Tower. Hot deck of Cooling Tower with fan motors in place. Fan's propeller blades (not in view) rotate within lower portion of vents. Inlet pipe is a left of view. Contractor's construction buildings in view to right. Photographer: Larry Page. Date: June 30, 1969. INEEL negative no. 69-3781 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  8. Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

    NASA Technical Reports Server (NTRS)

    Rojdev, Kristina; Christiansen, Eric

    2011-01-01

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

  9. Space reactor shielding fabrication

    NASA Technical Reports Server (NTRS)

    Welch, F. H.

    1972-01-01

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

  10. Ozonation of cooling tower waters

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  11. The Physics of Shot Towers

    ERIC Educational Resources Information Center

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-01-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: "How does the size of the lead shot depend on the height…

  12. Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

    NASA Technical Reports Server (NTRS)

    Rojdev, Kristina; Christiansen, Eric

    2013-01-01

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

  13. Tower Temperature and Humidity Sensors (TWR) Handbook

    SciTech Connect

    Cook, DR

    2010-02-01

    Three tall towers are installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility: a 60-meter triangular tower at the Southern Great Plains (SGP) Central Facility (CF), a 21-meter walkup scaffolding tower at the SGP Okmulgee forest site (E21), and a 40-meter triangular tower at the North Slope of Alaska (NSA) Barrow site. The towers are used for meteorological, radiological, and other measurements.

  14. EMI Shields made from intercalated graphite composites

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Terry, Jennifer

    1995-01-01

    Electromagnetic interference (EMI) shielding typically makes up about twenty percent of the mass of a spacecraft power system. Graphite fiber/polymer composites have significantly lower densities and higher strengths than aluminum, the present material of choice for EMI shields, but they lack the electrical conductivity that enables acceptable shielding effectiveness. Bromine intercalated pitch-based graphite/epoxy composites have conductivities fifty times higher than conventional structural graphite fibers. Calculations are presented which indicate that EMI shields made from such composites can have sufficient shielding at less than 20% of the mass of conventional aluminum shields. EMI shields provide many functions other than EMI shielding including physical protection, thermal management, and shielding from ionizing radiation. Intercalated graphite composites perform well in these areas also. Mechanically, they have much higher specific strength and modulus than aluminum. They also have shorter half thicknesses for x-rays and gamma radiation than aluminum. Thermally, they distribute infra-red radiation by absorbing and re-radiating it rather than concentrating it by reflection as aluminum does. The prospects for intercalated graphite fiber/polymer composites for EMI shielding are encouraging.

  15. Deployable tensegrity towers

    NASA Astrophysics Data System (ADS)

    Pinaud, Jean-Paul

    The design of a complete tensegrity system involves the analysis of static equilibria, the mechanical properties of the configuration, the deployment of the structure, and the regulation and dynamics of the system. This dissertation will explore these steps for two different types of structures. The first structure is the traditional Snelson Tower, where struts are disjointed, and is referred to as a Class 1 tensegrity. The second structure of interest is referred to as a Class 2 structure, where two struts come in contact at a joint. The first part of the thesis involves the dynamics of these tensegrity structures. Two complete nonlinear formulations for the dynamics of tensegrity systems are derived. In addition, a general formulation for the statics for an arbitrary tensegrity structure resulted from one of the dynamic formulations and is presented with symmetric and nonsymmetric tensegrity configurations. The second part of the thesis involves statics. The analysis of static equilibria and the implementation of this analysis into an open loop control law that will deploy the tensegrity structures along an equilibrium manifold are derived. The analysis of small stable tensegrity units allow for a modular design, where a collection of these units can be assembled into a larger structure that obeys the same control laws for deployment concepts. In addition, a loaded structure is analyzed to determine the optimal number of units required to obtain a minimal mass configuration. The third part of the thesis involves laboratory hardware that demonstrates the practical use of the methodology presented. A Class 2 symmetric structure is constructed, deployed, and stowed using the analysis from part two. In addition, the static equilibria of a Class 1 structure is computed to obtain nonsymmetric reconfigurations. The final part of the thesis involves the attenuation of white noise disturbances acting on nodes of both structures. The structures are simulated using linear

  16. Shielding for thermoacoustic tomography with RF excitation

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    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.

  17. Wind Shear Characteristics at Central Plains Tall Towers

    SciTech Connect

    Schwartz, M.; Elliott, D.

    2006-01-01

    The object of this study is to analyze wind shear characteristics at tall tower sites in the Central Plains of the United States. The hub heights of modern turbines used for wind farm projects are now 70 meters (m) to 100 m above ground and some advanced turbines under development for deployment during the second half of this decade are rated at 2-5 megawatts of energy generation with rotor diameters near 100 m and hub heights of 100-120 m. These advanced turbines will take advantage of the higher wind speeds aloft to generate more wind energy. Specific knowledge of important wind shear characteristics near and at turbine hub height is needed to optimize turbine design and wind farm layout. Unfortunately, wind speed shear measurements at heights of 80-120 m were virtually nonexistent a few years ago and are still quite uncommon today. The Central Plains is a prime wind energy development region and knowledge about the wind shear characteristics will reduce uncertainty about the resource and enhance wind farm design. Previous analyses of tall tower data (Schwartz and Elliott, 2005) concentrated on data from specific states. The wind energy community has recognized the need to fill the gap of direct wind speed measurements at levels 70 m and higher above the ground. Programs instituted during the last 5 years at the state level and supported by the U.S. Department of Energy's (DOE) State Energy Program initiative have placed anemometers and vanes at several levels on existing tall (70 m+) communication towers. The Central Plains has a fairly high concentration of tall tower sites. The distribution of tall tower sites varies among the states in the Central Plains, because the tall tower program is new and the available state and federal funding to establish tall towers is variable. Our wind resource assessment group at DOE's National Renewable Energy Laboratory (NREL) has obtained much of these necessary measurement data from both individual state sources and regional

  18. Stiffness and energy dissipation characteristics of guyed tower with dynamic mooring properties

    SciTech Connect

    Morrison, D.G.

    1984-03-01

    A simple model for a complex system is presented that contains the essential properties of the guyed tower. The dynamic response to wave load of a guyed tower is represented by a single degree of freedom model. Tower response, with different wave heights and hydrodynamic coefficients, using statically and dynamically determined mooring properties were calculated for a specific tower in 1100 ft (335 m) of water. The importance of this study lies in a good modeling of the cable forces, including the hysteretic effects of line damping, and in identifying cases where the quasi-static model may fail.

  19. Working through the Maze of Liability Shields.

    ERIC Educational Resources Information Center

    King, Jeff; Schmiesing, Ryan

    1998-01-01

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

  20. Preliminary radiation shielding design for BOOMERANG

    SciTech Connect

    Donahue, Richard J.

    2002-10-23

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

  1. Fabrication of reactor shields at the Y-12 plant

    NASA Astrophysics Data System (ADS)

    Asbury, W. L.; Kosinski, F. E.; Royer, L. T.

    The Oak Ridge Y-12 Plant is the lead DOE facility for the large scale synthesis, manufacture, and fabrication of lithium hydride/deuteride (LiH/D) materials. Fabrication of large crack free LiH/D parts of uniform density and strength is best achieved by isostatic pressing, using powder metallurgy methods. The highly reactive and moisture sensitive nature of LiH/D has required a number of unique facilities and processing methods at Y-12 to process LiH/D in a safe manner and to maintain high quality products. The history of the fabrication of neutron shields for the SNAP 10A reactor is discussed. Powder metallurgical techniques were used to fabricate that shielding system at Y-12, and the units were tested for shielding efficiency at the Tower Shielding Facility at ORNL.

  2. Testing the bioelectric shield.

    PubMed

    Blackmore, Susan J; Rose, Nicholas

    2002-01-01

    A pendant was claimed to provide numerous health benefits, including reduced stress, increased strength, and protection from electromagnetic radiation from computers and mobile phones. Three experiments tested the effectiveness of this pendant's effect as a bioelectric shield. In the first experiment, 12 subjects who work with computers wore shields (6 real, 6 sham) for several weeks and were regularly tested for hand strength and mood changes. Both types of shield increased calmness, but the real shields did not have any greater effect. In 2 further studies (in each N=40) hand strength was measured at baseline, with mobile phone, and with mobile phone and bioelectric or sham shield. The shields did not differ in their effects. Both studies showed a significant correlation between the change in strength with and without the shield and subjects'scores on a questionnaire concerning their belief in and use of alternative therapies. The shields appear to produce a measurable placebo effect but are otherwise ineffective. PMID:12233804

  3. NEUTRONIC REACTOR SHIELD

    DOEpatents

    Fermi, E.; Zinn, W.H.

    1957-09-24

    The reactor radiation shield material is comprised of alternate layers of iron-containing material and compressed cellulosic material, such as masonite. The shielding material may be prefabricated in the form of blocks, which can be stacked together in ary desired fashion to form an effective shield.

  4. Hot Cell Window Shielding Analysis Using MCNP

    SciTech Connect

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

    2009-05-01

    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.

  5. Tower-supported solar-energy collector

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K.

    1977-01-01

    Multiple-collector tower system supports three receiver/concentrators that absorb solar energy reflected from surrounding field of heliostats. System overcomes disadvantages of tower-supported collectors. Booms can be lowered during heavy winds to protect arms and collectors.

  6. Ion beam thruster shield

    NASA Technical Reports Server (NTRS)

    Power, J. L. (Inventor)

    1976-01-01

    An ion thruster beam shield is provided that comprises a cylindrical housing that extends downstream from the ion thruster and a plurality of annular vanes which are spaced along the length of the housing, and extend inwardly from the interior wall of the housing. The shield intercepts and stops all charge exchange and beam ions, neutral propellant, and sputter products formed due to the interaction of beam and shield emanating from the ion thruster outside of a fixed conical angle from the thruster axis. Further, the shield prevents the sputter products formed during the operation of the engine from escaping the interior volume of the shield.

  7. Rotating shielded crane system

    DOEpatents

    Commander, John C.

    1988-01-01

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

  8. 29 CFR 1926.1435 - Tower cranes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Tower cranes. 1926.1435 Section 1926.1435 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1435 Tower cranes. (a) This section contains supplemental requirements for tower cranes; all sections of...

  9. 29 CFR 1926.1435 - Tower cranes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Tower cranes. 1926.1435 Section 1926.1435 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1435 Tower cranes. (a) This section contains supplemental requirements for tower cranes; all sections of...

  10. Cooling tower hardware corrosion studies

    SciTech Connect

    Blue, S.C.

    1983-01-31

    The data presented in this report are interim results of a continuing investigation into the corrosion resistance of metals in the environment of a large cooling tower. Some of the significant observations are as follows: the corrosion of susceptible metals occurs most rapidly in the warm fog conditions between the deck and mist filters; the application of stainless steel must be made on the basis of alloy chemistry and processing history. Some corrosion resistant alloys may develop cracking problems after improper heat treating or welding; combinations of aluminum bronze, stainless steel, and silicon bronze hardware were not susceptible to galvanic corrosion; the service life of structural steel is extended by coal tar epoxy coatings; aluminum coatings appear to protect structural steel on the tower deck and below the distribution nozzles. The corrosion of cooling tower hardware can be easily controlled through the use of 316 stainless steel and silicon bronze. The use of other materials which exhibit general resistance should be specified only after they have been tested in the form of structural assemblies such as weldments and bolted joints in each of the different tower zones.

  11. Indiana State University Graduates to Advanced Plastic Cooling Towers

    ERIC Educational Resources Information Center

    Sullivan, Ed

    2012-01-01

    Perhaps more than many other industries, today's universities and colleges are beset by dramatically rising costs on every front. One of the areas where overhead can be contained or reduced is in the operation of the chilled water systems that support air conditioning throughout college campuses, specifically the cooling towers. Like many…

  12. A Meso-Climatology Study of the High-Resolution Tower Network Over the Florida Spaceport

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the US Air Force 45th Weather Squadron (45 WS) use wind and temperature data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria and to issue and verify temperature and wind advisories, watches, and warnings for ground operations. The Spaceflight Meteorology Group at the Johnson Space Center in Houston, TX also uses these data when issuing forecasts for shuttle landings at the KSC Shuttle Landing Facility. Systematic biases in these parameters at any of the towers could adversely affect an analysis, forecast, or verification for all of these operations. In addition, substantial geographical variations in temperature and wind speed can occur under specific wind directions. Therefore, the Applied Meteorology Unit (AMU), operated by ENSCO Inc., was tasked to develop a monthly and hourly climatology of temperatures and winds from the tower network, and identify the geographical variation, tower biases, and the magnitude of those biases. This paper presents a sub-set of results from a nine-year climatology of the KSC/CCAFS tower network, highlighting the geographical variations based on location, month, times of day, and specific wind direction regime. Section 2 provides a description of the tower mesonetwork and instrumentation characteristics. Section 3 presents the methodology used to construct the tower climatology including QC methods and data processing. The results of the tower climatology are presented in Section 4 and Section 5 summarizes the paper.

  13. Structural concept studies for a horizontal cylindrical lunar habitat and a lunar guyed tower

    NASA Technical Reports Server (NTRS)

    Yin, Paul K.

    1990-01-01

    A conceptual structural design of a horizontal cylindrical lunar habitat is presented. The design includes the interior floor framing, the exterior support structure, the foundation mat, and the radiation shielding. Particular attention was given on its efficiency in shipping and field erection, and on selection of structural materials. Presented also is a conceptual design of a 2000-foot lunar guyed tower. A special field erection scheme is implemented in the design. In order to analyze the over-all column buckling of the mast, where its axial compression includes its own body weight, a simple numerical procedure is formulated in a form ready for coding in FORTRAN. Selection of structural materials, effect of temperature variations, dynamic response of the tower to moonquake, and guy anchoring system are discussed. Proposed field erection concepts for the habitat and for the guyed tower are described.

  14. Wake Shield Target Protection

    SciTech Connect

    Valmianski, Emanuil I.; Petzoldt, Ronald W.; Alexander, Neil B.

    2003-05-15

    The heat flux from both gas convection and chamber radiation on a direct drive target must be limited to avoid target damage from excessive D-T temperature increase. One of the possibilities of protecting the target is a wake shield flying in front of the target. A shield will also reduce drag force on the target, thereby facilitating target tracking and position prediction. A Direct Simulation Monte Carlo (DSMC) code was used to calculate convection heat loads as boundary conditions input into ANSYS thermal calculations. These were used for studying the quality of target protection depending on various shapes of shields, target-shield distance, and protective properties of the shield moving relative to the target. The results show that the shield can reduce the convective heat flux by a factor of 2 to 5 depending on pressure, temperature, and velocity. The protective effect of a shield moving relative to the target is greater than the protective properties of a fixed shield. However, the protective effect of a shield moving under the drag force is not sufficient for bringing the heat load on the target down to the necessary limit. Some other ways of diminishing heat flux using a protective shield are discussed.

  15. Review of ORNL-TSF shielding experiments for the gas-cooled Fast Breeder Reactor Program

    SciTech Connect

    Abbott, L.S.; Ingersoll, D.T.; Muckenthaler, F.J.; Slater, C.O.

    1982-01-01

    During the period between 1975 and 1980 a series of experiments was performed at the ORNL Tower Shielding Facility in support of the shield design for a 300-MW(e) Gas Cooled Fast Breeder Demonstration Plant. This report reviews the experiments and calculations, which included studies of: (1) neutron streaming in the helium coolant passageways in the GCFR core; (2) the effectiveness of the shield designed to protect the reactor grid plate from radiation damage; (3) the adequacy of the radial shield in protecting the PCRV (prestressed concrete reactor vessel) from radiation damage; (4) neutron streaming between abutting sections of the radial shield; and (5) the effectiveness of the exit shield in reducing the neutron fluxes in the upper plenum region of the reactor.

  16. Hydrogen Storage in Wind Turbine Towers

    SciTech Connect

    Kottenstette, R.; Cotrell, J.

    2003-09-01

    Low-cost hydrogen storage is recognized as a cornerstone of a renewables-hydrogen economy. Modern utility-scale wind turbine towers are typically conical steel structures that, in addition to supporting the rotor, could be used to store hydrogen. This study has three objectives: (1) Identify the paramount considerations associated with using a wind turbine tower for hydrogen storage; (2)Propose and analyze a cost-effective design for a hydrogen-storing tower; and (3) Compare the cost of storage in hydrogen towers to the cost of storage in conventional pressure vessels. The paramount considerations associated with a hydrogen tower are corrosion (in the form of hydrogen embrittlement) and structural failure (through bursting or fatigue life degradation). Although hydrogen embrittlement (HE) requires more research, it does not appear to prohibit the use of turbine towers for hydrogen storage. Furthermore, the structural modifications required to store hydrogen in a tower are not cost prohibitive.

  17. Cable shield connecting device

    DOEpatents

    Silva, Frank A.

    1979-01-01

    A cable shield connecting device for installation on a high voltage cable of the type having a metallic shield, the device including a relatively conformable, looped metal bar for placement around a bared portion of the metallic shield to extend circumferentially around a major portion of the circumference of the metallic shield while being spaced radially therefrom, a plurality of relatively flexible metallic fingers affixed to the bar, projecting from the bar in an axial direction and spaced circumferentially along the bar, each finger being attached to the metallic shield at a portion located remote from the bar to make electrical contact with the metallic shield, and a connecting conductor integral with the bar.

  18. Meteorological Towers Display for Windows NT

    Energy Science and Technology Software Center (ESTSC)

    1999-05-20

    The Towers Display Program provides a convenient means of graphically depicting current wind speed and direction from a network of meteorological monitoring stations. The program was designed primarily for emergency response applications and, therefore, plots observed wind directions as a transport direction, i.e., the direction toward which the wind would transport a release of an atmospheric contaminant. Tabular summaries of wind speed and direction as well as temperature, relative humidity, and atmospheric turbulence measured atmore » each monitoring station can be displayed. The current implementation of the product at SRS displays data from eight Weather INformation and Display (WIND) System meteorological towers at SRS, meteorological stations established jointly by SRS/WSRC and the Augusta/Richmond County Emergency Management Agency in Augusta, GA, and National Weather Service stations in Augusta, GA. Wind speed and direction are plotted in a Beaufort scale format at the location of the station on a geographic map of the area. A GUI provides for easy specification of a desired date and time for the data to be displayed.« less

  19. RADIATION SHIELDING DEVICE

    DOEpatents

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

    1958-09-23

    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.

  20. Airport Remote Tower Sensor Systems

    NASA Technical Reports Server (NTRS)

    Papasin, Richard; Gawdiak, Yuri; Maluf, David A.; Leidich, Christopher; Tran, Peter B.

    2001-01-01

    Remote Tower Sensor Systems (RTSS) are proof-of-concept prototypes being developed by NASA/Ames Research Center (NASA/ARC) with collaboration with the FAA (Federal Aviation Administration) and NOAA (National Oceanic Atmospheric Administration). RTSS began with the deployment of an Airport Approach Zone Camera System that includes real-time weather observations at San Francisco International Airport. The goal of this research is to develop, deploy, and demonstrate remotely operated cameras and sensors at several major airport hubs and un-towered airports. RTSS can provide real-time weather observations of airport approach zone. RTSS will integrate and test airport sensor packages that will allow remote access to realtime airport conditions and aircraft status.

  1. RADIATION SHIELDING COMPOSITION

    DOEpatents

    Dunegan, H.L.

    1963-01-29

    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)

  2. Ozone Treatment For Cooling Towers

    NASA Technical Reports Server (NTRS)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  3. 2004 Savannah River Cooling Tower Collection (U)

    SciTech Connect

    Garrett, Alfred; Parker, Matthew J.; Villa-Aleman, E.

    2005-05-01

    The Savannah River National Laboratory (SRNL) collected ground truth in and around the Savannah River Site (SRS) F-Area cooling tower during the spring and summer of 2004. The ground truth data consisted of air temperatures and humidity inside and around the cooling tower, wind speed and direction, cooling water temperatures entering; inside adn leaving the cooling tower, cooling tower fan exhaust velocities and thermal images taken from helicopters. The F-Area cooling tower had six cells, some of which were operated with fans off during long periods of the collection. The operating status (fan on or off) for each of the six cells was derived from operations logbooks and added to the collection database. SRNL collected the F-Area cooling tower data to produce a database suitable for validation of a cooling tower model used by one of SRNL's customer agencies. SRNL considers the data to be accurate enough for use in a model validation effort. Also, the thermal images of the cooling tower decks and throats combined with the temperature measurements inside the tower provide valuable information about the appearance of cooling towers as a function of fan operating status and time of day.

  4. Update on the Purdue University 2-second Drop Tower

    NASA Astrophysics Data System (ADS)

    Collicott, Steven

    an update on progress for the micro-gravity community. The most noticeable current activity is testing of the air-bag decelerator. The tower is one that will use a free-falling experiment inside of a drag shield to avoid most aerodynamic drag. The airbag is designed from experiences of others yet the small, triangular room in which the tower terminates imposes challenges. The airbag is approximately 1.5m diameter and 1.5m tall. Initial testing led to a desire to increase vent area, and just this week the bag has returned from the shop that was modifying it. On-board computer, battery packs, lighting, and cameras have been acquired. Thanks to Lockheed Martin, one camera is 500 frames per second with 1.3 million 12-bit gray scale pixels per frame. The Spincraft company donated steel hemisphere-cylinders to serve as the nose of the drag shield. Wind tunnel and CFD modeling of the drag shield has been performed by Purdue undergraduate aerospace students. Currently the drag shield structure and experiment package structure are being design and analyzed. The experiment volume is approximately a cylinder 0.45m diameter and 0.6m tall. Tower operation is intended to commence in fall 2010 with inert package drops at full mass and full height. Developing the operations procedures, especially operational safety, are the goals of this work. First science is then expected in the winter. References 1. Y. Chen, "A Study of Capillary Flow in a Vane-wall Gap in Zero Gravity," Ph.D. thesis, School of Aeronautics and Astronautics, Purdue University. August 2003. 2. Y. Chen and S. H. Collicott, "Investigation of the Symmetric Wetting of a Vane-Wall Gap in Propellant Tanks," AIAA Journal, 42, No. 2, pp. 305-314, February 2004. 3. Y. Chen, and S. H. Collicott, "Experimental Study on the Capillary Flow in a Vane-Wall Gap Geometry," AIAA Journal, 43, No. 11, pp. 2395-2403, November, 2005. 4. Y. Chen and S. H. Collicott, "Study of Wetting in an Asymmetrical Vane-Wall Gap in Propellant Tanks

  5. Update on the Purdue University 2-second Drop Tower

    NASA Astrophysics Data System (ADS)

    Collicott, Steven

    an update on progress for the micro-gravity community. The most noticeable current activity is testing of the air-bag decelerator. The tower is one that will use a free-falling experiment inside of a drag shield to avoid most aerodynamic drag. The airbag is designed from experiences of others yet the small, triangular room in which the tower terminates imposes challenges. The airbag is approximately 1.5m diameter and 1.5m tall. Initial testing led to a desire to increase vent area, and just this week the bag has returned from the shop that was modifying it. On-board computer, battery packs, lighting, and cameras have been acquired. Thanks to Lockheed Martin, one camera is 500 frames per second with 1.3 million 12-bit gray scale pixels per frame. The Spincraft company donated steel hemisphere-cylinders to serve as the nose of the drag shield. Wind tunnel and CFD modeling of the drag shield has been performed by Purdue undergraduate aerospace students. Currently the drag shield structure and experiment package structure are being design and analyzed. The experiment volume is approximately a cylinder 0.45m diameter and 0.6m tall. Tower operation is intended to commence in fall 2010 with inert package drops at full mass and full height. Developing the operations procedures, especially operational safety, are the goals of this work. First science is then expected in the winter. References 1. Y. Chen, "A Study of Capillary Flow in a Vane-wall Gap in Zero Gravity," Ph.D. thesis, School of Aeronautics and Astronautics, Purdue University. August 2003. 2. Y. Chen and S. H. Collicott, "Investigation of the Symmetric Wetting of a Vane-Wall Gap in Propellant Tanks," AIAA Journal, 42, No. 2, pp. 305-314, February 2004. 3. Y. Chen, and S. H. Collicott, "Experimental Study on the Capillary Flow in a Vane-Wall Gap Geometry," AIAA Journal, 43, No. 11, pp. 2395-2403, November, 2005. 4. Y. Chen and S. H. Collicott, "Study of Wetting in an Asymmetrical Vane-Wall Gap in Propellant Tanks

  6. NEUTRONIC REACTOR SHIELDING

    DOEpatents

    Borst, L.B.

    1961-07-11

    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.

  7. Gamma ray detector shield

    DOEpatents

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

    1985-08-26

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

  8. Predictions for Radiation Shielding Materials

    NASA Technical Reports Server (NTRS)

    Kiefer, Richard L.

    2002-01-01

    Radiation from galactic cosmic rays (GCR) and solar particle events (SPE) is a serious hazard to humans and electronic instruments during space travel, particularly on prolonged missions outside the Earth s magnetic fields. Galactic cosmic radiation (GCR) is composed of approx. 98% nucleons and approx. 2% electrons and positrons. Although cosmic ray heavy ions are 1-2% of the fluence, these energetic heavy nuclei (HZE) contribute 50% of the long-term dose. These unusually high specific ionizations pose a significant health hazard acting as carcinogens and also causing microelectronics damage inside spacecraft and high-flying aircraft. These HZE ions are of concern for radiation protection and radiation shielding technology, because gross rearrangements and mutations and deletions in DNA are expected. Calculations have shown that HZE particles have a strong preference for interaction with light nuclei. The best shield for this radiation would be liquid hydrogen, which is totally impractical. For this reason, hydrogen-containing polymers make the most effective practical shields. Shielding is required during missions in Earth orbit and possibly for frequent flying at high altitude because of the broad GCR spectrum and during a passage into deep space and LunarMars habitation because of the protracted exposure encountered on a long space mission. An additional hazard comes from solar particle events (SPEs) which are mostly energetic protons that can produce heavy ion secondaries as well as neutrons in materials. These events occur at unpredictable times and can deliver a potentially lethal dose within several hours to an unshielded human. Radiation protection for humans requires safety in short-term missions and maintaining career exposure limits within acceptable levels on future long-term exploration missions. The selection of shield materials can alter the protection of humans by an order of magnitude. If improperly selected, shielding materials can actually

  9. 'Towers in the Tempest' Computer Animation Submission

    NASA Technical Reports Server (NTRS)

    Shirah, Greg

    2008-01-01

    The following describes a computer animation that has been submitted to the ACM/SIGGRAPH 2008 computer graphics conference: 'Towers in the Tempest' clearly communicates recent scientific research into how hurricanes intensify. This intensification can be caused by a phenomenon called a 'hot tower.' For the first time, research meteorologists have run complex atmospheric simulations at a very fine temporal resolution of 3 minutes. Combining this simulation data with satellite observations enables detailed study of 'hot towers.' The science of 'hot towers' is described using: satellite observation data, conceptual illustrations, and a volumetric atmospheric simulation data. The movie starts by showing a 'hot tower' observed by NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft's three dimensional precipitation radar data of Hurricane Bonnie. Next, the dynamics of a hurricane and the formation of 'hot towers' are briefly explained using conceptual illustrations. Finally, volumetric cloud, wind, and vorticity data from a supercomputer simulation of Hurricane Bonnie are shown using volume techniques such as ray marching.

  10. 1. Light tower/keeper's house and abandoned light tower, view northwest, ...

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

    1. Light tower/keeper's house and abandoned light tower, view northwest, south southeast and east northeast sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

  11. 2. Abandoned light tower and keeper's house/light tower, view southeast, ...

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

    2. Abandoned light tower and keeper's house/light tower, view southeast, north northwest and west southwest sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

  12. Vortex-augmented cooling tower - windmill combination

    DOEpatents

    McAllister, J.E. Jr.

    1982-09-02

    A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passage to provide power as a by-product.

  13. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800[degree]C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280[degree]F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found.

  14. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800{degree}C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280{degree}F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found.

  15. Optical design of airport control tower cabs.

    PubMed

    Carman, P D; Budde, H W

    1980-02-15

    A study has been made of optical aspects of airport control towers as part of a planned general optimization of control towers by Transport Canada. Problems found were reflections, glare, visual obstructions, identification of distant objects, and excessive solar heat. The study makes recommendations on cab shape, tower height, glazing, shades, sunglasses, binoculars, and internal lighting. Proper choice of cab shape (e.g., 30 degrees window inclination and 12-28 sides) provided effective control of reflections. Some plastic shades werefound to increase the risk of eye damage. Two tower cabs incorporating the recommendations have been built and were found to be satisfactory. PMID:20216882

  16. Optimal Inflatable Space Towers of High Height

    NASA Astrophysics Data System (ADS)

    Bolonkin, Alexander

    2002-01-01

    Author provides theory and computations for building inflatable space towers up to a hundred km in height. These towers can be used for tourism; scientific observation of space, earth's surface, weather, top atmosphere, as well as for radio, television, and communication transmissions. These towers can also be used to launch space ships and Earth satellites. These projects are not expensive and do not require rockets. They require thin strong films composed from artificial fibers and fabricated by current industry. Towers can be built using present technology. Towers can be used (for tourism, communication, etc.) during the construction process and provide self-financing for further construction. The tower design does not require work at high altitudes; all construction can be done at the earth's surface. The transport system for this tower consists a small engine (used only for friction compensation) located at the earth's surface. The tower is separated into sections and has special protection mechanism in case of a damage. Problems involving security, control, repair, and stability of the proposed towers are addressed in subsequent publications. The author is prepared to discuss these and other problems with serious organizations desiring to research and develop these projects.

  17. Optimal inflatable space towers of high height

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    Author suggested, developed theory, and computed some projects of an optimal inflatable space tower of the heights some hundreds km. These towers can be used for tourism, scientist observation of space, Earth surface, Earth weather, Earth top atmosphere, and for radio, TV, communication transmissions. These towers can be used for launching of the space ships and Earth s atellites. The computed projects not expensive, do not request rockets. They need only in thin strong films composed from the artificial fibers and fabricated by a current industry. Towers can be built by a current technology. Towers can be explored (for tourism, communication, etc.) in a time of the construction process and give a profit, self- financing for further constriction. They can permanent increase their height. The tower design does not request a work at the high altitudes. All construction works will be making at the Earth surface. Author suggests the transport system for this tower of a high capability, which does not request a power energy issue. The small engine (only for a friction compensation) is located at the Earth surface. The tower is separated on sections and has a special protection of a case of a damage. It is considered also the problems of security, control, repair, etc. of the suggested towers. The author has also solved additional problems, which appear in these projects and which can look as difficult for the given proposal and current technology. The author is prepared to discuss the problems with serious organizations, which want to research and develop these projects.

  18. Airport Remote Tower Sensor Systems

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Gawdiak, Yuri; Leidichj, Christopher; Papasin, Richard; Tran, Peter B.; Bass, Kevin

    2006-01-01

    Networks of video cameras, meteorological sensors, and ancillary electronic equipment are under development in collaboration among NASA Ames Research Center, the Federal Aviation Administration (FAA), and the National Oceanic Atmospheric Administration (NOAA). These networks are to be established at and near airports to provide real-time information on local weather conditions that affect aircraft approaches and landings. The prototype network is an airport-approach-zone camera system (AAZCS), which has been deployed at San Francisco International Airport (SFO) and San Carlos Airport (SQL). The AAZCS includes remotely controlled color video cameras located on top of SFO and SQL air-traffic control towers. The cameras are controlled by the NOAA Center Weather Service Unit located at the Oakland Air Route Traffic Control Center and are accessible via a secure Web site. The AAZCS cameras can be zoomed and can be panned and tilted to cover a field of view 220 wide. The NOAA observer can see the sky condition as it is changing, thereby making possible a real-time evaluation of the conditions along the approach zones of SFO and SQL. The next-generation network, denoted a remote tower sensor system (RTSS), will soon be deployed at the Half Moon Bay Airport and a version of it will eventually be deployed at Los Angeles International Airport. In addition to remote control of video cameras via secure Web links, the RTSS offers realtime weather observations, remote sensing, portability, and a capability for deployment at remote and uninhabited sites. The RTSS can be used at airports that lack control towers, as well as at major airport hubs, to provide synthetic augmentation of vision for both local and remote operations under what would otherwise be conditions of low or even zero visibility.

  19. Solar Power Tower Design Basis Document, Revision 0

    SciTech Connect

    ZAVOICO,ALEXIS B.

    2001-07-01

    This report contains the design basis for a generic molten-salt solar power tower. A solar power tower uses a field of tracking mirrors (heliostats) that redirect sunlight on to a centrally located receiver mounted on top a tower, which absorbs the concentrated sunlight. Molten nitrate salt, pumped from a tank at ground level, absorbs the sunlight, heating it up to 565 C. The heated salt flows back to ground level into another tank where it is stored, then pumped through a steam generator to produce steam and make electricity. This report establishes a set of criteria upon which the next generation of solar power towers will be designed. The report contains detailed criteria for each of the major systems: Collector System, Receiver System, Thermal Storage System, Steam Generator System, Master Control System, and Electric Heat Tracing System. The Electric Power Generation System and Balance of Plant discussions are limited to interface requirements. This design basis builds on the extensive experience gained from the Solar Two project and includes potential design innovations that will improve reliability and lower technical risk. This design basis document is a living document and contains several areas that require trade-studies and design analysis to fully complete the design basis. Project- and site-specific conditions and requirements will also resolve open To Be Determined issues.

  20. Structural health monitoring of wind towers: residual fatigue life estimation

    NASA Astrophysics Data System (ADS)

    Benedetti, M.; Fontanari, V.; Battisti, L.

    2013-04-01

    In a recent paper (Benedetti et al 2011 Smart Mater. Struct. 20 055009), the authors investigated the possibility of detecting cracks in critical sites of onshore wind towers using a radial arrangement of strain sensors around the tower periphery in the vicinity of the base welded joint. Specifically, the strain difference between adjacent strain sensors is used as a damage indicator. The number of sensors to be installed is determined by the minimum crack size to be detected, which in turn depends on the expected extreme wind conditions and programmed inspection/repair schedule. In this companion paper, we address these issues by investigating possible strategies for residual fatigue life assessment and management of onshore wind towers once the crack has been detected. For this purpose, fracture mechanics tests are carried out using welded samples to quantify the resistance to fatigue crack growth as well as the elastic-plastic fracture toughness of the welded joint at the tower base. These material strength characteristics are used to estimate (i) the critical crack size for structural integrity on the basis of fracture toughness tests, elastoplastic finite element analyses and loading spectra under extreme wind conditions, (ii) the residual life before structural collapse, applying a frequency-domain method to typical in-service wind actions and wind directionality.

  1. Drop Tower and Aircraft Capabilities

    NASA Technical Reports Server (NTRS)

    Urban, David L.

    2015-01-01

    This presentation is a brief introduction to existing capabilities in drop towers and low-gravity aircraft that will be presented as part of a Symposium: Microgravity Platforms Other Than the ISS, From Users to Suppliers which will be a half day program to bring together the international community of gravity-dependent scientists, program officials and technologists with the suppliers of low gravity platforms (current and future) to focus on the future requirements and use of platforms other than the International Space Station (ISS).

  2. European Sail Tower SPS concept

    NASA Astrophysics Data System (ADS)

    Seboldt, W.; Klimke, M.; Leipold, M.; Hanowski, N.

    2001-03-01

    Based on a DLR-study in 1998/99 on behalf of ESA/ESTEC called "System Concepts, Architectures and Technologies for Space Exploration and Utilization (SE&U)" a new design for an Earth-orbiting Solar Power Satellite (SPS) has been developed. The design is called "European Sail Tower SPS" and consists mainly of deployable sail-like structures derived from the ongoing DLR/ESA solar sail technology development activity. Such a SPS satellite features an extremely light-weight and large tower-like orbital system and could supply Europe with significant amounts of electrical power generated by photovoltaic cells and subsequently transmitted to Earth via microwaves. In order to build up the sail tower, 60 units - each consisting of a pair of square-shaped sails - are moved from LEO to GEO with electric propulsion and successively assembled in GEO robotically on a central strut. Each single sail has dimensions of 150m × 150 m and is automatically deployed, using four diagonal light-weight carbon fiber (CFRP) booms which are initially rolled up on a central hub. The electric thrusters for the transport to GEO could also be used for orbit and attitude control of the assembled tower which has a total length of about 15 km and would be mainly gravity gradient stabilized. Employing thin film solar cell technology, each sail is used as a solar array and produces an electric power in orbit of about 3.7 MW e. A microwave antenna with a diameter of 1 km transmits the power to a 10 km rectenna on the ground. The total mass of this 450 MW SPS is about 2100 tons. First estimates indicate that the costs for one kWh delivered in this way could compete with present day energy costs, if launch costs would decrease by two orders of magnitude. Furthermore, mass production and large numbers of installed SPS systems must be assumed in order to lower significantly the production costs and to reduce the influence of the expensive technology development. The paper presents the technical concept

  3. MEANS FOR SHIELDING REACTORS

    DOEpatents

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

    1959-03-10

    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.

  4. Space nuclear reactor shielding optimization studies

    NASA Astrophysics Data System (ADS)

    Jimenez, Richard D.; El-Genk, Mohamed S.

    The Institute for Space Nuclear Reactor Studies is investigating optimal techniques for shielding spacecraft (payload) electronics from the combined radiation effects of the SP-100 system nuclear reactor core and the natural space environment. The academic challenge of this research includes the investigation of the combined influences of radiation from the space environment and the radiations from the reactor power source. The technical application includes a series of shielding mass penalty tradeoffs for the SP-100 Program concept between the reactor core shield and the additional shielding of the spacecraft enclosure. These mass penalty tradeoffs are being conducted for several space flight orbits of future interest to the space military and civilian communities. It was shown that several potential mission orbits may pose environmental radiation dosages which are more severe than the SP-100 specification of core escape neutron and gamma ray particle fluences incident on the spacecraft.

  5. Combined-cycle power tower

    SciTech Connect

    Bohn, M S; Williams, T A; Price, H W

    1994-10-01

    This paper evaluates a new power tower concept that offers significant benefits for commercialization of power tower technology. The concept uses a molten nitrate salt centralreceiver plant to supply heat, in the form of combustion air preheat, to a conventional combined-cycle power plant. The evaluation focused on first commercial plants, examined three plant capacities (31, 100, and 300 MWe), and compared these plants with a solar-only 100-MWe plant and with gas-only combined-cycle plants in the same three capacities. Results of the analysis point to several benefits relative to the solar-only plant including low energy cost for first plants, low capital cost for first plants, reduced risk with respect to business uncertainties, and the potential for new markets. In addition, the concept appears to have minimal technology development requirements. Significantly, the results show that it is possible to build a first plant with this concept that can compete with existing gas-only combined-cycle plants.

  6. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

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

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  7. 98. SOUTH FRONT OF MODEL. FREESTANDING TOWER TOP AT RIGHT ...

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

    98. SOUTH FRONT OF MODEL. FREESTANDING TOWER TOP AT RIGHT REPRESENTED ALTERNATE PROPOSAL FOR NORTH TOWER TO MATCH FLAG TOWER - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  8. Wind turbine tower for storing hydrogen and energy

    DOEpatents

    Fingersh, Lee Jay

    2008-12-30

    A wind turbine tower assembly for storing compressed gas such as hydrogen. The tower assembly includes a wind turbine having a rotor, a generator driven by the rotor, and a nacelle housing the generator. The tower assembly includes a foundation and a tubular tower with one end mounted to the foundation and another end attached to the nacelle. The tower includes an in-tower storage configured for storing a pressurized gas and defined at least in part by inner surfaces of the tower wall. In one embodiment, the tower wall is steel and has a circular cross section. The in-tower storage may be defined by first and second end caps welded to the inner surface of the tower wall or by an end cap near the top of the tower and by a sealing element attached to the tower wall adjacent the foundation, with the sealing element abutting the foundation.

  9. 153. Copy of Louis Rosenberg Etching (original in the Tower ...

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

    153. Copy of Louis Rosenberg Etching (original in the Tower City Development Office, Cleveland, Ohio) TERMINAL TOWER UNDER CONSTRUCTION, PUBLIC SQUARE ELEVATION, VIEW NORTHWEST TO SOUTHEAST - Terminal Tower Building, Cleveland Union Terminal, 50 Public Square, Cleveland, Cuyahoga County, OH

  10. 158. Copy of Louis Rosenberg Etching (original in the Tower ...

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

    158. Copy of Louis Rosenberg Etching (original in the Tower City Development Office) TERMINAL TOWER UNDER CONSTRUCTION, PUBLIC SQUARE FACADE, VIEW WEST TO EAST - Terminal Tower Building, Cleveland Union Terminal, 50 Public Square, Cleveland, Cuyahoga County, OH

  11. DETAIL OF VALVE TOWER SHOWING SLUICE GATE ON EAST SIDE ...

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

    DETAIL OF VALVE TOWER SHOWING SLUICE GATE ON EAST SIDE OF TOWER. VIEW FACING WEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  12. Cold weather operating guidelines and experience for natural draft cooling towers on the American Electric Power system

    SciTech Connect

    Michell, F.L.; Drew, D.H.

    1996-10-01

    American Electric Power`s more than 30 years of experience in operating natural draft cooling towers during freezing winter weather conditions is discussed in the paper. Design features incorporated into the specifications for major rebuild/repack projects for crossflow and counterflow towers to facilitate cold weather operation are also reviewed.

  13. What Is Radiation Shielding?

    NASA Video Gallery

    Kerry Lee, NASA Orion radiation system manager, explains how radiation shielding is used to block harmful particles coming into the spacecraft without producing secondary particles that can cause e...

  14. SNS shielding analyses overview

    SciTech Connect

    Popova, Irina; Gallmeier, Franz; Iverson, Erik B; Lu, Wei; Remec, Igor

    2015-01-01

    This paper gives an overview on on-going shielding analyses for Spallation Neutron Source. Presently, the most of the shielding work is concentrated on the beam lines and instrument enclosures to prepare for commissioning, save operation and adequate radiation background in the future. There is on-going work for the accelerator facility. This includes radiation-protection analyses for radiation monitors placement, designing shielding for additional facilities to test accelerator structures, redesigning some parts of the facility, and designing test facilities to the main accelerator structure for component testing. Neutronics analyses are required as well to support spent structure management, including waste characterisation analyses, choice of proper transport/storage package and shielding enhancement for the package if required.

  15. Adhesive particle shielding

    DOEpatents

    Klebanoff, Leonard Elliott; Rader, Daniel John; Walton, Christopher; Folta, James

    2009-01-06

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

  16. ALS synchrotron radiation shielding

    SciTech Connect

    Donahue, R.J.

    1995-10-01

    This note discusses the assumptions and results of synchrotron radiation shielding estimates for ALS bend magnet and wiggler beamlines. Estimates of gas bremsstrahlung production are not included and are dealt with elsewhere.

  17. COKE QUENCH TOWER EMISSION TESTING PROGRAM

    EPA Science Inventory

    The report gives results of a field study to further define quench tower organic emissions, the character and magnitude of which are virtually unknown. (Limited testing in 1976 indicated that a large quantity of organic material was emitted from quench towers, but these data were...

  18. 76 FR 36983 - Marking Meteorological Evaluation Towers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... voluntary marking of METs less than 200 feet AGL (76 FR 1326). The FAA agrees that marking these structures... conspicuity of the towers for low level agricultural operations in the vicinity of these towers. FOR FURTHER... operators, associations representing agricultural operators, and state governments concerning the...

  19. Tower Water-Vapor Mixing Ratio

    SciTech Connect

    Guastad, Krista; Riihimaki, Laura; none,

    2013-04-01

    The purpose of the Tower Water-Vapor Mixing Ratio (TWRMR) value-added product (VAP) is to calculate water-vapor mixing ratio at the 25-meter and 60-meter levels of the meteorological tower at the Southern Great Plains (SGP) Central Facility.

  20. Measurements for the JASPER Program Axial Shield Re-measurement Experiment

    SciTech Connect

    Muckenthaler, F.J.; Spencer, R.R.; Hunter, H.T.; Hull, J.L.; Shono, A.

    1993-03-01

    With one modification, this series of measurements is a repeat of several of the mockups that were investigated during the Axial Shield Experiment performed earlier for the Japanese-American Shielding Program for Experimental Research (JASPER) program at the Tower Shielding Facility (TSF). For these re-runs, slabs of lithiated paraffin, 10.16 cm thick and 152.4 cm on an edge, were placed between the spectrum modifier and the axial shield and directly behind the axial shield. Each of the slabs contained a void area that corresponded in dimension and location,to the surface area of the seven hexagons in the axial shield plus the boron carbide (B{sub 4}C) collar that surrounded them. The lithiated paraffin was made part of the mockup to reduce the neutron contributions to the detector from those neutrons passing through the concrete surrounding the hexagon assemblies. The slabs were present in all of the mockups except one, for which the lithiated paraffin following the axial shield was removed. Spectral and integral flux measurements were made behind the axial shield for six B{sub 4}C homogeneous-type assembly containing: (1) the B{sub 4}C rod bundle assembly; (2) the B{sub 4}C central blockage type; (4) the B{sub 4}C central sodium type; and (4) another B{sub 4}C homogeneous-type assembly. The neutron source was the Tower Shielding Reactor II (TSR-II) modified to give a flux typical of that incident on the axial shielding in a Liquid Metal Reactor (LMR).

  1. Analysis of Wind Characteristics at United States Tall Tower Measurement Sites

    NASA Astrophysics Data System (ADS)

    Elliott, D.; Schwartz, M.; Scott, G.; Haymes, S.

    2008-12-01

    A major initiative of the U.S. Department of Energy (DOE) is to ensure that 20% of the country's electricity is produced by wind energy by the year 2030. An understanding of the boundary layer characteristics, especially at elevated heights greater than 80 meters (m) above the surface is a key factor for wind turbine design, wind plant layout, and identifying potential markets for advanced wind technology. The wind resource group at the DOE National Renewable Energy Laboratory is analyzing wind data collected at tall (80+ m) towers across the United States. The towers established by both public and private initiative, measure wind characteristics at multiple levels above the surface, with the highest measurement levels generally between 80 and 110 m. A few locations have measurements above 200 m. Measurements of wind characteristics over a wide range of heights are useful to: (1) characterize the local and regional wind climate; (2) validate wind resource estimates derived from numerical models; and (3) directly assess and analyze specific wind resource characteristics such as wind speed shear over the turbine blade swept area. The majority of the available public tall tower measurement sites are located between the Appalachian and Rocky Mountains. The towers are not evenly distributed among the states. The states with the largest number of towers include Indiana, Iowa, Missouri, and Kansas. These states have five or six towers collecting data. Other states with multiple tower locations include Texas, Oklahoma, Minnesota, and Ohio. The primary consideration when analyzing the data from the tall towers is identifying tower flow effects that not only can produce slightly misleading average wind speeds, but also significantly misleading wind speed shear values. In addition, the periods-of-record of most tall tower data are only one to two years in length. The short data collection time frame does not significantly affect the diurnal wind speed pattern though it does

  2. Shielded cells transfer automation

    SciTech Connect

    Fisher, J J

    1984-01-01

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

  3. Space Station MMOD Shielding

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric

    2006-01-01

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

  4. Carbon Nanotube Tower-Based Supercapacitor

    NASA Technical Reports Server (NTRS)

    Meyyappan, Meyya (Inventor)

    2012-01-01

    A supercapacitor system, including (i) first and second, spaced apart planar collectors, (ii) first and second arrays of multi-wall carbon nanotube (MWCNT) towers or single wall carbon nanotube (SWCNT) towers, serving as electrodes, that extend between the first and second collectors where the nanotube towers are grown directly on the collector surfaces without deposition of a catalyst and without deposition of a binder material on the collector surfaces, and (iii) a porous separator module having a transverse area that is substantially the same as the transverse area of at least one electrode, where (iv) at least one nanotube tower is functionalized to permit or encourage the tower to behave as a hydrophilic structure, with increased surface wettability.

  5. Flux Sampling Errors for Aircraft and Towers

    NASA Technical Reports Server (NTRS)

    Mahrt, Larry

    1998-01-01

    Various errors and influences leading to differences between tower- and aircraft-measured fluxes are surveyed. This survey is motivated by reports in the literature that aircraft fluxes are sometimes smaller than tower-measured fluxes. Both tower and aircraft flux errors are larger with surface heterogeneity due to several independent effects. Surface heterogeneity may cause tower flux errors to increase with decreasing wind speed. Techniques to assess flux sampling error are reviewed. Such error estimates suffer various degrees of inapplicability in real geophysical time series due to nonstationarity of tower time series (or inhomogeneity of aircraft data). A new measure for nonstationarity is developed that eliminates assumptions on the form of the nonstationarity inherent in previous methods. When this nonstationarity measure becomes large, the surface energy imbalance increases sharply. Finally, strategies for obtaining adequate flux sampling using repeated aircraft passes and grid patterns are outlined.

  6. VALVE TOWER FROM HIGH GROUND NEAR APPROACH BRIDGE. VIEW FACING ...

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

    VALVE TOWER FROM HIGH GROUND NEAR APPROACH BRIDGE. VIEW FACING NORTHEAST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  7. Preliminary study on the applicability of semi-geodesic winding in the design and manufacturing of composite towers

    NASA Astrophysics Data System (ADS)

    Kayran, A.; İbrahimoǧlu, C. S.

    2014-12-01

    During last twenty years, wind turbine manufacturers took the path of building larger machines to generate more electricity. However, the bigger the size became, the more material was required to support the loads, leading to great weight increases. Larger turbines and higher hub heights also resulted in larger tower base diameters which are limited considering their logistics. In many countries, the limit for transports with special permits maximizes the diameter to 4.5 metres. Considering this fact, the wind turbine market dominated by welded steel shell towers is looking for new structural solutions for their future turbines. Although, composite materials are not used as the structural material in the towers of today's turbines, the demand for larger wind turbines forces engineers to seek for alternative material systems with high specific strength and stiffness ratios to be used in towers. Inspired by the applicability of filament winding in tower production, in the present article we investigated the effect of semi-geodesic winding on the winding angle, thickness, stiffness coefficients and vibration characteristics of filament wound composite conical shells of revolution which simulate wind turbine towers at the structural level. Present study showed that the preset friction applied during semi-geodesic winding is an important design parameter which can be controlled to obtain gradually increasing thickness from tower top to the base of the tower, and favourably alter the dynamic characteristics of the composite towers.

  8. Measurements for the JASPER program Axial Shield Experiment

    SciTech Connect

    Muckenthaler, F.J.; Spencer, R.R.; Hunter, H.T.; Shono, A.; Chatani, K.

    1991-08-01

    The Axial Shield Experiment was conducted at the Oak Ridge National Laboratory (ORNL) during 1990--1991 as part of the continuing series of eight experiments planned for the Japanese-American Shielding Program for Experimental Research (JASPER) program starting in 1986. The program is intended to provide support for the development of current designs proposed for advanced liquid metal reactor (LMR) system both in Japan and the United States. As in the previous two experiments, the same spectrum modifier was used to alter the Tower Shielding Reactor source spectrum to one representing the LMR neutron spectra directly above the core in the area of the fission-gas plenum. In one of the measurements the spectrum was further modified by the fission gas plenum. In all cases the modified spectrum was followed by combinations of seven hexagon assemblies that represented different coolant flow and shielding patterns within the assemblies. The varied configuration permitted not only a study of the different designs, but also allowed a comparison to be made of the relative neutron attenuation effectiveness of boron carbide and stainless steel in such designs. This experiment was the third in a series of eight experiments to be performed as part of a cooperative effort between the United States Department of Energy (US DOE) and the Japan Power Reactor and Nuclear Fuel Development Corporation (PNC). This experiment, as was the previous Radial Shield Attenuation and Fission Gas Plenum Experiments, intended to provide support for the development of advanced sodium-cooled reactors. 5 refs.

  9. Strategies to design and place towers for long-term ecological observations at continental scale

    NASA Astrophysics Data System (ADS)

    Luo, H.; Loescher, H. W.; Ayres, E.; Clement, R.

    2010-12-01

    There are numerous tower-based measurements applied in ecological science worldwide. National Ecological Observatory Network (NEON) is designing a tower-based method at 60 sites continental wide to measure abiotic drivers of ecological change, carbon and energy fluxes, and to specifically provide ecological connectively to measurements of organism ecology and connectively to remote sensed data products. Several issues come to bear when designing an infrastructure that has to accommodate different suites of measurements that have various requirements, i.e., micrometeorological, scalar flux measurements, atmospheric chemistry and boundary layer properties, and have to be objectively placed across the entire range of climate and ecosystem structures found in North America. Here, we present a comprehensive strategy that combines wind roses, footprint models, ecosystem structure, vegetation and soil maps, as well as ‘eyes on’ site visits to design and place a tower. This methodology is being used to examine the 60 preliminary tower designs in the largest ecological observatory in the world today to optimize the long-term representative measurements over the ecosystems of interests. We found that some preliminary site designs do not meet our tower science requirements due to an inadequate fetch for prevailing wind directions, extent of ecosystems boundaries, or concerns of edge effects. In these cases, the tower location shall be either micro-sited at the current locale, or moved and relocated to a different site altogether. After site specific characterization, we also found that some designed tower heights could not access the well mixed surface layer above canopy and had to be extended in design. Because wind comes from all direction at some sites, presents a particular challenge to orient a square tower. In all cases, we optimized the tower orientation to acquire the most amounts of valid data. To avoid the effects of flow distortion on measurements, the boom

  10. Augmented Reality Tower Technology Assessment

    NASA Technical Reports Server (NTRS)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  11. Kinetic Space Towers and Launchers

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    The paper discusses a new revolutionary method for access to outer space. A cable stands up vertically and pulls up its payload to space with a maximum force determined by its strength. From the ground the cable is allowed to rise up to the required altitude. After this, one can climb to an altitude by this cable or deliver to altitude a required load. The paper shows this is possible and does not infringe on the law of gravity. The article contains the theory of the method and the computations for four projects for towers that are 4, 75, 225 and 160,000 km in height. The first three projects use conventional artificial fiber widely produced by current industry, while the fourth project uses nanotubes made in scientific laboratories. The paper also shows in a fifth project how this idea can be used to launch a load at high altitude.

  12. Blasting response of the Eiffel Tower

    NASA Astrophysics Data System (ADS)

    Horlyck, Lachlan; Hayes, Kieran; Caetano, Ryan; Tahmasebinia, Faham; Ansourian, Peter; Alonso-Marroquin, Fernando

    2016-08-01

    A finite element model of the Eiffel Tower was constructed using Strand7 software. The model replicates the existing tower, with dimensions justified through the use of original design drawings. A static and dynamic analysis was conducted to determine the actions of the tower under permanent, imposed and wind loadings, as well as under blast pressure loads and earthquake loads due to an explosion. It was observed that the tower utilises the full axial capacity of individual members by acting as a `truss of trusses'. As such, permanent and imposed loads are efficiently transferred to the primary columns through compression, while wind loads induce tensile forces in the windward legs and compressive forces in the leeward. Under blast loading, the tower experienced both ground vibrations and blast pressures. Ground vibrations induced a negligibly small earthquake loading into the structure which was ignored in subsequent analyses. The blast pressure was significant, and a dynamic analysis of this revealed that further research is required into the damping qualities of the structure due to soil and mechanical properties. In the worst case scenario, the blast was assumed to completely destroy several members in the adjacent leg. Despite this weakened condition, it was observed that the tower would still be able to sustain static loads, at least for enough time for occupant evacuation. Further, an optimised design revealed the structure was structurally sound under a 46% reduction of the metal tower's mass.

  13. Radiation shielding composition

    DOEpatents

    Quapp, William J.; Lessing, Paul A.

    1998-01-01

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

  14. Radiation shielding composition

    DOEpatents

    Quapp, William J.; Lessing, Paul A.

    2000-12-26

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

  15. Radiation shielding composition

    DOEpatents

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

    1998-07-28

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

  16. Recent experiences with shielding a PET/CT facility.

    PubMed

    Erdman, Mike; King, Steve; Miller, Ken

    2004-08-01

    Since the photon energy of positron emitting radionuclides is significantly higher than the maximum kVp of diagnostic x rays, designing a shielding plan for a PET/CT imaging facility requires careful consideration of future workloads and potential occupancy of surrounding spaces. The shielding calculations can be done by hand or with the aid of available software. In calculating the shielding, specific considerations arise. Some of these are presented as a checklist of things to consider when preparing to calculate the shielding required for a PET/CT facility. PMID:15220722

  17. Shields-1, A SmallSat Radiation Shielding Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Thomsen, D. Laurence, III; Kim, Wousik; Cutler, James W.

    2015-01-01

    The NASA Langley Research Center Shields CubeSat initiative is to develop a configurable platform that would allow lower cost access to Space for materials durability experiments, and to foster a pathway for both emerging and commercial-off-the-shelf (COTS) radiation shielding technologies to gain spaceflight heritage in a relevant environment. The Shields-1 will be Langleys' first CubeSat platform to carry out this mission. Radiation shielding tests on Shields-1 are planned for the expected severe radiation environment in a geotransfer orbit (GTO), where advertised commercial rideshare opportunities and CubeSat missions exist, such as Exploration Mission 1 (EM-1). To meet this objective, atomic number (Z) graded radiation shields (Zshields) have been developed. The Z-shield properties have been estimated, using the Space Environment Information System (SPENVIS) radiation shielding computational modeling, to have 30% increased shielding effectiveness of electrons, at half the thickness of a corresponding single layer of aluminum. The Shields-1 research payload will be made with the Z-graded radiation shields of varying thicknesses to create dose-depth curves to be compared with baseline materials. Additionally, Shields-1 demonstrates an engineered Z-grade radiation shielding vault protecting the systems' electronic boards. The radiation shielding materials' performances will be characterized using total ionizing dose sensors. Completion of these experiments is expected to raise the technology readiness levels (TRLs) of the tested atomic number (Z) graded materials. The most significant contribution of the Z-shields for the SmallSat community will be that it enables cost effective shielding for small satellite systems, with significant volume constraints, while increasing the operational lifetime of ionizing radiation sensitive components. These results are anticipated to increase the development of CubeSat hardware design for increased mission lifetimes, and enable

  18. Radiation shielding for underground low-background experiments

    SciTech Connect

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

    2006-11-17

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

  19. A comment on towers for windmills. [structural and economic criteria

    NASA Technical Reports Server (NTRS)

    Budgen, H. P.

    1973-01-01

    Design considerations for windmill tower structures include the effects of normal wind forces on the rotor and on the tower. Circular tabular or masonry towers present a relatively simple aerodynamic solution. Economic factors establish the tubular tower as superior for small and medium sized windmills. Concrete and standard concrete block designs are cheaper than refabricated steel structures that have to be freighted.

  20. 5. View of south tower, facing northnortheast from south bank ...

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

    5. View of south tower, facing north-northeast from south bank of the Columbia River. Center tower and north tower in background, lower right. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

  1. Composition for radiation shielding

    DOEpatents

    Kronberg, James W.

    1994-01-01

    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.

  2. Glove box shield

    DOEpatents

    Brackenbush, Larry W.; Hoenes, Glenn R.

    1981-01-01

    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.

  3. Glove box shield

    DOEpatents

    Brackenbush, L.W.; Hoenes, G.R.

    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 wthdraws 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.

  4. Bumper shield analysis

    SciTech Connect

    Oyer, A.T.

    1986-07-01

    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.

  5. Using ozone to treat cooling tower water

    SciTech Connect

    Webster, L.

    1995-07-01

    Ozone is a controversial but promising alternative to chemicals for treating water in cooling towers. A powerful disinfectant, ozone can prevent biofouling of heat exchange surfaces, and may mitigate scale and corrosion. Ozone treatment of cooling towers can cut costs for energy, water, sewage, and regulatory compliance. Ozone treatment is an electrotechnology, but ozone equipment represents only a small electric load. Although ozone has provided excellent results in some cooling tower applications, its effectiveness has not been proven conclusively. Less than 1,000 cooling towers use ozone water treatment in the United States. Acceptance of this technology is increasing, however, as indicated by its use by such large firms as IBM, AT and T, DuPont, and Xerox, and by its adoption by some chemical water treatment suppliers. The energy efficiency implications of ozone treatment are being researched. Southern California Edison found that in some systems, ozone treatment improved chiller efficiency up to 20 percent due to cleaner heat exchange surfaces.

  6. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  7. Rebuild cooling tower after partial collapse

    SciTech Connect

    Michell, F.L.; Demjanenko, W.

    1995-07-01

    When this tower suddenly went down, it forced the associated powerplant out of service. To restore operation required a quick assessment of the damage and fast action to reconstruct the tower. The partial collapse and prompt rebuild of a cooling tower at Columbus Southern Co`s Conesville station Unit 4 is a story of what can go wrong and what can be done to set matters right -- in a hurry. The utility is one of seven operating companies in American Electric Power Co`s system. Unit 4 is jointly owned with Cincinnati Gas and Electric Co and Dayton Power and Light Co. The 780-MW coal-fired unit`s closed-loop cooling-water system is served by two double-flow, seven-cell, mechanical-draft cooling towers (4A and 4B). The design basis calls for operating all 14 cells to maintain full load in the summer months.

  8. Ozone inhibits corrosion in cooling towers

    NASA Technical Reports Server (NTRS)

    French, K. R.; Howe, R. D.; Humphrey, M. F.

    1980-01-01

    Commercially available corona discharge ozone generator, fitted onto industrial cooling tower, significantly reduces formation of scales (calcium carbonate) and corrosion. System also controls growth of algae and other microorganisms. Modification lowers cost and improves life of cooling system.

  9. Aerodynamic tower shake force analysis for VAWT

    SciTech Connect

    Loth, J.L.

    1985-02-01

    Vertical axis wind turbines (VAWT) are subjected to blade lift forces which vary continuously in both magnitude and direction. These blade lift forces are transmitted via the blade support arms to the tower. The resulting tower force vector is a composite of: a downwind and a crosswind average force component, rotating force vectors, and force vectors oscillating in the crosswind direction. The frequency of the rotating and oscillating forces are multiples of the product of Bw, where B is the number of blades used and ..omega.. is the rotor angular velocity. The magnitude of the largest tower shake force vector is of the same order as the average downwind force component, and may represent a serious design constraint in the calculation of the required tower stiffness. A closed-form solution for the tower force vectors has been derived, by introducing a suitable wind interference model. It shows that the magnitude of the largest tower shake force vector, using a threebladed rotor, is four times smaller than a two-bladed rotor. The Betz limit and the optimum tip speed ratio as a function of solidity has been derived by comparison with two semicylindrical actuators in series.

  10. Stripping of phenols in model cooling towers

    SciTech Connect

    Turner, C.D.; Moe, T.A.; Wentz, C.A.

    1987-01-01

    Cooling towers are used to remove waste heat from unit operations in chemical processing plants. Using cooling towers for wastewater treatment and disposal through internal recycling has become an important alternative because of stricter wastewater discharge standards, the expense of specialized wastewater treatment systems and the limited availability and cost of water in arid regions. Designs for synfuels plants must address the problem of wastewater disposal. Alternative systems under consideration usually include zero discharge designs that incorporate evaporative cooling towers in the system. The mechanisms for contaminant removal in cooling towers are biological oxidation, stripping and chemical precipitation. Chemical precipitation is generally considered undesirable because of losses in heat transfer efficiency. Predicting whether stripping or biological oxidation will be the primary removal mechanism for phenolic compounds from coal conversion wastewaters used as makeup in cooling towers does not appear to be possible based on the results of these tests. The tests do indicate that the biological oxidation of phenol is possible in forced draft cooling towers.

  11. Rock Creek Tower Painting Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1988-10-01

    Bonneville Power Administration (BPA) built a 500-kV line across Rock Creek, a Class I trout stream about 20 miles east of Missoula, MT. Two 190-foot towers rise on either side of the Rock Creek valley, and the line between is suspended 600 feet over the valley floor. The crossing poses a hazard to passing airplanes and disrupts the natural landscape. The area where the line crosses Rock Creek is prized for its scenic beauty. In response to public demand that BPA protect the visual beauty of this area, BPA painted the towers gray to blend them best in with their natural surroundings. The issue now is to decide between either two gray towers or two orange-and-white towers. The underlying need is to resolve the conflict of pilot safety against scenic intrusion. The proposed action is to paint the gray tower aeronautical orange and white. Alternatives are to paint the orange-and-white tower back to its original gray; or leave the dilemma unresolved (the ''no-action'' alternative). 9 refs., 3 figs.

  12. Magsat investigation. [Canadian shield

    NASA Technical Reports Server (NTRS)

    Hall, D. H. (Principal Investigator)

    1980-01-01

    A computer program was prepared for modeling segments of the Earth's crust allowing for heterogeneity in magnetization in calculating the Earth's field at Magsat heights. This permits investigation of a large number of possible models in assessing the magnetic signatures of subprovinces of the Canadian shield. The fit between the model field and observed fields is optimized in a semi-automatic procedure.

  13. Analysis of shield tunnel

    NASA Astrophysics Data System (ADS)

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

    2004-01-01

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

  14. Shield For Flexible Pipe

    NASA Technical Reports Server (NTRS)

    Ponton, Michael K.; Williford, Clifford B.; Lagen, Nicholas T.

    1995-01-01

    Cylindrical shield designed to fit around flexible pipe to protect nearby workers from injury and equipment from damage if pipe ruptures. Designed as pressure-relief device. Absorbs impact of debris ejected radially from broken flexible pipe. Also redirects flow of pressurized fluid escaping from broken pipe onto flow path allowing for relief of pressure while minimizing potential for harm.

  15. Lightweight blast shield

    DOEpatents

    Mixon, Larry C.; Snyder, George W.; Hill, Scott D.; Johnson, Gregory L.; Wlodarski, J. Frank; von Spakovsky, Alexis P.; Emerson, John D.; Cole, James M.; Tipton, John P.

    1991-01-01

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

  16. Shield against radiations

    SciTech Connect

    Grifoni, S.

    1988-02-23

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

  17. Lightweight Shield Against Space Debris

    NASA Technical Reports Server (NTRS)

    Redmon, John W., Jr.; Lawson, Bobby E.; Miller, Andre E.; Cobb, W. E.

    1992-01-01

    Report presents concept for lightweight, deployable shield protecting orbiting spacecraft against meteoroids and debris, and functions as barrier to conductive and radiative losses of heat. Shield made in four segments providing 360 degree coverage of cylindrical space-station module.

  18. Efficacy of Cosmic Ray Shields

    NASA Astrophysics Data System (ADS)

    Rhodes, Nicholas

    2015-10-01

    This research involved testing various types of shielding with a self-constructed Berkeley style cosmic ray detector, in order to evaluate the materials of each type of shielding's effectiveness at blocking cosmic rays and the cost- and size-efficiency of the shields as well. The detector was constructed, then tested for functionality and reliability. Following confirmation, the detector was then used at three different locations to observe it altitude or atmospheric conditions had any effect on the effectiveness of certain shields. Multiple types of shielding were tested with the detector, including combinations of several shields, primarily aluminum, high-iron steel, polyethylene plastic, water, lead, and a lead-alternative radiation shield utilized in radiology. These tests regarding both the base effectiveness and the overall efficiency of shields is designed to support future space exploratory missions where the risk of exposure to possibly lethal amounts of cosmic rays for crew and the damage caused to unshielded electronics are of serious concern.

  19. Potentially pathogenic amoeba-associated microorganisms in cooling towers and their control.

    PubMed

    Pagnier, Isabelle; Merchat, Michèle; La Scola, Bernard

    2009-06-01

    Cooling towers provide a favorable environment for the proliferation of microorganisms. Cooling towers generate a biofilm and often aerosolize contaminated water, thereby increasing the risk of microorganism dissemination by human inhalation. This pathogen dissemination was first revealed by the epidemics of Legionnaires' disease that were directly related to the presence of cooling towers, and since then, the ecology of Legionella pneumophila has been well studied. Each country has specific standards regarding the acceptable amount of microorganisms in cooling tower systems. However, those standards typically only concern L. pneumophila, even though many other microorganisms can also be isolated from cooling towers, including protozoa, bacteria and viruses. Microbiological control of the cooling tower system can be principally achieved by chemical treatments and also by improving the system's construction. Several new treatments are being studied to improve the efficiency of disinfection. However, as most of these treatments continue to focus solely on L. pneumophila, reports of other types of pathogens continue to increase. Therefore, how their dissemination affects the human populous health should be addressed now. PMID:19492970

  20. Spacecraft Electrostatic Radiation Shielding

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This project analyzed the feasibility of placing an electrostatic field around a spacecraft to provide a shield against radiation. The concept was originally proposed in the 1960s and tested on a spacecraft by the Soviet Union in the 1970s. Such tests and analyses showed that this concept is not only feasible but operational. The problem though is that most of this work was aimed at protection from 10- to 100-MeV radiation. We now appreciate that the real problem is 1- to 2-GeV radiation. So, the question is one of scaling, in both energy and size. Can electrostatic shielding be made to work at these high energy levels and can it protect an entire vehicle? After significant analysis and consideration, an electrostatic shield configuration was proposed. The selected architecture was a torus, charged to a high negative voltage, surrounding the vehicle, and a set of positively charged spheres. Van de Graaff generators were proposed as the mechanism to move charge from the vehicle to the torus to generate the fields necessary to protect the spacecraft. This design minimized complexity, residual charge, and structural forces and resolved several concerns raised during the internal critical review. But, it still is not clear if such a system is costeffective or feasible, even though several studies have indicated usefulness for radiation protection at energies lower than that of the galactic cosmic rays. Constructing such a system will require power supplies that can generate voltages 10 times that of the state of the art. Of more concern is the difficulty of maintaining the proper net charge on the entire structure and ensuring that its interaction with solar wind will not cause rapid discharge. Yet, if these concerns can be resolved, such a scheme may provide significant radiation shielding to future vehicles, without the excessive weight or complexity of other active shielding techniques.

  1. Flexible Multi-Shock Shield

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  2. A qualitative analysis of power take-off driveline shields: barriers and motivators to shield use for New York State farmers.

    PubMed

    Weil, R; Mellors, P; Fiske, T; Sorensen, J A

    2014-01-01

    Machinery entanglements are one of the top three causes of death in farming. Education on the risks of unshielded power take-off (PTO) equipment does not appear to significantly alter farmers' willingness to replace missing or broken shielding. Different assessments conducted in various regions of the U.S. indicate that as many as one-third to one-half of PTOs are inadequately shielded. Qualitative research was conducted with New York farmers to identify the factors that influence the decision to replace damaged or missing PTO driveline shields. Interview topics included: knowledge of entanglement risks, decisions regarding safety in general, decisions relating to PTO driveline shielding specifically, and the barriers and motivators to replacing missing or broken PTO driveline shields. Interviews with 38 farmers revealed the following themes: (1) farmers are fully aware of PTO entanglement risk, (2) insufficient time and money are primary barriers to purchasing or replacing damaged or missing PTO driveline shields, (3) PTO driveline shield designs are problematic and have led to negative experiences with shielding, and (4) risk acceptance and alternate work strategies are preferred alternatives to replacing shields. Our findings indicate that more innovative approaches will be required to make PTO driveline shield use a viable and attractive choice for farmers. New shield designs that address the practical barriers farmers face, as well as the provision of logistical and financial assistance for shield replacement, may alter the decision environment sufficiently to make replacing PTO driveline shielding a more attractive option for farmers. PMID:24804464

  3. Analysis of the JASPER Program Radial Shield Attenuation Experiment

    SciTech Connect

    Slater, C.O.

    1993-01-01

    The results of the analysis of the JASPER Program Radial Shield Attenuation Experiment are presented. The experiment was performed in 1986 at the ORNL Tower Shielding Facility. It is the first of six experiments in this cooperative Japanese and American program in support of shielding designs for advanced sodium-cooled reactors. Six different shielding configurations and subconfigurations thereof were studied. The configurations were calculated with the DOT-IV two-dimensional discrete ordinates radiation transport computer code using the R-Z geometry option, a symmetric S{sub 12} quadrature (96 directions), and cross sections from ENDF/B versions IV and V in either a 51- or 61-group structure. Auxiliary codes were used to compute detector responses and prepare cross sections and source input for the DOT-IV calculations. Calculated detector responses were compared with measured responses and the agreement was good to excellent in many cases. However, the agreement for configurations having thick steel or B{sub 4}C regions or for some very large configurations was fair to poor. The disagreement was attributed to cross-section data, broad-group structure, or high background in the measurements. In particular, it is shown that two cross-section sets for ``B give very different results for neutron transmission through the thick B{sub 4}C regions used in one set of experimental configurations. Implications for design calculations are given.

  4. Four Operational Strategies For The Tower of Pisa

    NASA Astrophysics Data System (ADS)

    Bartolozzi, F.

    allow the present inclination of the Tower to be maintained, its verticality to be restored, and in some cases also for the counter-inclination to be executed. They are contributions for safeguarding the Tower, but like any other idea, they may be refined, modified or ignored. Readers are invited to inform me of any impressions, criticisms and consequently also of any specific suggestions aimed at improving the techniques proposed.

  5. Multidimensional shielding analysis of the JASPER in-vessel fuel storage experiments

    SciTech Connect

    Bucholz, J.A.

    1993-03-01

    The In-Vessel Fuel Storage (IVFS) experiments analyzed in this report were conducted at the Oak Ridge National Laboratory`s Tower Shielding Reactor (TSR) as part of the Japanese-American Shielding Program for Experimental Research (JASPER). These IVFS experiments were designed to study source multiplication and three-dimensional effects related to in-vessel storage of spent fuel elements in liquid metal reactor (LMR) systems. The present report describes the 2-D and 3-D models, analyses, and calculated results corresponding to a limited subset of those IVFS experiments in which the US LMR program has a particular interest.

  6. Shielding analysis of the LMR in-vessel fuel storage experiments

    SciTech Connect

    Bucholz, J.A.

    1994-06-01

    The In-Vessel Fuel Storage (IVFS) experiments analyzed in this paper were conducted at the Oak Ridge National Laboratory`s Tower Shielding Reactor (TSR) as part of the Japanese-American Shielding Program for Experimental Research (JASPER). These IVFS experiments were designed to study source multiplication and three-dimensional effects related to in-vessel storage of spent fuel elements in liquid metal reactor (LMR) systems. The present paper describes the 2- and 3-D calculations and results corresponding to a limited subset of those IVFS experiments in which the US LMR program had a particular interest.

  7. Static and Motion-Based Visual Features Used by Airport Tower Controllers: Some Implications for the Design of Remote or Virtual Towers

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Liston, Dorion B.

    2011-01-01

    Visual motion and other visual cues are used by tower controllers to provide important support for their control tasks at and near airports. These cues are particularly important for anticipated separation. Some of them, which we call visual features, have been identified from structured interviews and discussions with 24 active air traffic controllers or supervisors. The visual information that these features provide has been analyzed with respect to possible ways it could be presented at a remote tower that does not allow a direct view of the airport. Two types of remote towers are possible. One could be based on a plan-view, map-like computer-generated display of the airport and its immediate surroundings. An alternative would present a composite perspective view of the airport and its surroundings, possibly provided by an array of radially mounted cameras positioned at the airport in lieu of a tower. An initial more detailed analyses of one of the specific landing cues identified by the controllers, landing deceleration, is provided as a basis for evaluating how controllers might detect and use it. Understanding other such cues will help identify the information that may be degraded or lost in a remote or virtual tower not located at the airport. Some initial suggestions how some of the lost visual information may be presented in displays are mentioned. Many of the cues considered involve visual motion, though some important static cues are also discussed.

  8. TPX remote maintenance and shielding

    SciTech Connect

    Rennich, M.J.; Nelson, B.E.

    1994-09-01

    The Tokamak Physics Experiment machine design incorporates comprehensive planning for efficient and safe component maintenance. Three programmatic decisions have been made to insure the successful implementation of this objective. First, the tokamak incorporates radiation shielding to reduce activation of components and limit the dose rate to personnel working on the outside of the machine. This allows most of the ex-vessel equipment to be maintained through conventional ``hands-on`` procedures. Second, to the maximum extent possible, low activation materials will be used inside the shielding volume. This resulted in the selection of Titanium (Ti-6Al-4V) for the vacuum vessel and PFC structures. The third decision stipulated that the primary in-vessel components will be replaced or repaired via remote maintenance tools specifically provided for the task. The component designers have been given the responsibility of incorporating maintenance design and for proving the maintainability of the design concepts in full-scale mockup tests prior to the initiation of final fabrication. Remote maintenance of the TPX machine is facilitated by general purpose tools provided by a special purpose design team. Major tools will include an in-vessel transporter, a vessel transfer system and a large component transfer container. In addition, tools such as manipulators and remotely operable impact wrenches will be made available to the component designers by this group. Maintenance systems will also provide the necessary controls for this equipment.

  9. Summary of tower designs for large horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Frederick, G. R.; Savino, J. M.

    1986-01-01

    Towers for large horizontal axis wind turbines, machines with a rotor axis height above 30 meters and rated at more than 500 kW, have varied in configuration, materials of construction, type of construction, height, and stiffness. For example, the U.S. large HAWTs have utilized steel truss type towers and free-standing steel cylindrical towers. In Europe, the trend has been to use only free-standing and guyed cylindrical towers, but both steel and reinforced concrete have been used as materials of construction. These variations in materials of construction and type of construction reflect different engineering approaches to the design of cost effective towers for large HAWTs. Tower designs are the NASA/DOE Mod-5B presently being fabricated. Design goals and requirements that influence tower configuration, height and materials are discussed. In particular, experiences with United States large wind turbine towers are elucidated. Finally, current trends in tower designs for large HAWTs are highlighted.

  10. Shielding Structures for Interplanetary Human Mission

    NASA Astrophysics Data System (ADS)

    Tracino, Emanuele; Lobascio, Cesare

    2012-07-01

    Since the end of Apollo missions, human spaceflight has been limited to the Low Earth Orbit (LEO), inside the protective magnetic field of the Earth, because astronauts are, to the largest degree, protected from the harsh radiation environment of the interplanetary space. However, this situation will change when space exploration missions beyond LEO will become the real challenge of the human exploration program. The feasibility of these missions in the solar system is thus strongly connected to the capability to mitigate the radiation-induced biological effects on the crew during the journey and the permanence on the intended planet surface. Inside the International Space Station (ISS), the volumes in which the crew spends most of the time, namely the crew quarters are the only parts that implement dedicated additional radiation shielding made of polyethylene tiles designed for mitigating SPE effects. Furthermore, specific radiation shielding materials are often added to the described configuration to shield crew quarters or the entire habitat example of these materials are polyethylene, liquid hydrogen, etc. but, increasing the size of the exploration vehicles to bring humans beyond LEO, and without the magnetosphere protection, such approach is unsustainable because the mass involved is a huge limiting factor with the actual launcher engine technology. Moreover, shielding against GCR with materials that have a low probability of nuclear interactions and in parallel a high ionizing energy loss is not always the best solution. In particular there is the risk to increase the LET of ions arriving at the spacecraft shell, increasing their Radio-Biological Effectiveness. Besides, the production of secondary nuclei by projectile and target fragmentation is an important issue when performing an engineering assessment of materials to be used for radiation shielding. The goal of this work is to analyze different shielding solutions to increase as much as possible the

  11. Roof Shield for Advance and Retreat Mining

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1985-01-01

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

  12. Capacitive Proximity Sensors With Additional Driven Shields

    NASA Technical Reports Server (NTRS)

    Mcconnell, Robert L.

    1993-01-01

    Improved capacitive proximity sensors constructed by incorporating one or more additional driven shield(s). Sensitivity and range of sensor altered by adjusting driving signal(s) applied to shield(s). Includes sensing electrode and driven isolating shield that correspond to sensing electrode and driven shield.

  13. Gas shielding apparatus

    DOEpatents

    Brandt, D.

    1984-06-05

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

  14. Composition for radiation shielding

    DOEpatents

    Kronberg, J.W.

    1994-08-02

    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.

  15. Gas shielding apparatus

    DOEpatents

    Brandt, Daniel

    1985-01-01

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

  16. Multilayer radiation shield

    SciTech Connect

    Urbahn, John Arthur; Laskaris, Evangelos Trifon

    2009-06-16

    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.

  17. Whipple bumper shield simulations

    SciTech Connect

    Hertel, E.S.; Chhabildas, L.C. ); Hill, S.A. . George C. Marshall Space Flight Center)

    1991-01-01

    The Whipple bumper is a space shield designed to protect a space station from the most hazardous orbital space debris environment. A series of numerical simulations has been performed using the multi-dimensional hydrodynamics code CTH to estimate the effectiveness of the thin Whipple bumper design. These simulations are performed for impact velocities of {approximately}10 km/s which are now accessible by experiments using the Sandia hypervelocity launcher facility. For a {approximately}10 km/s impact by a 0.7 gm aluminum flier plate, the experimental results indicate that the debris cloud resulting upon impact of the bumper shield by the flier plate, completely penetrates the sub-structure. The CTH simulations also predict complete penetration by the subsequent debris cloud. 5 refs., 4 figs., 2 tabs.

  18. Combustor bulkhead heat shield assembly

    SciTech Connect

    Zeisser, M.H.

    1990-06-19

    This paper describes a gas turbine engine having an annular combustion chamber defined by an annular, inner liner, a concentric outer liner, and an upstream annular combustor head, wherein the head includes a radially extending bulkhead having circumferentially distributed openings for each receiving an individual fuel nozzle therethrough. It comprises: a segmented heat shield assembly, disposed between the combustion chamber interior and the bulkhead, including generally planar, sector shaped heat shields, each shield abutting circumferentially with two next adjacent shields and extending radially from proximate the inner liner to proximate the outer liner, the plurality of shields collectively defining an annular protective barrier, and wherein each sector shaped shield further includes an opening, corresponding to one of the bulkhead nozzle openings for likewise receiving the corresponding nozzle therethrough, the shield opening further including an annular lip extending toward the bulkhead and being received within the bulkhead opening, raised ridges on the shield backside, the ridges contacting the facing bulkhead surface and defining a flow path for a flow of cooling air issuing from a sized supply opening disposed in the bulkhead, the flow path running ultimately from adjacent the annular lip to the edges of each shield segment, wherein the raised edges extend fully along the lateral, circumferentially spaced edges of each shield segment and about the adjacent shield segments wherein the raised ridges further extend circumferentially between the annular lip and the abutting edge ridges.

  19. The Drop Tower Bremen -An Overview

    NASA Astrophysics Data System (ADS)

    von Kampen, Peter; Könemann, Thorben; Rath, Hans J.

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University of Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of ZARM`s drop tower began. Since its inau-guration in September 1990, the eye-catching Drop Tower Bremen with a height of 146m and its characteristic glass roof has become twice a landmark on the campus of the University of Bremen and the emblem of the technology park Bremen. As such an outstanding symbol of space science in Bremen the drop tower provides an european unique facility for experiments under conditions of high-quality weightlessness with residual gravitational accelerations in the microgravity regime. The period of maximum 4.74s of each freely falling experiment at the Drop Tower Bremen is only limited by the height of the drop tower vacuum tube, which was fully manufactured of steal and enclosed by an outer concrete shell. Thus, the pure free fall height of each microgravity drop experiment is approximately 110m. By using the later in-stalled catapult system established in 2004 ZARM`s short-term microgravity laboratory is able to nearly double the time of free fall. This world-wide inimitable capsule catapult system meets scientists` demand of extending the period of weightlessness. During the catapult operation the experiment capsule performs a vertical parabolic flight within the drop tower vacuum tube. In this way the time of microgravity can be extended to slightly over 9s. Either in the drop or in the catapult operation routine the repetition rates of microgravity experiments at ZARM`s drop tower facility are the same, generally up to 3 times per day. In comparison to orbital platforms the ground-based laboratory Drop Tower Bremen represents an economic alternative with a permanent access to weightlessness on earth. Moreover, the exceptional high quality of weightlessness in order of 1e-6 g (in the frequency range below 100

  20. Salt water cooling tower retrofit experience

    SciTech Connect

    Rittenhouse, R.C.

    1994-06-01

    This article describes the experience of engineers at Atlantic Electric Co. with a recent cooling tower fill retrofit at the company's B.L. England Station, Unit 3. Note that this tower is unique. It is the first natural draft salt water tower to be built in the United States. Unit 3's closed-loop saltwater cooling system features a double condenser and two 50% capacity horizontal circulating water pumps. A natural draft cooling tower rejects heat to the atmosphere through evaporation and sensible heat transfer. The tower is 180 ft in diameter at the base and 208 ft high, and features a counterflow design. It was designed to cool 63,500 gpm of circulating salt water through a range of 26 F with an approach of 19.2 degrees at an ambient wet bulb temperature of 76 F and 60% relative humidity. A drift rate of 0.002% of circulating water flow was specified to avoid excessive salt water carryover.

  1. Mycobacteria in Finnish cooling tower waters.

    PubMed

    Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

    2014-04-01

    Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. PMID:23937212

  2. Crumpled Heat Shield

    NASA Technical Reports Server (NTRS)

    2008-01-01

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

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

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

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

  3. Skylab Solar Shield

    NASA Technical Reports Server (NTRS)

    1973-01-01

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

  4. Design of Firmware Update Strategy in Tower Mounted Amplifier

    NASA Astrophysics Data System (ADS)

    Lv, Yi; Han, Shuqin

    With rapid development of radio communication, Tower mounted amplifier (TMA) that conform to AISG protocol will be increasingly applied. Remote firmware update function is essential for TMA. In this paper, a method about remote firmware update that conforms to AISG2.0 is proposed. In this paper, defect of traditional firmware storage is given, and the implementation procedure of firmware storing that based on internal flash of STR755 was introduced. According to corresponding specification in aisg2.0, the process of firmware download and activation are provided in detail. The key point of bootloader was given. Application result shows that the strategy is reliable and highly secure.

  5. Simple model of a cooling tower plume

    NASA Astrophysics Data System (ADS)

    Jan, Cizek; Jiri, Nozicka

    2016-06-01

    This article discusses the possibilities in the area of modeling of the so called cooling tower plume emergent at operating evaporating cooling systems. As opposed to recent publication, this text focuses on the possibilities of a simplified analytic description of the whole problem where this description shall - in the future - form the base of a calculation algorithms enabling to simulate the efficiency of systems reducing this cooling tower plume. The procedure is based on the application of basic formula for the calculation of the velocity and concentration fields in the area above the cooling tower. These calculation is then used to determine the form and the total volume of the plume. Although this approach does not offer more exact results, it can provide a basic understanding of the impact of individual quantities relating to this problem.

  6. The design of solar tower power plants

    NASA Astrophysics Data System (ADS)

    Gretz, J.

    The conversion of solar energy into electricity in solar thermal tower power plants is examined. Mirrors attached to mobile, sun-following heliostats concentrate solar rays into the opening of a receiver mounted on a tower. In the receiver, the radiant energy is absorbed by a system of pipes filled with a flowing material which is heated and drives a turbogenerator directly or via a heat exchanger. It is shown that the optics involved in this concept preclude the optimization of the pipe material, since the local distribution of rays in the heater of tower power plants varies diurnally and annually. This requires each pipe section to be designed for maximum stress, even though that stress occurs only at brief intervals during the day.

  7. Cooling tower water conditioning study. [using ozone

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  8. Foam Core Shielding for Spacecraft

    NASA Technical Reports Server (NTRS)

    Adams, Marc

    2007-01-01

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

  9. Engineering photochemical smog through convection towers

    SciTech Connect

    Elliott, S.; Prueitt, M.L.; Bossert, J.E.; Mroz, E.J.; Krakowski, R.A.; Miller, R.L.; Jacobson, M.Z.; Turco, R.P. |

    1995-02-01

    Reverse convection towers have attracted attention as a medium for cleansing modern cities. Evaporation of an aqueous mist injected at the tower opening could generate electrical power by creating descent, and simultaneously scavenge unsightly and unhealthful particulates. The study offered here assesses the influence to tower water droplets on the photochemical component of Los Angeles type smog. The primary radical chain initiator OH is likely removed into aqueous phases well within the residence time of air in the tower, and then reacts away rapidly. Organics do not dissolve, but nighttime hydrolysis of N{sub 2}O{sub 5} depletes the nitrogen oxides. A lack of HOx would slow hydrocarbon oxidation and so also ozone production. Lowering of NOx would also alter ozone production rates, but the direction is uncertain. SO{sub 2} is available in sufficient quantities in some urban areas to react with stable oxidants, and if seawater were the source of the mist, the high pH would lead to fast sulfur oxidation kinetics. With an accommodation coefficient of 10{sup {minus}3}, however, ozone may not enter the aqueous phase efficiently. Even if ozone is destroyed or its production suppressed, photochemical recovery times are on the order of hours, so that tower processing must be centered on a narrow midday time window. The cost of building the number of structures necessary for this brief turnover could be prohibitive. The increase in humidity accompanying mist evaporation could be controlled with condensers, but might otherwise counteract visibility enhancements by recreating aqueous aerosols. Quantification of the divergent forcings convection towers must exert upon the cityscape would call for coupled three dimensional modeling of transport, microphysics, and photochemistry. 112 refs.

  10. Measurement of the transient shielding effectiveness of shielding cabinets

    NASA Astrophysics Data System (ADS)

    Herlemann, H.; Koch, M.

    2008-05-01

    Recently, new definitions of shielding effectiveness (SE) for high-frequency and transient electromagnetic fields were introduced by Klinkenbusch (2005). Analytical results were shown for closed as well as for non closed cylindrical shields. In the present work, the shielding performance of different shielding cabinets is investigated by means of numerical simulations and measurements inside a fully anechoic chamber and a GTEM-cell. For the GTEM-cell-measurements, a downscaled model of the shielding cabinet is used. For the simulations, the numerical tools CONCEPT II and COMSOL MULTIPHYSICS were available. The numerical results agree well with the measurements. They can be used to interpret the behaviour of the shielding effectiveness of enclosures as function of frequency. From the measurement of the electric and magnetic fields with and without the enclosure in place, the electric and magnetic shielding effectiveness as well as the transient shielding effectiveness of the enclosure are calculated. The transient SE of four different shielding cabinets is determined and discussed.