Sample records for precision air-bearing floor

  1. The system integration and verification testing of an orbital maneuvering vehicle for an air bearing floor

    NASA Technical Reports Server (NTRS)

    Shields, N. L., Jr.; Martin, M. F.; Paulukaitis, K. R.; Haslam, J. W., Jr.; Henderson, D. E.

    1986-01-01

    The teleoperator and Robotics Evaluation Facility (TOREF) is composed of a 4,000 square foot precision air bearing floor, the Teleoperator Motion Base, the Target Motion and Support Simulator, the mock-ups of the Hubble Space Telescope, Multi-mission Modular Spacecraft, and the Orbital Maneuvering Vehicle (OMV). The TOREF and its general capabilities to support the OMV and other remote system simulations; the facility operating procedures and requirements; and the results of generic OMV investigations are summarized.

  2. Phenyl mercuric acetate (PMA): mercury-bearing flexible gymnasium floors in schools--evaluation of hazards and controlled abatement.

    PubMed

    Beaulieu, Harry J; Beaulieu, Serrita; Brown, Chris

    2008-06-01

    Phenyl mercuric acetate (PMA) historically has been used as a catalyst in polyurethane systems. In the 1950s-1970s, PMA was used as a catalyst in the 3M Tartan brand polyurethane flexible floors that were installed commonly in school gymnasiums. Mercury vapor is released into air above the surface of these floors. Sampling mercury in bulk flooring material and mercury vapor in air was conducted in nine Idaho schools in the spring of 2006. These evaluations were conducted in response to concerns by school officials that the floors could contain mercury and could release the mercury vapor into the air, presenting a potential health hazard for students, staff, and visitors. Controlled abatement was conducted in one school where remodeling would impact the mercury-bearing flexible gym floors ( approximately 9,000 ft(2) total). The controlled abatement consisted of containment of the work area with negative air technology; worker protection, including mercury-specific training, use of personal protective equipment, and biological and exposure monitoring; and environmental protection, including proper disposal of mercury-bearing hazardous waste material.

  3. STS-61 air-bearing floor training in bldg 9N with Astronaut Jeff Hoffman

    NASA Image and Video Library

    1993-06-07

    Making use of the air-bearing floor in JSC's Shuttle mockup and integration laboratory, Astronaut Jeffrey A. Hoffman practices working with the Hubble Space Telescope's Wide Field/Planetary Camera (WF/PC). Changing out the large camera is one of several jobs to be performed by STS-61.

  4. The flight robotics laboratory

    NASA Technical Reports Server (NTRS)

    Tobbe, Patrick A.; Williamson, Marlin J.; Glaese, John R.

    1988-01-01

    The Flight Robotics Laboratory of the Marshall Space Flight Center is described in detail. This facility, containing an eight degree of freedom manipulator, precision air bearing floor, teleoperated motion base, reconfigurable operator's console, and VAX 11/750 computer system, provides simulation capability to study human/system interactions of remote systems. The facility hardware, software and subsequent integration of these components into a real time man-in-the-loop simulation for the evaluation of spacecraft contact proximity and dynamics are described.

  5. STS-61 air-bearing floor training in bldg 9N with Astronaut Jeff Hoffman

    NASA Image and Video Library

    1993-06-07

    S93-35696 (7 June 1993) --- Making use of the air-bearing floor in Johnson Space Center's (JSC) Shuttle Mockup and Integration Laboratory, astronaut Jeffrey A. Hoffman practices working with the Hubble Space Telescope's (HST) Wide Field/Planetary Camera (WF/PC). Hoffman is one of four mission specialists who will participate in HST servicing on the scheduled December mission. Changing out the large camera is one of several chores to be performed by the four. Photo credit: NASA

  6. 36. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" AIR FILTERS LOOKING ...

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

    36. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" AIR FILTERS LOOKING SOUTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  7. Yaw rate control of an air bearing vehicle

    NASA Technical Reports Server (NTRS)

    Walcott, Bruce L.

    1989-01-01

    The results of a 6 week project which focused on the problem of controlling the yaw (rotational) rate the air bearing vehicle used on NASA's flat floor facility are summarized. Contained within is a listing of the equipment available for task completion and an evaluation of the suitability of this equipment. The identification (modeling) process of the air bearing vehicle is detailed as well as the subsequent closed-loop control strategy. The effectiveness of the solution is discussed and further recommendations are included.

  8. Understanding Skill in EVA Mass Handling. Volume 3; Empirical Developments and Conclusions

    NASA Technical Reports Server (NTRS)

    Riccio, Gary E.; McDonald, P. Vernon

    1998-01-01

    Key attributes of skilled mass handling were identified through an examination of lessons learned by the extravehicular activity operational community. These qualities were translated into measurable quantities. The operational validity of the ground-based investigation was improved by building a device that increased the degrees of freedom of extravehicular mobility unit motion on the Precision Air-Bearing Floor. The results revealed subtle patterns of interaction between motions of an orbital replacement unit mockup and mass handler that should be important for effective performance on orbit. The investigation also demonstrated that such patterns can be measured with a variety of common instruments and under imperfect conditions of observation.

  9. TPS Inspection and Repair

    NASA Technical Reports Server (NTRS)

    Parazynski, Scott

    2012-01-01

    Dr. Scott Parazynski provided a retrospective on the EVA tools and procedures efforts NASA went through in the aftermath of Columbia for the Shuttle Thermal Protection System (TPS) inspection and repair. He describes his role as the lead astronaut on this effort, and covered all of the Neutral Buoyancy Lab (NBL), KC 135 (reduced gravity aircraft), Precision Air Bearing Floor (PABF), vacuum chamber and 1 G testing that was done in order to develop the tools and techniques that were flown. Parazynski also discusses how the EVA community worked together to resolve a huge safety issue, and how his work in the spacesuit was critical to overcoming a design limitation of the Space Shuttle.

  10. Linear kinematic air bearing

    NASA Technical Reports Server (NTRS)

    Mayall, S. D.

    1974-01-01

    Bearing provides continuous, smooth movement of the cat's-eye mirror, eliminating wear and deterioration of bearing surface and resulting oscillation effects in servo system. Design features self-aligning configuration; single-point, pivotal pad mounting, having air passage through it; and design of pads that allows for precise control of discharge path of air from pads.

  11. A novel AFM-based 5-axis nanoscale machine tool for fabrication of nanostructures on a micro ball

    NASA Astrophysics Data System (ADS)

    Geng, Yanquan; Wang, Yuzhang; Yan, Yongda; Zhao, Xuesen

    2017-11-01

    This paper presents a novel atomic force microscopy (AFM)-based 5-axis nanoscale machine tool developed to fabricate nanostructures on different annuli of the micro ball. Different nanostructures can be obtained by combining the scratching trajectory of the AFM tip with the movement of the high precision air-bearing spindle. The center of the micro ball is aligned to be coincided with the gyration center of the high precision to guarantee the machining process during the rotating of the air-bearing spindle. Processing on different annuli of the micro ball is achieved by controlling the distance between the center of the micro ball and the rotation center of the AFM head. Nanostructures including square cavities, circular cavities, triangular cavities, and an annular nanochannel are machined successfully on the three different circumferences of a micro ball with a diameter of 1500 μm. Moreover, the influences of the error motions of the high precision air-bearing spindle and the eccentric between the micro ball and the gyration center of the high precision air-bearing spindle on the processing position error on the micro ball are also investigated. This proposed machining method has the potential to prepare the inertial confinement fusion target with the expected dimension defects, which would advance the application of the AFM tip-based nanomachining approach.

  12. Astronaut David Scott practicing for Gemini 8 EVA

    NASA Image and Video Library

    1966-02-01

    S66-19284 (1 Feb. 1966) --- Astronaut David R. Scott practicing for Gemini-8 extravehicular activity (EVA) in building 4 of the Manned Spacecraft Center on the air bearing floor. He is wearing the Hand-Held Maneuvering Unit which he will use during the EVA. Photo credit: NASA

  13. 78 FR 70209 - Airworthiness Directives; XtremeAir GmbH Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ...: Final rule; request for comments. SUMMARY: We are adopting a new airworthiness directive (AD) for Xtreme... lower left landing gear attachment bearing and the lower engine mount to the firewall attachment plate... Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590. Hand Delivery: U.S. Department of...

  14. Nano-level instrumentation for analyzing the dynamic accuracy of a rolling element bearing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Z.; Hong, J.; Zhang, J.

    2013-12-15

    The rotational performance of high-precision rolling bearings is fundamental to the overall accuracy of complex mechanical systems. A nano-level instrument to analyze rotational accuracy of high-precision bearings of machine tools under working conditions was developed. In this instrument, a high-precision (error motion < 0.15 μm) and high-stiffness (2600 N axial loading capacity) aerostatic spindle was applied to spin the test bearing. Operating conditions could be simulated effectively because of the large axial loading capacity. An air-cylinder, controlled by a proportional pressure regulator, was applied to drive an air-bearing subjected to non-contact and precise loaded axial forces. The measurement results onmore » axial loading and rotation constraint with five remaining degrees of freedom were completely unconstrained and uninfluenced by the instrument's structure. Dual capacity displacement sensors with 10 nm resolution were applied to measure the error motion of the spindle using a double-probe error separation method. This enabled the separation of the spindle's error motion from the measurement results of the test bearing which were measured using two orthogonal laser displacement sensors with 5 nm resolution. Finally, a Lissajous figure was used to evaluate the non-repetitive run-out (NRRO) of the bearing at different axial forces and speeds. The measurement results at various axial loadings and speeds showed the standard deviations of the measurements’ repeatability and accuracy were less than 1% and 2%. Future studies will analyze the relationship between geometrical errors and NRRO, such as the ball diameter differences of and the geometrical errors in the grooves of rings.« less

  15. Nano-level instrumentation for analyzing the dynamic accuracy of a rolling element bearing.

    PubMed

    Yang, Z; Hong, J; Zhang, J; Wang, M Y; Zhu, Y

    2013-12-01

    The rotational performance of high-precision rolling bearings is fundamental to the overall accuracy of complex mechanical systems. A nano-level instrument to analyze rotational accuracy of high-precision bearings of machine tools under working conditions was developed. In this instrument, a high-precision (error motion < 0.15 μm) and high-stiffness (2600 N axial loading capacity) aerostatic spindle was applied to spin the test bearing. Operating conditions could be simulated effectively because of the large axial loading capacity. An air-cylinder, controlled by a proportional pressure regulator, was applied to drive an air-bearing subjected to non-contact and precise loaded axial forces. The measurement results on axial loading and rotation constraint with five remaining degrees of freedom were completely unconstrained and uninfluenced by the instrument's structure. Dual capacity displacement sensors with 10 nm resolution were applied to measure the error motion of the spindle using a double-probe error separation method. This enabled the separation of the spindle's error motion from the measurement results of the test bearing which were measured using two orthogonal laser displacement sensors with 5 nm resolution. Finally, a Lissajous figure was used to evaluate the non-repetitive run-out (NRRO) of the bearing at different axial forces and speeds. The measurement results at various axial loadings and speeds showed the standard deviations of the measurements' repeatability and accuracy were less than 1% and 2%. Future studies will analyze the relationship between geometrical errors and NRRO, such as the ball diameter differences of and the geometrical errors in the grooves of rings.

  16. Understanding Skill in EVA Mass Handling. Volume 2; Empirical Investigation

    NASA Technical Reports Server (NTRS)

    Riccio, Gary; McDonald, Vernon; Peters, Brian; Layne, Charles; Bloomberg, Jacob

    1997-01-01

    In this report we describe the details of our empirical protocol effort investigating skill in extravehicular mass handling using NASA's principal mass handling simulator, the precision air bearing floor. Contents of this report include a description of the necessary modifications to the mass handling simulator; choice of task, and the description of an operationally relevant protocol. Our independent variables are presented in the context of the specific operational issues they were designed to simulate. The explanation of our dependent variables focuses on the specific data processing procedures used to transform data from common laboratory instruments into measures that are relevant to a special class of nested control systems (discussed in Volume 1): manual interactions between an individual and the substantial environment. The data reduction is explained in the context of the theoretical foundation described in Volume 1. Finally as a preface to the presentation of the empirical data in Volume 3 of this report series, a set of detailed hypotheses is presented.

  17. Positioner with long travel in two dimensions

    DOEpatents

    Trumper, David L.; Williams, Mark E.

    1997-12-23

    A precision positioning system is provided which provides long travel in two of the linear dimensions, while using non-contact bearings for both a first subassembly which provides long travel in one of the linear dimension and a second subassembly which provides long travel in the second linear dimension. The first or upper subassembly is preferably a magnetic subassembly which, in addition to providing long travel, also compensates or positions in three rotary dimensions and in the third linear dimension. The second subassembly is preferably either an air bearing or magnetic subassembly and is normally used only to provide long travel. Angled surfaces may be provided for magnetic bearings and capacitive or other gap sensing probes may be mounted to the stage and ground flush with the bearing actuators to provide more precise gap measurements.

  18. A high precision, compact electromechanical ground rotation sensor

    NASA Astrophysics Data System (ADS)

    Dergachev, V.; DeSalvo, R.; Asadoor, M.; Bhawal, A.; Gong, P.; Kim, C.; Lottarini, A.; Minenkov, Y.; Murphy, C.; O'Toole, A.; Peña Arellano, F. E.; Rodionov, A. V.; Shaner, M.; Sobacchi, E.

    2014-05-01

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of {1}{ × 10^{-11}}textrm { m}/sqrt{textrm {Hz}}. We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of {5.7}{ × 10^{-9}}textrm { rad}/sqrt{textrm {Hz}} at 10 mHz and {6.4}{ × 10^{-10}}textrm { rad}/sqrt{textrm {Hz}} at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

  19. Air Bearings Machined On Ultra Precision, Hydrostatic CNC-Lathe

    NASA Astrophysics Data System (ADS)

    Knol, Pierre H.; Szepesi, Denis; Deurwaarder, Jan M.

    1987-01-01

    Micromachining of precision elements requires an adequate machine concept to meet the high demand of surface finish, dimensional and shape accuracy. The Hembrug ultra precision lathes have been exclusively designed with hydrostatic principles for main spindle and guideways. This concept is to be explained with some major advantages of hydrostatics compared with aerostatics at universal micromachining applications. Hembrug has originally developed the conventional Mikroturn ultra precision facing lathes, for diamond turning of computer memory discs. This first generation of machines was followed by the advanced computer numerically controlled types for machining of complex precision workpieces. One of these parts, an aerostatic bearing component has been succesfully machined on the Super-Mikroturn CNC. A case study of airbearing machining confirms the statement that a good result of the micromachining does not depend on machine performance alone, but also on the technology applied.

  20. 27. FIFTH FLOOR BLDG. 29 LOOKING NORTH. Fafnir Bearing ...

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

    27. FIFTH FLOOR BLDG. 29 LOOKING NORTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  1. 13. FIRST FLOOR BLDG. 28 LOOKING EAST. Fafnir Bearing ...

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

    13. FIRST FLOOR BLDG. 28 LOOKING EAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  2. 26. SECOND FLOOR BLDG. 29 LOOKING NORTH. Fafnir Bearing ...

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

    26. SECOND FLOOR BLDG. 29 LOOKING NORTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  3. 9. FIRST FLOOR BLDG. 28B LOOKING WEST. Fafnir Bearing ...

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

    9. FIRST FLOOR BLDG. 28B LOOKING WEST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  4. 25. SIXTH FLOOR BLDG. 28B LOOKING EAST. Fafnir Bearing ...

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

    25. SIXTH FLOOR BLDG. 28B LOOKING EAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  5. 15. FIRST FLOOR BLDG. 28A LOOKING EAST. Fafnir Bearing ...

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

    15. FIRST FLOOR BLDG. 28A LOOKING EAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  6. Recent progress on air-bearing slumping of segmented thin-shell mirrors for x-ray telescopes: experiments and numerical analysis

    NASA Astrophysics Data System (ADS)

    Zuo, Heng E.; Yao, Youwei; Chalifoux, Brandon D.; DeTienne, Michael D.; Heilmann, Ralf K.; Schattenburg, Mark L.

    2017-08-01

    Slumping (or thermal-shaping) of thin glass sheets onto high precision mandrels was used successfully by NASA Goddard Space Flight Center to fabricate the NuSTAR telescope. But this process requires long thermal cycles and produces mid-range spatial frequency errors due to the anti-stick mandrel coatings. Over the last few years, we have designed and tested non-contact horizontal slumping of round flat glass sheets floating on thin layers of nitrogen between porous air-bearings using fast position control algorithms and precise fiber sensing techniques during short thermal cycles. We recently built a finite element model with ADINA to simulate the viscoelastic behavior of glass during the slumping process. The model utilizes fluid-structure interaction (FSI) to understand the deformation and motion of glass under the influence of air flow. We showed that for the 2D axisymmetric model, experimental and numerical approaches have comparable results. We also investigated the impact of bearing permeability on the resulting shape of the wafers. A novel vertical slumping set-up is also under development to eliminate the undesirable influence of gravity. Progress towards generating mirrors for good angular resolution and low mid-range spatial frequency errors is reported.

  7. Magnetic bearings for a high-performance optical disk buffer

    NASA Technical Reports Server (NTRS)

    Hockney, Richard; Hawkey, Timothy

    1993-01-01

    An optical disk buffer concept can provide gigabit-per-second data rates and terabit capacity through the use of arrays of solid state lasers applied to a stack of erasable/reusable optical disks. The RCA optical disk buffer has evoked interest by NASA for space applications. The porous graphite air bearings in the rotary spindle as well as those used in the linear translation of the read/write head would be replaced by magnetic bearings or mechanical (ball or roller) bearings. Based upon past experience, roller or ball bearings for the translation stages are not feasible. Unsatisfactory, although limited experience exists with ball bearing spindles also. Magnetic bearings, however, appear ideally suited for both applications. The use of magnetic bearings is advantageous in the optical disk buffer because of the absence of physical contact between the rotating and stationary members. This frictionless operation leads to extended life and reduced drag. The manufacturing tolerances that are required to fabricate magnetic bearings would also be relaxed from those required for precision ball and gas bearings. Since magnetic bearings require no lubricant, they are inherently compatible with a space (vacuum) environment. Magnetic bearings also allow the dynamics of the rotor/bearing system to be altered through the use of active control. This provides the potential for reduced vibration, extended regions of stable operation, and more precise control of position.

  8. 16. THIRD FLOOR BLDG. 28A, DETAIL CUTOUT IN FLOOR FOR ...

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

    16. THIRD FLOOR BLDG. 28A, DETAIL CUTOUT IN FLOOR FOR WOOD BLOCK FLOORING LOOKING EAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  9. Investigation of the spatial variability and possible origins of wind-induced air pressure fluctuations responsible for pressure pumping

    NASA Astrophysics Data System (ADS)

    Mohr, Manuel; Laemmel, Thomas; Maier, Martin; Zeeman, Matthias; Longdoz, Bernard; Schindler, Dirk

    2017-04-01

    The exchange of greenhouse gases between the soil and the atmosphere is highly relevant for the climate of the Earth. Recent research suggests that wind-induced air pressure fluctuations can alter the soil gas transport and therefore soil gas efflux significantly. Using a newly developed method, we measured soil gas transport in situ in a well aerated forest soil. Results from these measurements showed that the commonly used soil gas diffusion coefficient is enhanced up to 30% during periods of strong wind-induced air pressure fluctuations. The air pressure fluctuations above the forest floor are only induced at high above-canopy wind speeds (> 5 m s-1) and lie in the frequency range 0.01-0.1 Hz. Moreover, the amplitudes of air pressure fluctuations in this frequency range show a clear quadratic dependence on mean above-canopy wind speed. However, the origin of these wind-induced pressure fluctuations is still unclear. Airflow measurements and high-precision air pressure measurements were conducted at three different vegetation-covered sites (conifer forest, deciduous forest, grassland) to investigate the spatial variability of dominant air pressure fluctuations, their origin and vegetation-dependent characteristics. At the conifer forest site, a vertical profile of air pressure fluctuations was measured and an array consisting of five pressure sensors were installed at the forest floor. At the grassland site, the air pressure measurements were compared with wind observations made by ground-based LIDAR and spatial temperature observations from a fibre-optic sensing network (ScaleX Campaign 2016). Preliminary results show that at all sites the amplitudes of relevant air pressure fluctuations increase with increasing wind speed. Data from the array measurements reveal that there are no time lags between the air pressure signals of different heights, but a time lag existed between the air pressure signals of the sensors distributed laterally on the forest floor, suggesting a horizontal propagation of the air pressure waves.

  10. 23. FIFTH FLOOR BLDG. 28B, DETAIL WOOD BLOCK FLOORING LOOKING ...

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

    23. FIFTH FLOOR BLDG. 28B, DETAIL WOOD BLOCK FLOORING LOOKING WEST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  11. 18. FOURTH FLOOR BLDG. 28, RAISED CONCRETE SLAB FLOOR WITH ...

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

    18. FOURTH FLOOR BLDG. 28, RAISED CONCRETE SLAB FLOOR WITH BLOCKS AND PULLEYS OVERHEAD LOOKING NORTHEAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  12. 24. FIFTH FLOOR BLDG. 28B, DETAIL WOOD BLOCK FLOORING LOOKING ...

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

    24. FIFTH FLOOR BLDG. 28B, DETAIL WOOD BLOCK FLOORING LOOKING NORTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  13. Understanding Skill in EVA Mass Handling. Volume 1; Theoretical and Operational Foundations

    NASA Technical Reports Server (NTRS)

    Riccio, Gary; McDonald, Vernon; Peters, Brian; Layne, Charles; Bloomberg, Jacob

    1997-01-01

    This report describes the theoretical and operational foundations for our analysis of skill in extravehicular mass handling. A review of our research on postural control, human-environment interactions, and exploratory behavior in skill acquisition is used to motivate our analysis. This scientific material is presented within the context of operationally valid issues concerning extravehicular mass handling. We describe the development of meaningful empirical measures that are relevant to a special class of nested control systems: manual interactions between an individual and the substantial environment. These measures are incorporated into a unique empirical protocol implemented on NASA's principal mass handling simulator, the precision air-bearing floor, in order to evaluate skill in extravehicular mass handling. We discuss the components of such skill with reference to the relationship between postural configuration and controllability of an orbital replacement unit, the relationship between orbital replacement unit control and postural stability, the relationship between antecedent and consequent movements of an orbital replacement unit, and the relationship between antecedent and consequent postural movements. Finally, we describe our expectations regarding the operational relevance of the empirical results as it pertains to extravehicular activity tools, training, monitoring, and planning.

  14. Return to Flight: Crew Activities Resource Reel 1 of 2

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The crew of the STS-114 Discovery Mission is seen in various aspects of training for space flight. The crew activities include: 1) STS-114 Return to Flight Crew Photo Session; 2) Tile Repair Training on Precision Air Bearing Floor; 3) SAFER Tile Inspection Training in Virtual Reality Laboratory; 4) Guidance and Navigation Simulator Tile Survey Training; 5) Crew Inspects Orbital Boom and Sensor System (OBSS); 6) Bailout Training-Crew Compartment; 7) Emergency Egress Training-Crew Compartment Trainer (CCT); 8) Water Survival Training-Neutral Buoyancy Lab (NBL); 9) Ascent Training-Shuttle Motion Simulator; 10) External Tank Photo Training-Full Fuselage Trainer; 11) Rendezvous and Docking Training-Shuttle Engineering Simulator (SES) Dome; 12) Shuttle Robot Arm Training-SES Dome; 13) EVA Training Virtual Reality Lab; 14) EVA Training Neutral Buoyancy Lab; 15) EVA-2 Training-NBL; 16) EVA Tool Training-Partial Gravity Simulator; 17) Cure in Place Ablator Applicator (CIPAA) Training Glove Vacuum Chamber; 16) Crew Visit to Merritt Island Launch Area (MILA); 17) Crew Inspection-Space Shuttle Discovery; and 18) Crew Inspection-External Tank and Orbital Boom and Sensor System (OBSS). The crew are then seen answering questions from the media at the Space Shuttle Landing Facility.

  15. Real-Time EVA Troubleshooting

    NASA Technical Reports Server (NTRS)

    Parazynski, Scott

    2012-01-01

    Dr. Parazynski focused on the Shuttle Transportation System (STS)-120 Solar Array Repair Extravehicular Activity (EVA) with personal anecdotes and then spoke about what it takes to have a successful EVA during the event, what types of problems can occur during an EVA, particularly with the spacesuit and the safety of the crew, and how to resolve these quickly, safely, and efficiently. He also described the participants and the types of decisions and actions each had to take to ensure success. He described "Team 4," in Houston and on-orbit, as well as anecdotes from his STS-86 and STS-100 missions. Parazynski provided a retrospective on the EVA tools and procedures NASA used in the aftermath of Columbia for shuttle Thermal Protection System (TPS) inspection and repair. He described his role as the lead astronaut during this effort, and covered all the Neutral Buoyancy Laboratory (NBL), KC-135, precision air-bearing floor (PABF), vacuum chamber, and 1-G testing performed to develop the tools and techniques that were flown. Parazynski discussed how the EVA community worked together to resolve a huge safety issue, and how his work in the spacesuit was critical to overcoming a design limitation of the Space Shuttle.

  16. A testing machine for dental air-turbine handpiece characteristics: free-running speed, stall torque, bearing resistance.

    PubMed

    Darvell, Brain W; Dyson, J E

    2005-01-01

    The measurement of performance characteristics of dental air turbine handpieces is of interest with respect to product comparisons, standards specifications and monitoring of bearing longevity in clinical service. Previously, however, bulky and expensive laboratory equipment was required. A portable test machine is described for determining three key characteristics of dental air-turbine handpieces: free-running speed, stall torque and bearing resistance. It relies on a special circuit design for performing a hardware integration of a force signal with respect to rotational position, independent of the rate at which the turbine is allowed to turn during both stall torque and bearing resistance measurements. Free-running speed without the introduction of any imbalance can be readily monitored. From the essential linear relationship between torque and speed, dynamic torque and, hence, power, can then be calculated. In order for these measurements to be performed routinely with the necessary precision of location on the test stage, a detailed procedure for ensuring proper gripping of the handpiece is described. The machine may be used to verify performance claims, standard compliance checks should this be established as appropriate, monitor deterioration with time and usage in the clinical environment and for laboratory investigation of design development.

  17. Solid Footing.

    ERIC Educational Resources Information Center

    Franzen, Mark; Gorrell, Kyle

    2002-01-01

    Based on one school district's experience, discusses raised access flooring systems for schools. Addresses the nuts and bolts of such flooring systems, integrating an air delivery system below the flooring, advantages of floor-level air supply, and design issues. (EV)

  18. Tests of a sputtered MoS2 lubricant film in various environments

    NASA Technical Reports Server (NTRS)

    Vest, C. E.

    1976-01-01

    This paper discusses conditions and results of several tests of a DC sputtered MoS2 dry lubricant film. The test components were miniature precision ball bearings and rings and blocks; the surrounding atmospheres were laboratory air, pure helium, vacuum to 10 to the -8th power torr, and a perfluoroalkylpolyether oil. The results showed that the lubricant would perform satisfactorily under lightly loaded (450 gm) ball bearings in vacuum and would not perform well under a 66-kg load in air, a 132-kg load in helium, or a 330-kg load under oil. These tests and others show that the sputtered MoS2 film has some desirable features for space applications as well as some definite limitations.

  19. Upgrading Basements for Combined Nuclear Weapons Effects: Expedient Options

    DTIC Science & Technology

    1976-05-01

    reinforced concrete stairwell walls can be expected to be substantial in these cases, since they are supporting an axial load from higher floors. F...desirability) include: a. Stacked concrete block or brick b. Stacked timber * The latter situation is likely to occur only in load - bearing wall...concrete flat slab 4 Reinforced concrete flat plate 4 Load - bearing wall 3 The analysis of the floor systems for the 34 NSS buildings required the dynamic

  20. The crack effect on instability in a machine tool spindle with gas bearings

    NASA Astrophysics Data System (ADS)

    Huang, Bo-Wun

    2005-09-01

    Gas-bearing spindles are required for increased spindle speed in precise machining. Due to manufacturing flaws or cyclic loading, cracks frequently appear in a rotating spindle systems. Cracks markedly affect the dynamic characteristics of rotating machinery. Hence, in this study, high-speed spindles with gas bearings and the crack effect on the instability dynamics are considered. Most investigations on dynamic characteristics of the spindle system were confined to ball-bearing-type spindles. This work examines the dynamic instability in a cracked rotating spindle system with gas bearings. A round Euler-Bernoulli beam is used to approximate the spindle. The Hamilton principle is applied to derive the equation of motion for the spindle system. The effects of crack depth, rotation speed and provided air pressure on the dynamic instability of a rotating spindle system are studied

  1. Portable Linear Sled (PLS) for biomedical research

    NASA Technical Reports Server (NTRS)

    Vallotton, Will; Matsuhiro, Dennis; Wynn, Tom; Temple, John

    1993-01-01

    The PLS is a portable linear motion generating device conceived by researchers at Ames Research Center's Vestibular Research Facility and designed by engineers at Ames for the study of motion sickness in space. It is an extremely smooth apparatus, powered by linear motors and suspended on air bearings which ride on precision ground ceramic ways.

  2. STS-135 crew during Ingress/Egress Timeline training in building 9NW space station mockups

    NASA Image and Video Library

    2011-04-29

    JSC2011-E-043875 (29 April 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an EVA Thermal Protection System (TPS) overview training session in the TPS/Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Photo credit: NASA

  3. Understanding Skill in EVA Mass Handling. Volume 4; An Integrated Methodology for Evaluating Space Suit Mobility and Stability

    NASA Technical Reports Server (NTRS)

    McDonald, P. Vernon; Newman, Dava

    1999-01-01

    The empirical investigation of extravehicular activity (EVA) mass handling conducted on NASA's Precision Air-Bearing Floor led to a Phase I SBIR from JSC. The purpose of the SBIR was to design an innovative system for evaluating space suit mobility and stability in conditions that simulate EVA on the surface of the Moon or Mars. The approach we used to satisfy the Phase I objectives was based on a structured methodology for the development of human-systems technology. Accordingly the project was broken down into a number of tasks and subtasks. In sequence, the major tasks were: 1) Identify missions and tasks that will involve EVA and resulting mobility requirements in the near and long term; 2) Assess possible methods for evaluating mobility of space suits during field-based EVA tests; 3) Identify requirements for behavioral evaluation by interacting with NASA stakeholders;.4) Identify necessary and sufficient technology for implementation of a mobility evaluation system; and 5) Prioritize and select technology solutions. The work conducted in these tasks is described in this final volume of the series on EVA mass handling. While prior volumes in the series focus on novel data-analytic techniques, this volume addresses technology that is necessary for minimally intrusive data collection and near-real-time data analysis and display.

  4. Vinyl flooring in the home is associated with children’s airborne butylbenzyl phthalate and urinary metabolite concentrations

    PubMed Central

    Just, Allan C.; Miller, Rachel L.; Perzanowski, Matthew S.; Rundle, Andrew G.; Chen, Qixuan; Jung, Kyung Hwa; Hoepner, Lori; Camann, David E.; Calafat, Antonia M.; Perera, Frederica P.; Whyatt, Robin M.

    2015-01-01

    Prior studies have shown that vinyl flooring, as well as the vinyl-softening plasticizers butylbenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP), are associated with asthma and airway inflammation. While DEHP exposure is primarily dietary, whether home vinyl flooring contributes to indoor air and urinary metabolite concentrations for these two phthalates is unclear. Exposures to BBzP and DEHP were examined in a prospective birth cohort of New York City children (n=239) using: (1) visual observation of potential phthalate containing flooring, (2) a two-week home indoor air sample, and (3) concurrent urinary metabolites in a subset (n=193). The category “vinyl or linoleum” flooring was observed in 135 (56%) of monitored rooms; these rooms had statistically significantly higher indoor air geometric mean concentrations of BBzP (23.9 ng/m3) than rooms with wood or carpet flooring (10.6 ng/m3). Children from homes with “vinyl or linoleum” flooring also had significantly higher urinary BBzP metabolite concentrations than other children. Indoor air BBzP and urinary metabolite concentrations were correlated positively (Spearman’s rho 0.40). By contrast, indoor air DEHP was not associated with flooring type nor with its urinary metabolite concentrations. Vinyl flooring in the home may be an important source of children’s exposure to BBzP via indoor air. PMID:25690585

  5. Vinyl flooring in the home is associated with children's airborne butylbenzyl phthalate and urinary metabolite concentrations.

    PubMed

    Just, Allan C; Miller, Rachel L; Perzanowski, Matthew S; Rundle, Andrew G; Chen, Qixuan; Jung, Kyung Hwa; Hoepner, Lori; Camann, David E; Calafat, Antonia M; Perera, Frederica P; Whyatt, Robin M

    2015-01-01

    Prior studies have shown that vinyl flooring as well as the vinyl-softening plasticizers butylbenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) are associated with asthma and airway inflammation. Although DEHP exposure is primarily dietary, whether home vinyl flooring contributes to indoor air and urinary metabolite concentrations for these two phthalates is unclear. Exposures to BBzP and DEHP were examined in a prospective birth cohort of New York City children (n=239) using: (i) visual observation of potential phthalate containing flooring, (ii) a 2-week home indoor air sample, and (iii) concurrent urinary metabolites in a subset (n=193). The category "vinyl or linoleum" flooring was observed in 135 (56%) of monitored rooms; these rooms had statistically significantly higher indoor air geometric mean concentrations of BBzP (23.9 ng/m(3)) than rooms with wood or carpet flooring (10.6 ng/m(3)). Children from homes with "vinyl or linoleum" flooring also had significantly higher urinary BBzP metabolite concentrations than other children. Indoor air BBzP and urinary metabolite concentrations were correlated positively (Spearman's rho 0.40). By contrast, indoor air DEHP was not associated with flooring type nor with its urinary metabolite concentrations. Vinyl flooring in the home may be an important source of children's exposure to BBzP via indoor air.

  6. Stress-strain state of the structure in the service area of underground railway

    NASA Astrophysics Data System (ADS)

    Barabash, M.; Bashinsky, Y.; Korjakins, A.

    2017-10-01

    The paper focuses on numerical study how vibration due to underground trains influences the load-bearing building structures. Diagrams of vibration levels for monolithic floor slab depending on frequency are obtained. Levels of vibrations on floor slabs and columns are measured. The simulation of dynamic load from underground railway onto load-bearing building structures is presented as an example with account of load transmission through the soil. Recommendations for generation of design model in dynamic analysis of structure are provided.

  7. 97. VIEW NORTHWEST OF 4TH FLOOR OF BUILDING 112; NOTE ...

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

    97. VIEW NORTHWEST OF 4TH FLOOR OF BUILDING 112; NOTE REMNANTS OF BEARING SUPPORTS FOR OVERHEAD BELT AND PULLEY POWER TRANSMISSION SYSTEM - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  8. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284901 (15 Dec. 2009) --- NASA astronauts Gregory H. Johnson (left), STS-134 pilot; and Michael Fincke, mission specialist, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center.

  9. Bacterial community structures in air conditioners installed in Japanese residential buildings.

    PubMed

    Hatayama, Kouta; Oikawa, Yurika; Ito, Hiroyuki

    2018-01-01

    The bacterial community structures in four Japanese split-type air conditioners were analyzed using a next-generation sequencer. A variety of bacteria were detected in the air filter of an air conditioner installed on the first floor. In the evaporator of this air conditioner, bacteria belonging to the genus Methylobacterium, or the family of Sphingomonadaceae, were predominantly detected. On the other hand, the majority of bacteria detected in the air filters and evaporators of air conditioners installed on the fifth and twelfth floors belonged to the family Enterobacteriaceae. The source of bacteria belonging to the family Enterobacteriaceae may have been aerosols generated by toilet flushing in the buildings. Our results suggested the possibility that the bacterial contamination in the air conditioners was affected by the floor level on which they were installed. The air conditioner installed on the lower floor, near the ground, may have been contaminated by a variety of outdoor bacteria, whereas the air conditioners installed on floors more distant from the ground may have been less contaminated by outdoor bacteria. However, these suppositions may apply only to the specific split-type air conditioners that we analyzed, because our sample size was small.

  10. Design and optimization of surface profilometer based on coplanar guide rail

    NASA Astrophysics Data System (ADS)

    Chen, Shuai; Dai, Yifan; Hu, Hao; Tie, Guipeng

    2017-10-01

    In order to implement the sub-micron precision measurement, a surface profilometer which based on the coplanar guide rail is designed. This profilometer adopts the open type air floating load and is driven by the magnetic force. As to achieve sub-micron accuracy, the flatness of granite guide working face and aerodynamic block are both processed to the micron level based on the homogenization of air flotation film theory. Permanent magnet which could reduce the influence of the driving disturbance to the measurement accuracy is used as the driving part. In this paper, the bearing capacity and the air floating stiffness of air floating block are both simulated and analyzed as to optimize the design parameters firstly. The layout and magnetic force of the magnet are also simulated. According to the simulation results, type selection and the position arrangement of the magnets are then confirmed. The test results on the experimental platform show that the surface profilometer based on coplanar guide rail possess the basis for realizing the submicron precision measurement.

  11. Astronaut Anna Fisher practices control of the RMS in a trainer

    NASA Image and Video Library

    1984-08-21

    S84-40162 (21 Aug. 1984) --- Astronaut Anna L. Fisher controls the Remote Manipulator System (RMS) arm from inside the "orbiter" as part of her training program in the Johnson Space Center's Shuttle Mock-up and Integration Laboratory. Dr. Fisher, one of three mission specialists for mission 51-A, is inside the cabin portion of a trainer called the Manipulatory Development Facility (MDF). She is able to operate the arm in conjunction with an air bearing floor and to log a great deal of rehearsal time for her flight, on which the retrieval of a low-orbiting communications satellite is planned. Photo credit: NASA

  12. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284896 (15 Dec. 2009) --- NASA astronauts Gregory H. Johnson (left), STS-134 pilot; along with astronauts Michael Fincke (center) and Greg Chamitoff, both mission specialists, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center.

  13. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284893 (15 Dec. 2009) --- NASA astronaut Gregory H. Johnson (right), STS-134 pilot; and European Space Agency astronaut Roberto Vittori, mission specialist, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center.

  14. 29. FIRST FLOOR BLDG. 45, "TRANE CENTRAVAC" LOOKING EAST. ...

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

    29. FIRST FLOOR BLDG. 45, "TRANE CENTRAVAC" LOOKING EAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  15. 14. FIRST FLOOR BLDG. 28: DETAIL OCTAGONAL COLUMN. Fafnir ...

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

    14. FIRST FLOOR BLDG. 28: DETAIL OCTAGONAL COLUMN. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  16. 33. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" LOOKING NORTH. ...

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

    33. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" LOOKING NORTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  17. 87. SIXTH FLOOR BLDG. 19 "CLEAN ROOM" LOOKING WEST. ...

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

    87. SIXTH FLOOR BLDG. 19 "CLEAN ROOM" LOOKING WEST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  18. Carbon dioxide and methane emissions from the scale model of open dairy lots.

    PubMed

    Ding, Luyu; Cao, Wei; Shi, Zhengxiang; Li, Baoming; Wang, Chaoyuan; Zhang, Guoqiang; Kristensen, Simon

    2016-07-01

    To investigate the impacts of major factors on carbon loss via gaseous emissions, carbon dioxide (CO2) and methane (CH4) emissions from the ground of open dairy lots were tested by a scale model experiment at various air temperatures (15, 25, and 35 °C), surface velocities (0.4, 0.7, 1.0, and 1.2 m sec(-1)), and floor types (unpaved soil floor and brick-paved floor) in controlled laboratory conditions using the wind tunnel method. Generally, CO2 and CH4 emissions were significantly enhanced with the increase of air temperature and velocity (P < 0.05). Floor type had different effects on the CO2 and CH4 emissions, which were also affected by air temperature and soil characteristics of the floor. Although different patterns were observed on CH4 emission from the soil and brick floors at different air temperature-velocity combinations, statistical analysis showed no significant difference in CH4 emissions from different floors (P > 0.05). For CO2, similar emissions were found from the soil and brick floors at 15 and 25 °C, whereas higher rates were detected from the brick floor at 35 °C (P < 0.05). Results showed that CH4 emission from the scale model was exponentially related to CO2 flux, which might be helpful in CH4 emission estimation from manure management. Gaseous emissions from the open lots are largely dependent on outdoor climate, floor systems, and management practices, which are quite different from those indoors. This study assessed the effects of floor types and air velocities on CO2 and CH4 emissions from the open dairy lots at various temperatures by a wind tunnel. It provided some valuable information for decision-making and further studies on gaseous emissions from open lots.

  19. 12. FIRST FLOOR BLD 28B: DETAIL SOLVENT PUMPS. Fafnir ...

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

    12. FIRST FLOOR BLD 28B: DETAIL SOLVENT PUMPS. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  20. 10. FIRST FLOOR BLDG. 28B: DETAIL FLARED COLUMN. Fafnir ...

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

    10. FIRST FLOOR BLDG. 28B: DETAIL FLARED COLUMN. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  1. A Converse of a Result about the Floor Function by Hermite

    ERIC Educational Resources Information Center

    Mortici, Cristinel

    2012-01-01

    The floor function maps a real number to the largest previous integer. More precisely, floor(x)=[x] is the largest integer not greater than x. The square bracket notation [x] for the floor function was introduced by Gauss in his third proof of quadratic reciprocity in 1808. The floor function is also called the greatest integer or entier (French…

  2. 35. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" DINING AREA LOOKING ...

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

    35. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" DINING AREA LOOKING WEST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  3. 34. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" ENTRANCE CORRIDOR LOOKING ...

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

    34. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" ENTRANCE CORRIDOR LOOKING SOUTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  4. Performance Testing of a Magnetically Suspended Double Gimbal Control Moment Gyro Based on the Single Axis Air Bearing Table

    PubMed Central

    Cui, Peiling; Zhang, Huijuan; Yan, Ning; Fang, Jiancheng

    2012-01-01

    Integrating the advantage of magnetic bearings with a double gimble control moment gyroscope (DGCMG), a magnetically suspended DGCMG (MSDGCMG) is an ideal actuator in high-precision, long life, and rapid maneuver attitude control systems. The work presented here mainly focuses on performance testing of a MSDGCMG independently developed by Beihang University, based on the single axis air bearing table. In this paper, taking into sufficient consideration to the moving-gimbal effects and the response bandwidth limit of the gimbal, a special MSDGCMG steering law is proposed subject to the limits of gimbal angle rate and angle acceleration. Finally, multiple experiments are carried out, with different MSDGCMG angular momenta as well as different desired attitude angles. The experimental results indicate that the MSDGCMG has a good gimbal angle rate and output torque tracking capabilities, and that the attitude stability with MSDGCMG as actuator is superior to 10−3°/s. The MSDGCMG performance testing in this paper, carried out under moving-base condition, will offer a technique base for the future research and application of MSDGCMGs. PMID:23012536

  5. STS-135 crew during Ingress/Egress Timeline training in building 9NW space station mockups

    NASA Image and Video Library

    2011-04-29

    JSC2011-E-043876 (29 April 2011) --- NASA astronauts Sandy Magnus and Rex Walheim (mostly out of frame at right), both STS-135 mission specialists, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Photo credit: NASA

  6. STS-135 crew during Ingress/Egress Timeline training in building 9NW space station mockups

    NASA Image and Video Library

    2011-04-29

    JSC2011-E-043872 (29 April 2011) --- NASA astronauts Sandy Magnus and Rex Walheim, both STS-135 mission specialists, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. A crew instructor (right) assisted Magnus and Walheim. Photo credit: NASA

  7. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284898 (15 Dec. 2009) --- NASA astronauts Gregory H. Johnson (center), STS-134 pilot; and Michael Fincke (right), mission specialist; along with European Space Agency astronaut Roberto Vittori, mission specialist, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center.

  8. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284900 (15 Dec. 2009) --- NASA astronauts Gregory H. Johnson (center), STS-134 pilot; and Michael Fincke (right), mission specialist; along with European Space Agency astronaut Roberto Vittori, mission specialist, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center.

  9. The Bottom Line For Air Quality.

    ERIC Educational Resources Information Center

    Ellis, Tom

    2000-01-01

    Discusses how the right type of flooring can help schools reduce indoor-air-quality problems. Using vinyl composition flooring to handle moisture and reduce fungi growth is examined as are the benefits of vinyl cushion tufted textile flooring for cost effectiveness, learning environment improvement, installation, and effectiveness in emergencies.…

  10. Development of an aerostatic bearing system for roll-to-roll printed electronics

    NASA Astrophysics Data System (ADS)

    Chen, Shasha; Chen, Weihai; Liu, Jingmeng; Chen, Wenjie; Jin, Yan

    2018-06-01

    Roll-to-roll printed electronics is proved to be an effective way to fabricate electrical devices on various substrates. High precision overlay alignment plays a key role to create multi-layer electrical devices. Multiple rollers are adopted to support and transport the substrate web. In order to eliminate the negative effect of the machining error and assembling error of the roller, a whole roll-to-roll system including two aerostatic bearing devices with arrayed restrictors is proposed in this paper. Different to the conventional roller, the aerostatic bearing device can create a layer of air film between the web and the device to realize non-contact support and transport. Based on simplified Navier–Stokes equations, the theoretical model of the air film is established. Moreover, the pressure distribution of the whole flow field and single restrictor in different positions are modeled by conducting numerical simulation with computational fluid dynamics (CFD) software FLUENT. The load capacity curves and stiffness curves are generated to provide guidance for optimizing the structure of the device. A prototype of the aerostatic bearing system is set up and the experiment tests are carried out. For the proposed aerostatic bearing roller with a diameter of 100 mm and length of 200 mm, the experimental results show the aerostatic bearing method can achieve the position accuracy in a range of 1 μm in the vertical direction of the web, which is much better than that using existing methods.

  11. 20. FIFTH FLOOR BLDG. 28A, VIEW SOUND TEST ROOMS LOOKING ...

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

    20. FIFTH FLOOR BLDG. 28A, VIEW SOUND TEST ROOMS LOOKING NORTHEAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  12. 11. FIRST FLOOR BLDG. 28B: OVERVIEW SOLVENT PUMPS AND HEATING ...

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

    11. FIRST FLOOR BLDG. 28B: OVERVIEW SOLVENT PUMPS AND HEATING LOOKING WEST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  13. 22. FIFTH FLOOR BLDG. 28A, DETAIL DOUBLE DOORS SOUND TEST ...

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

    22. FIFTH FLOOR BLDG. 28A, DETAIL DOUBLE DOORS SOUND TEST ROOM LOOKING NORTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  14. 17. THIRD FLOOR BLDG. 28B, DETAIL ACOUSTIC TILE CEILING LOOKING ...

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

    17. THIRD FLOOR BLDG. 28B, DETAIL ACOUSTIC TILE CEILING LOOKING SOUTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  15. 21. FIFTH FLOOR BLDG. 28A, ELEVATION WEST END SOUND TEST ...

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

    21. FIFTH FLOOR BLDG. 28A, ELEVATION WEST END SOUND TEST ROOM. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  16. 19. FOURTH FLOOR BLDG. 28, DETAIL BLOCKS, PULLEYS, AND ELECTRIC ...

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

    19. FOURTH FLOOR BLDG. 28, DETAIL BLOCKS, PULLEYS, AND ELECTRIC MOTOR LOOKING EAST. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  17. 9. Photographic copy of first and second floor plans, undated, ...

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

    9. Photographic copy of first and second floor plans, undated, Department of the Air Force, Air Defense Command Installations, Washington, D.C., in possession of Selfridge Base Museum, Mt. Clemens, Michigan. FLOOR PLANS. - Selfridge Field, Building No. 509, Sugarbush Road east of West Perimeter Road, Mount Clemens, Macomb County, MI

  18. 6. Photographic copy of floor plan drawing, dated August 18, ...

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

    6. Photographic copy of floor plan drawing, dated August 18, 1968, Department of the Air Force Air Defense Command Installations, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. FLOOR PLAN BLDG. 1585. - Selfridge Field, Building No. 1585, South of East Joy Boulevard, west of Taxiway C, Mount Clemens, Macomb County, MI

  19. Photographic copy of floor plan drawing, dated March 7, 1968, ...

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

    Photographic copy of floor plan drawing, dated March 7, 1968, Department of the Air Force Air Defense Command Installations, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. FLOOR PLAN BLDG. 1575 - Selfridge Field, Building No. 1575, South of East Joy Boulevard, west of Taxiway C, Mount Clemens, Macomb County, MI

  20. Indoor air quality and health problems associated with damp floor coverings.

    PubMed

    Tuomainen, Anneli; Seuri, Markku; Sieppi, Anne

    2004-04-01

    To study the relationship between a high incidence of bronchial asthma among employees working in an office building and an indoor air problem related to the degradation of polyvinyl chloride (PVC) floor coverings in the building. The indoor air measurements and results of renovations are also described. Employees' symptoms were surveyed by a questionnaire, and the incidence of asthma was calculated from the medical records for 1997-2000. The quality of indoor air was assessed by microbial sampling and by investigation of the building for possible moisture damage. Indoor air was sampled for volatile organic compounds (VOCs) through Tenax adsorbent tubes. In situ volatile emission measurements from the concrete floor were performed via the field and laboratory emission cell (FLEC) method. In an office with approximately 150 employees, eight new cases of asthma were found in 4 years. In addition, the workers complained of respiratory, conjunctival and nasal symptoms. Emissions indicating the degradation of plastic floor coverings (e.g. 2-ethyl-1-hexanol, 1-butanol) were found in the indoor air and floor material samples. The plastic floor coverings, adhesives and the levelling layers were carefully removed from 12 rooms. The VOCs had diffused into the underlying concrete slabs. The concrete was warmed to remove the diffused VOCs from these areas. After the repairs the concentrations of the VOCs indicating the degradation of PVC, decreased, as did the prevalence of the employees' symptoms and several asthma patients' need for medication. The workers in the office building complained of several respiratory, conjunctival and dermal symptoms. The incidence of adult-onset asthma was approximately nine-times higher than that among Finns employed in similar work. The most probable single cause of the indoor air problem was the degradation of the plastic floor coverings.

  1. Investigating Solutions to Wind Washing Issues in Two-Story Florida Homes, Phase 2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Withers, Charles R.; Kono, Jamie

    2015-04-13

    With U.S. Department of Energy goals of reducing existing home energy use by 30% and new home energy use by 50%, it is imperative to focus on several energy efficiency measures, including the quality of air and thermal barriers. This report provides results from a second-phase research study of a phenomenon generally referred to as wind washing. Wind washing is the movement of unconditioned air around or through building thermal barriers in such a way as to diminish or nullify the intended thermal performance. In some cases, thermal and air barriers are installed very poorly or not at all, andmore » air can readily move from unconditioned attic spaces into quasi-conditioned interstitial spaces. This study focused on the impact of poorly sealed and insulated floor cavities adjacent to attic spaces in Florida homes. In these cases, unconditioned attic air can be transferred into floor cavities through pathways driven by natural factors such as wind, or by thermal differences between the floor cavity and the attic. Air can also be driven into a floor cavity through mechanical forces imposed by return duct leakage in the floor cavity.« less

  2. STS-135 crew during Ingress/Egress Timeline training in building 9NW space station mockups

    NASA Image and Video Library

    2011-04-29

    JSC2011-E-043869 (29 April 2011) --- NASA astronauts Sandy Magnus and Rex Walheim, both STS-135 mission specialists, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. A model of a space shuttle is in the foreground. Photo credit: NASA

  3. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183521 (3 Nov. 2010) --- NASA astronaut Chris Ferguson, STS-135 commander, participates in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  4. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284895 (15 Dec. 2009) --- NASA astronauts Gregory H. Johnson (left), STS-134 pilot; along with astronauts Michael Fincke, Greg Chamitoff and Andrew Feustel (mostly out of frame), all mission specialists, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center.

  5. 17. Detail view of ceiling and beams on third floor ...

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

    17. Detail view of ceiling and beams on third floor of south section of mill. Note the broom attached to the ceiling, which was used to sweep the leather belts used for power transmission, and the bearing pads bolted to the ceiling as well. - Lowe Mill, Eighth Avenue, Southwest, Huntsville, Madison County, AL

  6. High capacity aerodynamic air bearing (HCAB) for laser scanning applications

    NASA Astrophysics Data System (ADS)

    Coleman, Sean M.

    2005-08-01

    A high capacity aerodynamic air bearing (HCAB) has been developed for the laser scanning market. The need for increasing accuracies in the prepress and print plate-making market is causing a shift from ball bearing to air bearing scanners. Aerostatic air bearings are a good option to meet this demand for better performance however, these bearings tend to be expensive and require an additional air supply, filtering and drying system. Commercially available aerodynamic bearings have been typically limited to small mirrors, on the order of 3.5" diameter and less than 0.5" thick. A large optical facet, hence a larger mirror, is required to generate the high number of pixels needed for this type of application. The larger optic necessitated the development of a high capacity 'self-generating' or aerodynamic air bearing that would meet the needs of the optical scanning market. Its capacity is rated up to 6.0" diameter and 1.0" thick optics. The performance of an aerodynamic air bearing is better than a ball bearing and similar to an aerostatic air bearing. It retains the low costs while eliminating the need for ancillary equipment required by an aerostatic bearing.

  7. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183519 (3 Nov. 2010) --- NASA astronauts Doug Hurley, STS-135 pilot; and Sandy Magnus, mission specialist, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  8. The Calculation of VOCs Diffusion Coefficient for Building Materials

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Deng, Quancai; Chen, Haijiang; Wu, Xiaoyun

    2018-05-01

    Volatile Organic Compounds (VOCS), as one of the major sources of air contaminations, has an important bearing on one’s general health. The adsorption capacity and velocity of the material for VOCs can be described separately using. In this paper, the detailed process and method of VOCs diffusion and partition coefficients by genetic algorithm is introduced, the algorithm is realized easily by computer program and the result by the method is precise and practical.

  9. Phyllosilicate and sulfate-hematite deposits within Miyamoto crater in Southern Sinus Meridiani, Mars

    USGS Publications Warehouse

    Wiseman, S.M.; Arvidson, R. E.; Andrews-Hanna, J. C.; Clark, R.N.; Lanza, N.L.; des Marais, D.; Marzo, G.A.; Morris, R.V.; Murchie, S.L.; Newsom, Horton E.; Noe Dobrea, E.Z.; Ollila, A.M.; Poulet, F.; Roush, T.L.; Seelos, F.P.; Swayze, G.A.

    2008-01-01

    Orbital topographic, image, and spectral data show that sulfate- and hematite-bearing plains deposits similar to those explored by the MER rover Opportunity unconformably overlie the northeastern portion of the 160 km in diameter Miyamoto crater. Crater floor materials exhumed to the west of the contact exhibit CRISM and OMEGA NIR spectral signatures consistent with the presence of Fe/Mg-rich smectite phyllosilicates. Based on superposition relationships, the phyllosilicate-bearing deposits formed either in-situ or were deposited on the floor of Miyamoto crater prior to the formation of the sulfate-rich plains unit. These findings support the hypothesis that neutral pH aqueous conditions transitioned to a ground-water driven acid sulfate system in the Sinus Meridiani region. The presence of both phyllosilicate and sulfate- and hematite-bearing deposits within Miyamoto crater make it an attractive site for exploration by future rover missions. Copyright 2008 by the American Geophysical Union.

  10. Mounting arrangement for the drive system of an air-bearing spindle on a machine tool

    DOEpatents

    Lunsford, J.S.; Crisp, D.W.; Petrowski, P.L.

    1987-12-07

    The present invention is directed to a mounting arrangement for the drive system of an air-bearing spindle utilized on a machine tool such as a lathe. The mounting arrangement of the present invention comprises a housing which is secured to the casing of the air bearing in such a manner that the housing position can be selectively adjusted to provide alignment of the air-bearing drive shaft supported by the housing and the air-bearing spindle. Once this alignment is achieved the air between spindle and the drive arrangement is maintained in permanent alignment so as to overcome misalignment problems encountered in the operation of the machine tool between the air-bearing spindle and the shaft utilized for driving the air-bearing spindle.

  11. 50. Representative office, room 2024, second floor, Dwing, building 500, ...

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

    50. Representative office, room 2024, second floor, D-wing, building 500, looking west - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  12. 49. SAC Chief of Staff office, second floor, Awing, building ...

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

    49. SAC Chief of Staff office, second floor, A-wing, building 500, looking northwest - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  13. 46. SAC Commander in Chief entry, second floor, Awing, building ...

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

    46. SAC Commander in Chief entry, second floor, A-wing, building 500, looking north - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  14. 47. SAC Commander in Chief office, second floor, Awing, building ...

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

    47. SAC Commander in Chief office, second floor, A-wing, building 500, looking northwest - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  15. 27. UPPER STATION, LOWER FLOOR, BULL WHEEL, BRAKE AIR CYLINDER. ...

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

    27. UPPER STATION, LOWER FLOOR, BULL WHEEL, BRAKE AIR CYLINDER. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  16. Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics

    NASA Technical Reports Server (NTRS)

    Ahearn, D. G.; Crow, S. A.; Simmons, R. B.; Price, D. L.; Mishra, S. K.; Pierson, D. L.

    1997-01-01

    Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

  17. Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics.

    PubMed

    Ahearn, D G; Crow, S A; Simmons, R B; Price, D L; Mishra, S K; Pierson, D L

    1997-11-01

    Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

  18. 2. VIEW OF LOWER MILL FLOOR FOUNDATION, SHOWING, LEFT TO ...

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

    2. VIEW OF LOWER MILL FLOOR FOUNDATION, SHOWING, LEFT TO RIGHT, EDGE OF MILLING FLOOR, TABLE FLOOR, VANNING FLOOR, LOADING LEVEL, TAILINGS POND IN RIGHT BACKGROUND. VIEW IS LOOKING FROM THE NORTHWEST - Mountain King Gold Mine & Mill, 4.3 Air miles Northwest of Copperopolis, Copperopolis, Calaveras County, CA

  19. Repair Air Conditioning, COC Bldg 2605, First Floor Plan. By ...

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

    Repair Air Conditioning, COC Bldg 2605, First Floor Plan. By Strategic Air Command, Civil Engineering. Drawing no. R-156, sheet no. 2 of 4, 15 August 1968; project no. MAR-125-8;CE-572; file drawer 2605-6. Scale one-eighth inch to one foot. 29x41 inches. pencil on paper 405 - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  20. FLOOR PLAN Dyess Air Force Base, Atlas F Missle ...

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

    FLOOR PLAN - Dyess Air Force Base, Atlas F Missle Site S-8, Launch Control Center (LCC), Approximately 3 miles east of Winters, 500 feet southwest of Highway 17700, northwest of Launch Facility, Winters, Runnels County, TX

  1. SECTION BB, FLOOR PLAN Dyess Air Force Base, Atlas ...

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

    SECTION B-B, FLOOR PLAN - Dyess Air Force Base, Atlas F Missle Site S-8, Launch Facility, Approximately 3 miles east of Winters, 500 feet southwest of Highway 1770, center of complex, Winters, Runnels County, TX

  2. 43. Main entry to SAC Control offices, second floor, Awing, ...

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

    43. Main entry to SAC Control offices, second floor, A-wing, building 500, looking southeast - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  3. 48. SAC Deputy Commander in Chief office, second floor, Awing, ...

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

    48. SAC Deputy Commander in Chief office, second floor, A-wing, building 500, looking southeast - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  4. Numerical Modelling and Analysis of Hydrostatic Thrust Air Bearings for High Loading Capacities and Low Air Consumption

    NASA Astrophysics Data System (ADS)

    Yu, Yunluo; Pu, Guang; Jiang, Kyle

    2017-12-01

    The paper presents a numerical simulation study on hydrostatic thrust air bearings to assess the load capacity, compressed air consumptions, and the dynamic response. Finite Difference Method (FDM) and Finite Volume Method (FVM) are combined to solve the non-linear Reynolds equation to find the pressure distribution of the air bearing gas film and the total loading capacity of the bearing. The influence of design parameters on air film gap characteristics, including the air film thickness, supplied pressure, depth of the groove and external load, are investigated based on the proposed FDM model. The simulation results show that the thrust air bearings with a groove have a higher load capacity and air consumption than without a groove, and the load capacity and air consumption both increase with the depth of the groove. Bearings without the groove are better damped than those with the grooves, and the stability of thrust bearing decreases when the groove depth increases. The stability of the thrust bearings is also affected by their loading.

  5. Technology for an intelligent, free-flying robot for crew and equipment retrieval in space

    NASA Technical Reports Server (NTRS)

    Erickson, J. D.; Reuter, G. J.; Healey, Kathleen J.; Phinney, D. E.

    1990-01-01

    Crew rescue and equipment retrieval is a Space Station Freedom requirement. During Freedom's lifetime, there is a high probability that a number of objects will accidently become separated. Members of the crew, replacement units, and key tools are examples. Retrieval of these objects within a short time is essential. Systems engineering studies were conducted to identify system requirements and candidate approaches. One such approach, based on a voice-supervised, intelligent, free-flying robot was selected for further analysis. A ground-based technology demonstration, now in its second phase, was designed to provide an integrated robotic hardware and software testbed supporting design of a space-borne system. The ground system, known as the EVA Retriever, is examining the problem of autonomously planning and executing a target rendezvous, grapple, and return to base while avoiding stationary and moving obstacles. The current prototype is an anthropomorphic manipulator unit with dexterous arms and hands attached to a robot body and latched in a manned maneuvering unit. A precision air-bearing floor is used to simulate space. Sensor data include two vision systems and force/proximity/tactile sensors on the hands and arms. Planning for a shuttle file experiment is underway. A set of scenarios and strawman requirements were defined to support conceptual development. Initial design activities are expected to begin in late 1989 with the flight occurring in 1994. The flight hardware and software will be based on lessons learned from both the ground prototype and computer simulations.

  6. 76 FR 18747 - Teton Power Funding, LLC; Topsham Hydro Partners Limited Partnership; Topsham Hydroelectric...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    .... Topsham Hydro Partners Limited Partnership: Christine M. Miller, Brown Bear GP, LLC, c/o ArcLight Capital.... Miller, Brown Bear Power, LLC, c/o ArcLight Capital Partners, LLC, 200 Clarendon Street, 55th Floor.... Bose, Secretary, Federal Energy Regulatory Commission, 888 First Street, NE., Washington, DC 20426...

  7. 45. SAC conference room 2A8, second floor, Dwing, building 500, ...

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

    45. SAC conference room 2A8, second floor, D-wing, building 500, looking southeast - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  8. 52. 2E corridor, from intersection of 2F corridor, second floor, ...

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

    52. 2E corridor, from intersection of 2F corridor, second floor, building 500, looking east - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  9. 73. New addition building 500 floor plan, drawing number AW600201, ...

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

    73. New addition building 500 floor plan, drawing number AW-60-02-01, dated 26 January, 1970 - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  10. 72. SAC control center underground structure lower floor plan, drawing ...

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

    72. SAC control center underground structure lower floor plan, drawing number 32-02-03, dated 1 February 1955 - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  11. The effect of sub-floor heating on house-dust-mite populations on floors and in furniture.

    PubMed

    de Boer, Rob

    2003-01-01

    It is well known that dehydrating conditions for house dust mites can be created by simply raising the temperature, causing loss of body water and eventually death. Thus, it can be expected that conditions for dust mites are less favourable on floors supplied with sub-floor heating. This was examined in a study of 16 houses with sub-floor heating and 21 without. The pattern of changes in air humidity and temperature on the floors was investigated and compared to known data of the tolerance of dust mites. Also the resident mite populations were compared. Floors with sub-floor heating had, on average, fewer mites, but the difference with unheated floors was small. It was remarkable that mite numbers were also lower in upholstered furniture. Another important observation was that some houses with sub-floor heating had high mite numbers, indicating that this type of heating is compatible with a thriving mite population. Temperature and humidity conditions of heated floors may allow mites not only to survive, but also to remain active in winter. A moderate increase in temperature, a moderate decrease in (absolute) air humidity, or a combination of both, will suffice to keep the humidity all winter below the Critical Equilibrium Humidity, the level of air humidity that is critical for mite growth and reproduction, hence for allergen production. However, it is argued that measures to suppress allergen production by house dust mites are likely to be far more effective if taken in summer rather than in winter.

  12. Rotor and stator assembly configured as an aspirating face seal

    NASA Technical Reports Server (NTRS)

    Turnquist, Norman Arnold (Inventor); Bagepalli, Bharat Sampathkumaran (Inventor); Reluzco, George (Inventor); Tseng, Wu-Yang (Inventor)

    1999-01-01

    A rotor and stator assembly having a rotor and a stator with opposing surfaces defining an air bearing and an air dam of an aspirating face seal. In a first embodiment, the air bearing and the air dam are axially offset. In a second embodiment, the rotor has an axially extending protuberance located radially between the air bearing and the air dam. The axial offset and the protuberance each act to divert the air flow (e.g., compressed gas or combustion gases in a gas turbine or steam in a steam turbine) in a direction transverse to the air flow direction through the air bearing and the air dam, thus isolating the air flows from the air bearing and the air dam which improves seal performance.

  13. Blast and Impact Resistant Composite Structures for Navy Ships

    DTIC Science & Technology

    2013-03-15

    Navy cargo ships, Air Force tactical shelters, Air Force runway matting, vehicular bridge decks, railcar floors and wind turbine blades. The US Army...bridge decks, railcar floors and wind turbine blades. NAVY RELEVANCE Producing stronger, safer and more cost-effective platforms for the new generation...floors and wind turbine blades. 32 NAVY RELEVANCE Producing stronger, safer and more cost-effective platforms for the new generation naval ships

  14. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183523 (3 Nov. 2010) --- NASA astronauts Rex Walheim (left), STS-135 mission specialist; and Doug Hurley, pilot, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  15. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183524 (3 Nov. 2010) --- NASA astronauts Rex Walheim (left), STS-135 mission specialist; and Doug Hurley, pilot, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  16. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284891 (15 Dec. 2009) --- STS-134 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center. Pictured from the right are NASA astronauts Andrew Feustel, Greg Chamitoff, Michael Fincke, all mission specialists; along with NASA astronaut Gregory H. Johnson, pilot; and European Space Agency astronaut Roberto Vittori, mission specialist.

  17. Performance of Radiant Heating Systems of Low-Energy Buildings

    NASA Astrophysics Data System (ADS)

    Sarbu, Ioan; Mirza, Matei; Crasmareanu, Emanuel

    2017-10-01

    After the introduction of plastic piping, the application of water-based radiant heating with pipes embedded in room surfaces (i.e., floors, walls, and ceilings), has significantly increased worldwide. Additionally, interest and growth in radiant heating and cooling systems have increased in recent years because they have been demonstrated to be energy efficient in comparison to all-air distribution systems. This paper briefly describes the heat distribution systems in buildings, focusing on the radiant panels (floor, wall, ceiling, and floor-ceiling). Main objective of this study is the performance investigation of different types of low-temperature heating systems with different methods. Additionally, a comparative analysis of the energy, environmental, and economic performances of floor, wall, ceiling, and floor-ceiling heating using numerical simulation with Transient Systems Simulation (TRNSYS) software is performed. This study showed that the floor-ceiling heating system has the best performance in terms of the lowest energy consumption, operation cost, CO2 emission, and the nominal boiler power. The comparison of the room operative air temperatures and the set-point operative air temperature indicates also that all radiant panel systems provide satisfactory results without significant deviations.

  18. Experimental research on the structural instability mechanism and the effect of multi-echelon support of deep roadways in a kilometre-deep well

    PubMed Central

    Peng, Rui; Zhao, Guangming; Li, Yingming; Zhu, Jianming

    2018-01-01

    We study the structural instability mechanism and effect of a multi-echelon support in very-deep roadways. We conduct a scale model test for analysing the structural failure mechanism and the effect of multi-echelon support of roadways under high horizontal stress. Mechanical bearing structures are classified according to their secondary stress distribution and the strength degradation of the surrounding rock after roadway excavation. A new method is proposed by partitioning the mechanical bearing structure of the surrounding rock into weak, key and main coupling bearing stratums. In the surrounding rock, the main bearing stratum is the plastic reshaping and flowing area. The weak bearing stratum is the peeling layer or the caving part. And the key bearing stratum is the shearing and yielding area. The structural fracture mechanism of roadways is considered in analysing the bearing structure instability of the surrounding rock, and multi-echelon support that considers the structural characteristics of roadway bearings is proposed. Results of the experimental study indicate that horizontal pressure seriously influences the stability of the surrounding rock, as indicated by extension of the weak bearing area and the transfer of the main and key bearing zones. The falling roof, rib spalling, and floor heave indicate the decline of the bearing capacity of surrounding rock, thereby causing roadway structural instability. Multi-echelon support is proposed according to the mechanical bearing structure of the surrounding rock without support. The redesigned support can reduce the scope of the weak bearing area and limit the transfer of the main and key bearing areas. Consequently, kilometre-deep roadway disasters, such as wedge roof caving, floor heave, and rib spalling, can be avoided to a certain degree, and plastic flow in the surrounding rock is relieved. The adverse effect of horizontal stress on the vault, spandrel and arch foot decreases. The stability of the soft rock surrounding the roadways is maintained. PMID:29447180

  19. Compressor ported shroud for foil bearing cooling

    DOEpatents

    Elpern, David G [Los Angeles, CA; McCabe, Niall [Torrance, CA; Gee, Mark [South Pasadena, CA

    2011-08-02

    A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

  20. Sealed rotary hearth furnace with central bearing support

    DOEpatents

    Docherty, James P.; Johnson, Beverly E.; Beri, Joseph

    1989-01-01

    The furnace has a hearth which rotates inside a stationary closed chamber and is supported therein on vertical cylindrical conduit which extends through the furnace floor and is supported by a single center bearing. The charge is deposited through the furnace roof on the rim of the hearth as it rotates and is moved toward the center of the hearth by rabbles. Externally generated hot gases are introduced into the furnace chamber below the hearth and rise through perforations in the hearth and up through the charge. Exhaust gases are withdrawn through the furnace roof. Treated charge drops from a center outlet on the hearth into the vertical cylindrical conduit which extends downwardly through the furnace floor to which it is also sealed.

  1. Feasibility of Air Levitated Surface Stage for Lithography Tool

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi

    The application of light-weight drive technology into the lithography stage has been the current state of art because of minimization of power loss. The purpose of this article is to point out the so-called, "surface stage" which is composed of Lorentz forced 3 DOF (Degree Of Freedom) planar motor (x, y and theta z), air levitation (bearing) system and motor cooling system, is the most balanced concept for the next generation lithography through the verification of each component by manufacturing simple parts and test stand. This paper presents the design method and procedure, and experimental results of the air levitated surface stage which was conducted several years ago, however the author is convinced that the results are enough to adapt various developments of precision machining tool.

  2. STS-134 crew during EVA TPS Overview training in the TPS/PABF

    NASA Image and Video Library

    2009-12-15

    JSC2009-E-284897 (15 Dec. 2009) --- STS-134 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center. Pictured from the right are NASA astronauts Andrew Feustel, Greg Chamitoff, Michael Fincke, all mission specialists; along with NASA astronaut Gregory H. Johnson, pilot; and European Space Agency astronaut Roberto Vittori, mission specialist. John Ray (left) assisted the crew members.

  3. Discussion on the installation checking method of precast composite floor slab with lattice girders

    NASA Astrophysics Data System (ADS)

    Chen, Li; Jin, Xing; Wang, Yahui; Zhou, Hele; Gu, Jianing

    2018-03-01

    Based on the installation checking requirements of China’s current standards and the international norms for prefabricated structural precast components, it proposed an installation checking method for precast composite floor slab with lattice girders. By taking an equivalent composite beam consisted of a single lattice girder and the precast concrete slab as the checking object, compression instability stress of upper chords and yield stress of slab distribution reinforcement at the maximum positive moment, tensile yield stress of upper chords, slab normal section normal compression stress and shear instability stress of diagonal bars at the maximum negative moment were checked. And the bending stress and deflection of support beams, strength and compression stability bearing capacity of the vertical support, shear bearing capacity of the bolt and compression bearing capacity of steel tube wall at the bolt were checked at the same time. Every different checking object was given a specific load value and load combination. Application of installation checking method was given and testified by example.

  4. 15. View looking up Dramp from middle floor level showing ...

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

    15. View looking up D-ramp from middle floor level showing lighting conduits and manometer panel on wall of decontamination area. Building 501, October 2, 1956 - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Command Center, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  5. 18. VIEW OF THE SECOND FLOOR OF BUILDING 707. AIR ...

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

    18. VIEW OF THE SECOND FLOOR OF BUILDING 707. AIR EXHAUST FANS ARE USED TO MAINTAIN PRESSURE DIFFERENTIALS WITHIN THE BUILDING. (5/70) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  6. 7. Photographic copy of floor plan sketch, undated, Selfridge Air ...

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

    7. Photographic copy of floor plan sketch, undated, Selfridge Air National Guard Base Civil Engineers Office in possession of Selfridge Base Civil Engineers Office, Mt. Clemens, Michigan. - Selfridge Field, Building No. 1514, Schoolhouse Road north of South Perimeter Road, Mount Clemens, Macomb County, MI

  7. On buoyancy-driven natural ventilation of a room with a heated floor

    NASA Astrophysics Data System (ADS)

    Gladstone, Charlotte; Woods, Andrew W.

    2001-08-01

    The natural ventilation of a room, both with a heated floor and connected to a cold exterior through two openings, is investigated by combining quantitative models with analogue laboratory experiments. The heated floor generates an areal source of buoyancy while the openings allow displacement ventilation to operate. When combined, these produce a steady state in which the air in the room is well-mixed, and the heat provided by the floor equals the heat lost by displacement. We develop a quantitative model describing this process, in which the advective heat transfer through the openings is balanced with the heat flux supplied at the floor. This model is successfully tested with observations from small-scale analogue laboratory experiments. We compare our results with the steady-state flow associated with a point source of buoyancy: for a given applied heat flux, an areal source produces heated air of lower temperature but a greater volume flux of air circulates through the room. We generalize the model to account for the effects of (i) a cooled roof as well as a heated floor, and (ii) an external wind or temperature gradient. In the former case, the direction of the flow through the openings depends on the temperature of the exterior air relative to an averaged roof and floor temperature. In the latter case, the flow is either buoyancy dominated or wind dominated depending on the strength of the pressure associated with the wind. Furthermore, there is an intermediate multiple-solution regime in which either flow regime may develop.

  8. Highly precise and compact ultrahigh vacuum rotary feedthrough.

    PubMed

    Aiura, Y; Kitano, K

    2012-03-01

    The precision and rigidity of compact ultrahigh vacuum (UHV) rotary feedthroughs were substantially improved by preparing and installing an optimal crossed roller bearing with mounting holes. Since there are mounting holes on both the outer and inner races, the bearing can be mounted directly to rotary and stationary stages without any fixing plates and housing. As a result, it is possible to increase the thickness of the bearing or the size of the rolling elements in the bearing without increasing the distance between the rotating and fixing International Conflat flanges of the UHV rotary feedthrough. Larger rolling elements enhance the rigidity of the UHV rotary feedthrough. Moreover, owing to the structure having integrated inner and outer races and mounting holes, the performance is almost entirely unaffected by the installation of the bearing, allowing for a precise optical encoder to be installed in the compact UHV rotary feedthrough. Using position feedback via a worm gear system driven by a stepper motor and a precise rotary encoder, the actual angle of the compact UHV rotary feedthrough can be controlled with extremely high precision.

  9. Highly precise and compact ultrahigh vacuum rotary feedthrough

    NASA Astrophysics Data System (ADS)

    Aiura, Y.; Kitano, K.

    2012-03-01

    The precision and rigidity of compact ultrahigh vacuum (UHV) rotary feedthroughs were substantially improved by preparing and installing an optimal crossed roller bearing with mounting holes. Since there are mounting holes on both the outer and inner races, the bearing can be mounted directly to rotary and stationary stages without any fixing plates and housing. As a result, it is possible to increase the thickness of the bearing or the size of the rolling elements in the bearing without increasing the distance between the rotating and fixing International Conflat flanges of the UHV rotary feedthrough. Larger rolling elements enhance the rigidity of the UHV rotary feedthrough. Moreover, owing to the structure having integrated inner and outer races and mounting holes, the performance is almost entirely unaffected by the installation of the bearing, allowing for a precise optical encoder to be installed in the compact UHV rotary feedthrough. Using position feedback via a worm gear system driven by a stepper motor and a precise rotary encoder, the actual angle of the compact UHV rotary feedthrough can be controlled with extremely high precision.

  10. 7. Photographic copy of floor plan drawing, dated August 10, ...

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

    7. Photographic copy of floor plan drawing, dated August 10, 1968, Department of the Air Force Air Defense Command Installations, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. - Selfridge Field, Building No. 592, South of East Joy Boulevard, west of Taxiway C, Mount Clemens, Macomb County, MI

  11. 6. Photographic copy of floor plan, dated August 10, 1968, ...

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

    6. Photographic copy of floor plan, dated August 10, 1968, Department of the Air Force Air Defense Command Installation, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. - Selfridge Field, Building No. 1576, South of East Joy Boulevard, west of Taxiway C, Mount Clemens, Macomb County, MI

  12. Photographic copy of floor plan drawing, dated August 10, 1968, ...

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

    Photographic copy of floor plan drawing, dated August 10, 1968, Department of the Air Force Air Defense Command Installations, in possession of Selfridge Base Museum, Mt. Clemens, Michigan - Selfridge Field, Building No. 1580, South of East Joy Boulevard, west of Taxiway C, Mount Clemens, Macomb County, MI

  13. Spatial and seasonal characteristics of cold-air pools in the upper Zêzere valley (Serra da Estrela, Portugal)

    NASA Astrophysics Data System (ADS)

    Mora, Carla

    2010-05-01

    Occurrence, formation, spatial patterns and intensity of cold air pools/lakes were studied in the Serra da Estrela (40° 20'N 7° 35'W, 1993m, Central Portugal) from January to December 2000. Data was collected using a network of air temperature dataloggers installed at different topographic positions (interfluves, valley floors and slopes) recording at 2-h intervals. A k-means classification was applied to the dataset of instantaneous air temperatures, and 3 types of thermal patterns were identified. Type 1 (66% cases) shows events with decreasing air temperatures with altitude. Type 2 (27% cases) shows accumulation of cold air in the valleys with higher valley floors showing the lowest temperatures. Type 3 (7% cases) show accumulation of cold air, but with lowest air temperatures in the valleys at lower altitudes. Causal factors for the occurrence of the patterns were studied by applying discriminant analysis on meteorological and topographical variables. Type 1 occurs under atmospheric instability conditions, while types 2 and 3 relate to atmospheric stability. Types 2 and 3 are controlled by seasonality and local insolation/shadowing effects. For the detailed study of cold air accumulations, two approaches were followed: the analysis of temperature differences between a station in a crest and a station in a glacial cirque floor; and, the analysis of 5-min interval temperature data along a transect in the Zêzere valley.The differences in air temperature between the glacier cirque floor (Covão Cimeiro, 1620m) and the crest (Cântaro Gordo, 1870m) were classified into 9 types of regime. Thermal inversions in the cirque were found in 6 types (48%). These are characterized in detail and the geographical and meteorological controlling factors are analyzed using one-way ANOVA and discriminant analysis. The 6 types show different daily regimes and inversion intensities, as well as a seasonal trend. The maximum inversion intensity was 9 °C, and the minimum temperature -17 °C at the cirque floor. Simultaneoulsy, the ridge showed -9 °C. Thermal inversions show atmospheric stability with low wind speed and low cloudiness. The sequence of patterns throughout the year is controlled by topographic factors and insolation at the cirque floor. The formation of thermal inversions in a NNE-SSW direction valley (Zêzere valley), their durationand dissipation were studied in detail during 5 days of atmospheric stability using air temperature recorded at 5-min intervals. During the day, air temperature decreased with altitude (-0.7 °C/100m to -1 °C/100m), and during the night, the valley floor showed lower temperatures than the mountain summit. During the night a thermal belt formed and the valley floor was 3 °C colder than the top of the inversion layer. During the day there was an asymmetry in the distribution of temperatures along the valley controlled by solar radiation. Air temperatures ranged from -5 °C to 16 °C. The results show the effect of topography on air temperatures in situations of atmospheric stability and can be extrapolated to the mountains with similar climatic and topographic conditions. The identification of the shadowing effect induced by valleys and its impact on the maintenance of cold air lakes during the morning in the valleys of North-South orientation can be of special interest for planning and environmental impact studies.

  14. Method for forming precision clockplate with pivot pins

    DOEpatents

    Wild, Ronald L [Albuquerque, NM

    2010-06-01

    Methods are disclosed for producing a precision clockplate with rotational bearing surfaces (e.g. pivot pins). The methods comprise providing an electrically conductive blank, conventionally machining oversize features comprising bearing surfaces into the blank, optionally machining of a relief on non-bearing surfaces, providing wire accesses adjacent to bearing surfaces, threading the wire of an electrical discharge machine through the accesses and finishing the bearing surfaces by wire electrical discharge machining. The methods have been shown to produce bearing surfaces of comparable dimension and tolerances as those produced by micro-machining methods such as LIGA, at reduced cost and complexity.

  15. Air Bearing for Small Planar Vibrations

    NASA Technical Reports Server (NTRS)

    Wolf, M. F.

    1985-01-01

    Air-cushion device provides vibrations along axes 90 degrees apart. Bearing includes movable slide sandwiched between two fixed support plates. Separation between plates adjusted to standard air-bearing tolerances. Pressurized air supplied to slide so it floats between plates on cushion of air. Air exhausts on top and bottom surfaces of three arms of slide. Developed for stirring crystal-growth liquids in containers.

  16. Numerical and experimental investigations of micro air bearings for micro systems

    NASA Astrophysics Data System (ADS)

    Zhang, Qide; Shan, X. C.

    2006-04-01

    The paper investigated performance of air bearing system in a micro device. A parametric study is carried out. The dynamic performance of a very short journal bearing (L/D < 0.1) and thrust bearing is studied. The parameters that affect the performance of the air bearing are discussed. The optimum values of the important parameters are explored, and the stability of the thrust bearing is discussed. The prototype and test result are presented.

  17. 45 CFR 98.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... decree, the grandchild, great grandchild, sibling (if such provider lives in separate residence), niece...) structural changes to the foundation, roof, floor, exterior or load-bearing walls of a facility, or the...

  18. 45 CFR 98.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... decree, the grandchild, great grandchild, sibling (if such provider lives in separate residence), niece...) structural changes to the foundation, roof, floor, exterior or load-bearing walls of a facility, or the...

  19. 45 CFR 98.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... decree, the grandchild, great grandchild, sibling (if such provider lives in separate residence), niece...) structural changes to the foundation, roof, floor, exterior or load-bearing walls of a facility, or the...

  20. 45 CFR 98.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... decree, the grandchild, great grandchild, sibling (if such provider lives in separate residence), niece...) structural changes to the foundation, roof, floor, exterior or load-bearing walls of a facility, or the...

  1. 45 CFR 98.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... decree, the grandchild, great grandchild, sibling (if such provider lives in separate residence), niece...) structural changes to the foundation, roof, floor, exterior or load-bearing walls of a facility, or the...

  2. Weather support area, floor plan and details. ("Alter COC, Bldg. ...

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

    Weather support area, floor plan and details. ("Alter COC, Bldg. 2605, Weather Support Area, Floor Plan & Details" Also includes a site plan and a finish schedule. The exact location of this construction is obscure, but it appears to be the enclosure of space at the north end of room 101, the "Display Area" or "War Room") Strategic Air Command, Civil Engineering. Drawing no. B-1081, sheet no. 1 of 2, 9 July 1968; project no. MAR-132-8; CE-562; file drawer 2605-9, also 1315. Various scales. 29x41 inches. pencil on paper - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  3. The Effect of Environmentally Friendly Wallpaper and Flooring Material on Indoor Air Quality and Atopic Dermatitis: A Pilot Study

    PubMed Central

    Na, Jung Im; Byun, Sang Young; Jeong, Mi Young; Park, Kyoung Chan

    2014-01-01

    Background Formaldehyde (FA) and other volatile organic compounds (VOCs) are considered among the main causes of atopic aggravation. Their main sources include wallpapers, paints, adhesives, and flooring materials. Objective To assess the effects of environmentally friendly wallpaper and flooring material on indoor air quality and atopic dermatitis severity. Methods Thirty patients with atopic dermatitis were enrolled in this study. To improve air quality, the wallpaper and flooring in the homes of the subjects were replaced with plant- or silica-based materials. The indoor air concentration of FA and the total VOCs (TVOCs) were measured before remodeling and 2, 6, and 10 weeks thereafter. Pruritus and the severity of atopic eczema were evaluated by using a questionnaire and the eczema area and severity index (EASI) score before and at 4, 8, and 12 weeks after remodeling. The subjects were instructed to continue their therapy for atopic dermatitis. Results The houses of 24 subjects were remodeled; all subjects completed the study. The concentration of FA in ambient air significantly decreased within 2 weeks after remodeling. The TVOC level showed a decrease at week 2 but increased again at weeks 6 and 10. The reduction of pruritus and EASI score was statistically significant in patients whose baseline EASI score was >3. Conclusion Replacing the wallpaper and flooring of houses with environmentally friendly material reduced FA in ambient air and improved pruritus and the severity of atopic eczema. The improvement of pruritus and eczema was statistically significant in patients whose baseline EASI score was >3. PMID:25473219

  4. Physiological and subjective responses in the elderly when using floor heating and air conditioning systems.

    PubMed

    Hashiguchi, Nobuko; Tochihara, Yutaka; Ohnaka, Tadakatsu; Tsuchida, Chiaki; Otsuki, Tamio

    2004-11-01

    The purpose of this study was to investigate the effects of a floor heating and air conditioning system on thermal responses of the elderly. Eight elderly men and eight university students sat for 90 minutes in a chair under the following 3 conditions: air conditioning system (A), floor heating system (F) and no heating system (C). The air temperature of sitting head height for condition A was 25 degrees C, and the maximum difference in vertical air temperature was 4 degrees C. The air and floor temperature for condition F were 21 and 29 degrees C, respectively. The air temperature for condition C was 15 degrees C. There were no significant differences in rectal temperature and mean skin temperature between condition A and F. Systolic blood pressure of the elderly men in condition C significantly increased compared to those in condition A and F. No significant differences in systolic blood pressure between condition A and F were found. The percentage of subjects who felt comfortable under condition F was higher than that of those under condition A in both age groups, though the differences between condition F and A was not significant. Relationships between thermal comfort and peripheral (e.g., instep, calf, hand) skin temperature, and the relationship between thermal comfort and leg thermal sensation were significant for both age groups. However, the back and chest skin temperature and back thermal sensation for the elderly, in contrast to that for the young, was not significantly related to thermal comfort. These findings suggested that thermal responses and physiological strain using the floor heating system did not significantly differ from that using the air conditioning system, regardless of the subject age and despite the fact that the air temperature with the floor heating system was lower. An increase in BP for elderly was observed under the condition in which the air temperature was 15 degrees C, and it was suggested that it was necessary for the elderly people to heat the room somehow in winter. Moreover, it is particularly important for elderly people to avoid a decrease in peripheral skin temperature, and maintain awareness of the warmth of peripheral areas, such as the leg, in order to ensure thermal comfort.

  5. A New Foil Air Bearing Test Rig for Use to 700 C and 70,000 rpm

    NASA Technical Reports Server (NTRS)

    DellaCorte, Chris

    1997-01-01

    A new test rig has been developed for evaluating foil air bearings at high temperatures and speeds. These bearings are self acting hydrodynamic air bearings which have been successfully applied to a variety of turbomachinery operating up to 650 C. This unique test rig is capable of measuring bearing torque during start-up, shut-down and high speed operation. Load capacity and general performance characteristics, such as durability, can be measured at temperatures to 700 C and speeds to 70,000 rpm. This paper describes the new test rig and demonstrates its capabilities through the preliminary characterization of several bearings. The bearing performance data from this facility can be used to develop advanced turbomachinery incorporating high temperature oil-free air bearing technology.

  6. Human Occupancy as a Source of Indoor Airborne Bacteria

    PubMed Central

    Hospodsky, Denina; Qian, Jing; Nazaroff, William W.; Yamamoto, Naomichi; Bibby, Kyle; Rismani-Yazdi, Hamid; Peccia, Jordan

    2012-01-01

    Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM10 and PM2.5 size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM10. On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments. PMID:22529946

  7. 6. FLOOR 1; LOOKING WEST; SHOWS UNDERDRIFT SYSTEM, FOUR POSTS ...

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

    6. FLOOR 1; LOOKING WEST; SHOWS UNDERDRIFT SYSTEM, FOUR POSTS SUPPORT BRIDGE BEAM FOR FOOT BEARING OF UPRIGHT SHAFT, SPUR PINION STONE NUTS SLIDE DOWN STONE SPINDLE TO ENGAGE, CENTRIFUGAL GOVERNOR IS MOUNTED ON A SEPARATE SPINDLE DRIVEN BY A BELT FROM THE STONE SPINDLE; ALSO SHOWN ARE THE GREAT SPUR WHEEL AND A LAYSHAFT RUNNING OFF A CROWN WHEEL JUST ABOVE THE GREAT SPUR WHEEL - Gardiner Windmill, East Hampton, Suffolk County, NY

  8. 57. Photocopy of Architectural Layout drawing, dated 25 June, 1993 ...

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

    57. Photocopy of Architectural Layout drawing, dated 25 June, 1993 by US Air Force Space Command. Original drawing property of United States Air Force, 21" Space Command. AL-3 PAVE PAWS SUPPORT SYSTEMS - CAPE COD AFB, MASSACHUSETTS - LAYOUT 1 FLOOR AND 1sr FLOOR ROOF. DRAWING NO. AL-3 - SHEET 4 OF 21. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  9. KSC-2014-4230

    NASA Image and Video Library

    2014-09-25

    CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, crew chief Mark Smith of URS looks out the side door down at the Bambi Bucket. Securely strapped to the helicopter floor, his position allows him to tell the pilot precisely when to release the water over the target. Firefighters respond to wildfires with teams on the ground and in the air. The most up-to-date tools include helicopters that use Bambi Buckets large quantities of water. NASA Flight Operations teams are training to perfect the skills needed to ensure they are ready to use tools, such as the Bambi Bucket, in the event of an out-of-control blaze at the spaceport. Photo credit: NASA/Frankie Martin

  10. A marine dynamic penetrometer for the determination of sea floor geotechnical properties

    NASA Astrophysics Data System (ADS)

    Stephan, S.; Kaul, N. E.; Villinger, H. W.

    2013-12-01

    We present a seafloor lance penetration monitoring system: the Lance Insertion Retardation Meter (LIRmeter). The device can be used to infer geotechnical seafloor properties, such as bearing capacity by monitoring the deceleration of a free-fall penetrating lance. The deceleration record can be furthermore used to estimate mean grain size and mud content of the sea floor as well as total penetration depth. The LIRmeter is contained in a pressure vessel (440 x 110 mm) and equipped with accelerometers of different sensitivities to (i) determine sea floor resistance during penetration and (ii) to generate a depth axis. Typically, measurements are carried out in a pogo style fashion to allow a rapid measurement progress during field campaigns. The LIRmeter is intended to determine sea floor properties on the sole basis of deceleration measurements in order to achieve a mechanically and electronically robust system. Data is sampled at a resolution of 16 bit and at a rate of typically 500 Hz for each channel. The device can either be installed in any type of lance i.e. marine heat flow probes, gravity corers, piston corers or can be used in combination with a purpose built lance as a standalone instrument. It has a usable length of four meters, a total weight of 280 kg in air and can be operated up to full ocean depth (6000m). The bearing capacity of the sea floor is a critical factor for marine engineering projects such as burial of marine cables, pipeline laying and foundations. Knowledge of the mud content can provide constraints for the estimation of hydraulic conductivity. The identification of weak zones along a slope can moreover provide vital information for risk assessment studies. Traditionally, frame based, quasi static Cone Penetration Tests (CPT) or sampling methods like gravity coring are used to conduct these types of investigation. In comparison to established but time consuming and rather costly methods, the LIRmeter is intended (i) for near surface investigations and/or (ii) to complement and connect conventional but isolated CPT measurements in a very efficient and rapid way. We show results from measurements in the North Sea, as well as results of laboratory experiments. During sea trials, the LIRmeter was equipped with an additional CPT sensor, which delivered data for cone (tip) resistance, sleeve friction and pore pressure, thus allowing a direct comparison between results of the acceleration measurements and results from conventional CPT sensors. The laboratory measurements were also carried out using both acceleration and tip resistance sensors. Resulting values show a very good agreement between tip resistance calculated from deceleration data and tip resistance from direct laboratory and field measurements. The influence of sediment type (mainly mud content) will be discussed within the context of laboratory measurements.

  11. Modeling and Analysis of the Static Characteristics and Dynamic Responses of Herringbone-grooved Thrust Bearings

    NASA Astrophysics Data System (ADS)

    Yu, Yunluo; Pu, Guang; Jiang, Kyle

    2017-12-01

    This paper describes a theoretical investigation of static and dynamic characteristics of herringbone-grooved air thrust bearings. Firstly, Finite Difference Method (FDM) and Finite Volume Method (FVM) are used in combination to solve the non-linear Reynolds equation and to find the pressure distribution of the film and the total loading capacity of the bearing. The influence of design parameters on air film gap characteristics, including the air film thickness, depth of the groove and rotating speed, are analyzed based on the FDM model. The simulation results show that hydrostatic thrust bearings can achieve a better load capacity with less air consumption than herringbone grooved thrust bearings at low compressibility number; herringbone grooved thrust bearings can achieve a higher load capacity but with more air consumption than hydrostatic thrust bearing at high compressibility number; herringbone grooved thrust bearings would lose stability at high rotating speeds, and the stability increases with the depth of the grooves.

  12. An experimental parametric study of VOC from flooring systems exposed to alkaline solutions.

    PubMed

    Sjöberg, A; Ramnäs, O

    2007-12-01

    This study outlined the influence of a number of parameters affecting the emission rate from one of the largest sources of VOC in the building stock in the Nordic countries. This source is flooring systems of polyvinyl chloride or linoleum attached to a substrate of moisture damaged or insufficiently dried concrete. The secondary emission rate of degradation products was measured, with the Field and Laboratory Emission Cell, on different flooring systems consisting of three different floorings and three adhesives, exposed to three different aqueous solutions in the range of 11-13.1 pH. The conclusion drawn in this study is that the great majority of the secondary emission originates from the floor adhesive. The occurrence of adhesive and the amount of adhesive used have a significant influence on the emission rate. A critical pH value for degradation of the adhesive seems to lie somewhere between 11 and 13 pH. When designing a floor system or a renovation of a damaged flooring system, it is important to bear in mind the influence of parameters that may drastically shorten the service life. Flooring adhesive may decompose in a moist alkaline environment and give rise to unacceptable secondary emission rates.

  13. 75 FR 81287 - Buy American Exceptions Under the American Recovery and Reinvestment Act of 2009

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... Housing Authority for the purchase and installation of through-the-wall air conditioners, floor-mounted... exception was granted by HUD on the basis that the relevant manufactured goods (through-the-wall air conditioners, floor-mounted water closets, and low voltage electrical components) are not produced in the U.S...

  14. Buffing, burnishing, and stripping of vinyl asbestos floor tile

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hollett, B.A.; Edwards, A.; Clark, P.J.

    Studies were conducted to evaluate airborne asbestos concentrations during the three principal types of preventative maintenance (low-speed spray-buffing, ultra high-speed burnishing, and wet-stripping) used on asbestos-containing floor tiles. These were done under pre-existing and prepared levels of floor care maintenance. Airborne asbestos concentrations were measured before and during each floor care procedure to determine the magnitude of the increase in airborne asbestos levels during each procedure. Airborne total fiber concentrations were also measured for comparison with the Occupational Safety and Health Administration`s (OSHA) Permissible Exposure Limit (PEL) of 0.1 f/cm{sup 3}. Low-speed spray-buffing and wet-stripping were evaluated on pre-existing floormore » conditions and three levels of prepared floor care conditions (poor, medium, and good). Ultra high-speed burnishing and wet-stripping were evaluated on two levels of prepared floor care conditions (poor and good). Floor care conditions were defined in consultation with the Chemical Specialty Manufacturers Association and other representatives of floor-care chemical manufacturers. Controlled studies were conducted in an unoccupied building at the decommissioned Chanute Air Force Base in Rantoul, Illinois, with the cooperation of the U.S. Air Force. The building offered approximately 8600 ft{sup 2} of open floor space tiled with 9-inch by 9-inch resilient floor tile containing approximately 5% chrysotile asbestos.« less

  15. Simulator for Testing Spacecraft Separation Devices

    NASA Technical Reports Server (NTRS)

    Johnston, Nick; Gaines, Joe; Bryan, Tom

    2006-01-01

    A report describes the main features of a system for testing pyrotechnic and mechanical devices used to separate spacecraft and modules of spacecraft during flight. The system includes a spacecraft simulator [also denoted a large mobility base (LMB)] equipped with air thrusters, sensors, and data-acquisition equipment. The spacecraft simulator floats on air bearings over an epoxy-covered concrete floor. This free-flotation arrangement enables simulation of motion in outer space in three degrees of freedom: translation along two orthogonal horizontal axes and rotation about a vertical axis. The system also includes a static stand. In one application, the system was used to test a bolt-retraction system (BRS) intended for separation of the lifting-body and deorbit-propulsion stages of the X- 38 spacecraft. The LMB was connected via the BRS to the static stand, then pyrotechnic devices that actuate the BRS were fired. The separation distance and acceleration were measured. The report cites a document, not yet published at the time of reporting the information for this article, that is said to present additional detailed information.

  16. 77 FR 28569 - Foreign-Trade Zone 92-Gulfport, MS Notification of Proposed Production Activity; Gulf Ship, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ... engines, winches, steering gears, electric motors, generators, raceways, doors, tefrotex, floor coatings..., vibration control dampeners, oil booms, lighting equipment, controllers, electrical cabinets, bearings...

  17. Late Quaternary sedimentary features of Bear Lake, Utah and Idaho

    USGS Publications Warehouse

    Smoot, J.P.

    2009-01-01

    Bear Lake sediments were predominantly aragonite for most of the Holocene, reflecting a hydrologically closed lake fed by groundwater and small streams. During the late Pleistocene, the Bear River flowed into Bear Lake and the lake waters spilled back into the Bear River drainage. At that time, sediment deposition was dominated by siliciclastic sediment and calcite. Lake-level fluctuation during the Holocene and late Pleistocene produced three types of aragonite deposits in the central lake area that are differentiated primarily by grain size, sorting, and diatom assemblage. Lake-margin deposits during this period consisted of sandy deposits including well-developed shoreface deposits on margins adjacent to relatively steep gradient lake floors and thin, graded shell gravel on margins adjacent to very low gradient lake-floor areas. Throughout the period of aragonite deposition, episodic drops in lake level resulted in erosion of shallow-water deposits, which were redeposited into the deeper lake. These sediment-focusing episodes are recognized by mixing of different mineralogies and crystal habits and mixing of a range of diatom fauna into poorly sorted mud layers. Lake-level drops are also indicated by erosional gaps in the shallow-water records and the occurrence of shoreline deposits in areas now covered by as much as 30 m of water. Calcite precipitation occurred for a short interval of time during the Holocene in response to an influx of Bear River water ca. 8 ka. The Pleistocene sedimentary record of Bear Lake until ca. 18 ka is dominated by siliciclastic glacial fl our derived from glaciers in the Uinta Mountains. The Bear Lake deep-water siliciclastic deposits are thoroughly bioturbated, whereas shallow-water deposits transitional to deltas in the northern part of the basin are upward-coarsening sequences of laminated mud, silt, and sand. A major drop in lake level occurred ca. 18 ka, resulting in subaerial exposure of the lake floor in areas now covered by over 40 m of water. The subaerial surfaces are indicated by root casts and gypsum-rich soil features. Bear Lake remained at this low state with a minor transgression until ca. 15 ka. A new influx of Bear River water produced a major lake transgression and deposited a thin calcite deposit. Bear Lake quickly dropped to a shallow-water state, accumulating a mixture of calcite and siliciclastic sediment that contains at least two intervals of root-disrupted horizons indicating lake-level drops to more than 40 m below the modern highstand. About 11,500 yr B.P., the lake level rose again through an influx of Bear River water producing another thin calcite layer. The Bear River ceased to flow into the basin and the lake salinity increased, resulting in the aragonite deposition that persisted until modern human activity. The climatic record of Bear Lake sediment is difficult to ascertain by using standard chemical and biological techniques because of variations in the inflow hydrology and the significant amount of erosion and redeposition of chemical and biological sediment components. Copyright ?? 2009 The Geological Society of America.

  18. A study of building structural features associated with high indoor air concentrations of organochlorine termiticides.

    PubMed

    Pisaniello, D L; Gun, R T; Tkaczuk, M N; Hann, C; Crea, J

    1993-09-01

    As part of a two-year study of post-treatment residential exposure to the termiticide, aldrin, the building structural features of ten houses with crawl-space-type floors were assessed by an independent inspector. Building attributes recorded on a checklist included the age of the dwelling, room characteristics, floor details and the nature of subfloor ventilation. At the end of each inspection, the inspector, who was blinded to data on airborne aldrin concentrations, provided a rating of expected indoor air contamination. Several of the building attributes, including the age of the house, the area of exterior subfloor vents, as well as the inspector's rating, were significantly correlated with airborne aldrin values. No single building variable, however, was highly correlated with every measure of aldrin concentration over a 12-month period. The observed data are consistent with poor subfloor ventilation and a 'leaky' floor being important contributors to indoor air pollution. It is recommended that pest control companies advise householders about any obvious floor and ventilation deficiencies before soil treatment work is undertaken. Pesticide exposure (by analogy with geological radon exposure) may be reduced by sealing gaps in floors and/or by improving subfloor ventilation.

  19. Distribution of 2,4-D in air and on surfaces inside residences after lawn applications: comparing exposure estimates from various media for young children.

    PubMed Central

    Nishioka, M G; Lewis, R G; Brinkman, M C; Burkholder, H M; Hines, C E; Menkedick, J R

    2001-01-01

    We collected indoor air, surface wipes (floors, table tops, and window sills), and floor dust samples at multiple locations within 11 occupied and two unoccupied homes both before and after lawn application of the herbicide 2,4-D. We measured residues 1 week before and after application. We used collected samples to determine transport routes of 2,4-D from the lawn into the homes, its subsequent distribution between the indoor surfaces, and air concentration as a function of airborne particle size. We used residue measurements to estimate potential exposures within these homes. After lawn application, 2,4-D was detected in indoor air and on all surfaces throughout all homes. Track-in by an active dog and by the homeowner applicator were the most significant factors for intrusion. Resuspension of floor dust was the major source of 2,4-D in indoor air, with highest levels of 2,4-D found in the particle size range of 2.5-10 microm. Resuspended floor dust was also a major source of 2,4-D on tables and window sills. Estimated postapplication indoor exposure levels for young children from nondietary ingestion may be 1-10 microg/day from contact with floors, and 0.2-30 microg/day from contact with table tops. These are estimated to be about 10 times higher than the preapplication exposures. By comparison, dietary ingestion of 2,4-D is approximately 1.3 microg/day. PMID:11713005

  20. Air-Bearing Table for Machine Shops

    NASA Technical Reports Server (NTRS)

    Ambrisco, D.

    1986-01-01

    Frequent workpiece repositioning made easier. Air-bearing table facilitates movement of heavy workpiece during machining or between repeated operations at different positions. Table assembly consists of workpiece supporting fixture riding on air bearing. Table especially useful for inertia welding, in which ease of mobility is important.

  1. 53. VIEW FROM FLOOR OF MAST TRENCH SHOWING BASE OF ...

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

    53. VIEW FROM FLOOR OF MAST TRENCH SHOWING BASE OF ERECT UMBILICAL MAST. AIR-CONDITIONING DUCTS VISIBLE ON RIGHT SIDE OF MAST. HYDRAULIC ACTUATOR ARMS FOR OPENING TRENCH DOORS VISIBLE ON LEFT SIDE OF PHOTO. 'DOOR STOP' PEDESTAL IN FOREGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  2. New Whole-House Solutions Case Study: Schneider Homes, Inc.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    none,

    2013-02-01

    Schneider Homes cut energy use by 50% over the 2004 IECC on 28 homes built near Seattle in 2008. Schneider packed the walls with R-23 of blown fiberglass and blanketed the ceiling with R-38 of blown cellulose. Ducts went into conditioned space through open-web floor trusses between floors and air handlers went into an air sealed garage closet.

  3. 4. "ARCHITECTURAL, FLOOR PLANELEVATIONSSECTIONS, OBSERVATION BUNKERS." Specifications No. ENG (NASA)04353631; ...

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

    4. "ARCHITECTURAL, FLOOR PLAN-ELEVATIONS-SECTIONS, OBSERVATION BUNKERS." Specifications No. ENG (NASA)04-353-63-1; Drawing No. 60-09-34; sheet 325. Ref. No. A-13. D.O. SERIES 1597/87. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Observation Bunker 1-D-3, Test Area 1-125, northwest end of Altair Boulevard, Boron, Kern County, CA

  4. DISTRIBUTION OF 2,4-D IN AIR AND ON SURFACES INSIDE RESIDENCES FOLLOWING LAWN APPLICATIONS: COMPARING EXPOSURE ESTIMATES FOR YOUNG CHILDREN FROM VARIOUS MEDIA

    EPA Science Inventory

    Indoor air, surface wipes (floors, table tops and window sills) and floor dust samples were collected at multiple locations within 11 occupied and 2 unoccupied homes both prior to and following lawn application of the herbicide 2,4-D. Residue measurements were made over period...

  5. Effect of different flooring systems on weight and pressure distribution on claws of dairy cows.

    PubMed

    Telezhenko, E; Bergsten, C; Magnusson, M; Ventorp, M; Nilsson, C

    2008-05-01

    Weight and pressure distribution on the claw were studied in Swedish Holsteins housed in different flooring systems. A total of 127 cows housed in different sections of the experimental barn were used. Each section had different flooring in the walking and standing areas. There were rubber mats or abrasive mastic asphalt flooring on the alleys or a low-abrasive slatted concrete floor. Some sections had feed-stalls equipped with rubber mats; other sections did not. The vertical ground reaction force, contact area, and average contact pressure were determined on the left hind foot using the I-Scan system and analyzed with the F-scan system. These determinations were made in each of the following 3 zones of the claw: bulb, wall, and sole. Most of the weight on claws exposed to concrete floors was carried by the bulb (37.4 +/- 3.5 and 18.3 +/- 2.9% of weight exerted on the foot in the lateral and medial claw, respectively) and the wall zone (20.0 +/- 2.6 and 13.4 +/- 2.4% on lateral and medial claw, respectively). The weight and pressure distribution in cows kept on sections with rubber covered alleys but passing daily over the asphalt floor on their way to the milking parlor did not differ in any zones, except for lateral bulbs, compared with those exposed to slatted concrete alone. Still, the weight bearing of the sole zone in cows kept on rubber mats without access to asphalt was less than that of cows kept on concrete slatted floors (5.1 +/- 0.7 vs. 12.7 +/- 1.1% and 1.1 +/- 0.5 vs. 8.7 +/- 0.7% in lateral and medial claws, respectively). In cows kept on asphalt flooring without feed-stalls, most weight was exerted to the sole zone (36.2 +/- 2.9 and 22.2 +/- 1.8% in lateral and medial claws, respectively). Feed-stalls in combination with asphalt flooring yielded a decreased total contact area (30.1 +/- 1.2 cm(2)) compared with asphalt floors without feed-stalls (35.7 +/- 1.2 cm(2)). The largest total contact area was obtained on the asphalt floor without feed-stalls, resulting in a lower contact pressure (39.8 +/- 2.3 N/cm(2)) than in claws exposed to concrete (66.0 +/- 2.7 N/ cm(2)) or rubber mats (56.7 +/- 1.7 N/cm(2)). In conclusion, housing with abrasive floors resulted in claws with increased contact area at the sole surface and therefore, decreased contact pressure, but reduced the weight-bearing role of the strongest part of the claw capsule, the claw wall.

  6. Rotor-Bearing Dynamics Technology Design Guide. Part VI. Status of Gas Bearing Technology Applicable to Aero Propulsion Machinery

    DTIC Science & Technology

    1980-10-01

    by block number) Air bearings, gas bearings, air lubrication, gas lubrication, rotor dynamics , gas turbines, turbomachinery, foil bearings, compliant...coverage of the subject at this time. Therefore, as a part of the Rotor -Bearing Dynamics Technology Design Guide update, this document is prepared...of the inertia and flexure properties of the rotor together with the dynamic character- istics of the bearing(s). However, an examination of the

  7. Endotoxins in indoor air and settled dust in primary schools in a subtropical climate.

    PubMed

    Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Clifford, Sam; Morawska, Lidia

    2013-09-03

    Endotoxins can significantly affect the air quality in school environments. However, there is currently no reliable method for the measurement of endotoxins, and there is a lack of reference values for endotoxin concentrations to aid in the interpretation of measurement results in school settings. We benchmarked the "baseline" range of endotoxin concentration in indoor air, together with endotoxin load in floor dust, and evaluated the correlation between endotoxin levels in indoor air and settled dust, as well as the effects of temperature and humidity on these levels in subtropical school settings. Bayesian hierarchical modeling indicated that the concentration in indoor air and the load in floor dust were generally (<95th percentile) <13 EU/m(3) and <24,570 EU/m(2), respectively. Exceeding these levels would indicate abnormal sources of endotoxins in the school environment and the need for further investigation. Metaregression indicated no relationship between endotoxin concentration and load, which points to the necessity for measuring endotoxin levels in both the air and settled dust. Temperature increases were associated with lower concentrations in indoor air and higher loads in floor dust. Higher levels of humidity may be associated with lower airborne endotoxin concentrations.

  8. Bed topography of Jakobshavn Isbræ, Greenland from high-resolution gravity data

    NASA Astrophysics Data System (ADS)

    An, L.; Rignot, E. J.; Morlighem, M.; Paden, J. D.; Holland, D. M.

    2015-12-01

    Jakobshavn Isbræ (JKS) is one of the largest marine terminating outlet glaciers in Greenland, feeding a fjord about 800 m deep in the west coast. JKS sped up more than twofold since 2002 and contributed nearly 1 mm of global sea level rise during the period from 2000 to 2011. Holland et al. (2008) posit that these changes coincided with a change in ocean conditions beneath the former ice tongue, yet little is known about the depth of the glacier at its grounding line and upstream of the grounding line and the sea floor depth of the fjord is not well known either. Here, we present a new approach to infer the glacier bed topography, ice thickness and sea floor bathymetry near the grounding line of JKS using high-resolution airborne gravity data from AirGRAV. AirGRAV data were collected in August 2012 from a helicopter platform. The data combined with radio echo sounding data, discrete point soundings in the fjord and the mass conservation approach on land ice. AirGRAV acquired a 500m spacing grid of free-air gravity data at 50 knots with sub-milligal accuracy, i.e. much higher than NASA Operation IceBridge (OIB)'s 5.2km resolution at 290 knots. We use a 3D inversion of the gravity data combining our observations and a forward modeling of the surrounding gravity field, and constrained at the boundary by radar echo soundings and point bathymetry. We reconstruct seamless bed topography at the grounding line that matches interior data and the sea floor bathymetry. The results reveal the true depth at the elbow of the terminal valley and the bed reversal in the proximity of the current grounding line. The analysis provides guidelines for future gravity survey of narrow fjords in terms of spatial resolution and gravity precision. The results also demonstrate the practicality of using high resolution gravity survey to resolve bed topography near glacier snouts, in places where radar sounding has been significantly challenged in the past. The inversion results are critical to re-interpret the recent evolution of JKS and reduce uncertainties in projecting its future contribution to sea level. This work was conducted at UCI and at Caltech's Jet Propulsion Laboratory under a contract with the Gordon and Betty More Foundation and with NASA's Cryospheric Science Program.

  9. Second floor plan. (Also includes a roof plan and finish ...

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

    Second floor plan. (Also includes a roof plan and finish schedule.) March Air Force Base, Riverside, California, Combat Operations Center, Combat Operations Building. By Moffatt and Nichol, Engineers, 122 West Fifth Street, Long Beach, California; for the Corps of Engineers, U.S. Army, Office of the District Engineer, Los Angeles, California. Drawing no. AW-60-02-03, sheet no. 13, approved March, 1962; specifications no. OCI-62-66; D.O. series AW 1596/13, Rev. "C"; file drawer 1290. Last revised 7 February 1984. Roof plan scale one-sixteenth inch to one foot; second floor plan scale one-eighth inch to one foot. 28.75x41 inches. pencil on paper - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  10. Formaldehyde and TVOC emission behavior of laminate flooring by structure of laminate flooring and heating condition.

    PubMed

    An, Jae-Yoon; Kim, Sumin; Kim, Hyun-Joong

    2011-03-15

    Formaldehyde was measured with a desiccator, a 20 L chamber and the FLEC method. The formaldehyde emission rate from laminate was the highest at 32 °C using the desiccator, which then decreased with time. The formaldehyde emission using the 20 L small chamber and FLEC showed a similar tendency. There was a strong correlation between the formaldehyde and total volatile organic compounds (TVOCs) with both types of floorings using the two different methods. The formaldehyde emission rate and TVOC results were higher when tested using the FLEC method than with the 20 L small chamber method. The emission rate was affected by the joint edge length in laminate flooring. Toluene, ethylbenzene and xylene were the main VOCs emitted from laminate flooring, and there were more unidentified VOCs emitted than identified VOCs. The samples heated with a floor heating system emitted more formaldehyde than those heated using an air circulation system due to the temperature difference between the bottom panel and flooring. The TVOC emission level of the samples was higher when an air circulation system was used than when a floor heating system was used due to the high ventilation rate. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Martian 'Brain'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    5 May 2004 Most middle-latitude craters on Mars have strange landforms on their floors. Often, the floors have pitted and convoluted features that lack simple explanation. In this case, the central part of the crater floor shown in this 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image bears some resemblance to the folded nature of a brain. Or not. It depends upon the 'eye of the beholder,' perhaps. The light-toned 'ring' around the 'brain' feature is more easily explained--windblown ripples and dunes. The crater occurs near 33.1oS, 91.2oW, and is illuminated from the upper left. The picture covers an area about 3 km (1.9 mi) across.

  12. Experimental feasibility study of radial injection cooling of three-pad radial air foil bearings

    NASA Astrophysics Data System (ADS)

    Shrestha, Suman K.

    Air foil bearings use ambient air as a lubricant allowing environment-friendly operation. When they are designed, installed, and operated properly, air foil bearings are very cost effective and reliable solution to oil-free turbomachinery. Because air is used as a lubricant, there are no mechanical contacts between the rotor and bearings and when the rotor is lifted off the bearing, near frictionless quiet operation is possible. However, due to the high speed operation, thermal management is one of the very important design factors to consider. Most widely accepted practice of the cooling method is axial cooling, which uses cooling air passing through heat exchange channels formed underneath the bearing pad. Advantage is no hardware modification to implement the axial cooling because elastic foundation structure of foil bearing serves as a heat exchange channels. Disadvantage is axial temperature gradient on the journal shaft and bearing. This work presents the experimental feasibility study of alternative cooling method using radial injection of cooling air directly on the rotor shaft. The injection speeds, number of nozzles, location of nozzles, total air flow rate are important factors determining the effectiveness of the radial injection cooling method. Effectiveness of the radial injection cooling was compared with traditional axial cooling method. A previously constructed test rig was modified to accommodate a new motor with higher torque and radial injection cooling. The radial injection cooling utilizes the direct air injection to the inlet region of air film from three locations at 120° from one another with each location having three axially separated holes. In axial cooling, a certain axial pressure gradient is applied across the bearing to induce axial cooling air through bump foil channels. For the comparison of the two methods, the same amount of cooling air flow rate was used for both axial cooling and radial injection. Cooling air flow rate was referenced to the rotor surface speed for radial injection cooling. The mass flow rates for the radial injection were 0.032, 0.0432, 0.054 and 0.068 Kg/min, which result in average injection speed of 150, 200, 250 and 300% of rotor surface speed. Several thermocouples were attached at various circumferential directions of the bearing sleeve, two plenums, bearing holder and ball bearing housings to collect the temperature data of the bearing at 30krpm under 10lb of load. Both axial cooling and radial injection are effective cooling mechanism and effectiveness of both cooling methods is directly proportional to the total mass flow rates. However, axial cooling is slightly more efficient in controlling the average temperature of the bearing sleeve, but results in higher thermal gradient of the shaft along the axial direction and also higher thermal gradient of the bearing sleeve along the circumferential direction compared to the radial injection cooling. The smaller thermal gradient of the radial injection cooling is due to the direct cooling effect of the shaft by impinging jets. While the axial cooling has an effect on only the bearing, the radial injection has a cooling effect on both the bearing sleeve and shaft. It is considered the radial injection cooling needs to be further optimized in terms of number of injection holes and their locations.

  13. A Novel Thermal Management Approach for Radial Foil Air Bearings

    DTIC Science & Technology

    2010-07-01

    injection air. The tests were conducted at room temperature with the bearing operating at speeds from 20 to 50 krpm while supporting 222N. Two different...14  List of Tables Table 1. Bearing temperature results for the two injection air flows at three different operating...no further than the research stage (3, 4). However, during the last 15 years, more advanced, higher load capacity bearings and high temperature

  14. INTERIOR OF SECOND FLOOR AIRFIELD MANAGEMENT SUPERINTENDENT'S OFFICE. VIEW TO ...

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

    INTERIOR OF SECOND FLOOR AIRFIELD MANAGEMENT SUPERINTENDENT'S OFFICE. VIEW TO SOUTHEAST - Plattsburgh Air Force Base, Base Operations Building, Idaho at Alabama Avenue, Plattsburgh, Clinton County, NY

  15. Development of a large support surface for an air-bearing type zero-gravity simulator

    NASA Technical Reports Server (NTRS)

    Glover, K. E.

    1976-01-01

    The methods used in producing a large, flat surface to serve as the supporting surface for an air-bearing type zero-gravity simulator using low clearance, thrust-pad type air bearings are described. Major problems encountered in the use of self-leveled epoxy coatings in this surface are discussed and techniques are recommended which proved effective in overcoming these problems. Performance requirements of the zero-gravity simulator vehicle which were pertinent to the specification of the air-bearing support surface are also discussed.

  16. Comparison Between Oil-mist and Oil-jet Lubrication of High-speed, Small-bore, Angular-contact Ball Bearings

    NASA Technical Reports Server (NTRS)

    Pinel, Stanley I.; Signer, Hans R.; Zaretsky, Erwin V.

    2001-01-01

    Parametric tests were conducted with an optimized 35-mm-bore-angular-contact ball bearing on a high-speed, high-temperature bearing tester. Results from both air-oil mist lubrication and oil-jet lubrication systems used to lubricate the bearing were compared to speeds of 2.5 x 10(exp 6) DN. The maximum obtainable speed with air-oil mist lubrication is 2.5 x 10(exp 6) DN. Lower bearing temperatures and higher power losses are obtained with oil-jet lubrication than with air-oil mist lubrication. Bearing power loss is a direct function of oil flow to the bearing and independent of oil delivery system. For a given oil-flow rate, bearing temperature and power loss increase with increases in speed. Bearing life is an inverse function of temperature, the difference in temperature between the individual bearing ring components, and the resultant elastohydrodynamic (EHD) film thicknesses. Bearing life is independent of the oil delivery system except as it affects temperature. Cage slip increased with increases in speed. Cage slip as high as 7 percent was measured and was generally higher with air-oil mist lubrication than with oil-jet lubrication.

  17. Late quaternary brown bear (Ursidae: Ursus cf. arctos) from a cave in the Huachuca Mountains, Arizona

    Treesearch

    Nicholas J. Czaplewski; Steve Willsey

    2013-01-01

    In 2008, Steve Willsey discovered the fragmentary cranium of a bear loose on the floor of a cave at about 2270 m elevation near the crest of the Huachuca Mountains. In 2009, we revisited the cave to examine the specimen with the intention of identifying the species. We photographed and measured the main pieces and left them in the cave. The skull is from an adult,...

  18. Development of a high performance surface slope measuring system for two-dimensional mapping of x-ray optics

    NASA Astrophysics Data System (ADS)

    Lacey, Ian; Adam, Jérôme; Centers, Gary P.; Gevorkyan, Gevork S.; Nikitin, Sergey M.; Smith, Brian V.; Yashchuk, Valeriy V.

    2017-09-01

    The research and development work on the Advanced Light Source (ALS) upgrade to a diffraction limited storage ring light source, ALS-U, has brought to focus the need for near-perfect x-ray optics, capable of delivering light to experiments without significant degradation of brightness and coherence. The desired surface quality is characterized with residual (after subtraction of an ideal shape) surface slope and height errors of <50-100 nrad (rms) and <1-2 nm (rms), respectively. The ex-situ metrology that supports the optimal usage of the optics at the beamlines has to offer even higher measurement accuracy. At the ALS X-Ray Optics Laboratory, we are developing a new surface slope profiler, the Optical Surface Measuring System (OSMS), capable of two-dimensional (2D) surface-slope metrology at an absolute accuracy below the above optical specification. In this article we provide the results of comprehensive characterization of the key elements of the OSMS, a NOM-like high-precision granite gantry system with air-bearing translation and a custom-made precision air-bearing stage for tilting and flipping the surface under test. We show that the high performance of the gantry system allows implementing an original scanning mode for 2D mapping. We demonstrate the efficiency of the developed 2D mapping via comparison with 1D slope measurements performed with the same hyperbolic test mirror using the ALS developmental long trace profiler. The details of the OSMS design and the developed measuring techniques are also provided.

  19. Current asthma, respiratory symptoms and airway infections among students in relation to the school and home environment in Japan.

    PubMed

    Takaoka, Motoko; Suzuki, Kyoko; Norbäck, Dan

    2017-08-01

    To study associations between the school and home environment and current asthma, respiratory symptoms and airway infections among Japanese students. Japanese students (12-15 y) (N = 1048) in four schools responded to a questionnaire on respiratory health, allergy and the home environment. Temperature, relative air humidity (RH) and student density (students/m 2 floor area) was measured in the classrooms: dust was collected from floors and in classroom air and analysed for cat (Fel d 1) and dog (Can f 1) allergens. Health associations were analysed by multi-level logistic regression. Doctor's diagnosed asthma was common (13.4%), 8.8% reported cat allergy and 6.1% dog allergy. The median level in floor dust was 41 ng/g (IQR 23-92) for Fel d 1 and 101 ng/g (IQR 54-101) for Can f 1. The median level in air was 18.6 ng/ m 2 / day (IQR5.9-25.1) for Fel d 1 and 18.6 ng/ m 2 / day (IQR 6.0-13.3) for Can f 1. High RH, high student density and airborne cat allergen was associated with airway infections. In the home environment, recent indoor painting, new floor materials, odour, having cats as pets, window pane condensation in winter, and dampness in floor construction were associated with respiratory illness. High relative air humidity, high student density and airborne cat allergens at school may increase the risk of airway infections. Having cats as pets, chemical emissions from paint and new floor materials, odour and dampness can constitute domestic risk factors for respiratory symptoms while having dogs as pets could be protective.

  20. Reducing ingress of organic vapours into homes situated on contaminated land.

    PubMed

    Crump, D; Brown, V; Rowley, J; Squire, R

    2004-04-01

    The efficacy of current landfill gas and radon mitigation measures for the prevention of ingress of organic vapours was investigated by the study of four houses situated on contaminated land in North West England. The chemical present in the ground of greatest concern for health due to exposure to vapour in the indoor air was hexachlorobutadiene (HCBD) and the concentration of this compound was used to assess the effectiveness of the remedial measures. A two stage remediation was undertaken. For a house with a solid floor the top surface of the floor was sealed and then for the second stage a fan was used to pressurise the soil gas beneath the house. In a house with a suspended timber floor, extra air bricks were installed to increase ventilation of the floor void and then a fan to further increase air exchange in the void. HCBD in air was monitored by both pumped and diffusive sampling methods. Control houses were also monitored that were not subject to remediation. It is concluded that the remedial measures used for radon protection of a suspended floor have the potential to reduce indoor HCBD concentrations by about 80%, at least in downstairs rooms (where initial levels were highest). The two techniques used for properties with solid floors do not appear to be as effective, and no benefit at all was seen without making allowances for changes in concentration that occurred in the control house over the same period. Further work is required to test the efficacy of the techniques over a longer period and under different circumstances of type of contamination and building characteristics.

  1. Instrumentation and control building, architectural, floor plans. Specifications no. Eng043535572; ...

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

    Instrumentation and control building, architectural, floor plans. Specifications no. Eng-04-353-55-72; Drawing No. 60-09-12' sheet 64 of 148; file no. 1321/15. Stamped: record drawing - as constructed. Below stamp: Contract no. 4338, no change. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Control Center, Test Area 1-115, near Altair & Saturn Boulevards, Boron, Kern County, CA

  2. Grating exchange system of independent mirror supported by floating rotary stage

    NASA Astrophysics Data System (ADS)

    Zhang, Jianhuan; Tao, Jin; Liu, Yan; Nan, Yan

    2015-10-01

    The performance of The Grating Exchange System can satisfy the Thirty Meter Telescope - TMT for astronomical observation WFOS index requirements and satisfy the requirement of accuracy in the grating exchange. It is used to install in the MOBIE and a key device of MOBIE. The Wide Field Optical Spectrograph (WFOS) is one of the three first-light observing capabilities selected by the TMT Science Advisory Committee. The Multi-Object Broadband Imaging Echellette (MOBIE) instrument design concept has been developed to address the WFOS requirements as described in the TMT Science-Based Requirements Document (SRD). The Grating Exchange System uses a new type of separate movement way of three grating devices and a mirror device. Three grating devices with a mirror are able to achieve independence movement. This kind of grating exchange system can effectively solve the problem that the volume of the grating change system is too large and that the installed space of MOBIE instruments is too limit. This system adopts the good stability, high precision of rotary stage - a kind of using air bearing (Air bearing is famous for its ultra-high precision, and can meet the optical accuracy requirement) and rotation positioning feedback gauge turntable to support grating device. And with a kind of device which can carry greater weight bracket fixed on the MOBIE instrument, with two sets of servo motor control rotary stage and the mirror device respectively. And we use the control program to realize the need of exercising of the grating device and the mirror device. Using the stress strain analysis software--SolidWorks for stress and strain analysis of this structure. And then checking the structure of the rationality and feasibility. And prove that this system can realize the positioning precision under different working conditions can meet the requirements of imaging optical grating diffraction efficiency and error by the calculation and optical performance analysis.

  3. 22. VIEW OF THE SECOND FLOOR PLAN. THE SECOND FLOOR ...

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

    22. VIEW OF THE SECOND FLOOR PLAN. THE SECOND FLOOR CONTAINS THE AIR PLENUM ND SOME OFFICE SPACE. THE ORIGINAL DRAWING HAS BEEN ARCHIVED ON MICROFILM. THE DRAWING WAS REPRODUCED AT THE BEST QUALITY POSSIBLE. LETTERS AND NUMBERS IN THE CIRCLES INDICATE FOOTER AND/OR COLUMN LOCATIONS. - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  4. Thermal Management Techniques for Oil-Free Turbomachinery Systems

    NASA Technical Reports Server (NTRS)

    Radil, Kevin; DellaCorte, Chris; Zeszotek, Michelle

    2006-01-01

    Tests were performed to evaluate three different methods of utilizing air to provide thermal management control for compliant journal foil air bearings. The effectiveness of the methods was based on bearing bulk temperature and axial thermal gradient reductions during air delivery. The first method utilized direct impingement of air on the inner surface of a hollow test journal during operation. The second, less indirect method achieved heat removal by blowing air inside the test journal to simulate air flowing axially through a hollow, rotating shaft. The third method emulated the most common approach to removing heat by forcing air axially through the bearing s support structure. Internal bearing temperatures were measured with three, type K thermocouples embedded in the bearing that measured general internal temperatures and axial thermal gradients. Testing was performed in a 1 atm, 260 C ambient environment with the bearing operating at 60 krpm and supporting a load of 222 N. Air volumetric flows of 0.06, 0.11, and 0.17 cubic meters per minute at approximately 150 to 200 C were used. The tests indicate that all three methods provide thermal management but at different levels of effectiveness. Axial cooling of the bearing support structure had a greater effect on bulk temperature for each air flow and demonstrated that the thermal gradients could be influenced by the directionality of the air flow. Direct air impingement on the journal's inside surface provided uniform reductions in both bulk temperature and thermal gradients. Similar to the direct method, indirect journal cooling had a uniform cooling effect on both bulk temperatures and thermal gradients but was the least effective of the three methods.

  5. Interior, second floor south side of building toward east end ...

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

    Interior, second floor south side of building toward east end - Fitzsimons General Hospital, Open Air Tuberculosis Ward, West Pennington Avenue & North Hickey Street Southwest Corner, Aurora, Adams County, CO

  6. Interior, second floor north side of building toward east end ...

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

    Interior, second floor north side of building toward east end - Fitzsimons General Hospital, Open Air Tuberculosis Ward, West Pennington Avenue & North Hickey Street Southwest Corner, Aurora, Adams County, CO

  7. INTERIOR OF SECOND FLOOR, OUTSIDE PROJECTION ROOM ABOVE ENTRY PORCH, ...

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

    INTERIOR OF SECOND FLOOR, OUTSIDE PROJECTION ROOM ABOVE ENTRY PORCH, VIEW FACING WEST. - Naval Air Station Barbers Point, Theater, Yorktown Avenue between Wasp & Saipan Streets, Ewa, Honolulu County, HI

  8. The Role of Radial Clearance on the Performance of Foil Air Bearings

    NASA Technical Reports Server (NTRS)

    Radil, Kevin; Howard, Samuel; Dykas, Brian

    2002-01-01

    Load capacity tests were conducted to determine how radial clearance variations affect the load capacity coefficient of foil air bearings. Two Generation III foil air bearings with the same design but possessing different initial radial clearances were tested at room temperature against an as-ground PS304 coated journal operating at 30,000 rpm. Increases in radial clearance were accomplished by reducing the journal's outside diameter via an in-place grinding system. From each load capacity test the bearing load capacity coefficient was calculated from the rule-of-thumb (ROT) model developed for foil air bearings. The test results indicate that, in terms of the load capacity coefficient, radial clearance has a direct impact on the performance of the foil air bearing. Each test bearing exhibited an optimum radial clearance that resulted in a maximum load capacity coefficient. Relative to this optimum value are two separate operating regimes that are governed by different modes of failure. Bearings operating with radial clearances less than the optimum exhibit load capacity coefficients that are a strong function of radial clearance and are prone to a thermal runaway failure mechanism and bearing seizure. Conversely, a bearing operating with a radial clearance twice the optimum suffered only a 20 percent decline in its maximum load capacity coefficient and did not experience any thermal management problems. However, it is unknown to what degree these changes in radial clearance had on other performance parameters, such as the stiffness and damping properties of the bearings.

  9. Prevention of Salmonella cross-contamination in an oilmeal manufacturing plant.

    PubMed

    Morita, T; Kitazawa, H; Iida, T; Kamata, S

    2006-08-01

    The mechanisms of Salmonella contamination in an oilmeal plant were investigated and the basic data were collected in order to achieve control of Salmonella in oilmeal. Salmonella was detected in all contamination vectors and environmental factors investigated, namely: operators, processing floor, dust in the air and rodents. In particular, high concentrations of Salmonella were detected on the processing floor of the manufacturing area, which has high oil content. Steam was the most effective disinfection method used for the processing floor, as the effects of heat sterilization and disinfection may work in tandem. In addition, restricting the movement of operators of the production chain remarkably reduced Salmonella contamination, even in areas of otherwise high contamination. Within the oilmeal plant, high Salmonella contamination rates for the processing floor represent the greatest risk of contamination of oilmeal via operators, dust in the air and rodents. Therefore, control of the processing floor is the most important means for reducing the oilmeal contamination rate. Specific Salmonella control methods for oilmeal plants have been established.

  10. Research Capabilities for Oil-Free Turbomachinery Expanded by New Rotordynamic Simulator Facility

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.

    2004-01-01

    A new test rig has been developed for simulating high-speed turbomachinery shafting using Oil-Free foil air bearing technology. Foil air journal bearings are self-acting hydrodynamic bearings with a flexible inner sleeve surface using air as the lubricant. These bearings have been used in turbomachinery, primarily air cycle machines, for the past four decades to eliminate the need for oil lubrication. More recently, interest has been growing in applying foil bearings to aircraft gas turbine engines. They offer potential improvements in efficiency and power density, decreased maintenance costs, and other secondary benefits. The goal of applying foil air bearings to aircraft gas turbine engines prompted the fabrication of this test rig. The facility enables bearing designers to test potential bearing designs with shafts that simulate the rotating components of a target engine without the high cost of building actual flight hardware. The data collected from this rig can be used to make changes to the shaft and bearings in subsequent design iterations. The rest of this article describes the new test rig and demonstrates some of its capabilities with an initial simulated shaft system. The test rig has two support structures, each housing a foil air journal bearing. The structures are designed to accept any size foil journal bearing smaller than 63 mm (2.5 in.) in diameter. The bearing support structures are mounted to a 91- by 152-cm (3- by 5-ft) table and can be separated by as much as 122 cm (4 ft) and as little as 20 cm (8 in.) to accommodate a wide range of shaft sizes. In the initial configuration, a 9.5-cm (3.75-in.) impulse air turbine drives the test shaft. The impulse turbine, as well as virtually any number of "dummy" compressor and turbine disks, can be mounted on the shaft inboard or outboard of the bearings. This flexibility allows researchers to simulate various engine shaft configurations. The bearing support structures include a unique bearing mounting fixture that rotates to accommodate a laserbased alignment system. This can measure the misalignment of the bearing centers in each of 2 translational degrees of freedom and 2 rotational degrees of freedom. In the initial configuration, with roughly a 30.5-cm- (12-in.-) long shaft, two simulated aerocomponent disks, and two 50.8-cm (2-in.) foil journal bearings, the rig can operate at 65,000 rpm at room temperature. The test facility can measure shaft displacements in both the vertical and horizontal directions at each bearing location. Horizontal and vertical structural vibrations are monitored using accelerometers mounted on the bearing support structures. This information is used to determine system rotordynamic response, including critical speeds, mode shapes, orbit size and shape, and potentially the onset of instabilities. Bearing torque can be monitored as well to predict the power loss in the foil bearings. All of this information is fed back and forth between NASA and the foil bearing designers in an iterative fashion to converge on a final bearing and shaft design for a given engine application. In addition to its application development capabilities, the test rig offers several unique capabilities for basic bearing research. Using the laser alignment system mentioned earlier, the facility will be used to map foil air journal bearing performance. A known misalignment of increasing severity will be induced to determine the sensitivity of foil bearings to misalignment. Other future plans include oil-free integral starter generator testing and development, and dynamic load testing of foil journal bearings.

  11. Incorrect installation and use of materials as the cause of a severe air pollution incident in a school building.

    PubMed

    Rella, Rocco; Sturaro, Alberto; Vianello, Alvise

    2014-07-15

    The proofing treatment of the floor slabs with a solvent based material and successive treatment with epoxy resin resulted in significant air contamination in a primary school. The contamination caused illnesses in many occupants of school. The GC/MS investigations of the air showed the presence of indane and other aromatic solvents, which was unusual as they are not correlated to outdoor pollution and derived from inner layers of the new flooring. The total concentration of these chemicals in air was in the order of several mg/m(3). Copyright © 2014 Elsevier B.V. All rights reserved.

  12. 11. INTERIOR VIEW OF BALCONY FROM GROUND FLOOR LEVEL. ...

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

    11. INTERIOR VIEW OF BALCONY FROM GROUND FLOOR LEVEL. - Wright-Patterson Air Force Base, Area B, Building No. 12, Technical Data Building, Third Street, between B & D Streets, Dayton, Montgomery County, OH

  13. 145. ELECTRONICS SHOP (BUILDING 60), FIRST FLOOR PLAN AND ELEVATION, ...

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

    145. ELECTRONICS SHOP (BUILDING 60), FIRST FLOOR PLAN AND ELEVATION, CHARLES A. MAGUIRE, MARCH 25, 1952. PWD 10332. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  14. Tooling Converts Stock Bearings To Custom Bearings

    NASA Technical Reports Server (NTRS)

    Fleenor, E. N., Jr.

    1983-01-01

    Technique for reworking stock bearings saves time and produces helicopter-rotor bearings ground more precisely. Split tapered ring at one end of threaded bolt expands to hold inside of inner race bearing assembly; nut, at other end of bolt, adjusts amount of spring tension. Piece of hardware grasps bearing firmly without interfering with grinding operation. Operation produces bearing of higher quality than commercially available bearings.

  15. Ammonia emissions from air cleaners at pig farms in Denmark using a Picarro cavity ring-down spectrometer

    NASA Astrophysics Data System (ADS)

    Winkler, Renato; Adamsen, Anders Peter S.

    2017-04-01

    Ammonia emissions from agricultural activities such as, cattle, pig and poultry farms have become an ever more important topic both for scientists as well as for regulatory bodies due to the severe impacts of ammonia on human health and the environment. In the European Union, the agricultural sector accounts for most of the ammonia emissions, and therefore the EU authorities have put in place reduction targets for the member states. In Denmark, most pig farmers have to deploy one or more ammonia abatement technologies in order to fulfill the national regulation when building new pig houses. A promising ammonia abatement technology is partial floor ventilation and subsequent cleaning using one or two step chemical air cleaners. The cleaned air will have ammonia concentration is the sub-ppm level and with high humidity. Here we present method of monitoring NH3 emissions from air cleaners deployed on pig farms using the G2103 Picarro laser spectrometer. The Picarro G2103 NH3 analyzer is a high precision cavity ring-down spectrometer using a high finesse optical cavity and a near infra-red light laser light source with a very narrow light band. The latter eliminates cross-interferences from other gases present in livestock air. Picarro instruments are built for field measurements and have been widely used for atmospheric monitoring of greenhouse gases and of air pollutants such as NH3.

  16. Changes in canopy cover alter surface air and forest floor temperature in a high-elevation red spruce (Picea rubens Sarg.) forest

    Treesearch

    Johnny L. Boggs; Steven G. McNulty

    2010-01-01

    The objective of this study is to describe winter and summer surface air and forest floor temperature patterns and diurnal fluctuations in high-elevation red spruce (Picea rubens Sarg.) forests with different levels of canopy cover. In 1988, a series of 10- x 10-meter plots (control, low nitrogen [N] addition, and high nitrogen addition) were...

  17. 8. "TEST STAND, ARCHITECTURAL, FLOOR PLANS AND SCHEDULES." Specifications No. ...

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

    8. "TEST STAND, ARCHITECTURAL, FLOOR PLANS AND SCHEDULES." Specifications No. ENG-04-353-55-72; Drawing No. 60-0912; sheet 22 of 148; file no. 1320/73. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 4338, no change. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A Terminal Room, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  18. 31. View of mezzanine floor level in transmitter building no. ...

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

    31. View of mezzanine floor level in transmitter building no. 102 showing various electronic central indicator panel to control building air conditioning, steam pressure, supply temperature, discharge temperature, supply pressure, transformer vault status, and radome conditioning system. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  19. Floor cleaning: effect on bacteria and organic materials in hospital rooms.

    PubMed

    Andersen, B M; Rasch, M; Kvist, J; Tollefsen, T; Lukkassen, R; Sandvik, L; Welo, A

    2009-01-01

    Routine surface cleaning is recommended to control the spread of pathogens in hospital environments. In Norway, ordinary cleaning of patient rooms is traditionally performed with soap and water. In this study, four floor-mopping methods--dry, spray, moist and wet mopping--were compared by two systems using adenosine triphosphate (ATP) bioluminescence (Hygiena and Biotrace). These systems assess residual organic soil on surfaces. The floor-mopping methods were also assessed by microbiological samples from the floor and air, before and after cleaning. All methods reduced organic material on the floors but wet and moist mopping seemed to be the most effective (P < 0.001, P < 0.011, respectively, ATP Hygiena). The two ATP methods were easy to use, although each had their own reading scales. Cleaning reduced organic material to 5-36% of the level present before cleaning, depending upon mopping method. All four mopping methods reduced bacteria on the floor from about 60-100 to 30-60 colony-forming units (cfu)/20cm2 floor. Wet, moist and dry mopping seemed to be more effective in reducing bacteria on the floor, than the spray mopping (P=0.007, P=0.002 and P=0.011, respectively). The burden of bacteria in air increased for all methods just after mopping. The overall best cleaning methods seemed to be moist and wet mopping.

  20. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  1. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  2. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183513 (3 Nov. 2010) --- STS-135 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Pictured from the left are NASA astronauts Chris Ferguson, commander; Rex Walheim, mission specialist; Doug Hurley, pilot; and Sandy Magnus, mission specialist. John Ray (right) assisted the crew members. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  3. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183514 (3 Nov. 2010) --- STS-135 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Pictured from the left are NASA astronauts Chris Ferguson, commander; Rex Walheim, mission specialist; Doug Hurley, pilot; and Sandy Magnus, mission specialist. John Ray (right) assisted the crew members. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  4. STS-335 crew training, EVA TPS Overview with instructor John Ray

    NASA Image and Video Library

    2010-11-03

    JSC2010-E-183512 (3 Nov. 2010) --- STS-135 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Pictured from the left are NASA astronauts Chris Ferguson, commander; Rex Walheim, mission specialist; Doug Hurley, pilot; and Sandy Magnus, mission specialist. John Ray (right) assisted the crew members. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

  5. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage.

    PubMed

    Yang, Z; Chen, H; Yu, T; Li, B

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  6. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Chen, H.; Yu, T.; Li, B.

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  7. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Z., E-mail: zhaohui@nwpu.edu.cn; Yu, T.; Chen, H.

    2016-08-15

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images whenmore » the bearing works at high speeds. A 3D trajectory tracking software TEMA Motion is used to track the spot which marked the cage surface. Finally, by developing the MATLAB program, a Lissajous’ figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.« less

  8. Interior, first floor southeast side of building, showing french doors ...

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

    Interior, first floor southeast side of building, showing french doors and interior windows - Fitzsimons General Hospital, Open Air Tuberculosis Ward, West Pennington Avenue & North Hickey Street Southwest Corner, Aurora, Adams County, CO

  9. 104. VIEW OF CABLE RACEWAY BENEATH REMOVABLE FLOOR PANEL IN ...

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

    104. VIEW OF CABLE RACEWAY BENEATH REMOVABLE FLOOR PANEL IN LANDLINE INSTRUMENTATION ROOM - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  10. 73. SECOND FLOOR, HEATER ROOM, BAY 31/5 SOUTH, WITH FANFORCED ...

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

    73. SECOND FLOOR, HEATER ROOM, BAY 31/5 SOUTH, WITH FAN-FORCED HOT AIR HEATER; TO SOUTHEAST - Ford Motor Company Edgewater Assembly Plant, Assembly Building, 309 River Road, Edgewater, Bergen County, NJ

  11. 18. Power plant engine piping floor plan, sheet 71 of ...

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

    18. Power plant engine piping floor plan, sheet 71 of 130 - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  12. Precision Magnetic Bearing Six Degree of Freedom Stage

    NASA Technical Reports Server (NTRS)

    Williams, M. E.; Trumper, David L.

    1996-01-01

    Magnetic bearings are capable of applying force and torque to a suspended object without rigidly constraining any degrees of freedom. Additionally, the resolution of magnetic bearings is limited only by sensors and control, and not by the finish of a bearing surface. For these reasons, magnetic bearings appear to be ideal for precision wafer positioning in lithography systems. To demonstrate this capability a linear magnetic bearing has been constructed which uses variable reluctance actuators to control the motion of a 14.5 kg suspended platen in five degrees of freedom. A Lorentz type linear motor of our own design and construction is used to provide motion and position control in the sixth degree of freedom. The stage performance results verify that the positioning requirements of photolithography can be met with a system of this type. This paper describes the design, control, and performance of the linear magnetic bearing.

  13. 4. AERIAL VIEW, LOOKING SOUTHSOUTHWEST, OF BUILDING 371 GROUND FLOOR ...

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

    4. AERIAL VIEW, LOOKING SOUTH-SOUTHWEST, OF BUILDING 371 GROUND FLOOR UNDER CONSTRUCTION. THE GROUND FLOOR, WHICH CONTAINS THE MAJORITY OF THE PLUTONIUM RECOVERY PROCESSING EQUIPMENT, IS DIVIDED INTO COMPARTMENTS BY FIREWALLS, AIRLOCKS, AND USE OF NEGATIVE AIR PRESSURE. (1/7/75) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  14. Microfog lubrication for aircraft engine bearings

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1976-01-01

    An analysis and system study was performed to provide design information regarding lubricant and coolant flow rates and flow paths for effective utilization of the lubricant and coolant in a once through bearing oil mist (microfog) and coolant air system. Both static and dynamic tests were performed. Static tests were executed to evaluate and calibrate the mist supply system. A total of thirteen dynamic step speed bearing tests were performed using four different lubricants and several different mist and air supply configurations. The most effective configuration consisted of supplying the mist and the major portion of the cooling air axially through the bearing. The results of these tests have shown the feasibility of using a once through oil mist and cooling air system to lubricate and cool a high speed, high temperature aircraft engine mainshaft bearing.

  15. 7. "CONTROL BUILDING; FLOOR PLAN, ELEVATIONS AND DETAILS." Specifications No. ...

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

    7. "CONTROL BUILDING; FLOOR PLAN, ELEVATIONS AND DETAILS." Specifications No. OC1-59-53; Drawing No. 5841-A-1; D.O. SERIES AW1525/2 Rev. B. Stamped: RECORD DRAWING AS CONSTRUCTED. Below stamp: Contract No. 5619, Rev. B. Date: 7-8-59. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Firing Control Building, Test Area 1-100, northeast end of Test Area 1-100 Road, Boron, Kern County, CA

  16. Equipment Location Plan, partial first floor plan. (Includes identification of ...

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

    Equipment Location Plan, partial first floor plan. (Includes identification of each separate CPU, tape drive, hard drive, printer, keyboard, etc., within the data processing center in the southwest part of the first floor.) March Air Force Base, Riverside, California, Combat Operations Center, 465-L EDTCC/EDLCC. By International Electric Corporation, Paramus, New Jersey (3/5/62); for Moffatt and Nichol, Engineers, 122 West Fifth Street, Long Beach, California; for the Corps of Engineers, U.S. Army, Office of the District Engineer, Los Angeles, California. Drawing no. AW-60-02-03, sheet no. 85, approved March, 1962; specifications no. OCI-62-66; D.O. series AW 1596/85, Rev. "A"; file drawer 1290. Last revised 3 October 1966. Scale one-quarter inch to one foot. 28.75x40.5 inches. ink on linen - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  17. Load Capacity Estimation of Foil Air Journal Bearings for Oil-Free Turbomachinery Applications

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Valco, Mark J.

    2000-01-01

    This paper introduces a simple "Rule of Thumb" (ROT) method to estimate the load capacity of foil air journal bearings, which are self-acting compliant-surface hydrodynamic bearings being considered for Oil-Free turbo-machinery applications such as gas turbine engines. The ROT is based on first principles and data available in the literature and it relates bearing load capacity to the bearing size and speed through an empirically based load capacity coefficient, D. It is shown that load capacity is a linear function of bearing surface velocity and bearing projected area. Furthermore, it was found that the load capacity coefficient, D, is related to the design features of the bearing compliant members and operating conditions (speed and ambient temperature). Early bearing designs with basic or "first generation" compliant support elements have relatively low load capacity. More advanced bearings, in which the compliance of the support structure is tailored, have load capacities up to five times those of simpler designs. The ROT enables simplified load capacity estimation for foil air journal bearings and can guide development of new Oil-Free turbomachinery systems.

  18. The Design & Development of the Ocean Color Instrument Precision Superduplex Hybrid Bearing Cartridge

    NASA Technical Reports Server (NTRS)

    Schepis, Joseph; Woodard, Timothy; Hakun, Claef; Bergandy, Konrad; Church, Joseph; Ward, Peter; Lee, Michael; Conti, Alfred; Guzek, Jeffrey

    2018-01-01

    A high precision, high-resolution Ocean Color Imaging (OCI) instrument is under development for the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission which requires a pair of medium speed mechanisms to scan the ocean surface continuously. The design of the rotating telescope (RT) mechanism operating at 360 RPM and the half-angle mirror (HAM) mechanism synchronized at 180 RPM was concern for maintaining pointing precision over the required life and continuous operations. An effort was undertaken with the manufacturer to design and analyze a special bearing configuration to minimize axial and radial runout, minimize torque, and maintain nominal contact stresses and stiffness over the operating temperature range and to maximize life. The bearing design, development effort, analysis and testing will be discussed as will the technical challenges that this specific design imposed upon the mechanism engineers. Bearing performance, runout as achieved and verified during encoder installation and operating torque will be described.

  19. View north of inside machine shop 36; shop floor accommodates ...

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

    View north of inside machine shop 36; shop floor accommodates lathes capable of machining a cylinder 60 inches in diameter and 75 feet long; other equipment includes horizontal and vertical jig borders, hydraulic tube straighteners and other equipment for precision machining of large ship components. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  20. Exterior doorway detail south side of building (first floor) east ...

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

    Exterior doorway detail south side of building (first floor) east inset porch; interior staircase visible in background - Fitzsimons General Hospital, Open Air Tuberculosis Ward, West Pennington Avenue & North Hickey Street Southwest Corner, Aurora, Adams County, CO

  1. Photocopy of drawing (this photograph is an 8" x 10" ...

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

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1990 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters "4" as built floor plans, architectural floor plan (first floor), sheet 1 of 2 - U.S. Naval Air Station, Senior Officers' Quarters Q-4, Q-4 North Avenue, Pensacola, Escambia County, FL

  2. Photocopy of drawing (this photograph is an 8" x 10" ...

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

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1990 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters "4" as built floor plans, architectural floor plan (second floor), sheet 2 of 2 - U.S. Naval Air Station, Senior Officers' Quarters Q-4, Q-4 North Avenue, Pensacola, Escambia County, FL

  3. A mid-holocene fauna from Bear Den Cave, Sequoia National Park, California

    USGS Publications Warehouse

    Mead, Jim I.; McGinnis, Thomas W.; Keeley, Jon E.

    2006-01-01

    Test excavation of floor fill deposits in the first room in Bear Den Cave, Sequoia National Park, produced fossiliferous sediments down to at least 40 cm depth. Radiocarbon analysis of charcoal from this layer indicates an early-middle Holocene age of 7220 CAL BP. The fossil accumulation represents prey recovered from generations of ringtail (Bassariscus astutus) dung. Microvertebrate remains include salamanders, lizards, snakes, and mammals. The recovery of Aneides ferreus/vagransfrom early-middle Holocene deposits in Bear Den Cave is a first for this species group. Equally interesting is the recovery of Plethodon sp. Neither taxa live in the Sierra Nevada today. The fossil-rich deposits of Bear Den Cave indicate that future paleoecological studies will be productive in Sequoia National Park.

  4. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  5. Mystery of Foil Air Bearings for Oil-free Turbomachinery Unlocked: Load Capacity Rule-of-thumb Allows Simple Estimation of Performance

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Valco, Mark J.

    2002-01-01

    The Oil-Free Turbomachinery team at the NASA Glenn Research Center has unlocked one of the mysteries surrounding foil air bearing performance. Foil air bearings are self-acting hydrodynamic bearings that use ambient air, or any fluid, as their lubricant. In operation, the motion of the shaft's surface drags fluid into the bearing by viscous action, creating a pressurized lubricant film. This lubricating film separates the stationary foil bearing surface from the moving shaft and supports load. Foil bearings have been around for decades and are widely employed in the air cycle machines used for cabin pressurization and cooling aboard commercial jetliners. The Oil-Free Turbomachinery team is fostering the maturation of this technology for integration into advanced Oil-Free aircraft engines. Elimination of the engine oil system can significantly reduce weight and cost and could enable revolutionary new engine designs. Foil bearings, however, have complex elastic support structures (spring packs) that make the prediction of bearing performance, such as load capacity, difficult if not impossible. Researchers at Glenn recently found a link between foil bearing design and load capacity performance. The results have led to a simple rule-of-thumb that relates a bearing's size, speed, and design to its load capacity. Early simple designs (Generation I) had simple elastic (spring) support elements, and performance was limited. More advanced bearings (Generation III) with elastic supports, in which the stiffness is varied locally to optimize gas film pressures, exhibit load capacities that are more than double those of the best previous designs. This is shown graphically in the figure. These more advanced bearings have enabled industry to introduce commercial Oil-Free gas-turbine-based electrical generators and are allowing the aeropropulsion industry to incorporate the technology into aircraft engines. The rule-of-thumb enables engine and bearing designers to easily size and select bearing technology for a new application and determine the level of complexity required in the bearings. This new understanding enables industry to assess the feasibility of new engine designs and provides critical guidance toward the future development of Oil-Free turbomachinery propulsion systems.

  6. Radial Clearance Found To Play a Key Role in the Performance of Compliant Foil Air Bearings

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.

    2003-01-01

    Compliant foil air bearings are at the forefront of the Oil-Free turbomachinery revolution, which supports gas turbine engines with hydrodynamic bearings that use air instead of oil as the working fluid. These types of bearings have been around for almost 50 years and have found a home in several commercial applications, such as in air cycle machines, turbocompressors, and microturbines, but are now being aggressively pursued for use in small and midrange aircraft gas turbine engines. Benefits include higher operating speeds and temperatures, lower maintenance costs, and greater reliability. The Oil-Free Turbomachinery team at the NASA Glenn Research Center is working to foster the transition of Oil-Free technology into gas turbine engines by performing in-house experiments on foil air bearings in order to gain a greater insight into their complex operating principles. A research program recently undertaken at Glenn focused on the concept of radial clearance and its influence on bearing performance. The tests were conducted on foil bearings with different radial clearances. As defined for a foil bearing, radial clearance is a measure of the small amount of shaft radial motion that is present from play that exists in the elastic support structure, such as between the top and bump foils and the bump foils and bearing shell (see the drawing). With an insufficient amount of radial clearance, the bearing imparts a high preload on the shaft, which when excessive, can reduce the loadcarrying capability of the bearing. On the other hand, systems using foil bearings with excessive radial clearance may experience rotordynamic instabilities because of low bearing preload. Therefore, without a more thorough understanding of radial clearance, it is difficult to accurately predict the performance of a given bearing design. The test program demonstrated that there is a direct correlation between radial clearance and the performance of foil air bearings. As shown in the graph, an optimum radial clearance exists that will maximize the amount of load that the bearing is capable of supporting. With respect to this optimum, two different performance regimes were observed that are a function of the amount of radial clearance. Tests showed that bearings with radial clearances below the optimum in regime I were susceptible to sudden seizure, a failure mode indicative of thermal runaway caused by high preload. The high preload is in response to an insufficient amount of radial clearance available to accommodate the thermal growth of the bearing and shaft. However, radial clearances greater than the optimum in regime II resulted in low bearing preloads that did not cause any heat-related problems, and the failure mode was due to fluid-film breakdown. In fact, bearings operating with radial clearances twice as much as the optimum suffered a decrease in the maximum load capacity of only about 20 percent. Therefore, special attention has to be given to the range of operating conditions expected in the bearing/shaft system since changes in temperature, centrifugal, and hydrodynamic effects can all affect radial clearance. This enhanced understanding of foil air bearing behavior will greatly aid our efforts to transition Oil-Free technology to future aircraft engines.

  7. Carpeting in hospitals: an epidemiological evaluation.

    PubMed Central

    Anderson, R L; Mackel, D C; Stoler, B S; Mallison, G F

    1982-01-01

    Epidemiological and microbiological studies were conducted in a hospital room with carpet (CR) and in one with carpet (NCR). Microbiological profiles were determined with specimens obtained from patients admitted to these rooms. Patient records were reviewed to note infection status and other case identities. Eleven-millimeter cylindrical core samples of carpet were obtained, and swab template techniques were used on the bare floor for subsequent enumeration and identification of contaminating microorganisms. In each sampling period, higher microbial counts per square inch (1 in(2) = ca 6.452 cm(2)) were measured for the carpet than for the bare floor. Recovery rates of Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli were higher from carpet samples than from bare floor samples. Typable organisms (such as E. coli, Pseudomonas aeruginosa, K. pneumoniae, and Staphylococcus aureus) obtained from patients were also more frequently recovered from the carpet than from the bare flooring. Patients who stayed in the CR were shown to be colonized with the same types of organisms as those initially recovered from the carpet. However, no statistically significant differences were found in patients in the CR versus NCR in colonization with all typable and nontypable organisms first found on the floor. Disease in patients was found not to be associated with organisms found as contaminants of the carpet or the bare floor. Air above carpeting contained more consistent concentrations of organisms than air above the bare flooring. PMID:7076814

  8. Global rates of marine sulfate reduction and implications for sub-sea-floor metabolic activities

    NASA Astrophysics Data System (ADS)

    Bowles, Marshall W.; Mogollón, José M.; Kasten, Sabine; Zabel, Matthias; Hinrichs, Kai-Uwe

    2014-05-01

    Sulfate reduction is a globally important redox process in marine sediments, yet global rates are poorly quantified. We developed an artificial neural network trained with 199 sulfate profiles, constrained with geomorphological and geochemical maps to estimate global sulfate-reduction rate distributions. Globally, 11.3 teramoles of sulfate are reduced yearly (~15% of previous estimates), accounting for the oxidation of 12 to 29% of the organic carbon flux to the sea floor. Combined with global cell distributions in marine sediments, these results indicate a strong contrast in sub-sea-floor prokaryote habitats: In continental margins, global cell numbers in sulfate-depleted sediment exceed those in the overlying sulfate-bearing sediment by one order of magnitude, whereas in the abyss, most life occurs in oxic and/or sulfate-reducing sediments.

  9. Note: high precision angle generator using multiple ultrasonic motors and a self-calibratable encoder.

    PubMed

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan; Eom, Tae Bong

    2011-11-01

    We present an angle generator with high resolution and accuracy, which uses multiple ultrasonic motors and a self-calibratable encoder. A cylindrical air bearing guides a rotational motion, and the ultrasonic motors achieve high resolution over the full circle range with a simple configuration. The self-calibratable encoder can compensate the scale error of a divided circle (signal period: 20") effectively by applying the equal-division-averaged method. The angle generator configures a position feedback control loop using the readout of the encoder. By combining the ac and dc operation mode, the angle generator produced stepwise angular motion with 0.005" resolution. We also evaluated the performance of the angle generator using a precision angle encoder and an autocollimator. The expanded uncertainty (k = 2) in the angle generation was estimated less than 0.03", which included the calibrated scale error and the nonlinearity error. © 2011 American Institute of Physics

  10. INTERIOR SHOWING STAIRCASE TO SECOND FLOOR FROM MAIN LOBBY/RECEPTION AREA, ...

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

    INTERIOR SHOWING STAIRCASE TO SECOND FLOOR FROM MAIN LOBBY/RECEPTION AREA, VIEW FACING WEST-SOUTHWEST. - Naval Air Station Barbers Point, Control Tower & Aviation Operations Building, Near intersection of runways between Hangar 110 & Building 115, Ewa, Honolulu County, HI

  11. 72. SECOND FLOOR, HEATER ROOM ENTRANCE (UPPER RIGHT) AND STEEL, ...

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

    72. SECOND FLOOR, HEATER ROOM ENTRANCE (UPPER RIGHT) AND STEEL, CONCRETE, BRICK, AND SPRING AIR CONDITIONER BASE, BAY 31-32/4 SOUTH, TO WEST - Ford Motor Company Edgewater Assembly Plant, Assembly Building, 309 River Road, Edgewater, Bergen County, NJ

  12. GENERAL VIEW OF THE MAIN FLOOR LEVEL, PLATFORM DSOUTH, HB3, ...

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

    GENERAL VIEW OF THE MAIN FLOOR LEVEL, PLATFORM D-SOUTH, HB-3, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  13. DETAIL VIEW OF VIDEO CAMERA, MAIN FLOOR LEVEL, PLATFORM ESOUTH, ...

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

    DETAIL VIEW OF VIDEO CAMERA, MAIN FLOOR LEVEL, PLATFORM E-SOUTH, HB-3, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  14. Distribution and fate of polybrominated diphenyl ethers in indoor environments of elementary schools.

    PubMed

    Wu, Q; Baek, S-Y; Fang, M; Chang, Y-S

    2010-06-01

    Polybrominated diphenyl ethers (PBDEs) are considered harmful to human health because of their toxicities and persistence in environments. In the current study, the distribution and fate of PBDEs in classrooms and computer rooms in 17 elementary schools in South Korea have been described. Eight congeners (brominated diphenyl ether-28, -47, -99, -100, -153, -154, -183, and -209) in air, floor dust, and product surface dust were measured. While Sigma(8)PBDEs in the air in classrooms showed considerable variations (0.659-1600 pg/m(3), arithmetic mean +/- s.d.: 377 +/- 441 pg/m(3)), those in computer rooms were somewhat similar (134-220 pg/m(3), arithmetic mean +/- s.d.: 169 +/- 40 pg/m(3)). Sigma(8)PBDEs in floor dust varied over a wide range, from 453 to 45,700 ng/g, for all rooms. Based on congener patterns, two groups were created--CL-1 that is dominated by high-brominated congeners and CL-2 primarily comprising low-brominated congeners--for both air and floor dust of classrooms. Surface dust had low concentrations, ranged from ND to 181, from ND to 128, and from ND to 256 pg/cm(2) for desk/chair sets, lockers, and playing tools, respectively. Pearson correlation coefficients were calculated individually for air, floor dust, and surface dust. The results indicate that both surface dust and floor dust may act as a secondary source of PBDEs in indoor environments after emission from facilities. Children have been estimated to have a higher potential exposure to PBDEs than adults. Since children spend most of their day time at school, PBDE distributions in school environments should be a matter of great concern.

  15. Do Carpets Impair Indoor Air Quality and Cause Adverse Health Outcomes: A Review.

    PubMed

    Becher, Rune; Øvrevik, Johan; Schwarze, Per E; Nilsen, Steinar; Hongslo, Jan K; Bakke, Jan Vilhelm

    2018-01-23

    Several earlier studies have shown the presence of more dust and allergens in carpets compared with non-carpeted floors. At the same time, adverse effects of carpeted floors on perceived indoor air quality as well as worsening of symptoms in individuals with asthma and allergies were reported. Avoiding extensive carpet use in offices, schools, kindergartens and bedrooms has therefore been recommended by several health authorities. More recently, carpet producers have argued that former assessments were obsolete and that modern rugs are unproblematic, even for those with asthma and allergies. To investigate whether the recommendation to be cautious with the use of carpets is still valid, or whether there are new data supporting that carpet flooring do not present a problem for indoor air quality and health, we have reviewed the literature on this matter. We have not found updated peer reviewed evidence that carpeted floor is unproblematic for the indoor environment. On the contrary, also more recent data support that carpets may act as a repository for pollutants which may become resuspended upon activity in the carpeted area. Also, the use of carpets is still linked to perception of reduced indoor air quality as well as adverse health effects as previously reported. To our knowledge, there are no publications that report on deposition of pollutants and adverse health outcomes associated with modern rugs. However, due to the three-dimensional structure of carpets, any carpet will to some extent act like a sink. Thus, continued caution should still be exercised when considering the use of wall-to-wall carpeted floors in schools, kindergartens and offices, as well as in children's bedrooms unless special needs indicate that carpets are preferable.

  16. Do Carpets Impair Indoor Air Quality and Cause Adverse Health Outcomes: A Review

    PubMed Central

    Becher, Rune; Øvrevik, Johan; Schwarze, Per E.; Nilsen, Steinar; Hongslo, Jan K.; Bakke, Jan Vilhelm

    2018-01-01

    Several earlier studies have shown the presence of more dust and allergens in carpets compared with non-carpeted floors. At the same time, adverse effects of carpeted floors on perceived indoor air quality as well as worsening of symptoms in individuals with asthma and allergies were reported. Avoiding extensive carpet use in offices, schools, kindergartens and bedrooms has therefore been recommended by several health authorities. More recently, carpet producers have argued that former assessments were obsolete and that modern rugs are unproblematic, even for those with asthma and allergies. To investigate whether the recommendation to be cautious with the use of carpets is still valid, or whether there are new data supporting that carpet flooring do not present a problem for indoor air quality and health, we have reviewed the literature on this matter. We have not found updated peer reviewed evidence that carpeted floor is unproblematic for the indoor environment. On the contrary, also more recent data support that carpets may act as a repository for pollutants which may become resuspended upon activity in the carpeted area. Also, the use of carpets is still linked to perception of reduced indoor air quality as well as adverse health effects as previously reported. To our knowledge, there are no publications that report on deposition of pollutants and adverse health outcomes associated with modern rugs. However, due to the three-dimensional structure of carpets, any carpet will to some extent act like a sink. Thus, continued caution should still be exercised when considering the use of wall-to-wall carpeted floors in schools, kindergartens and offices, as well as in children’s bedrooms unless special needs indicate that carpets are preferable. PMID:29360764

  17. Poultry rearing on perforated plastic floors and the effect on air quality, growth performance, and carcass injuries-Experiment 1: Thermal Comfort.

    PubMed

    de Almeida, Eduardo Alves; Arantes de Souza, Lilian Francisco; Sant'Anna, Aline Cristina; Bahiense, Raphael Nogueira; Macari, Marcos; Furlan, Renato Luis

    2017-09-01

    The present study investigated the use of perforated plastic floors in the rearing of male and female poultry under thermal comfort conditions. The study was conducted in 2 climate chambers, in one was conventional poultry litter (wood shavings) and in the other was a perforated plastic floor. The experimental design was a completely randomized design with the factors wood shavings and plastic floor. In each chamber, the animals were divided into 16 experimental pens (8 with males and 8 with females) with a density of 12 birds/m2. The poultry rearing effect was evaluated in terms of air quality (% concentration of ammonia [NH3] and carbon dioxide [CO2]); broiler performance, e.g., weight gain (kg), feed intake (kg), feed conversion, carcass yield and parts (%), meat production (kg/m2), and viability (% of live birds at d 42); scores of hygiene and mobility; and injuries in the chest, hocks, and footpads. Treatments affected air quality, with higher concentrations of NH3 on d 42 (25 ppm vs. 2 ppm) and CO2 (1,400 ppm vs. 1,000 ppm) for wood shavings than for perforated plastic floor, respectively. Males showed a better performance (weight gain, feed intake and feed conversion) than females on d 42 in both floor types (wood shavings and plastic floor). Males reared on wood shavings showed a higher meet production (35.992 kg/m2) than females (32.257 kg/m2). On the plastic floor, males showed a better viability (100%) than females (94.05%), as well better meet production for males (38.55 kg·m-2) than females (31.64 kg/m2). There was no incidence of breast lesions in any of the studied systems. The birds reared on the plastic floor had better hygiene scores and lower hock injury rates than birds reared in the wood shavings chambers. The results of the present study show that the use of perforated plastic floors in chicken farming is an efficient method, which promotes a better-quality environment, superior production rates, and reduced incidence of injuries. © 2017 Poultry Science Association Inc.

  18. Five degree-of-freedom control of an ultra-precision magnetically-suspended linear bearing. Ph.D. Thesis - MIT

    NASA Technical Reports Server (NTRS)

    Trumper, David L.; Slocum, A. H.

    1991-01-01

    The authors constructed a high precision linear bearing. A 10.7 kg platen measuring 125 mm by 125 mm by 350 mm is suspended and controlled in five degrees of freedom by seven electromagnets. The position of the platen is measured by five capacitive probes which have nanometer resolution. The suspension acts as a linear bearing, allowing linear travel of 50 mm in the sixth degree of freedom. In the laboratory, this bearing system has demonstrated position stability of 5 nm peak-to-peak. This is believed to be the highest position stability yet demonstrated in a magnetic suspension system. Performance at this level confirms that magnetic suspensions can address motion control requirements at the nanometer level. The experimental effort associated with this linear bearing system is described. Major topics are the development of models for the suspension, implementation of control algorithms, and measurement of the actual bearing performance. Suggestions for the future improvement of the bearing system are given.

  19. 26. View of second floor of transmitter building no. 102 ...

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

    26. View of second floor of transmitter building no. 102 looking across electronic equipment cabinets in area of missile impact predictor (MIP) area. Note U.S. Air Force emblem in mid-center of photograph. This area is in front of the Missile Warning Operations Center (MWOC) office. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  20. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  1. 77 FR 39209 - Foreign-Trade Zone 74-Baltimore, MD, Notification of Proposed Production Activity, J.D. Neuhaus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... from abroad include: air and hydraulic powered hoist and trolley subassemblies and parts, cranes/ winches and related parts, hoist chain, lubricating oils, plastic air hoses, rubber gaskets and o-rings, fasteners, springs, air filters, air pressure regulators, valves and related parts, and bearings and bearing...

  2. Fungal colonization of fiberglass insulation in the air distribution system of a multi-story office building: VOC production and possible relationship to a sick building syndrome.

    PubMed

    Ahearn, D G; Crow, S A; Simmons, R B; Price, D L; Noble, J A; Mishra, S K; Pierson, D L

    1996-05-01

    Complaints characteristic of those for sick building syndrome prompted mycological investigations of a modern multi-story office building on the Gulf coast in the Southeastern United States (Houston-Galveston area). The air handling units and fiberglass duct liner of the heating, ventilating and air conditioning system of the building, without a history of catastrophic or chronic water damage, demonstrated extensive colonization with Penicillium spp and Cladosporium herbarum. Although dense fungal growth was observed on surfaces within the heating-cooling system, most air samples yielded fewer than 200 CFU m-3. Several volatile compounds found in the building air were released also from colonized fiberglass. Removal of colonized insulation from the floor receiving the majority of complaints of mouldy air and continuous operation of the units supplying this floor resulted in a reduction in the number of complaints.

  3. Fungal colonization of fiberglass insulation in the air distribution system of a multi-story office building: VOC production and possible relationship to a sick building syndrome

    NASA Technical Reports Server (NTRS)

    Ahearn, D. G.; Crow, S. A.; Simmons, R. B.; Price, D. L.; Noble, J. A.; Mishra, S. K.; Pierson, D. L.

    1996-01-01

    Complaints characteristic of those for sick building syndrome prompted mycological investigations of a modern multi-story office building on the Gulf coast in the Southeastern United States (Houston-Galveston area). The air handling units and fiberglass duct liner of the heating, ventilating and air conditioning system of the building, without a history of catastrophic or chronic water damage, demonstrated extensive colonization with Penicillium spp and Cladosporium herbarum. Although dense fungal growth was observed on surfaces within the heating-cooling system, most air samples yielded fewer than 200 CFU m-3. Several volatile compounds found in the building air were released also from colonized fiberglass. Removal of colonized insulation from the floor receiving the majority of complaints of mouldy air and continuous operation of the units supplying this floor resulted in a reduction in the number of complaints.

  4. Hydrodynamic air lubricated compliant surface bearing for an automotive gas turbine engine. 1: Journal bearing performance

    NASA Technical Reports Server (NTRS)

    Ruscitto, D.; Mccormick, J.; Gray, S.

    1978-01-01

    A 38.1 mm (1.5 inch) diameter Hydresil Compliant Surface Air Lubricated Journal Bearing was designed and tested to obtain bearing performance characteristics at both room temperature and 315 C (600 F). Testing was performed at various speeds up to 60,000 rpm with varying loads. Rotating sensors provided an opportunity to examine the film characteristics of the compliant surface bearing. In addition to providing minimum film thickness values and profiles, many other insights into bearing operation were gained such as the influence of bearing fabrication accuracy and the influence of smooth foil deflection between the bumps.

  5. Changes in Hardware in Order to Accommodate Compliant Foil Air Bearings of a Larger Size

    NASA Technical Reports Server (NTRS)

    Zeszotek, Michelle

    2004-01-01

    Compliant foil air bearings are at the forefront of the Oil-Free turbomachinery revolution of supporting gas turbine engines with air lubricated hydrodynamic bearings. Foil air bearings have existed for almost fifty years, yet their commercialization has been confined to relatively small, high-speed systems characterized by low temperatures and loads, such as in air cycle machines, turbocompressors and micro-turbines. Recent breakthroughs in foil air bearing design and solid lubricant coating technology, have caused a resurgence of research towards applying Oil-Free technology to more demanding applications on the scale of small and mid range aircraft gas turbine engines. In order to foster the transition of Oil-Free technology into gas turbine engines, in-house experiments need to be performed on foil air bearings to further the understanding of their complex operating principles. During my internship at NASA Glenn in the summer of 2003, a series of tests were performed to determine the internal temperature profile in a compliant bump- type foil journal air bearing operating at room temperature under various speeds and load conditions. From these tests, a temperature profile was compiled, indicating that the circumferential thermal gradients were negligible. The tests further indicated that both journal rotational speed and radial load are responsible for heat generation with speed playing a more significant role in the magnitude of the temperatures. As a result of the findings from the tests done during the summer of 2003, it was decided that further testing would need to be done, but with a bearing of a larger diameter. The bearing diameter would now be increased from two inches to three inches. All of the currently used testing apparatus was designed specifically for a bearing that was two inches in diameter. Thus, my project for the summer of 2004 was to focus specifically on the scatter shield put around the testing rig while running the bearings. Essentially I was to design a scatter shield that would be able to accommodate the three inch bearing and that would also meet all safety requirements. Furthermore, the new scatter shield also had to house a heater, used for high-speed and temperature testing. Using Solidworks, a computer aided modeling program, I was able to accomplish the task set out for me and designed the new scatter shield. Furthermore, I also guided the fabrication process. As a result of this containment shield being designed, the Oil-Free turbomachinery team now has the ability to test bearings of larger diameters. Finally, it is expected that these tests will provide information useful for the validation of future analytical modeling codes.

  6. Cooling system for a bearing of a turbine rotor

    DOEpatents

    Schmidt, Mark Christopher

    2002-01-01

    In a gas turbine, a bore tube assembly radially inwardly of an aft bearing conveys cooling steam to the buckets of the turbine and returns the cooling steam to a return. To cool the bearing and thermally insulate the bearing from the cooling steam paths, a radiation shield is spaced from the bore tube assembly by a dead air gap. Additionally, an air passageway is provided between the radiation shield and the inner surface of an aft shaft forming part of the rotor. Air is supplied from an inlet for flow along the passage and radially outwardly through bores in the aft shaft disk to cool the bearing and insulate it from transfer of heat from the cooling steam.

  7. New Investigations of the Gow Lake Impact Structure, Saskatchewan, Canada: Impact Melt Rocks, Astronaut Training, and More

    NASA Astrophysics Data System (ADS)

    Osinski, G. R.; Singleton, A. C.; Ozaruk, A.; Hansen, J. R.

    2012-03-01

    New investigations of the Gow Lake impact structure has revealed an almost complete sequence of impactites from the crater floor upward through a series of melt-free and melt-bearing rocks. This research involved an astronaut training component.

  8. An Oil-Free Thrust Foil Bearing Facility Design, Calibration, and Operation

    NASA Technical Reports Server (NTRS)

    Bauman, Steve

    2005-01-01

    New testing capabilities are needed in order to foster thrust foil air bearing technology development and aid its transition into future Oil-Free gas turbines. This paper describes a new test apparatus capable of testing thrust foil air bearings up to 100 mm in diameter at speeds to 80,000 rpm and temperatures to 650 C (1200 F). Measured parameters include bearing torque, load capacity, and bearing temperatures. This data will be used for design performance evaluations and for validation of foil bearing models. Preliminary test results demonstrate that the rig is capable of testing thrust foil air bearings under a wide range of conditions which are anticipated in future Oil-Free gas turbines. Torque as a function of speed and temperature corroborates results expected from rudimentary performance models. A number of bearings were intentionally failed with no resultant damage whatsoever to the test rig. Several test conditions (specific speeds and loads) revealed undesirable axial shaft vibrations which have been attributed to the magnetic bearing control system and are under study. Based upon these preliminary results, this test rig will be a valuable tool for thrust foil bearing research, parametric studies and technology development.

  9. Verification of Spin Magnetic Attitude Control System using air-bearing-based attitude control simulator

    NASA Astrophysics Data System (ADS)

    Ousaloo, H. S.; Nodeh, M. T.; Mehrabian, R.

    2016-09-01

    This paper accomplishes one goal and it was to verify and to validate a Spin Magnetic Attitude Control System (SMACS) program and to perform Hardware-In-the-Loop (HIL) air-bearing experiments. A study of a closed-loop magnetic spin controller is presented using only magnetic rods as actuators. The magnetic spin rate control approach is able to perform spin rate control and it is verified with an Attitude Control System (ACS) air-bearing MATLAB® SIMULINK® model and a hardware-embedded LABVIEW® algorithm that controls the spin rate of the test platform on a spherical air bearing table. The SIMULINK® model includes dynamic model of air-bearing, its disturbances, actuator emulation and the time delays caused by on-board calculations. The air-bearing simulator is employed to develop, improve, and carry out objective tests of magnetic torque rods and spin rate control algorithm in the experimental framework and to provide a more realistic demonstration of expected performance of attitude control as compared with software-based architectures. Six sets of two torque rods are used as actuators for the SMACS. It is implemented and simulated to fulfill mission requirement including spin the satellite up to 12 degs-1 around the z-axis. These techniques are documented for the full nonlinear equations of motion of the system and the performances of these techniques are compared in several simulations.

  10. High precision detector robot arm system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shu, Deming; Chu, Yong

    A method and high precision robot arm system are provided, for example, for X-ray nanodiffraction with an X-ray nanoprobe. The robot arm system includes duo-vertical-stages and a kinematic linkage system. A two-dimensional (2D) vertical plane ultra-precision robot arm supporting an X-ray detector provides positioning and manipulating of the X-ray detector. A vertical support for the 2D vertical plane robot arm includes spaced apart rails respectively engaging a first bearing structure and a second bearing structure carried by the 2D vertical plane robot arm.

  11. Cleaning devices

    NASA Technical Reports Server (NTRS)

    Schneider, Horst W. (Inventor)

    1981-01-01

    Cleaning devices are described which include a vacuum cleaner nozzle with a sharp rim for directing incoming air down against the floor; a vacuum cleaner wherein electrostatically charged brushes that brush dirt off a floor, are electrically grounded to remove charges that could tend to hold dirt to the brushes; a vacuum cleaner head having slots that form a pair of counter-rotating vortices, and that includes an outlet that blows a stream of air at the floor region which lies between the vortices; a cleaning device that sweeps a group of brushes against the ground along a first direction, and then sweeps them along the same ground area but in a second direction angled from the first by an amount such as 90.degree., to sweep up particles lying in crevices extending along any direction; a device that gently cleans a surface to remove bacteria for analysis, including an inclined wall along which cleaning fluid flows onto the surface, a vacuum chamber for drawing in the cleaning fluid, and a dividing wall spaced slightly from the surface to separate the fluid source from the vacuum cleaner chamber; and a device for providing pulses of pressured air including a chamber to which pressured air is supplied, a ball that circulates around the chamber to repeatedly close an outlet, and an air source that directs air circumferentially to move the ball around the chamber.

  12. Localization of wood floor structure by infrared thermography

    NASA Astrophysics Data System (ADS)

    Cochior Plescanu, C.; Klein, M.; Ibarra-Castanedo, C.; Bendada, A.; Maldague, X.

    2008-03-01

    One of our industrial partners, Assek Technologie, is interested in developing a technique that would improve the drying process of wood floor in basements after flooding. In order to optimize the procedure, the floor structure and the damaged (wet) area extent must first be determined with minimum intrusion (minimum or no dismantling). The present study presents the use of infrared thermography to reveal the structure of (flooded) wood floors. The procedure involves opening holes in the floor. Injecting some hot air through those holes reveals the framing structure even if the floor is covered by vinyl or ceramic tiles. This study indicates that thermal imaging can also be used as a tool to validate the decontamination process after drying. Thermal images were obtained on small-scale models and in a demonstration room.

  13. A New High-Speed Oil-Free Turbine Engine Rotordynamic Simulator Test Rig

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.

    2007-01-01

    A new test rig has been developed for simulating high-speed turbomachinery rotor systems using Oil-Free foil air bearing technology. Foil air bearings have been used in turbomachinery, primarily air cycle machines, for the past four decades to eliminate the need for oil lubrication. The goal of applying this bearing technology to other classes of turbomachinery has prompted the fabrication of this test rig. The facility gives bearing designers the capability to test potential bearing designs with shafts that simulate the rotating components of a target machine without the high cost of building "make-and-break" hardware. The data collected from this rig can be used to make design changes to the shaft and bearings in subsequent design iterations. This paper describes the new test rig and demonstrates its capabilities through the initial run with a simulated shaft system.

  14. An air bearing system for small high speed gas turbines

    NASA Astrophysics Data System (ADS)

    Turner, A. B.; Davies, S. J.; Nimir, Y. L.

    1994-03-01

    This paper describes the second phase of an experimental program concerning the application of air bearings to small turbomachinery test rigs and small gas turbines. The first phase examined externally pressurized (EP) journal bearings, with a novel EP thrust bearing, for application to 'warm air' test rigs, and was entirely successful at rotational speeds in excess of 100,000 rpm. This second phase examined several designs of tilting pad-spiring journal bearings, one with a novel form of externally pressurized pad, but all using the original EP thrust bearing. The designs tested are described, including some oscillogram traces, for tests up to a maximum of 70,000 rpm; the most successful using a carbon pad-titanium beam spring arrangement. The thrust bearing which gave trouble-free operation throughout, is also described. The results of an original experiment to measure the 'runway speed' of a radial inflow turbine are also presented, which show that overspeeds of 58 percent above the design speed can result from free-power turbine coupling failure.

  15. Near-Field Phase-Change Optical Recording of 1.36 Numerical Aperture

    NASA Astrophysics Data System (ADS)

    Ichimura, Isao; Kishima, Koichiro; Osato, Kiyoshi; Yamamoto, Kenji; Kuroda, Yuji; Saito, Kimihiro

    2000-02-01

    A bit density of 125 nm was demonstrated through near-field phase-change (PC) optical recording at the wavelength of 657 nm by using a supersphere solid immersion lens (SIL). The lens unit consists of a standard objective and a φ2.5 mm SIL@. Since this lens size still prevents the unit from being mounted on an air-bearing slider, we developed a one-axis positioning actuator and an active capacitance servo for precise gap control to thoroughly investigate near-field recording. An electrode was fabricated on the bottom of the SIL, and a capacitor was formed facing a disk material. This setup realized a stable air gap below 50 nm, and a new method of simulating modulation transfer function (MTF) optimized the PC disk structure at this gap height. Obtained jitter of 8.8% and a clear eye-pattern prove that our system successfully attained the designed numerical-aperture (\\mathit{NA}) of 1.36.

  16. Bubbles in solvent microextraction: the influence of intentionally introduced bubbles on extraction efficiency.

    PubMed

    Williams, D Bradley G; George, Mosotho J; Meyer, Riaan; Marjanovic, Ljiljana

    2011-09-01

    Significant improvements to microdrop extractions of triazine pesticides are realized by the intentional incorporation of an air bubble into the solvent microdroplet used in this microextraction technique. The increase is attributed partly to greater droplet surface area resulting from the air bubble being incorporated into the solvent droplet as opposed to it sitting thereon and partly to thin film phenomena. The method is useful at nanogram/liter levels (LOD 0.002-0.012 μg/L, LOQ 0.007-0.039 μg/L), is precise (7-12% at 10 μg/L concentration level), and is validated against certified reference materials containing 0.5 and 5.0 μg/L analyte. It tolerates water and fruit juice as matrixes without serious matrix effects. This new development brings a simple, inexpensive, and efficient preconcentration technique to bear which rivals solid phase microextraction methods.

  17. This photocopy of an engineering drawing shows the floor plan ...

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

    This photocopy of an engineering drawing shows the floor plan of the Liner Lab, including room functions. Austin, Field & Fry, Architects Engineers, 22311 West Third Street, Los Angeles 57, California: Edwards Test Station Complex Phase II, Jet Propulsion Laboratory, California Institute of Technology, Edwards Air Force Base, Edwards, California: "Liner Laboratory, Floor Plan and Schedules," drawing no. E33/4-2, 26 June 1962. California Institute of Technology, Jet Propulsion Laboratory, Plant Engineering: engineering drawings of structures at JPL Edwards Facility. Drawings on file at JPL Plant Engineering, Pasadena, California. California Institute of Technology, Jet Propulsion Laboratory, Plant Engineering: engineering drawings of structures at JPL Edwards Facility. Drawings on file at JPL Plant Engineering, Pasadena, California - Jet Propulsion Laboratory Edwards Facility, Liner Laboratory, Edwards Air Force Base, Boron, Kern County, CA

  18. SOIL TYPE AND FOREST VEGETATION INFLUENCES ON FOREST FLOOR NITROGEN DYNAMICS AT THE BEAR BROOK WATERSHED IN MAINE. (R825762)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. 77 FR 46937 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain... bearing attachment. This AD requires repetitive inspections for cracking of the left-hand (LH) and right... Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC. FOR...

  20. Solid Lubricants for Space Structures

    DTIC Science & Technology

    1993-04-17

    will utilize mechanically interlocked hardware (caged bearings or bearings for ultra precision gimbals pointing mechanisms) controlled through precision...structure unless the lubricant were of low vapor pressure and/or suitably sealed to I prevent molecular effusion . While temperatures within spacecraft or...incorporation in the continuous cast system. The die made of graphite, consists of a plurality of openings or holes located in the die and positioned (unlined

  1. A Pilot Study of the Effectiveness of Indoor Plants for Removal of Volatile Organic Compounds in Indoor Air in a Seven-Story Office Building

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Apte, Michael G.; Apte, Joshua S.

    2010-04-27

    The Paharpur Business Centre and Software Technology Incubator Park (PBC) is a 7 story, 50,400 ft{sup 2} office building located near Nehru Place in New Delhi India. The occupancy of the building at full normal operations is about 500 people. The building management philosophy embodies innovation in energy efficiency while providing full service and a comfortable, safe, healthy environment to the occupants. Provision of excellent Indoor Air Quality (IAQ) is an expressed goal of the facility, and the management has gone to great lengths to achieve it. This is particularly challenging in New Delhi, where ambient urban pollution levels rankmore » among the worst on the planet. The approach to provide good IAQ in the building includes a range of technical elements: air washing and filtration of ventilation intake air from rooftop air handler, the use of an enclosed rooftop greenhouse with a high density of potted plants as a bio-filtration system, dedicated secondary HVAC/air handling units on each floor with re-circulating high efficiency filtration and UVC treatment of the heat exchanger coils, additional potted plants for bio-filtration on each floor, and a final exhaust via the restrooms located at each floor. The conditioned building exhaust air is passed through an energy recovery wheel and chemisorbent cartridge, transferring some heat to the incoming air to increase the HVAC energy efficiency. The management uses 'green' cleaning products exclusively in the building. Flooring is a combination of stone, tile and 'zero VOC' carpeting. Wood trim and finish appears to be primarily of solid sawn materials, with very little evidence of composite wood products. Furniture is likewise in large proportion constructed from solid wood materials. The overall impression is that of a very clean and well-kept facility. Surfaces are polished to a high sheen, probably with wax products. There was an odor of urinal cake in the restrooms. Smoking is not allowed in the building. The plants used in the rooftop greenhouse and on the floors were made up of a number of species selected for the following functions: daytime metabolic carbon dioxide (CO{sub 2}) absorption, nighttime metabolic CO{sub 2} absorption, and volatile organic compound (VOC) and inorganic gas absorption/removal for air cleaning. The building contains a reported 910 indoor plants. Daytime metabolic species reported by the PBC include Areca Palm, Oxycardium, Rubber Plant, and Ficus alii totaling 188 plants (21%). The single nighttime metabolic species is the Sansevieria with a total of 28 plants (3%). The 'air cleaning' plant species reported by the PBC include the Money Plant, Aglaonema, Dracaena Warneckii, Bamboo Palm, and Raphis Palm with a total of 694 plants (76%). The plants in the greenhouse (Areca Palm, Rubber Plant, Ficus alii, Bamboo Palm, and Raphis Palm) numbering 161 (18%) of those in the building are grown hydroponically, with the room air blown by fan across the plant root zones. The plants on the building floors are grown in pots and are located on floors 1-6. We conducted a one-day monitoring session in the PBC on January 1, 2010. The date of the study was based on availability of the measurement equipment that the researchers had shipped from Lawrence Berkeley National Lab in the U.S.A. The study date was not optimal because a large proportion of the regular building occupants were not present being New Year's Day. An estimated 40 people were present in the building all day during January 1. This being said, the building systems were in normal operations, including the air handlers and other HVAC components. The study was focused primarily on measurements in the Greenhouse and 3rd and 5th floor environments as well as rooftop outdoors. Measurements included a set of volatile organic compounds (VOCs) and aldehydes, with a more limited set of observations of indoor and outdoor particulate and carbon dioxide concentrations. Continuous measurements of Temperature (T) and relative humidity (RH) were made selected indoor and outdoor locations.« less

  2. 29. SITE BUILDING 002 SCANNER BUILDING FLOOR 3A ...

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

    29. SITE BUILDING 002 - SCANNER BUILDING - FLOOR 3A ("A" FACE) AT SYSTEM LAYOUT GRID 17. GENERAL OBLIQUE VIEW OF "A" FACE INTERIOR SHOWING RADAR EMITTER/ANTENNA INTERFACE ELECTRONICS. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  3. Technology Solutions Case Study: Investigating Solutions to Wind Washing Issues in Two-Story Florida Homes: Phase 2, Southeastern United States

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    In many two-story homes, there are attic spaces above the first-floor of the home that border portions of the second-story conditioned space. These spaces have breaches of the air and thermal boundaries, creating a phenomenon known as wind washing. This can cause attic air above the first-floor space to be driven into the cavity between the first and second floors by wind, thermal buoyancy forces, or mechanical driving forces as well as circulation of hot attic air against the wallboard because of gaps between insulation batts installed on knee walls and the gypsum wallboard. In this project, the U.S. Departmentmore » of Energy team Building America Partnership for Improved Residential Construction (BA-PIRC) investigated wind washing in 56 homes. The goals were to identify the failure mechanisms that lead to wind washing, characterize the pathways for air and heat to enter the house, and evaluate the seasonal energy savings and peak demand reduction that can result from repairing these wind washing problems. Based on this research, the team developed recommendations for cost-effective retrofit solutions and information that can help avoid these problems in new construction.« less

  4. Radon entry into basements: Approach, experimental structures, and instrumentation of the small structures research project

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fisk, W.J.; Modera, M.P.; Sextro, R.G.

    1992-02-01

    We describe the experimental approach, structures, and instrumentation of a research project on radon generation and transport in soil and entry into basements. The overall approach is to construct small precisely-fabricated basements in areas of different geology and climate, to control the pressures and ventilation rates in the structures, and to monitor radon concentrations and other relevant parameters over a period of one year or more. Two nearly air-tight structures have been constructed at the first site. The floor of each structure contains adjustable-width slots that serve as the only significant pathway for advective entry of radon. A layer ofmore » gravel underlays the floor of one structure; otherwise they are identical. The structures are instrumented for continuous or periodic monitoring of soil, structural, and meteorological parameters that affect radon entry. The pressure difference that drives advective radon entry can be maintained constant or varied over time. Soil gas and radon entry rates and associated parameters, such as soil gas pressures and radon concentrations, have been monitored for a range of steady-state and time-varying pressure differences between the interior of the structure and the soil. Examples of the experimentally-measured pressure and permeability fields in the soil around a structure are presented and discussed.« less

  5. An Overview of Magnetic Bearing Technology for Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    Clark, Daniel J.; Jansen, Mark J.; Montague, Gerald T.

    2004-01-01

    The idea of the magnetic bearing and its use in exotic applications has been conceptualized for many years, over a century, in fact. Patented, passive systems using permanent magnets date back over 150 years. More recently, scientists of the 1930s began investigating active systems using electromagnets for high-speed ultracentrifuges. However, passive magnetic bearings are physically unstable and active systems only provide proper stiffness and damping through sophisticated controllers and algorithms. This is precisely why, until the last decade, magnetic bearings did not become a practical alternative to rolling element bearings. Today, magnetic bearing technology has become viable because of advances in micro-processing controllers that allow for confident and robust active control. Further advances in the following areas: rotor and stator materials and designs which maximize flux, minimize energy losses, and minimize stress limitations; wire materials and coatings for high temperature operation; high-speed micro processing for advanced controller designs and extremely robust capabilities; back-up bearing technology for providing a viable touchdown surface; and precision sensor technology; have put magnetic bearings on the forefront of advanced, lubrication free support systems. This paper will discuss a specific joint program for the advancement of gas turbine engines and how it implies the vitality of magnetic bearings, a brief comparison between magnetic bearings and other bearing technologies in both their advantages and limitations, and an examination of foreseeable solutions to historically perceived limitations to magnetic bearing.

  6. First floor plan. (Also includes a door schedule and door ...

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

    First floor plan. (Also includes a door schedule and door elevations). March Air Force Base, Riverside, California, Combat Operations Center, Combat Operations Building. By Moffatt and Nichol, Engineers, 122 West Fifth Street, Long Beach, California; for the Corps of Engineers, U.S. Army, Office of the District Engineer, Los Angeles, California. Drawing no. AW-60-02-03, sheet no. 12, approved March 1962; specifications no. OCI-62-66; D.O. series AW 1596/12, Rev. "C"; file drawer 1290. Last revised 25 August 1975. Scale one-eighth inch to one foot. 28.5x 41 inches. pencil on paper - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  7. Cosmology with liquid mirror telescopes

    NASA Technical Reports Server (NTRS)

    Hogg, David W.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    Liquid mirrors provide an exciting means to obtain large optical telescopes for substantially lower costs than conventional technologies. The liquid mirror concept has been demonstrated in the lab with the construction of a diffraction limited 1.5 m mirror. The mirror surface, using liquid mercury, forms a perfect parabolic shape when the mirror cell is rotated at a uniform velocity. A liquid mirror must be able to support a heavy mercury load with minimal flexure and have a fundamental resonant frequency that is as high as possible, to suppress the amplitude of surface waves caused by small vibrations transmitted to the mirror. To minimize the transmission of vibrations to the liquid surface, the entire mirror rests on an air bearing. This necessitates the mirror cell being lightweight, due to the limited load capabilities of the air bearing. The mirror components must also have physical characteristics which minimize the effects of thermal expansion with ambient temperature fluctuations in the observatory. In addition, the 2.7 m mirror construction is designed so that the techniques used may be readily extended to the construction of large mirrors. To attain the goals of a lightweight, rigid mirror, a composite laminant construction was used. The mirror consists of a foam core cut to the desired parabolic shape, with an accuracy of a few mm. An aluminum hub serves as an anchor for the foam and skin, and allows precise centering of the mirror on the air bearing and drive system. Several plys of Kevlar, covered in an epoxy matrix, are then applied to the foam. A final layer of pure epoxy is formed by spin casting. This final layer is parabolic to within a fraction of a mm. An aluminum ring bonded to the circumference of the mirror retains the mercury, and incorporates stainless-steel hard-points for the attachment of balance weights.

  8. Forced-Air Warming Discontinued: Periprosthetic Joint Infection Rates Drop.

    PubMed

    Augustine, Scott D

    2017-06-23

    Several studies have shown that the waste heat from forced-air warming (FAW) escapes near the floor and warms the contaminated air resident near the floor. The waste heat then forms into convection currents that rise up and contaminate the sterile field above the surgical table. It has been shown that a single airborne bacterium can cause a periprosthetic joint infection (PJI) following joint replacement surgery. We retrospectively compared PJI rates during a period of FAW to a period of air-free conductive fabric electric warming (CFW) at three hospitals. Surgical and antibiotic protocols were held constant. The pooled multicenter data showed a decreased PJI rate of 78% following the discontinuation of FAW and a switch to air-free CFW (n=2034; P=0.002). The 78% reduction in joint implant infections observed when FAW was discontinued suggests that there is a link between the waste FAW heat and PJIs.

  9. Forced-Air Warming Discontinued: Periprosthetic Joint Infection Rates Drop

    PubMed Central

    Augustine, Scott D.

    2017-01-01

    Several studies have shown that the waste heat from forced-air warming (FAW) escapes near the floor and warms the contaminated air resident near the floor. The waste heat then forms into convection currents that rise up and contaminate the sterile field above the surgical table. It has been shown that a single airborne bacterium can cause a periprosthetic joint infection (PJI) following joint replacement surgery. We retrospectively compared PJI rates during a period of FAW to a period of air-free conductive fabric electric warming (CFW) at three hospitals. Surgical and antibiotic protocols were held constant. The pooled multicenter data showed a decreased PJI rate of 78% following the discontinuation of FAW and a switch to air-free CFW (n=2034; P=0.002). The 78% reduction in joint implant infections observed when FAW was discontinued suggests that there is a link between the waste FAW heat and PJIs. PMID:28713524

  10. Fungi of the house dust in Riyadh, Saudi Arabia.

    PubMed

    Saad, R R; el-Gindy, A A

    1990-01-01

    30 species belonging to 18 genera were isolated from floor dust of 30 homes in Riyadh. Out of them 16 species and 10 genera were isolated from dust of air conditioners of the same homes. The most common genera in floor dust were Aspergillus, Penicillium and Cladosporium. Aspergillus repens, A. amstelodami, A. versicolor, A. fumigatus, Penicillium purpurogenum, P. crustosum, Cladosporium cladosporoides and C. herbarum were frequently isolated. The most abundant genera in air conditioner dust were Aspergillus and Penicillium. Aspergillus fumigatus, A. ochraceus, A. terreus, Penicillium oxalicium and P. crustosum were most frequent species.

  11. Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry

    PubMed Central

    Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

    2016-01-01

    Objective: Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Methods: Twenty automotive workers were individually fitted out with three different pairs of safety shoes ( "normal" shoes, cushioned shoes, and midfoot bearing shoes). They walked at a given speed of 1.5 m/s. The CUELA measuring system and shoe insoles were used for gait analysis and plantar pressure measurements, respectively. Statistical analysis was conducted by ANOVA analysis for repeated measures. Results: Walking with cushioned safety shoes or a midfoot bearing safety shoe led to a significant decrease of the average trunk inclination (p<0.005). Furthermore, the average hip flexion angle decreased for cushioned shoes as well as midfoot bearing shoes (p<0.002). The range of motion of the knee joint increased for cushioned shoes. As expected, plantar pressure distributions varied significantly between cushioned or midfoot bearing shoes and shoes without ergonomic components. Conclusion: The overall function of safety shoes is the avoidance of injury in case of an industrial accident, but in addition, safety shoes could be a long-term preventive instrument for maintaining health of the employees' musculoskeletal system, as they are able to affect gait parameters. Further research needs to focus on safety shoes in working situations. PMID:27488038

  12. Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry.

    PubMed

    Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

    2016-09-30

    Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Twenty automotive workers were individually fitted out with three different pairs of safety shoes ( "normal" shoes, cushioned shoes, and midfoot bearing shoes). They walked at a given speed of 1.5 m/s. The CUELA measuring system and shoe insoles were used for gait analysis and plantar pressure measurements, respectively. Statistical analysis was conducted by ANOVA analysis for repeated measures. Walking with cushioned safety shoes or a midfoot bearing safety shoe led to a significant decrease of the average trunk inclination (p<0.005). Furthermore, the average hip flexion angle decreased for cushioned shoes as well as midfoot bearing shoes (p<0.002). The range of motion of the knee joint increased for cushioned shoes. As expected, plantar pressure distributions varied significantly between cushioned or midfoot bearing shoes and shoes without ergonomic components. The overall function of safety shoes is the avoidance of injury in case of an industrial accident, but in addition, safety shoes could be a long-term preventive instrument for maintaining health of the employees' musculoskeletal system, as they are able to affect gait parameters. Further research needs to focus on safety shoes in working situations.

  13. Carpet vs. Hard Surface Floors: Studies Compare Health Effects of Each.

    ERIC Educational Resources Information Center

    Schmidt, Edward A.

    1994-01-01

    This article, third in a three-part series of articles that discuss indoor air quality (IAQ) issues affecting schools, looks at studies that compare the health effect of carpet and hard surface floors. Concludes that carpet is appropriate for use in schools when it is properly maintained. (MLF)

  14. 49 CFR 38.73 - Doorways.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... inches and the height of the vehicle floor shall be within plus or minus 5/8 inch of the platform height. Vertical alignment may be accomplished by vehicle air suspension, automatic ramps or lifts, or any combination. (2) Exception. New vehicles operating in existing stations may have a floor height within plus or...

  15. 49 CFR 38.73 - Doorways.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inches and the height of the vehicle floor shall be within plus or minus 5/8 inch of the platform height. Vertical alignment may be accomplished by vehicle air suspension, automatic ramps or lifts, or any combination. (2) Exception. New vehicles operating in existing stations may have a floor height within plus or...

  16. 49 CFR 38.73 - Doorways.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... inches and the height of the vehicle floor shall be within plus or minus 5/8 inch of the platform height. Vertical alignment may be accomplished by vehicle air suspension, automatic ramps or lifts, or any combination. (2) Exception. New vehicles operating in existing stations may have a floor height within plus or...

  17. 49 CFR 38.73 - Doorways.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... inches and the height of the vehicle floor shall be within plus or minus 5/8 inch of the platform height. Vertical alignment may be accomplished by vehicle air suspension, automatic ramps or lifts, or any combination. (2) Exception. New vehicles operating in existing stations may have a floor height within plus or...

  18. A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Zaldana, Antonio R.; Radil, Kevin C.

    2002-01-01

    Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.

  19. Evaluation of chromium oxide and molybdenum disulfide coatings in self-acting stops of an air-lubricated Rayleigh step thrust bearing

    NASA Technical Reports Server (NTRS)

    Nemeth, Z. N.

    1974-01-01

    Two coatings for a Rayleigh step thrust bearing were tested when coasting down and stopping under self-acting operation in air. The thrust bearing had an outside diameter of 8.9 cm (3.5 in.), an inside diameter of 5.4 cm (2.1 in.), and nine sectors. The load was 73 N (16.4 lbf). The load pressure was 19.1 kN/per square meter (2.77 lbf/per square inch) on the total thrust bearing area. The chromium oxide coating was good to 150 stops without bearing deterioration, and the molybdenum disulfide coating was good for only four stops before bearing deterioration. The molybdenum disulfide coated bearing failed after nine stops.

  20. Pressure measurements of a three wave journal air bearing

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin; Addy, Harold E., Jr.

    1994-01-01

    In order to validate theoretical predictions of a wave journal bearing concept, a bench test rig was assembled at NASA Lewis Research Center to measure the steady-state performance of a journal air bearing. The tester can run up to 30,000 RPM and the spindle has a run out of less than 1 micron. A three wave journal bearing (50 mm diameter and 58 mm length) has been machined at NASA Lewis. The pressures at 16 ports along the bearing circumference at the middle of the bearing length were measured and compared to the theoretical prediction. The bearing ran at speeds up to 15,000 RPM and certain loads. Good agreement was found between the measured and calculated pressures.

  1. Oil-Free Turbomachinery Research Enhanced by Thrust Bearing Test Capability

    NASA Technical Reports Server (NTRS)

    Bauman, Steven W.

    2003-01-01

    NASA Glenn Research Center s Oil-Free Turbomachinery research team is developing aircraft turbine engines that will not require an oil lubrication system. Oil systems are required today to lubricate rolling-element bearings used by the turbine and fan shafts. For the Oil-Free Turbomachinery concept, researchers combined the most advanced foil (air) bearings from industry with NASA-developed high-temperature solid lubricant technology. In 1999, the world s first Oil-Free turbocharger was demonstrated using these technologies. Now we are working with industry to demonstrate Oil-Free turbomachinery technology in a small business jet engine, the EJ-22 produced by Williams International and developed during Glenn s recently concluded General Aviation Propulsion (GAP) program. Eliminating the oil system in this engine will make it simpler, lighter (approximately 15 percent), more reliable, and less costly to purchase and maintain. Propulsion gas turbines will place high demands on foil air bearings, especially the thrust bearings. Up until now, the Oil-Free Turbomachinery research team only had the capability to test radial, journal bearings. This research has resulted in major improvements in the bearings performance, but journal bearings are cylindrical, and can only support radial shaft loads. To counteract axial thrust loads, thrust foil bearings, which are disk shaped, are required. Since relatively little research has been conducted on thrust foil air bearings, their performance lags behind that of journal bearings.

  2. Experimental analysis of the bearing greases lifetime

    NASA Astrophysics Data System (ADS)

    Albagachiev, A. U.; Smirnov, N. I.; Prozhega, M. V.; Smirnov, N. N.

    2018-04-01

    The purpose of the presented work is to increase the lifetime of space mechanisms bearings. The authors reviewed the studies of the bearings and linear mechanisms operating in air and in vacuum. A testing equipment is developed to assess the lubricity and lifetime of greases in the air. Criteria for the evaluation of relative lifetime are defined. Four types of space greases are tested.

  3. PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

    PubMed Central

    Rudel, Ruthann A; Seryak, Liesel M; Brody, Julia G

    2008-01-01

    Background Polychlorinated biphenyls (PCBs) are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. PCBs were also used widely in building materials, including caulks and paints, but few studies have evaluated the contribution of these exposures to body burden. Methods In an earlier study, we detected PCBs in indoor air in 31% of 120 homes on Cape Cod, MA. Two of the homes had much higher concentrations than the rest, so we retested to verify the initial finding, evaluate blood PCB concentrations of residents, and identify the PCB source. Results Air and dust concentrations remained elevated over 5 years between initial and follow-up sampling. Blood serum concentrations of PCBs in residents of the homes were generally elevated above the 95th percentile of a representative sample of the US population. Serum concentrations in residents and air and dust concentrations were especially high in a home where a resident reported use of PCB-containing floor finish in the past, and where the floor of one room was sanded and refinished just prior to sample collection. Conclusion This case-study suggests that PCB residues in homes may be more significant contributors to overall exposure than diet for some people, and that use of a commercially-available PCB-containing wood floor finish in residences during the 1950s and 1960s is an overlooked but potentially important source of current PCB exposure in the general population. PMID:18201376

  4. Safety by design: effects of operating room floor marking on the position of surgical devices to promote clean air flow compliance and minimise infection risks.

    PubMed

    de Korne, Dirk F; van Wijngaarden, Jeroen D H; van Rooij, Jeroen; Wauben, Linda S G L; Hiddema, U Frans; Klazinga, Niek S

    2012-09-01

    To evaluate the use of floor marking on the positioning of surgical devices within the clean air flow in an operating room (OR) to minimise infection risk. Laminar flow clean air systems are important in preventing infection in ORs but, for optimal results, surgical devices must be correctly positioned. The authors evaluated floor marking in four ORs at an eye hospital using time series analysis. Through observations during 829 surgeries over a 20-month period, the positions of surgical devices were determined. Eight semistructured interviews with surgical staff were conducted to assess user experiences and team dynamics. Before marking, the instrument table was positioned completely within the laminar flow in only 6.1% of the cases. This increased to 36.1% and finally 53.8%. Mayo stands were increasingly positioned within the laminar flow: from 74.2% to 84.7%. The surgical lamp decreasingly obstructed flow: from 41.8% to 28.7%. At T3 (20 months), however, in 48.6% of the applicable cases the lamp was positioned in the flow again. Discussions and site visits between airside operators and surgical staff resulted in increasing awareness of specific risk areas in the OR. OR floor markings facilitated and stimulated safety awareness and resulted in significantly increased compliance with the positioning of surgical devices in the clean air flow. Safety and quality approaches in hospital care, therefore, should include a human factors approach that focuses on system design in addition to teaching clinical and non-technical skills.

  5. Navier-Stokes Simulation of Airconditioning Facility of a Large Modem Computer Room

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA recently assembled one of the world's fastest operational supercomputers to meet the agency's new high performance computing needs. This large-scale system, named Columbia, consists of 20 interconnected SGI Altix 512-processor systems, for a total of 10,240 Intel Itanium-2 processors. High-fidelity CFD simulations were performed for the NASA Advanced Supercomputing (NAS) computer room at Ames Research Center. The purpose of the simulations was to assess the adequacy of the existing air handling and conditioning system and make recommendations for changes in the design of the system if needed. The simulations were performed with NASA's OVERFLOW-2 CFD code which utilizes overset structured grids. A new set of boundary conditions were developed and added to the flow solver for modeling the roomls air-conditioning and proper cooling of the equipment. Boundary condition parameters for the flow solver are based on cooler CFM (flow rate) ratings and some reasonable assumptions of flow and heat transfer data for the floor and central processing units (CPU) . The geometry modeling from blue prints and grid generation were handled by the NASA Ames software package Chimera Grid Tools (CGT). This geometric model was developed as a CGT-scripted template, which can be easily modified to accommodate any changes in shape and size of the room, locations and dimensions of the CPU racks, disk racks, coolers, power distribution units, and mass-storage system. The compute nodes are grouped in pairs of racks with an aisle in the middle. High-speed connection cables connect the racks with overhead cable trays. The cool air from the cooling units is pumped into the computer room from a sub-floor through perforated floor tiles. The CPU cooling fans draw cool air from the floor tiles, which run along the outside length of each rack, and eject warm air into the center isle between the racks. This warm air is eventually drawn into the cooling units located near the walls of the room. One major concern is that the hot air ejected to the middle isle might recirculate back into the cool rack side and cause thermal short-cycling. The simulations analyzed and addressed the following important elements of the computer room: 1) High-temperature build-up in certain regions of the room; 2) Areas of low air circulation in the room; 3) Potential short-cycling of the computer rack cooling system; 4) Effectiveness of the perforated cooling floor tiles; 5) Effect of changes in various aspects of the cooling units. Detailed flow visualization is performed to show temperature distribution, air-flow streamlines and velocities in the computer room.

  6. Wolfhounds and Polar Bears in Siberia: America’s Military Intervention, 1918-1920

    DTIC Science & Technology

    1986-01-01

    including sable, sea otter, otter, beaver, mink, muskrat, squirrel, fox, skunk, woodchuck, marmot , badger, glutton, and rabbit. Vast forests provided wood for...venti- lated, heated, and lighted. A kitchen was found on the end of each floor in the barracks. Latrines drained into open cesspools. Wood burning

  7. The effect of differing support surfaces on the efficacy of chest compressions using a resuscitation manikin model.

    PubMed

    Tweed, M; Tweed, C; Perkins, G D

    2001-11-01

    External chest compression (ECC) efficacy is influenced by factors including the surface supporting the patient. Air-filled support surfaces are deflated for cardiopulmonary resuscitation, with little evidence to substantiate this. We investigated the effect that differing support surfaces had on ECC efficacy using a CPR manikin model. Four participants carried out four cycles of ECC with an assistant ventilating. The subjects were blinded to the seven support surfaces and the order was randomised. For each participant/surface combination, ECC variables and the participants' perceptions were measured. Participants produced effective ECC with the manikin on the floor (mean proportion correct, 94.5%; mean depth, 42.5 mm). Compared with the floor: the proportion of correct ECC was less for the overlay inflated (P<0.05); the depth of ECC was less effective (30-37 mm) for the overlay inflated/deflated and low-air-loss inflated and foam mattresses (P<0.05). The foam mattress, overlay inflated/deflated, and low-air-loss inflated were perceived as being less stable and as having reduced ECC efficacy compared with the floor. There was no difference or agreement, regarding subjects' perceptions or ECC variables, between the support surfaces or between inflated/deflated air-filled support surfaces. The efficacy of ECC is affected by the support surfaces. There seems little evidence to substantiate deflating all air-filled support surfaces for CPR.

  8. A Novel Method of Orbital Floor Reconstruction Using Virtual Planning, 3-Dimensional Printing, and Autologous Bone.

    PubMed

    Vehmeijer, Maarten; van Eijnatten, Maureen; Liberton, Niels; Wolff, Jan

    2016-08-01

    Fractures of the orbital floor are often a result of traffic accidents or interpersonal violence. To date, numerous materials and methods have been used to reconstruct the orbital floor. However, simple and cost-effective 3-dimensional (3D) printing technologies for the treatment of orbital floor fractures are still sought. This study describes a simple, precise, cost-effective method of treating orbital fractures using 3D printing technologies in combination with autologous bone. Enophthalmos and diplopia developed in a 64-year-old female patient with an orbital floor fracture. A virtual 3D model of the fracture site was generated from computed tomography images of the patient. The fracture was virtually closed using spline interpolation. Furthermore, a virtual individualized mold of the defect site was created, which was manufactured using an inkjet printer. The tangible mold was subsequently used during surgery to sculpture an individualized autologous orbital floor implant. Virtual reconstruction of the orbital floor and the resulting mold enhanced the overall accuracy and efficiency of the surgical procedure. The sculptured autologous orbital floor implant showed an excellent fit in vivo. The combination of virtual planning and 3D printing offers an accurate and cost-effective treatment method for orbital floor fractures. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  9. A comparison between the dimensions of positive transtibial residual limb molds prepared by air pressure casting and weight-bearing casting methods.

    PubMed

    Hajiaghaei, Behnam; Ebrahimi, Ismail; Kamyab, Mojtaba; Saeedi, Hassan; Jalali, Maryam

    2016-01-01

    Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.

  10. Low-cost Radon Reduction Pilot Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rose, William B.; Francisco, Paul W.; Merrin, Zachary

    The U.S. Department of Energy's Building America research team Partnership for Advanced Residential Retrofits conducted a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation and living space floor assembly. Fifteen homes in the Champaign, Illinois, area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity measurements. Blower door and zone pressure diagnostics were conducted at each house. The treatments consisted of using air-sealing foams at the underside of the floor that separated the living space frommore » the foundation and providing duct sealing on the ductwork that is situated in the foundation area. The hypothesis was that air sealing the floor system that separated the foundation from the living space should better isolate the living space from the foundation; this isolation should lead to less radon entering the living space from the foundation. If the hypothesis had been proven, retrofit energy-efficiency programs may have chosen to adopt these isolation methods for enhanced radon protection to the living space.« less

  11. 24. Interior view of entrance corridor looking down east corridor; ...

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

    24. Interior view of entrance corridor looking down east corridor; showing unoccupied corner office space and stairs going down to lower floor; center of main section of building on main floor; view to northeast. - Ellsworth Air Force Base, Group Administration & Secure Storage Building, 2372 Westover Avenue, Blackhawk, Meade County, SD

  12. 24. View of lobby area on first floor transmitter building ...

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

    24. View of lobby area on first floor transmitter building no. 102 looking into controlled access corridor and door system - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  13. 30. View of mezzanine floor level in transmitter building no. ...

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

    30. View of mezzanine floor level in transmitter building no. 102 showing control transmitter electronic cabinets and control modules. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  14. Air-Bearing-Piston Suspension System

    NASA Technical Reports Server (NTRS)

    Mullen, Donald; Bishop, Stephen J.

    1992-01-01

    Suspension system based on air-bearing piston holds up steel ball against gravitation while allowing ball to translate vertically and rotate freely. System designed to simulate effect of microgravity on ball. Applicable to suppression of vibrations and delicate machining processes.

  15. The Effect of Journal Roughness and Foil Coatings on the Performance of Heavily Loaded Foil Air Bearings

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.; DellaCorte, Christopher

    2001-01-01

    Foil air bearing load capacity tests were conducted to investigate if a solid lubricant coating applied to the surface of the bearing's top foil can function as a break-in coating. Two foil coating materials, a conventional soft polymer film (polyimide) and a hard ceramic (alumina), were independently evaluated against as-ground and worn (run-in) journals coated with NASA PS304, a high-temperature solid lubricant composite coating. The foil coatings were evaluated at journal rotational speeds of 30,000 rpm and at 25 C. Tests were also performed on a foil bearing with a bare (uncoated) nickel-based superalloy top foil to establish a baseline for comparison. The test results indicate that the presence of a top foil solid lubricant coating is effective at increasing the load capacity performance of the foil bearing. Compared to the uncoated baseline, the addition of the soft polymer coating on the top foil increased the bearing load coefficient by 120% when operating against an as-ground journal surface and 85 percent against a run-in journal surface. The alumina coating increased the load coefficient by 40% against the as-ground journal but did not have any affect when the bearing was operated with the run-in journal. The results suggest that the addition of solid lubricant films provide added lubrication when the air film is marginal indicating that as the load capacity is approached foil air bearings transition from hydrodynamic to mixed and boundary lubrication.

  16. 78 FR 17082 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbojet Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... flight. (5) If you find any broken bolt in the HPT shaft air seal sleeve, visually inspect the HPT stage... assembly, high pressure turbine (HPT) bearing support assembly and HPT air seal sleeve bolts identified... turbine (HPT) bearing support assembly, and HPT air seal sleeve within 100 engine cycles-in-service. (2...

  17. 77 FR 66769 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbojet Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    .... (5) If any bolt is found broken in the HPT shaft air seal sleeve, inspect the HPT stage 1 disc for...) bearing support assembly and HPT air seal sleeve bolts identified that, before installation, those bolts... assembly, high-pressure turbine (HPT) bearing support assembly, and HPT air seal sleeve. (2) If engine...

  18. Looking North at Reactor Number One and Air Vent on ...

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

    Looking North at Reactor Number One and Air Vent on Fourth Floor of Oxide Building - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO

  19. Effect of forced-air warming on the performance of operating theatre laminar flow ventilation.

    PubMed

    Dasari, K B; Albrecht, M; Harper, M

    2012-03-01

    Forced-air warming exhaust may disrupt operating theatre airflows via formation of convection currents, which depends upon differences in exhaust and operating room air temperatures. We investigated whether the floor-to-ceiling temperatures around a draped manikin in a laminar-flow theatre differed when using three types of warming devices: a forced-air warming blanket (Bair Hugger™); an over-body conductive blanket (Hot Dog™); and an under-body resistive mattress (Inditherm™). With forced-air warming, mean (SD) temperatures were significantly elevated over the surgical site vs those measured with the conductive blanket (+2.73 (0.7) °C; p<0.001) or resistive mattress (+3.63 (0.7) °C; p<0.001). Air temperature differences were insignificant between devices at floor (p=0.339), knee (p=0.799) and head height levels (p=0.573). We conclude that forced-air warming generates convection current activity in the vicinity of the surgical site. The clinical concern is that these currents may disrupt ventilation airflows intended to clear airborne contaminants from the surgical site. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

  20. Investigation of Pressurized Wave Bearings

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Dimofte, Florin

    2003-01-01

    The wave bearing has been pioneered and developed by Dr. Dimofte over the past several years. This bearing will be the main focus of this research. It is believed that the wave bearing offers a number of advantages over the foil bearing, which is the bearing that NASA is currently pursuing for turbomachinery applications. The wave bearing is basically a journal bearing whose film thickness varies around the circumference approximately sinusoidally, with usually 3 or 4 waves. Being a rigid geometry bearing, it provides precise control of shaft centerlines. The wave profile also provides good load capacity and makes the bearing very stable. Manufacturing techniques have been devised that should allow the production of wave bearings almost as cheaply as conventional full-circular bearings.

  1. Start-stop testing of two self-acting air-lubricated spiral groove thrust bearing coatings

    NASA Technical Reports Server (NTRS)

    Dunfee, J. D.; Shapiro, W.

    1974-01-01

    Start-stop tests were conducted on air-lubricated spiral-groove thrust bearings. Application of a matrix-bonded molybdenum disulfide (MoS2) coating over a porous chrome oxide coating resulted in significantly lower friction, compared to bearings coated with chrome oxide only. The MoS2 coated bearing sustained 15,000 start-stop cycles at a maximum of 3600 rpm. Each cycle was 15 seconds on, 30 seconds off. The chrome oxide coated bearing failed by local welding after 2030 cycles. Both types of coatings exhibited early failures under higher thrust loads when operating films were insufficient to sustain the load without overheating.

  2. Applicability of the environmental relative moldiness index for quantification of residential mold contamination in an air pollution health effects study.

    PubMed

    Kamal, Ali; Burke, Janet; Vesper, Stephen; Batterman, Stuart; Vette, Alan; Godwin, Christopher; Chavez-Camarena, Marina; Norris, Gary

    2014-01-01

    The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigated the impact of exposure to traffic-related air pollution on the respiratory health of asthmatic children in Detroit, Michigan. Since indoor mold exposure may also contribute to asthma, floor dust samples were collected in participants homes (n = 112) to assess mold contamination using the Environmental Relative Moldiness Index (ERMI). The repeatability of the ERMI over time, as well as ERMI differences between rooms and dust collection methods, was evaluated for insights into the application of the ERMI metric. ERMI values for the standard settled floor dust samples had a mean ± standard deviation of 14.5 ± 7.9, indicating high levels of mold contamination. ERMI values for samples collected from the same home 1 to 7 months apart (n = 52) were consistent and without systematic bias. ERMI values for separate bedroom and living room samples were highly correlated (r = 0.69, n = 66). Vacuum bag dust ERMI values were lower than for floor dust but correlated (r = 0.58, n = 28). These results support the use of the ERMI to evaluate residential mold exposure as a confounder in air pollution health effects studies.

  3. 40 CFR 85.2222 - On-board diagnostic test procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... 85.2222 Section 85.2222 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Control System Performance... inspected at the EPA Docket No. A-94-21 at EPA's Air Docket (LE-131), Room 1500 M, 1st Floor, Waterside Mall...

  4. A new magnetic bearing using Halbach magnet arrays for a magnetic levitation stage.

    PubMed

    Choi, Young-Man; Lee, Moon G; Gweon, Dae-Gab; Jeong, Jaehwa

    2009-04-01

    Next-generation lithography requires a high precision stage, which is compatible with a high vacuum condition. A magnetic levitation stage with six degrees-of-freedom is considered state-of-the-art technology for a high vacuum condition. The noncontact characteristic of magnetic levitation enables high precision positioning as well as no particle generation. To position the stage against gravity, z-directional electromagnetic levitation mechanisms are widely used. However, if electromagnetic actuators for levitation are used, heat is inevitably generated, which deforms the structures and degrades accuracy of the stage. Thus, a gravity compensator is required. In this paper, we propose a new magnetic bearing using Halbach magnet arrays for a magnetic levitation stage. The novel Halbach magnetic bearing exerts a force four times larger than a conventional magnetic bearing with the same volume. We also discuss the complementary characteristics of the two magnetic bearings. By modifying the height of the center magnet in a Halbach magnetic bearing, a performance compromise between levitating force density and force uniformity is obtained. The Halbach linear active magnetic bearing can be a good solution for magnetic levitation stages because of its large and uniform levitation force.

  5. Planar air-bearing microgravity simulators: Review of applications, existing solutions and design parameters

    NASA Astrophysics Data System (ADS)

    Rybus, Tomasz; Seweryn, Karol

    2016-03-01

    All devices designed to be used in space must be thoroughly tested in relevant conditions. For several classes of devices the reduced gravity conditions are the key factor. In early stages of development and later due to financial reasons, the tests need to be done on Earth. However, in Earth conditions it is impossible to obtain a different gravity field independent on all linear and rotational spatial coordinates. Therefore, various test-bed systems are used, with their design driven by the device's specific needs. One of such test-beds are planar air-bearing microgravity simulators. In such an approach, the tested objects (e.g., manipulators intended for on-orbit operations or vehicles simulating satellites in a close formation flight) are mounted on planar air-bearings that allow almost frictionless motion on a flat surface, thus simulating microgravity conditions in two dimensions. In this paper we present a comprehensive review of research activities related to planar air-bearing microgravity simulators, demonstrating achievements of the most active research groups and describing newest trends and ideas, such as tests of landing gears for low-g bodies. Major design parameters of air-bearing test-beds are also reviewed and a list of notable existing test-beds is presented.

  6. 53. Intersection of H (right) and D (left) corridor, second ...

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

    53. Intersection of H (right) and D (left) corridor, second floor, building 500, looking northwest - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  7. History of ball bearings

    NASA Technical Reports Server (NTRS)

    Dowson, D.; Hamrock, B. J.

    1981-01-01

    The familiar precision rolling-element bearings of the twentieth century are products of exacting technology and sophisticated science. Their very effectiveness and basic simplicity of form may discourage further interest in their history and development. Yet the full story covers a large portion of recorded history and surprising evidence of an early recognition of the advantages of rolling motion over sliding action and progress toward the development of rolling-element bearings. The development of rolling-element bearings is followed from the earliest civilizations to the end of the eighteenth century. The influence of general technological developments, particularly those concerned with the movement of large building blocks, road transportation, instruments, water-raising equipment, and windmills are discussed, together with the emergence of studies of the nature of rolling friction and the impact of economic factors. By 1800 the essential features of ball and rolling-element bearings had emerged and it only remained for precision manufacture and mass production to confirm the value of these fascinating machine elements.

  8. Consideration of Alternate Working Fluid Properties in Gas Lubricated Foil Journal Bearings

    NASA Technical Reports Server (NTRS)

    Smith, Matthew J.

    2004-01-01

    The Oil-Free Turbomachinery Program at the NASA Glenn Research center is committed to, revolutionary improvements in performance, efficiency and reliability of turbomachinery propulsion systems. One of the key breakthroughs by which this goal is being achieved is the maturation of air lubricated foil bearing technology. Through experimental testing, foil bearings have demonstrated a variety of exceptional qualities that show them to have an important role in the future of rotordynamic lubrication. Most of the work done with foil bearings thus far has considered ambient air at atmospheric pressure as the working fluid or lubricating fluid in the bearing. However, special applications of oil-free technology require the use of air at non- standard ambient conditions or completely different working fluids altogether. The NASA Jupiter Icy Moon Orbiter program presents power generation needs far beyond that of any previous space exploration effort. The proposed spacecraft will require significant power generation to provide the propulsion necessary to reach the moons of Jupiter and navigate between them. Once there, extensive scientific research will be conducted that will also present significant power requirements. Such extreme needs require exploring a new method for power generation in space. A proposed solution involves a Brayton cycle nuclear fission reactor. The nature of this application requires reliable performance of all reactor components for many years of operation under demanding conditions. This includes the bearings which will be operating with an alternative working fluid that is a combination of Helium and Xenon gases commonly known as HeXe. This fluid has transport and thermal properties that vary significantly from that of air and the effect of these property differences on bearing performance must be considered. One of the most promising applications of oil-free technology is in aircraft turbine engines. Eliminating the oil supply systems from aircraft engines will lead to significant weight and maintenance reduction. In such applications, the lubricating fluid will be high altitude air. This air will be at much lower pressure than that at sea level. Again this property change will result in a change in bearing performance, and analysis is required to quantify this effect. The study of these alternate working fluid properties will be conducted in two ways: analytically and experimentally. Analytical research will include the use of a mathematical code that can predict film thickness profiles for various ambient conditions. Estimations of load capacity can be made based upon the film thickness trends. These values will then be compared to those obtained from classical rigid bearing analysis. Experimental Research will include testing a foil bearing at a variety of ambient air pressures. The analytical and experimental data will be compared to draw conclusions on bearing performance under alternate working fluid properties.

  9. 75 FR 19307 - Safety Zone; Milwaukee Air and Water Show, Milwaukee, Lake Michigan, Milwaukee, WI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ... Management Facility (M-30), U.S. Department of Transportation, West Building Ground Floor, Room W12-140, 1200... shape in the ``Actions'' column. If you submit your comments by mail or hand delivery, submit them in an... ground floor of the Department of Transportation West Building, 1200 New Jersey Avenue, SE., Washington...

  10. An Experimental Investigation Into the Temperature Profile of a Compliant Foil Air Bearing

    NASA Technical Reports Server (NTRS)

    Radil, Kevin; Zeszotek, Michelle

    2004-01-01

    A series of tests was performed to determine the internal temperature profile in a compliant bump-type foil journal air bearing operating at room temperature under various speeds and load conditions. The temperature profile was collected by instrumenting a foil bearing with nine, type K thermocouples arranged in the center and along the bearing s edges in order to measure local temperatures and estimate thermal gradients in the axial and circumferential directions. To facilitate the measurement of maximum temperatures from viscous shearing in the air film, the thermocouples were tack welded to the backside of the bumps that were in direct contact with the top foil. The mating journal was coated with a high temperature solid lubricant that, together with the bearing, underwent high temperature start-stop cycles to produce a smooth, steady-state run-in surface. Tests were conducted at speeds from 20 to 50 krpm and loads ranging from 9 to 222 N. The results indicate that, over the conditions tested, both journal rotational speed and radial load are responsible for heat generation with speed playing a more significant role in the magnitude of the temperatures. The temperature distribution was nearly symmetric about the bearing center at 20 and 30 krpm but became slightly skewed toward one side at 40 and 50 krpm. Surprisingly, the maximum temperatures did not occur at the bearing edge where the minimum film thickness is expected but rather in the middle of the bearing where analytical investigations have predicted the air film to be much thicker. Thermal gradients were common during testing and were strongest in the axial direction from the middle of the bearing to its edges, reaching 3.78 8C/mm. The temperature profile indicated the circumferential thermal gradients were negligible.

  11. System Being Developed to Measure the Rotordynamic Characteristics of Air Foil Bearings

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; DellaCorte, Christopher; Valco, Mark J.

    2000-01-01

    Because of the many possible advantages of oil-free engine operation, interest in using air lubricated foil-bearing technology in advanced oil-free engine concepts has recently increased. The Oil-Free Turbomachinery Program at the NASA Glenn Research Center at Lewis Field has partially driven this recent push for oil-free technology. The program's goal of developing an innovative, practical, oil-free gas turbine engine for aeropropulsion began with the development of NASA's high-temperature solid-lubricant coating, PS304. This coating virtually eliminates the life-limiting wear that occurs during the startup and shutdown of the bearings. With practically unlimited life, foil air bearings are now very attractive to rotating machinery designers for use in turbomachinery. Unfortunately, the current knowledge base of these types of bearings is limited. In particular, the understanding of how these types of bearings contribute to the rotordynamic stability of turbomachinery is insufficient for designers to design with confidence. Recent work in oil-free turbomachinery has concentrated on advancing the understanding of foil bearings. A high-temperature fiber-optic displacement probe system and measurement method were developed to study the effects of speed, load, temperature, and other environmental issues on the stiffness characteristics of air foil bearings. Since high temperature data are to be collected in future testing, the testing method was intentionally simplified to minimize the need for expensive test hardware. The method measures the displacement induced upon a bearing in response to an applied perturbation load. The early results of these studies, which are shown in the accompanying figure, indicate trends in steady state stiffness that suggest stiffness increases with load and decreases with speed. It can be seen, even from these data, that stiffness is not expected to change by orders of magnitude over the normal operating range of most turbomachinery; a promising sign for their eventual integration into oil-free turbomachines. Planned future testing will generate similar plots for stiffness changes with temperature and geometry, as well as damping data. The data collected by this method represent a critical step toward understanding how to successfully apply foil air bearings to future oil-free turbomachinery systems.

  12. Six Basic Plan Concepts Used for California School Housing. A Sequential Development from 1900 to Today.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Bureau of School Planning.

    A floor plan accompanies each of six chronologically arranged schemes for housing educational programs. Scheme A represents the in-line corridor plan whose main characteristics are--(1) double loaded corridors with fixed bearing walls, (2) single window walls providing minimal light and ventilation, and (3) small classrooms with fixed desks and…

  13. 30. SITE BUILDING 002 SCANNER BUILDING FLOOR 3A ...

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

    30. SITE BUILDING 002 - SCANNER BUILDING - FLOOR 3A ("A" FACE) INTERIOR BETWEEN GRIDS 17-A1 AND 18-A1, SHOWING REAR OF RADAR EMITTER ELECTRONIC INTERFACE TERMINAL NO. 3147-20, "RECEIVER TRANSMITTER RADAR" MODULE. VIEW IS ALSO SHOWING BUILDING FIRE STOP MATERIAL AT BOTTOM OF FLOOR. NOTE: WALL SLOPES BOTTOM TO TOP INWARD; STRUCTURAL ELEMENT IN FOREGROUND. VIEW ALSO SHOWS PIPING GRID OF CHILLED WATER LINES FOR ELECTRONIC SYSTEMS COOLING. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  14. Pneumo MSG-325 Lathe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rhorer, R.L.

    1980-01-01

    The LASL Shop Department has recently installed a Pneumo MSG-325 two-axis contouring lathe. This one-microinch resolution lathe, which utilizes both air-bearing spindle and air bearing slide ways, was purchased primarily for miniature work, but can also single point diamond turn metal optics.

  15. New paradigm for patient-reported outcomes assessment in foot & ankle research: computerized adaptive testing.

    PubMed

    Hung, Man; Nickisch, Florian; Beals, Timothy C; Greene, Tom; Clegg, Daniel O; Saltzman, Charles L

    2012-08-01

    Accurately measuring, reporting and comparing outcomes is essential for improving health care delivery. Current challenges with available health status scales include patient fatigue, floor/ceiling effects and validity/reliability. This study compared Patient Reported Outcomes Measurement Information System (PROMIS)-based Lower Extremity Physical Function Computerized Adaptive Test (LE CAT) and two legacy scales -the Foot and Function Index (FFI) and the sport module from the Foot and Ankle Ability Measure (spFAAM) -for 287 patients scheduled for elective foot and ankle surgery. We documented the time required by patients to complete the instrument, instrument precision, and the extent to which each instrument covered the full range of physical functioning across the patient sample. Average time of test administration: 66 seconds for LE CAT, 130 seconds for spFAAM and 239 seconds for FFI. All three instruments were fairly precise at intermediate physical functioning levels (i.e., Standard Error of Measurement < 0.35), were relatively less precise at the higher trait levels and the LE CAT maintained precision in the lower range while the spFAAM and FFI's had decreased precision. The LE CAT had less floor/ceiling effects than the FFI and the spFAAM. The LE CAT showed considerable advantage compared to legacy scales for measuring patient-reported outcomes in orthopaedic patients with foot and ankle problems. A paradigm shift to broader use of PROMIS-based CATs should be considered to improve precision and reduce patient burden with patient-reported outcome measuremen foot and ankle patients.

  16. Motor cortical representation of the pelvic floor muscles.

    PubMed

    Schrum, A; Wolff, S; van der Horst, C; Kuhtz-Buschbeck, J P

    2011-07-01

    Pelvic floor muscle training involves rhythmical voluntary contractions of the external urethral sphincter and ancillary pelvic floor muscles. The representation of these muscles in the motor cortex has not been located precisely and unambiguously. We used functional magnetic resonance imaging to determine brain activity during slow and fast pelvic floor contractions. Cerebral responses were recorded in 17 healthy male volunteers, 21 to 47 years old, with normal bladder control. Functional magnetic resonance imaging was performed during metronome paced slow (0.25 Hertz) and fast (0.7 Hertz) contractions of the pelvic floor that mimicked the interruption of voiding. To study the somatotopy of the cortical representations, flexion-extension movements of the right toes were performed as a control task. Functional magnetic resonance imaging during pelvic floor contractions detected activity of the supplementary motor area in the medial wall and of the midcingulate cortex, insula, posterior parietal cortex, putamen, thalamus, cerebellar vermis and upper ventral pons. There were no significant differences in activation between slow and fast contractions. Toe movements involved significantly stronger activity of the paracentral lobule (ie the medial primary motor cortex) than did the pelvic floor contractions. Otherwise the areas active during pelvic floor and leg muscle contractions overlapped considerably. The motor cortical representation of pelvic floor muscles is located mostly in the supplementary motor area. It extends further ventrally and anteriorly than the representation of distal leg muscles. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. Squeeze-Film Air Damping of a Five-Axis Electrostatic Bearing for Rotary Micromotors

    PubMed Central

    Wang, Shunyue; Han, Fengtian; Sun, Boqian; Li, Haixia

    2017-01-01

    Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeeze-film air damping results of an electrostatic bearing for use in a rotary high-speed micromotor. It is shown that the boundary condition to solve the three-dimensional Reynolds equation, which governs the squeeze-film damping in the air gap between the rotor and its surrounding stator sealed in a three-layer evacuated cavity, behaves with strong cross-axis coupling characteristics. To accurately characterize the damping effect, a set of multiphysics finite-element simulations are performed by computing both the rotor velocity and the distribution of the viscous damping force acting on the rotor. The damping characteristics varying with several key structure parameters are simulated and discussed to optimize the device structure for desirable rotor dynamics. An electrical measurement method is also proposed and applied to validate the numerical results of the damping coefficients experimentally. Given that the frequency response of the electric bearing is critically dependent on the damping coefficients at atmospheric pressure, a solution to the air-film damping measurement problem is presented by taking approximate curve fitting of multi-axis experimental frequency responses. The measured squeeze-film damping coefficients for the five-axis electric bearing agrees well with the numerical solutions. This indicates that numerical multiphysics simulation is an effective method to accurately examine the air-film damping effect for complex device geometry and arbitrary boundary condition. The accurate damping coefficients obtained by FEM simulation will greatly simplify the design of the five-axis bearing control system and facilitate the initial suspension test of the rotor for various micromotor devices. PMID:28505089

  18. Squeeze-Film Air Damping of a Five-Axis Electrostatic Bearing for Rotary Micromotors.

    PubMed

    Wang, Shunyue; Han, Fengtian; Sun, Boqian; Li, Haixia

    2017-05-13

    Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeeze-film air damping results of an electrostatic bearing for use in a rotary high-speed micromotor. It is shown that the boundary condition to solve the three-dimensional Reynolds equation, which governs the squeeze-film damping in the air gap between the rotor and its surrounding stator sealed in a three-layer evacuated cavity, behaves with strong cross-axis coupling characteristics. To accurately characterize the damping effect, a set of multiphysics finite-element simulations are performed by computing both the rotor velocity and the distribution of the viscous damping force acting on the rotor. The damping characteristics varying with several key structure parameters are simulated and discussed to optimize the device structure for desirable rotor dynamics. An electrical measurement method is also proposed and applied to validate the numerical results of the damping coefficients experimentally. Given that the frequency response of the electric bearing is critically dependent on the damping coefficients at atmospheric pressure, a solution to the air-film damping measurement problem is presented by taking approximate curve fitting of multi-axis experimental frequency responses. The measured squeeze-film damping coefficients for the five-axis electric bearing agrees well with the numerical solutions. This indicates that numerical multiphysics simulation is an effective method to accurately examine the air-film damping effect for complex device geometry and arbitrary boundary condition. The accurate damping coefficients obtained by FEM simulation will greatly simplify the design of the five-axis bearing control system and facilitate the initial suspension test of the rotor for various micromotor devices.

  19. Acoustic stratigraphy of Bear Lake, Utah-Idaho: late Quaternary sedimentation patterns in a simple half-graben

    USGS Publications Warehouse

    Colman, Steven M.

    2006-01-01

    A 277-km network of high-resolution seismic-reflection profiles, supplemented with a sidescan-sonar mosaic of the lake floor, was collected in Bear Lake, Utah–Idaho, in order to explore the sedimentary framework of the lake's paleoclimate record. The acoustic stratigraphy is tied to a 120 m deep, continuously cored drill hole in the lake. Based on the age model for the drill core, the oldest continuously mapped acoustic reflector in the data set has an age of about 100 ka, although older sediments were locally imaged. The acoustic stratigraphy of the sediments below the lake indicates that the basin developed primarily as a simple half-graben, with a steep normal-fault margin on the east and a flexural margin on the west. As expected for a basin controlled by a listric master fault, seismic reflections steepen and diverge toward the fault, bounding eastward-thickening sediment wedges. Secondary normal faults west of the master fault were imaged beneath the lake and many of these faults show progressively increasing offset with depth and age. Several faults cut the youngest sediments in the lake as well as the modern lake floor. The relative simplicity of the sedimentary sequence is interrupted in the northwestern part of the basin by a unit that is interpreted as a large (4 × 10 km) paleodelta of the Bear River. The delta overlies a horizon with an age of about 97 ka, outcrops at the lake floor and is onlapped by much of the uppermost sequence of lake sediments. A feature interpreted as a wave-cut bench occurs in many places on the western side of the lake. The base of this bench occurs at a depth (22–24 m) similar to that (20–25 m) of the distal surface of the paleodelta. Pinch-outs of sedimentary units are common in relatively shallow water on the gentle western margin of the basin and little Holocene sediment has accumulated in water depths of less than 30 m. On the steep eastern margin of the basin, sediments commonly onlap the hanging wall of the East Bear Lake Fault. However, no major erosional or depositional features suggestive of shoreline processes were observed on acoustic profiles in water deeper than about 20–25 m.

  20. Clay-bearing Fluvial Deposits in Western Ladon Basin, Mars

    NASA Astrophysics Data System (ADS)

    Weitz, C. M.; Grant, J. A.; Irwin, R. P.; Wilson, S. A.

    2013-12-01

    More than a dozen outcrops of light-toned layered deposits occur in the uplands to the west of Ladon basin in Margaritifer Terra, Mars. We are evaluating the morphology, mineralogy, and distribution of these sedimentary deposits and associated valley systems that dissect the local Noachian bedrock to understand how they reflect source materials and record environmental and climatic conditions during their emplacement. Several craters, including secondary craters from the Holden impact event, also contain sedimentary deposits, suggesting at least some of the deposits are younger than Mid-to-Late Hesperian. All the deposits appear confined within basins, valleys or craters that are breached by valleys. The deposits typically show numerous beds with variable lithologies, suggesting multiple episodes of deposition and/or changing aqueous conditions over time. CRISM spectra extracted from the deposits typically have absorption features around 1.93 and 2.29 μm, consistent with Fe/Mg-smectites. Several deposits within Arda Valles may have been emplaced when the system was blocked at the eastern end by topography associated with two unnamed craters. Deposition emplaced the clay-bearing layered sediments before an outlet was established, enabling drainage onto the lower-lying floor of Ladon basin and formation of an inverted channel within one of the valleys (Figure 1). All the deposits are located 0.5-2 km above clay-bearing deposits found on the Ladon basin floor, including within Ladon Valles, thereby indicating they were not associated with a lake within the basin or late-stage discharge from Ladon Valles. Instead, their sources appear to be localized and associated with the rim materials of the ancient impact structures or nearby weathered bedrock. The upland deposits may have formed concurrently with deposits found to the south in Eberswalde and Holden craters, indicating precipitation and/or snow melt across much of Margaritifer Terra during the Late Hesperian to Early Amazonian. Figure 1. HiRISE Digital Terrain Model at 5X vertical exaggeration with CRISM spectral parameters overlain in color showing one of the sedimentary deposits in the uplands west of Ladon basin. Clay-bearing deposits appear light-green along the floors of ~150 m deep valleys. Yellow arrows indicate a 15-m high inverted channel within one of the valleys.

  1. Energy Expenditure During Cane-Assisted Gait in Patients with Knee Osteoarthritis

    PubMed Central

    Jones, Anamaria; Alves, Ana Claudia Monteiro; de Oliveira, Leda Magalhães; Saad, Marcelo; Natour, Jamil

    2008-01-01

    OBJECTIVE To compare the energy expenditure in patients with unilateral knee osteoarthritis while walking with canes of different lengths. METHODS A quasi-experimental study (single-group) was carried out on thirty patients with unilateral knee osteoarthritis. An adjustable aluminum cane was used, and three different cane lengths were determined for each subject: C1 – length from the floor to the greater trochanter; C2 – length from the floor to the distal wrist crease; and C3 – length obtained by the formula: height x 0.45 + 0.87 m. Resting and walking heart rates were measured with a Polar hear rate meter. Walking speed was calculated by the time required for the patient to walk 10 m. Gait energy cost was estimated using the physiological cost index, and results were compared. RESULTS The sample consisted of 25 women and five men (average age of 68 years). Statistically significant differences in physiological cost index measurements were observed between unassisted walking and assisted walking with a cane of any length (p<0.001), as well as between walking with a C2-length cane and unassisted walking, and walking with a C1-length cane and walking with a C3-length cane (p=0.001; p = 0.037; p=0.001; respectively). CONCLUSION These data demonstrate that small alterations in the length of canes used for weight-bearing ambulation in patients with unilateral knee osteoarthritis increase the energy expenditure measured by the physiological cost index during walking. Further studies are needed for a more precise quantification of the increase in energy expenditure during cane-assisted gait and an assessment of the effectiveness of cane use in relieving pain and improving function in patients with knee osteoarthritis. PMID:18438573

  2. 40. Photocopy of building model photograph, ca., 1974, photographer unknown. ...

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

    40. Photocopy of building model photograph, ca., 1974, photographer unknown. Original photograph property of United States Air Force, 21" Space Command. CAPE COD AIR STATION PAVE PAWS FACILITY MODEL - ELEVATION SHOWING FLOOR AND EQUIPMENT LAYOUT. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  3. 77 FR 47533 - Determination of Failure To Attain the One-Hour Ozone Standard by 2007, Determination of Current...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-09

    ... CFR Part 52 Environmental protection, Air pollution control, Intergovernmental relations, Nitrogen... Office, Air Programs Branch, 290 Broadway, 25th Floor, New York, New York 10007-1866. This Docket... telephone number is 212-637-4249. FOR FURTHER INFORMATION CONTACT: Paul Truchan, Air Programs Branch...

  4. 78 FR 20852 - Safety Zones; Marine Week Air Ground Demonstration, Lake Washington; Seattle, WA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ...-AA00 Safety Zones; Marine Week Air Ground Demonstration, Lake Washington; Seattle, WA AGENCY: Coast... safety zones around vessels and persons involved in the Marine Week Seattle Special Marine Air Ground...: Docket Management Facility (M-30), U.S. Department of Transportation, West Building Ground Floor, Room...

  5. Concept verification of three dimensional free motion simulator for space robot

    NASA Technical Reports Server (NTRS)

    Okamoto, Osamu; Nakaya, Teruomi; Pokines, Brett

    1994-01-01

    In the development of automatic assembling technologies for space structures, it is an indispensable matter to investigate and simulate the movements of robot satellites concerned with mission operation. The movement investigation and simulation on the ground will be effectively realized by a free motion simulator. Various types of ground systems for simulating free motion have been proposed and utilized. Some of these methods are a neutral buoyancy system, an air or magnetic suspension system, a passive suspension balance system, and a free flying aircraft or drop tower system. In addition, systems can be simulated by computers using an analytical model. Each free motion simulation method has limitations and well known problems, specifically, disturbance by water viscosity, limited number of degrees-of-freedom, complex dynamics induced by the attachment of the simulation system, short experiment time, and the lack of high speed super-computer simulation systems, respectively. The basic idea presented here is to realize 3-dimensional free motion. This is achieved by combining a spherical air bearing, a cylindrical air bearing, and a flat air bearing. A conventional air bearing system has difficulty realizing free vertical motion suspension. The idea of free vertical suspension is that a cylindrical air bearing and counter balance weight realize vertical free motion. This paper presents a design concept, configuration, and basic performance characteristics of an innovative free motion simulator. A prototype simulator verifies the feasibility of 3-dimensional free motion simulation.

  6. Controlling a rabbet load and air/oil seal temperatures in a turbine

    DOEpatents

    Schmidt, Mark Christopher

    2002-01-01

    During a standard fired shutdown of a turbine, a loaded rabbet joint between the fourth stage wheel and the aft shaft of the machine can become unloaded causing a gap to occur due to a thermal mismatch at the rabbet joint with the bearing blower turned on. An open or unloaded rabbet could cause the parts to move relative to each other and therefore cause the rotor to lose balance. If the bearing blower is turned off during a shutdown, the forward air/oil seal temperature may exceed maximum design practice criterion due to "soak-back." An air/oil seal temperature above the established maximum design limits could cause a bearing fire to occur, with catastrophic consequences to the machine. By controlling the bearing blower according to an optimized blower profile, the rabbet load can be maintained, and the air/oil seal temperature can be maintained below the established limits. A blower profile is determined according to a thermodynamic model of the system.

  7. Improving inference for aerial surveys of bears: The importance of assumptions and the cost of unnecessary complexity.

    PubMed

    Schmidt, Joshua H; Wilson, Tammy L; Thompson, William L; Reynolds, Joel H

    2017-07-01

    Obtaining useful estimates of wildlife abundance or density requires thoughtful attention to potential sources of bias and precision, and it is widely understood that addressing incomplete detection is critical to appropriate inference. When the underlying assumptions of sampling approaches are violated, both increased bias and reduced precision of the population estimator may result. Bear ( Ursus spp.) populations can be difficult to sample and are often monitored using mark-recapture distance sampling (MRDS) methods, although obtaining adequate sample sizes can be cost prohibitive. With the goal of improving inference, we examined the underlying methodological assumptions and estimator efficiency of three datasets collected under an MRDS protocol designed specifically for bears. We analyzed these data using MRDS, conventional distance sampling (CDS), and open-distance sampling approaches to evaluate the apparent bias-precision tradeoff relative to the assumptions inherent under each approach. We also evaluated the incorporation of informative priors on detection parameters within a Bayesian context. We found that the CDS estimator had low apparent bias and was more efficient than the more complex MRDS estimator. When combined with informative priors on the detection process, precision was increased by >50% compared to the MRDS approach with little apparent bias. In addition, open-distance sampling models revealed a serious violation of the assumption that all bears were available to be sampled. Inference is directly related to the underlying assumptions of the survey design and the analytical tools employed. We show that for aerial surveys of bears, avoidance of unnecessary model complexity, use of prior information, and the application of open population models can be used to greatly improve estimator performance and simplify field protocols. Although we focused on distance sampling-based aerial surveys for bears, the general concepts we addressed apply to a variety of wildlife survey contexts.

  8. Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments - A review

    NASA Astrophysics Data System (ADS)

    Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Laitinen, Sirpa; Clifford, Sam; Mikkola, Raimo; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

    2016-10-01

    As endotoxin exposure has known effects on human health, it is important to know the generally existing levels of endotoxins as well as their contributing factors. This work reviews current knowledge on the endotoxin loads in settled floor dust, concentrations of endotoxins in indoor air, and different environmental factors potentially affecting endotoxin levels. The literature review consists of peer-reviewed manuscripts located using Google and PubMed, with search terms based on individual words and combinations. References from relevant articles have also been searched. Analysis of the data showed that in residential, school, and office environments, the mean endotoxin loads in settled floor dust varied between 660 and 107,000 EU/m2, 2180 and 48,000 EU/m2, and 2700 and 12,890 EU/m2, respectively. Correspondingly, the mean endotoxin concentrations in indoor air varied between 0.04 and 1610 EU/m3 in residences, and 0.07 and 9.30 EU/m3 in schools and offices. There is strong scientific evidence indicating that age of houses (or housing unit year category), cleaning, farm or rural living, flooring materials (the presence of carpets), number of occupants, the presence of dogs or cats indoors, and relative humidity affect endotoxin loads in settled floor dust. The presence of pets (especially dogs) was extremely strongly associated with endotoxin concentrations in indoor air. However, as reviewed articles show inconsistency, additional studies on these and other possible predicting factors are needed.

  9. The argonaut shell: gas-mediated buoyancy control in a pelagic octopus.

    PubMed

    Finn, Julian K; Norman, Mark D

    2010-10-07

    Argonauts (Cephalopoda: Argonautidae) are a group of rarely encountered open-ocean pelagic octopuses with benthic ancestry. Female argonauts inhabit a brittle 'paper nautilus' shell, the role of which has puzzled naturalists for millennia. The primary role attributed to the shell has been as a receptacle for egg deposition and brooding. Our observations of wild argonauts have revealed that the thin calcareous shell also functions as a hydrostatic structure, employed by the female argonaut to precisely control buoyancy at varying depths. Female argonauts use the shell to 'gulp' a measured volume of air at the sea surface, seal off the captured gas using flanged arms and forcefully dive to a depth where the compressed gas buoyancy counteracts body weight. This process allows the female argonaut to attain neutral buoyancy at depth and potentially adjust buoyancy to counter the increased (and significant) weight of eggs during reproductive periods. Evolution of this air-capture strategy enables this negatively buoyant octopus to survive free of the sea floor. This major shift in life mode from benthic to pelagic shows strong evolutionary parallels with the origins of all cephalopods, which attained gas-mediated buoyancy via the closed-chambered shells of the true nautiluses and their relatives.

  10. Two gimbal bearing case studies: Some lessons learned

    NASA Technical Reports Server (NTRS)

    Loewenthal, Stuart H.

    1988-01-01

    Two troublesome, torque related problems associated with gimbal actuators are discussed. Large, thin section angular contact bearings can have a surprisingly high torque sensitivity to radial thermal gradients. A predictive thermal-mechanical bearing analysis, as described, was helpful in establishing a safe temperature operating envelope. In the second example, end-of-travel torque limits of an oscillatory gimbal bearing appoached motor stall during limit cycling life tests. Bearing modifications required to restore acceptable torque performance are described. The lessons learned from these case studies should benefit designers of precision gimbals where singular bearing torque related problems are not uncommon.

  11. INTERIOR VIEW OF THE LIVING ROOM SHOWING THE FLOOR TO ...

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

    INTERIOR VIEW OF THE LIVING ROOM SHOWING THE FLOOR TO CEILING WINDOWS. NOTE THE OPENING IN THE RIGHT SIDE WALL FOR AN AIR CONDITIONER. VIEW FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Three-Bedroom Duplex Type 3, Acacia Road, Birch Circle, and Cedar Drive, Pearl City, Honolulu County, HI

  12. 90. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO ...

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

    90. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO SUMP, LOWER RIGHT QUADRANT. DIAGONAL PIPE IN UPPER RIGHT IS AIR LINE TO AGITATORS. LAUNDER PARALLEL TO LEFT EDGE (FILLED WITH DEBRIS) RUNS FROM PRIMARY THICKENER No. 2 TO GOLD TANK No. 2. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  13. 169. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO ...

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

    169. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO SUMP, LOWER RIGHT QUADRANT. DIAGONAL PIPE IN UPPER RIGHT IS AIR LINE TO AGITATORS. LAUNDER PARALLEL TO LEFT EDGE (FILLED WITH DEBRIS) RUNS FROM PRIMARY THICKENER No. 2 TO GOLD TANK No. 2 - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  14. DETAIL OF INTERIOR OF MISSILE TUBE AT GROUND FLOOR LEVEL ...

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

    DETAIL OF INTERIOR OF MISSILE TUBE AT GROUND FLOOR LEVEL SHOWING AIR COMPRESSOR TANKS AND CURVING STEEL PIECE. VIEW FACING EAST - U.S. Naval Base, Pearl Harbor, Ford Island Polaris Missile Lab & U.S. Fleet Ballistic Missile Submarine Training Center, Between Lexington Boulvevard and the sea plane ramps on the southwest side of Ford Island, Pearl City, Honolulu County, HI

  15. Polar bear and walrus response to the rapid decline in Arctic sea ice

    USGS Publications Warehouse

    Oakley, K.; Whalen, M.; Douglas, David C.; Udevitz, Mark S.; Atwood, Todd C.; Jay, C.

    2012-01-01

    The Arctic is warming faster than other regions of the world due to positive climate feedbacks associated with loss of snow and ice. One highly visible consequence has been a rapid decline in Arctic sea ice over the past 3 decades - a decline projected to continue and result in ice-free summers likely as soon as 2030. The polar bear (Ursus maritimus) and the Pacific walrus (Odobenus rosmarus divergens) are dependent on sea ice over the continental shelves of the Arctic Ocean's marginal seas. The continental shelves are shallow regions with high biological productivity, supporting abundant marine life within the water column and on the sea floor. Polar bears use sea ice as a platform for hunting ice seals; walruses use sea ice as a resting platform between dives to forage for clams and other bottom-dwelling invertebrates. How have sea ice changes affected polar bears and walruses? How will anticipated changes affect them in the future?

  16. Single crystal diamond lapping procedure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grayson, R.A.

    A facility capable of resharpening quality cutting edges on single crystal diamond cutting tools was needed as the demand in precision machining of special optical surfaces became a common occurrence here at Lawrence Livermore National Laboratory. A specially constructed lapping machine using an air bearing spindle was built to achieve the required edge quality. The basic design for this lap was taken out of a technical report by W.L. Duke and R.T. Lovell of Oak Ridge Y-12 Plant Union Carbide Corp. We have also purchased two commercially built lapping machines recommended to us by Mr. Cory A. Knottenbelt, formerly ofmore » R.C.A. Diamond Lapping Facility, in Indianapolis, Indiana, now doing state-of-the-art polishing and relapping at LLNL facilities.« less

  17. Lift-Off Performance in Flexure Pivot Pad and Hybrid Bearings

    DTIC Science & Technology

    2008-12-01

    and Dawson, M. P., 1998, "Experience in the Use of Flexure Pivot Tilt Pad Bearings in Boiler Feed Water Pumps ," Proc. of the 15th International...freely. Test Procedure 1) Turn on the pump to buffer water to the test bearing. 2) Turn on air to the air seal that prevents water flowing... Pump Users Symposium, Turbomachinery Laboratory, College Station, Texas, pp. 77-84. [6] Rodriguez, L., 2004, “Experimental Frequency-Dependent

  18. The Role of Tribology in the Development of an Oil-Free Turbocharger

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher

    1997-01-01

    Gas-turbine-based aeropropulsion engines are technologically mature. Thus, as with any mature technology, revolutionary approaches will be needed to achieve the significant performance gains that will keep the U.S. propulsion manufacturers well ahead of foreign competition. One such approach is the development of oil-free turbomachinery utilizing advanced foil air bearings, seals, and solid lubricants. By eliminating oil-lubricated bearings and seals and supporting an engine rotor on an air film, significant improvements can be realized. For example, the entire oil system including pipes, lines, filters, cooler, and tanks could be removed, thereby saving considerable weight. Since air has no thermal decomposition temperature, engine systems could operate without excessive cooling. Also, since air bearings have no diameter-rpm fatigue limits (D-N limits), engines could be designed to operate at much higher speeds and higher density, which would result in a smaller aeropropulsion package. Because of recent advances in compliant foil air bearings and high temperature solid lubricants, these technologies can be applied to oil-free turbomachinery. In an effort to develop these technologies and to demonstrate a project along the path to an oil-free gas turbine engine, NASA has undertaken the development of an oil-free turbocharger for a heavy duty diesel engine. This turbomachine can reach 120000 rpm at a bearing temperature of 540 C (1000 F) and, in comparison to oil-lubricated bearings, can increase efficiency by 10 to 15 percent because of reduced friction. In addition, because there are no oil lubricants, there are no seal-leakage-induced emissions.

  19. Precise bearing support ditherer with piezoelectric drive means

    NASA Astrophysics Data System (ADS)

    Assard, G. L.; Moorcroft, A. L.

    1985-06-01

    A relatively solid mounting surface, which may be part of a leveling gimbal, supports a piezoelectric bearing mount which has the properties of an acoustic transducer. The transducer has electrodes thereon which are powered from multi-phase electrical sources causing the bearing mount, and a bearing jewel which is rigid therewith, to move so as to dither the jewel in a rotary or other preselected fashion, thereby reducing bearing friction. Bandwidth, level and phasing sequence of the power sources are adjustable permitting optimized average dynamic motion and corresponding increased readout accuracy.

  20. Comparison of cavity preparation quality using an electric motor handpiece and an air turbine dental handpiece.

    PubMed

    Kenyon, Brian J; Van Zyl, Ian; Louie, Kenneth G

    2005-08-01

    The high-speed high-torque (electric motor) handpiece is becoming more popular in dental offices and laboratories in the United States. It is reported to cut more precisely and to assist in the creation of finer margins that enhance cavity preparations. The authors conducted an in vitro study to compare the quality of cavity preparations fabricated with a high-speed high-torque (electric motor) handpiece and a high-speed low-torque (air turbine) handpiece. Eighty-six dental students each cut two Class I preparations, one with an air turbine handpiece and the other with an electric motor high-speed handpiece. The authors asked the students to cut each preparation accurately to a circular outline and to establish a flat pulpal floor with 1.5 millimeters' depth, 90-degree exit angles, parallel vertical walls and sharp internal line angles, as well as to refine the preparation to achieve flat, smooth walls with a well-defined cavosurface margin. A single faculty member scored the preparations for criteria and refinement using a nine-point scale (range, 1-9). The authors analyzed the data statistically using paired t tests. In preparation criteria, the electric motor high-speed handpiece had a higher average grade than did the air turbine handpiece (5.07 and 4.90, respectively). For refinement, the average grade for the air turbine high-speed handpiece was greater than that for the electric motor high-speed handpiece (5.72 and 5.52, respectively). The differences were not statistically significant. The electric motor high-speed handpiece performed as well as, but not better than, the air turbine handpiece in the fabrication of high-quality cavity preparations.

  1. High-Temperature Solid Lubricants Developed by NASA Lewis Offer Virtually "Unlimited Life" for Oil-Free Turbomachinery

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Valco, Mark J.

    1999-01-01

    The NASA Lewis Research Center is capitalizing on breakthroughs in foil air bearing performance, tribological coatings, and computer analyses to formulate the Oil-free Turbomachinery Program. The program s long-term goal is to develop an innovative, yet practical, oil-free aeropropulsion gas turbine engine that floats on advanced air bearings. This type of engine would operate at higher speeds and temperatures with lower weight and friction than conventional oil-lubricated engines. During startup and shutdown, solid lubricant coatings are required to prevent wear in such engines before the self-generating air-lubrication film develops. NASA s Tribology Branch has created PS304, a chrome-oxide-based plasma spray coating specifically tailored for shafts run against foil bearings. PS304 contains silver and barium fluoride/calcium fluoride eutectic (BaF2/CaF2) lubricant additives that, together, provide lubrication from cold start temperatures to over 650 C, the maximum use temperature for foil bearings. Recent lab tests show that bearings lubricated with PS304 survive over 100 000 start-stop cycles without experiencing any degradation in performance due to wear. The accompanying photograph shows a test bearing after it was run at 650 C. The rubbing process created a "polished" surface that enhances bearing load capacity.

  2. Photographic copy of plan drawing, Department of the Air Force, ...

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

    Photographic copy of plan drawing, Department of the Air Force, Air Defense Command Directorate of Installations, May 28, 1954, Civil Engineers Office, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. FLOOR PLAN, 826-198-4 - Selfridge Field, Building No. 199, South of George Avenue between Walnut & Birch Streets, Mount Clemens, Macomb County, MI

  3. 3. PHOTOCOPY OF DRAWING (1960 ARCHITECTURAL DRAWING BY THE RALPH ...

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

    3. PHOTOCOPY OF DRAWING (1960 ARCHITECTURAL DRAWING BY THE RALPH M. PARSONS COMPANY) FLOOR PLAN, ELEVATIONS, AND SECTION FOR THE SAMOS TECHNICAL SUPPORT BUILDING (BLDG. 761; NOW CALLED SLC-3 AIR FORCE BUILDING), SHEET A14 - Vandenberg Air Force Base, Space Launch Complex 3, SLC-3 Air Force Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  4. Technology test results from an intelligent, free-flying robot for crew and equipment retrieval in space

    NASA Technical Reports Server (NTRS)

    Erickson, J.; Goode, R.; Grimm, K.; Hess, C.; Norsworthy, R.; Anderson, G.; Merkel, L.; Phinney, D.

    1992-01-01

    The ground-based demonstrations of Extra Vehicular Activity (EVA) Retriever, a voice-supervised, intelligent, free-flying robot, are designed to evaluate the capability to retrieve objects (astronauts, equipment, and tools) which have accidentally separated from the Space Station. The EVA Retriever software is required to autonomously plan and execute a target rendezvous, grapple, and return to base while avoiding stationary and moving obstacles with subsequent object handover. The software architecture incorporates a heirarchical decomposition of the control system that is horizontally partitioned into five major functional subsystems: sensing, perception, world model, reasoning, and acting. The design provides for supervised autonomy as the primary mode of operation. It is intended to be an evolutionary system improving in capability over time and as it earns crew trust through reliable and safe operation. This paper gives an overview of the hardware, a focus on software, and a summary of results achieved recently from both computer simulations and air bearing floor demonstrations. Limitations of the technology used are evaluated. Plans for the next phase, during which moving targets and obstacles drive realtime behavior requirements, are discussed.

  5. Technology test results from an intelligent, free-flying robot for crew and equipment retrieval in space

    NASA Astrophysics Data System (ADS)

    Erickson, Jon D.; Goode, R.; Grimm, K. A.; Hess, Clifford W.; Norsworthy, Robert S.; Anderson, Greg D.; Merkel, L.; Phinney, Dale E.

    1992-03-01

    The ground-based demonstrations of Extra Vehicular Activity (EVA) Retriever, a voice- supervised, intelligent, free-flying robot, are designed to evaluate the capability to retrieve objects (astronauts, equipment, and tools) which have accidentally separated from the space station. The EVA Retriever software is required to autonomously plan and execute a target rendezvous, grapple, and return to base while avoiding stationary and moving obstacles with subsequent object handover. The software architecture incorporates a hierarchical decomposition of the control system that is horizontally partitioned into five major functional subsystems: sensing, perception, world model, reasoning, and acting. The design provides for supervised autonomy as the primary mode of operation. It is intended to be an evolutionary system improving in capability over time and as it earns crew trust through reliable and safe operation. This paper gives an overview of the hardware, a focus on software, and a summary of results achieved recently from both computer simulations and air bearing floor demonstrations. Limitations of the technology used are evaluated. Plans for the next phase, during which moving targets and obstacles drive realtime behavior requirements, are discussed.

  6. 5. Photographic copy of architectural floor plans for Officers' Quarters ...

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

    5. Photographic copy of architectural floor plans for Officers' Quarters "A" & "B": Taylor & Barnes, Architects & Engineers, 803 W. Third Street, Los Angeles California, O.C.E. Office of Civil Engineer Job No. Muroc ESA 210-48 and 210-49, Military Construction: Muroc Flight Test Base, Muroc, California, Warehouses and Additional Housing for Officers: Officers Quarters, Floor Plan, Foundation Plan & Details, Sheet No. 12 of 16, May 1945. Reproduced from the holdings of the National Archives, Pacific Southwest Region - Edwards Air Force Base, North Base, Officers' Quarters A, North Base Road, Boron, Kern County, CA

  7. Forest floor leachate fluxes under six different tree species on a metal contaminated site.

    PubMed

    Van Nevel, Lotte; Mertens, Jan; De Schrijver, An; Baeten, Lander; De Neve, Stefaan; Tack, Filip M G; Meers, Erik; Verheyen, Kris

    2013-03-01

    Trees play an important role in the biogeochemical cycling of metals, although the influence of different tree species on the mobilization of metals is not yet clear. This study examined effects of six tree species on fluxes of Cd, Zn, DOC, H(+) and base cations in forest floor leachates on a metal polluted site in Belgium. Forest floor leachates were sampled with zero-tension lysimeters in a 12-year-old post-agricultural forest on a sandy soil. The tree species included were silver birch (Betula pendula), oak (Quercus robur and Q. petraea), black locust (Robinia pseudoacacia), aspen (Populus tremula), Scots pine (Pinus sylvestris) and Douglas fir (Pseudotsuga menziesii). We show that total Cd fluxes in forest floor leachate under aspen were slightly higher than those in the other species' leachates, yet the relative differences between the species were considerably smaller when looking at dissolved Cd fluxes. The latter was probably caused by extremely low H(+) amounts leaching from aspen's forest floor. No tree species effect was found for Zn leachate fluxes. We expected higher metal leachate fluxes under aspen as its leaf litter was significantly contaminated with Cd and Zn. We propose that the low amounts of Cd and Zn leaching under aspen's forest floor were possibly caused by high activity of soil biota, for example burrowing earthworms. Furthermore, our results reveal that Scots pine and oak were characterized by high H(+) and DOC fluxes as well as low base cation fluxes in their forest floor leachates, implying that those species might enhance metal mobilization in the soil profile and thus bear a potential risk for belowground metal dispersion. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Ambient Pressure Test Rig Developed for Testing Oil-Free Bearings in Alternate Gases and Variable Pressures

    NASA Technical Reports Server (NTRS)

    Bauman, Steven W.

    1990-01-01

    The Oil-Free Turbomachinery research team at the NASA Glenn Research Center is conducting research to develop turbomachinery systems that utilize high-speed, high temperature foil (air) bearings that do not require an oil lubrication system. Such systems combine the most advanced foil bearings from industry with NASA-developed hightemperature solid-lubricant technology. New applications are being pursued, such as Oil- Free turbochargers, auxiliary power units, and turbine propulsion systems for aircraft. An Oil-Free business jet engine, for example, would be simpler, lighter, more reliable, and less costly to purchase and maintain than current engines. Another application is NASA's Prometheus mission, where gas bearings will be required for the closed-cycle turbine based power-conversion system of a nuclear power generator for deep space. To support these applications, Glenn's Oil-Free Turbomachinery research team developed the Ambient Pressure Test Rig. Using this facility, researchers can load and heat a bearing and evaluate its performance with reduced air pressure to simulate high altitude conditions. For the nuclear application, the test chamber can be purged with gases such as helium to study foil gas bearing operation in working fluids other than air.

  9. Photocopy of drawing (this photograph is an 8" x 10" ...

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

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1989 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Renovation and revised office layout, Building No. 45, third floor, architectural floor plans, details and schedules, Sheet 1 of 3 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  10. Fire Ecology of Seeds from Rubus Spp.: A Competitor During Natural Pine Regeneration

    Treesearch

    Michael D. Cain; Michael G. Shelton

    1999-01-01

    Air-dried blackbeny (Rubus spp.) fruits were placed at three depths in a reconstructed forest floor and subjected to a simulated prescribed summer bum. Within the forest floor, fruits were placed on the L layer, at the upper-F/lower-F interface, and at the lower-F/mineral-soil interface. Wind for a headfire was generated by electric boxfans....

  11. 75 FR 20802 - Safety Zone; New York Air Show at Jones Beach State Park, Atlantic Ocean off of Jones Beach...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590-0001. Hand Delivery... the ``Keyword'' box. Click ``Search'' then click on the balloon shape in the ``Actions'' column. If... also visit the Docket Management Facility in Room W12-140 on the ground floor of the Department of...

  12. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to Subpart IIIII of Part 63 Protection... Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt. IIIII... and Cell Room Monitoring Plans Your Floor-Level Mercury Vapor Measurement Plan required by § 63.8192(d...

  13. 25. Similar view of lobby area on first floor transmitter ...

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

    25. Similar view of lobby area on first floor transmitter building no. 102 looking at door in photograph AK-30-A-24 in closed position showing locking system and restricted access notification. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  14. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to Subpart IIIII of Part 63 Protection... Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt. IIIII... and Cell Room Monitoring Plans Your Floor-Level Mercury Vapor Measurement Plan required by § 63.8192(d...

  15. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to Subpart IIIII of Part 63 Protection... Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt. IIIII... and Cell Room Monitoring Plans Your Floor-Level Mercury Vapor Measurement Plan required by § 63.8192(d...

  16. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to Subpart IIIII of Part 63 Protection... Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt. IIIII... and Cell Room Monitoring Plans Your Floor-Level Mercury Vapor Measurement Plan required by § 63.8192(d...

  17. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to Subpart IIIII of Part 63 Protection... Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt. IIIII... and Cell Room Monitoring Plans Your Floor-Level Mercury Vapor Measurement Plan required by § 63.8192(d...

  18. Faulting of gas-hydrate-bearing marine sediments - contribution to permeability

    USGS Publications Warehouse

    Dillon, William P.; Holbrook, W.S.; Drury, Rebecca; Gettrust, Joseph; Hutchinson, Deborah; Booth, James; Taylor, Michael

    1997-01-01

    Extensive faulting is observed in sediments containing high concentrations of methane hydrate off the southeastern coast of the United States. Faults that break the sea floor show evidence of both extension and shortening; mud diapirs are also present. The zone of recent faulting apparently extends from the ocean floor down to the base of gas-hydrate stability. We infer that the faulting resulted from excess pore pressure in gas trapped beneath the gas hydrate-beating layer and/or weakening and mobilization of sediments in the region just below the gas-hydrate stability zone. In addition to the zone of surface faults, we identified two buried zones of faulting, that may have similar origins. Subsurface faulted zones appear to act as gas traps.

  19. Comparing the field and laboratory emission cell (FLEC) with traditional emissions testing chambers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roache, N.F.; Guo, Z.; Fortmann, R.

    1996-12-31

    A series of tests was designed to evaluate the performance of the field and laboratory emission cell (FLEC) as applied to the testing of emissions from two indoor coating materials, floor wax and latex paint. These tests included validation of the repeatability of the test method, evaluation of the effect of different air velocities on source emissions, and a comparison of FLEC versus small chamber characterization of emissions. The FLEC exhibited good repeatability in characterization of emissions when applied to both sources under identical conditions. Tests with different air velocities showed significant effects on the emissions from latex paint, yetmore » little effect on emissions from the floor wax. Comparisons of data from the FLEC and small chamber show good correlation for measurements involving floor wax, but less favorable results for emissions from latex paint. The procedures and findings are discussed; conclusions are limited and include emphasis on the need for additional study and development of a standard method.« less

  20. A Model for Axial Magnetic Bearings Including Eddy Currents

    NASA Technical Reports Server (NTRS)

    Kucera, Ladislav; Ahrens, Markus

    1996-01-01

    This paper presents an analytical method of modelling eddy currents inside axial bearings. The problem is solved by dividing an axial bearing into elementary geometric forms, solving the Maxwell equations for these simplified geometries, defining boundary conditions and combining the geometries. The final result is an analytical solution for the flux, from which the impedance and the force of an axial bearing can be derived. Several impedance measurements have shown that the analytical solution can fit the measured data with a precision of approximately 5%.

  1. Error in telemetry studies: Effects of animal movement on triangulation

    USGS Publications Warehouse

    Schmutz, Joel A.; White, Gary C.

    1990-01-01

    We used Monte Carlo simulations to investigate the effects of animal movement on error of estimated animal locations derived from radio-telemetry triangulation of sequentially obtained bearings. Simulated movements of 0-534 m resulted in up to 10-fold increases in average location error but <10% decreases in location precision when observer-to-animal distances were <1,000 m. Location error and precision were minimally affected by censorship of poor locations with Chi-square goodness-of-fit tests. Location error caused by animal movement can only be eliminated by taking simultaneous bearings.

  2. Emitter location errors in electronic recognition system

    NASA Astrophysics Data System (ADS)

    Matuszewski, Jan; Dikta, Anna

    2017-04-01

    The paper describes some of the problems associated with emitter location calculations. This aspect is the most important part of the series of tasks in the electronic recognition systems. The basic tasks include: detection of emission of electromagnetic signals, tracking (determining the direction of emitter sources), signal analysis in order to classify different emitter types and the identification of the sources of emission of the same type. The paper presents a brief description of the main methods of emitter localization and the basic mathematical formulae for calculating their location. The errors' estimation has been made to determine the emitter location for three different methods and different scenarios of emitters and direction finding (DF) sensors deployment in the electromagnetic environment. The emitter has been established using a special computer program. On the basis of extensive numerical calculations, the evaluation of precise emitter location in the recognition systems for different configuration alignment of bearing devices and emitter was conducted. The calculations which have been made based on the simulated data for different methods of location are presented in the figures and respective tables. The obtained results demonstrate that calculation of the precise emitter location depends on: the number of DF sensors, the distances between emitter and DF sensors, their mutual location in the reconnaissance area and bearing errors. The precise emitter location varies depending on the number of obtained bearings. The higher the number of bearings, the better the accuracy of calculated emitter location in spite of relatively high bearing errors for each DF sensor.

  3. Manufacture of ultra high precision aerostatic bearings based on glass guide

    NASA Astrophysics Data System (ADS)

    Guo, Meng; Dai, Yifan; Peng, Xiaoqiang; Tie, Guipeng; Lai, Tao

    2017-10-01

    The aerostatic guide in the traditional three-coordinate measuring machine and profilometer generally use metal or ceramics material. Limited by the guide processing precision, the measurement accuracy of these traditional instruments is around micro-meter level. By selection of optical materials as guide material, optical processing method and laser interference measurement can be introduced to the traditional aerostatic bearings manufacturing field. By using the large aperture wave-front interference measuring equipment , the shape and position error of the glass guide can be obtained in high accuracy and then it can be processed to 0.1μm or even better with the aid of Magnetorheological Finishing(MRF) and Computer Controlled Optical Surfacing (CCOS) process and other modern optical processing method, so the accuracy of aerostatic bearings can be fundamentally improved and ultra high precision coordinate measuring can be achieved. This paper introduces the fabrication and measurement process of the glass guide by K9 with 300mm measuring range, and its working surface accuracy is up to 0.1μm PV, the verticality and parallelism error between the two guide rail face is better than 2μm, and the straightness of the aerostatic bearings by this K9 glass guide is up to 40nm after error compensation.

  4. Strategy Guideline: Compact Air Distribution Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burdick, A.

    2013-06-01

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward themore » exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.« less

  5. Optimetrics for Precise Navigation

    NASA Technical Reports Server (NTRS)

    Yang, Guangning; Heckler, Gregory; Gramling, Cheryl

    2017-01-01

    Optimetrics for Precise Navigation will be implemented on existing optical communication links. The ranging and Doppler measurements are conducted over communication data frame and clock. The measurement accuracy is two orders of magnitude better than TDRSS. It also has other advantages of: The high optical carrier frequency enables: (1) Immunity from ionosphere and interplanetary Plasma noise floor, which is a performance limitation for RF tracking; and (2) High antenna gain reduces terminal size and volume, enables high precision tracking in Cubesat, and in deep space smallsat. High Optical Pointing Precision provides: (a) spacecraft orientation, (b) Minimal additional hardware to implement Precise Optimetrics over optical comm link; and (c) Continuous optical carrier phase measurement will enable the system presented here to accept future optical frequency standard with much higher clock accuracy.

  6. Performance of Simple Gas Foil Thrust Bearings in Air

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2012-01-01

    Foil bearings are self-acting hydrodynamics devices used to support high speed rotating machinery. The advantages that they offer to process fluid lubricated machines include: high rotational speed capability, no auxiliary lubrication system, non-contacting high speed operation, and improved damping as compared to rigid hydrodynamic bearings. NASA has had a sporadic research program in this technology for almost 6 decades. Advances in the technology and understanding of foil journal bearings have enabled several new commercial products in recent years. These products include oil-free turbochargers for both heavy trucks and automobiles, high speed electric motors, microturbines for distributed power generation, and turbojet engines. However, the foil thrust bearing has not received a complimentary level of research and therefore has become the weak link of oil-free turbomachinery. In an effort to both provide machine designers with basic performance parameters and to elucidate the underlying physics of foil thrust bearings, NASA Glenn Research Center has completed an effort to experimentally measure the performance of simple gas foil thrust bearing in air. The database includes simple bump foil supported thrust bearings with full geometry and manufacturing techniques available to the user. Test conditions consist of air at ambient pressure and temperatures up to 500 C and rotational speeds to 55,000 rpm. A complete set of axial load, frictional torque, and rotational speed is presented for two different compliant sub-structures and inter-pad gaps. Data obtained from commercially available foil thrust bearings both with and without active cooling is presented for comparison. A significant observation made possible by this data set is the speed-load capacity characteristic of foil thrust bearings. Whereas for the foil journal bearing the load capacity increases linearly with rotational speed, the foil thrust bearing operates in the hydrodynamic high speed limit. In this case, the load capacity is constant and in fact often decreases with speed if other factors such as thermal conditions and runner distortions are permitted to dominate the bearing performance.

  7. New step toward geodetic range observations at the sea floor with the BBOBS system

    NASA Astrophysics Data System (ADS)

    Shiobara, H.; Shinohara, M.; Isse, T.

    2011-12-01

    Since 1999, we had developed the broadband ocean bottom seismometer (BBOBS) and its new generation model (BBOBS-NX), and performed several practical observations with them in these ten years to create a category of the ocean floor broadband seismology. Now, the BBOBS data is proved to be acceptable for broadband seismic analyses. In these studies, the period range of the data used is about 10 - 200 s, but in longer period range, i.e. geodetic range, is an unknown region in observations at the sea floor. The acoustic GPS link observation is one of successful methods to know horizontal movement of the sea floor, but it is difficult to obtain continuous data in time. The borehole tilt-meter system is ideal in observational conditions, but it is impossible to expand spatially dense observation network. On the other hand, high mobility of our BBOBS and BBOBS-NX can be a breakthrough for this kind of observation network. So that, based on our BBOBS technology, two kinds of attempts to expand observation range toward the geodetic one have been started since 2009. Our aim in these attempts is to extend observation periods more than one week long for detecting slow slip events, as a first step. Finally, we would like to build the observation network by using them. The first attempt is a precise pressure measurement to detect vertical displacement at the sea floor by attaching an absolute pressure gauge and a parasitic data logger to the original OBS data recorder. The stable frequency oscillator (MCXO) in the data recorder is useful for precise pressure measurement of the gauge with frequency outputs. Although the final resolution of the pressure becomes smaller than 1 Pa, we still have problems due to the drift of the gauge and some scale of sea level change in practical observations. The total precision of the pressure value is also affected by the shift and drift of the frequency standard to measure frequency output signals of the gauge. In our measurements, this effect is estimated less than 60 Pa from the maximum frequency deviation of the MCXO, but it will be negligible by using a small chip scale atomic clock (CSAC), which is available now, as the frequency standard. The second one is a tilt observation just beneath the sea floor by using the BBOBS-NX system, which had been tested 6 times in 2008 - 2010 by free falling deployment with appropriate penetration to the sea floor sediment. The tilt is measured by using two horizontal mass position (acceleration) signals of the broadband sensor. The noise reduction ratio in horizontal components of the BBOBS-NX compared with those of the BBOBS staying on the sea floor is more than 10 in the period range longer than 10 s. It means the possibility of the BBOBS-NX system for the tilt observation in the geodetic range. As we didn't record the mass position signal continuously, a test observation was performed by using the same sensor of the BBOBS-NX at the ERI's Nokogiriyama observatory in 2010. The result is comparable with that of the water tube tilt-meter there in the diurnal Earth tide range. In July 2011, we started a test observation of the tilt measurement at the sea floor SE off Kii peninsula by using the BBOBS-NX as the feasibility study. The deployment was ideally performed by the ROV, and the recovery is planned in January 2012.

  8. Human health risk assessment based on trace metals in suspended air particulates, surface dust, and floor dust from e-waste recycling workshops in Hong Kong, China.

    PubMed

    Lau, Winifred Ka Yan; Liang, Peng; Man, Yu Bon; Chung, Shan Shan; Wong, Ming Hung

    2014-03-01

    This study investigated health risks exerted on electronic waste (e-waste) recycling workers exposed to cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), mercury (Hg), and zinc (Zn) in Hong Kong. E-waste recycling workshops were classified into eight working areas: 1 = office, 2 = repair, 3 = dismantling, 4 = storage, 5 = desoldering, 6 = loading, 7 = cable shredding, and 8 = chemical waste. The aforementioned metal concentrations were analyzed in suspended air particulates, surface dust and floor dust collected from the above study areas in five workshops. Elevated Pb levels were measured in dismantling and desoldering areas (582 and 486 μg/100 cm(2) in surface and 3,610 and 19,172 mg/kg in floor dust, respectively). Blood lead levels of 10 and 39.5 μg/dl were estimated using United States Environmental Protection Agency's Adult Lead Model as a result of exposure to the floor dust from these two areas. Human health risk assessments were conducted to evaluate cancer and noncancer risks resulting from exposure to floor dust through the combined pathways of ingestion, dermal contact, and inhalation. Findings indicated that workers may be exposed to cancer risks above the acceptable range at 147 in a million at the 95th percentile in the dismantling area. Workers should be informed of associated risks to safeguard their health.

  9. Effects of ventilation rate per person and per floor area on perceived air quality, sick building syndrome symptoms, and decision-making.

    PubMed

    Maddalena, R; Mendell, M J; Eliseeva, K; Chan, W R; Sullivan, D P; Russell, M; Satish, U; Fisk, W J

    2015-08-01

    Ventilation rates (VRs) in buildings must adequately control indoor levels of pollutants; however, VRs are constrained by the energy costs. Experiments in a simulated office assessed the effects of VR per occupant on perceived air quality (PAQ), Sick Building Syndrome (SBS) symptoms, and decision-making performance. A parallel set of experiments assessed the effects of VR per unit floor area on the same outcomes. Sixteen blinded healthy young adult subjects participated in each study. Each exposure lasted four hours and each subject experienced two conditions in a within-subject study design. The order of presentation of test conditions, day of testing, and gender were balanced. Temperature, relative humidity, VRs, and concentrations of pollutants were monitored. Online surveys assessed PAQ and SBS symptoms and a validated computer-based tool measured decision-making performance. Neither changing the VR per person nor changing the VR per floor area, had consistent statistically significant effects on PAQ or SBS symptoms. However, reductions in either occupant-based VR or floor-area-based VR had a significant and independent negative impact on most decision-making measures. These results indicate that the changes in VR employed in the study influence performance of healthy young adults even when PAQ and SBS symptoms are unaffected. The study results indicate the importance of avoiding low VRs per person and low VRs per floor area to minimize decrements in cognitive performance. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Reaerosolization of Spores from Flooring Surfaces To Assess the Risk of Dissemination and Transmission of Infections.

    PubMed

    Paton, Susan; Thompson, Katy-Anne; Parks, Simon R; Bennett, Allan M

    2015-08-01

    The aim of this study was to quantify reaerosolization of microorganisms caused by walking on contaminated flooring to assess the risk to individuals accessing areas contaminated with pathogenic organisms, for example, spores of Bacillus anthracis. Industrial carpet and polyvinyl chloride (PVC) floor coverings were contaminated with aerosolized spores of Bacillus atrophaeus by using an artist airbrush to produce deposition of ∼10(3) to 10(4) CFU · cm(-2). Microbiological air samplers were used to quantify the particle size distribution of the aerosol generated when a person walked over the floorings in an environmental chamber. Results were expressed as reaerosolization factors (percent per square centimeter per liter), to represent the ratio of air concentration to surface concentration generated. Walking on carpet generated a statistically significantly higher reaerosolization factor value than did walking on PVC (t = 20.42; P < 0.001). Heavier walking produced a statistically significantly higher reaerosolization factor value than did lighter walking (t = 12.421; P < 0.001). Height also had a statistically significant effect on the reaerosolization factor, with higher rates of recovery of B. atrophaeus at lower levels, demonstrating a height-dependent gradient of particle reaerosolization. Particles in the respirable size range were recovered in all sampling scenarios (mass mean diameters ranged from 2.6 to 4.1 μm). The results of this study can be used to produce a risk assessment of the potential aerosol exposure of a person accessing areas with contaminated flooring in order to inform the choice of appropriate respiratory protective equipment and may aid in the selection of the most suitable flooring types for use in health care environments, to reduce aerosol transmission in the event of contamination. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Reaerosolization of Spores from Flooring Surfaces To Assess the Risk of Dissemination and Transmission of Infections

    PubMed Central

    Thompson, Katy-Anne; Parks, Simon R.; Bennett, Allan M.

    2015-01-01

    The aim of this study was to quantify reaerosolization of microorganisms caused by walking on contaminated flooring to assess the risk to individuals accessing areas contaminated with pathogenic organisms, for example, spores of Bacillus anthracis. Industrial carpet and polyvinyl chloride (PVC) floor coverings were contaminated with aerosolized spores of Bacillus atrophaeus by using an artist airbrush to produce deposition of ∼103 to 104 CFU · cm−2. Microbiological air samplers were used to quantify the particle size distribution of the aerosol generated when a person walked over the floorings in an environmental chamber. Results were expressed as reaerosolization factors (percent per square centimeter per liter), to represent the ratio of air concentration to surface concentration generated. Walking on carpet generated a statistically significantly higher reaerosolization factor value than did walking on PVC (t = 20.42; P < 0.001). Heavier walking produced a statistically significantly higher reaerosolization factor value than did lighter walking (t = 12.421; P < 0.001). Height also had a statistically significant effect on the reaerosolization factor, with higher rates of recovery of B. atrophaeus at lower levels, demonstrating a height-dependent gradient of particle reaerosolization. Particles in the respirable size range were recovered in all sampling scenarios (mass mean diameters ranged from 2.6 to 4.1 μm). The results of this study can be used to produce a risk assessment of the potential aerosol exposure of a person accessing areas with contaminated flooring in order to inform the choice of appropriate respiratory protective equipment and may aid in the selection of the most suitable flooring types for use in health care environments, to reduce aerosol transmission in the event of contamination. PMID:25979883

  12. Performance and Durability of High Temperature Foil Air Bearings for Oil-Free Turbomachinery

    NASA Technical Reports Server (NTRS)

    DellaCorte, C.; Lukaszewicz, V.; Valco, M. J.; Radil, K. C.; Heshmat, H.

    2000-01-01

    The performance and durability of advanced, high temperature foil air bearings are evaluated under a wide range (10-50 kPa) of loads at temperatures from 25 to 650 C. The bearings are made from uncoated nickel based superalloy foils. The foil surface experiences sliding contact with the shaft during initial start/stop operation. To reduce friction and wear, the solid lubricant coating, PS304, is applied to the shaft by plasma spraying. PS304 is a NiCr based Cr2O3 coating with silver and barium fluoride/calcium fluoride solid lubricant additions. The results show that the bearings provide lives well in excess of 30,000 cycles under all of the conditions tested. Several bearings exhibited lives in excess of 100,000 cycles. Wear is a linear function of the bearing load. The excellent performance measured in this study suggests that these bearings and the PS304 coating are well suited for advanced high temperature, oil-free turbomachinery applications.

  13. Segmented air bearing in micronozzle technology for the project SOFIA

    NASA Astrophysics Data System (ADS)

    Muth, Michael; Schulz, Bernd

    1997-10-01

    Since 1986 there is a cooperation between NASA and DARA, Germany's space agency, to develop a flying telescope three times the size and ten times the light gathering ability of its predecessor -- the Kuiper Airborne Observatory. This project is called SOFIA -- Stratospheric Observatory for Infrared Astronomy. The 2.5 meter telescope for the visible through the infrared and the sub-millimeter wavelengths to the microwaves will be mounted in a modified Boeing 747-SP with a cavity at the port side behind the wings. It can be opened at stratospheric altitudes of around 41,000 feet, above 99.9 percent of the interfering water vapor. When not in use, the telescope will be sheltered from environment by a door in the fuselage. Vibrations of the aircraft would spoil the telescope's images. Therefore the telescope has to be isolated from the aircraft's structure. One promising solution for the rotational uncoupling is a segmented spherical air bearing with a bearing sphere diameter of 1.2 meter, which carries the telescope on a thin air cushion. In this paper a new technology of air bearings with micro nozzles manufactured with the aid of a laser is presented. The innovation is rooted in the unique combination of excellent static and dynamic characteristics. These types of air bearings were developed at the Lehrstuhl fur Feingeratebau und Mikrotechnik at the Technical University of Munich, and they are produced in series by the AeroLas GmbH, Munich.

  14. A waved journal bearing concept with improved steady-state and dynamic performance

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin

    1994-01-01

    Analysis of the waved journal bearing concept featuring a waved inner bearing diameter for use with a compressible lubricant (gas) is presented. A three wave, waved journal bearing geometry is used to show the geometry of this concept. The performance of generic waved bearings having either three, four, six, or eight waves is predicted for air lubricated bearings. Steady-state performance is discussed in terms of bearing load capacity, while the dynamic performance is discussed in terms of dynamic coefficients and fluid film stability. It was found that the bearing wave amplitude has an important influence on both steady-state and dynamic performance of the waved journal bearing. For a fixed eccentricity ratio, the bearing steady-state load capacity and direct dynamic stiffness coefficient increase as the wave amplitude increases. Also, the waved bearing becomes more stable as the wave amplitude increases. In addition, increasing the number of waves reduces the waved bearing's sensitivity to the direction of the applied load relative to the wave. However, the range in which the bearing performance can be varied decreases as the number of waves increases. Therefore, both the number and the amplitude of the waves must be properly selected to optimize the waved bearing design for a specific application. It is concluded that the stiffness of an air bearing, due to the hydrodynamic effect, could be doubled and made to run stably by using a six or eight wave geometry with a wave amplitude approximately half of the bearing radial clearance.

  15. Low-cost three-dimensional gait analysis system for mice with an infrared depth sensor.

    PubMed

    Nakamura, Akihiro; Funaya, Hiroyuki; Uezono, Naohiro; Nakashima, Kinichi; Ishida, Yasumasa; Suzuki, Tomohiro; Wakana, Shigeharu; Shibata, Tomohiro

    2015-11-01

    Three-dimensional (3D) open-field gait analysis of mice is an essential procedure in genetic and nerve regeneration research. Existing gait analysis systems are generally expensive and may interfere with the natural behaviors of mice because of optical markers and transparent floors. In contrast, the proposed system captures the subjects shape from beneath using a low-cost infrared depth sensor (Microsoft Kinect) and an opaque infrared pass filter. This means that we can track footprints and 3D paw-tip positions without optical markers or a transparent floor, thereby preventing any behavioral changes. Our experimental results suggest with healthy mice that they are more active on opaque floors and spend more time in the center of the open-field, when compared with transparent floors. The proposed system detected footprints with a comparable performance to existing systems, and precisely tracked the 3D paw-tip positions in the depth image coordinates. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  16. CATALOG OF MATERIALS AS POTENTIAL SOURCES OF INDOOR AIR EMISSIONS - VOLUME 1. INSULATION, WALLCOVERINGS, RESILIENT FLOOR COVERINGS, CARPET, ADHESIVES, SEALANTS AND CAULKS, AND PESTICIDES

    EPA Science Inventory

    The report discusses and presents data on constituents and emissions from products that have the potential to impact the indoor air environment. t is a tool to be used by researchers to help organize the study of materials as potential sources of indoor air emissions. ncluded are...

  17. General view of the Space Shuttle Main Engine (SSME) assembly ...

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

    General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-Pressure Fuel Turbopump (LPFTP) on the upper left of the engine assembly, the LPFTP Discharge Duct looping around the assembly, the Gimbal Bearing on the top center of the assembly, the Electrical Interface Panel sits just below the Gimbal Bearing and the Low-Pressure Oxidizer Turbopump is mounted on the top right of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  18. Modification of Bushing Test Rig and Research of Variable Inlet Guide Vane Bushings For Further Development of PM304 Bushings

    NASA Technical Reports Server (NTRS)

    Yanke, Anne

    2004-01-01

    PS304 is a high temperature solid lubricant coating comprised of a nickel-chrome binder, chrome oxide hardener, barium-calcium fluoride high temperature lubricant, and silver as the low temperature lubricant. This coating is used to lubricate Oil-Free Foil Air Bearings as they experience friction and wear during start up and shut down. The coating deposition process begins with undercutting the shaft. This area is then sandblasted to provide a rough surface for the coating to adhere to. The coating powder is then sent through the plasma spray gun and a reasonably thick layer is applied to the undercut area of the shaft. The coating is then ground down even with the surface of the shaft and gets a nice polished finish. The foil air bearings use the solid lubricant, as mentioned above, during start up and shut down. During normal operating conditions, generally above 2000RPM, the bearings utilize air as their lubricant. Foil air bearings are comprised of a thin top foil and a corrugated bump foil. They have an interference fit with the shaft before operation. As the air gets "trapped" between the top foil and the shaft, it presses the top foil against the bump foil, in turn compressing the bumps. As the bumps compress, it allows for the air to separate the top foil from the shaft, therefore, utilizing the trapped air as its lubricant.

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rockaway, J.D.; Stephenson, R.W.

    The study described was accomplished through an investigation of both the intact and insitu geotechnical properties of the subcoal strata and through the installation of floor movement monitoring instrumentation. The method of bearing capacity analysis developed by A.S. Vesic was used to define pillar stability. This method includes provisions for taking into consideration a two-layer system such as assumed for mine conditions where a weak underclay overlies firmer strata. 4 refs.

  20. Ultra-precision turning of complex spiral optical delay line

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaodong; Li, Po; Fang, Fengzhou; Wang, Qichang

    2011-11-01

    Optical delay line (ODL) implements the vertical or depth scanning of optical coherence tomography, which is the most important factor affecting the scanning resolution and speed. The spinning spiral mirror is found as an excellent optical delay device because of the high-speed and high-repetition-rate. However, it is one difficult task to machine the mirror due to the special shape and precision requirement. In this paper, the spiral mirror with titled parabolic generatrix is proposed, and the ultra-precision turning method is studied for its machining using the spiral mathematic model. Another type of ODL with the segmental shape is also introduced and machined to make rotation balance for the mass equalization when scanning. The efficiency improvement is considered in details, including the rough cutting with the 5- axis milling machine, the machining coordinates unification, and the selection of layer direction in turning. The onmachine measuring method based on stylus gauge is designed to analyze the shape deviation. The air bearing is used as the measuring staff and the laser interferometer sensor as the position sensor, whose repeatability accuracy is proved up to 10nm and the stable feature keeps well. With this method developed, the complex mirror with nanometric finish of 10.7nm in Ra and the form error within 1um are achieved.

  1. Evaluation of four sampling methods for determining exposure of children to lead-contaminated household dust

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sterling, D.A.; Roegner, K.C.; Lewis, R.D.

    Childhood exposure to lead has been demonstrated to result in health effects and lead-contaminated household dust is a primary exposure source. There is a need to establish reliable methods for sampling surfaces to determine levels of lead contamination. Three vacuums (HVS3, GS80, and MVM) and one wipe method were evaluated for the collection of household floor dust under field sampling conditions within a Superfund site and demographically similar control area. Side-by-side floor samples were taken from three locations within 41 randomly selected households between August and September 1995: a child's bedroom, primary play area, and primary entrance. Analysis was performedmore » to assess the relative collection performance of each sampler, spatial distribution of lead within a household, and correlation of lead loading with observed blood lead level, and to determine if discrete or composites samples were more predictive of blood lead levels. Approximately 90% of the floor surfaces were carpeted. The rank order of sampling methods from greatest to lowest collection efficiency was HVS3 > G80 > wipe > MVM. The HVS3 had the highest level of precision (CV = 0.05), with the GS80 and wipe precisions 0.48 and 0.053, respectively.« less

  2. Generation of airborne Listeria innocua from model floor drains.

    PubMed

    Berrang, Mark E; Frank, Joseph F

    2012-07-01

    Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 10(8) cells per ml of phosphate-buffered saline and 10(4) attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

  3. Detail of one way mirror, mail slot, and electrical box ...

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

    Detail of one way mirror, mail slot, and electrical box at sentry post no. 3, top of east stairs near the end of second floor corridor - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  4. Pneumatic vacuum tube message center, basement room 23, looking southeast ...

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

    Pneumatic vacuum tube message center, basement room 23, looking southeast toward doorway and corridor. Note soundproof walls, pedestal flooring, and cable tray suspended from the ceiling - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  5. 23. Photocopy of engineering drawing, April 10, 1958 (original drawing ...

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

    23. Photocopy of engineering drawing, April 10, 1958 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering Vault). READINESS CREW BUILDING, UPPER FLOOR PLANS - Fairchild Air Force Base, Bomber Alert Facility, 803G South Taxi Way, Spokane, Spokane County, WA

  6. 22. Photocopy of engineering drawing, April 10, 1958 (original drawing ...

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

    22. Photocopy of engineering drawing, April 10, 1958 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering Vault). READINESS CREW BUILDING, LOWER FLOOR PLANS - Fairchild Air Force Base, Bomber Alert Facility, 803G South Taxi Way, Spokane, Spokane County, WA

  7. Tribological composition optimization of chromium-carbide-based solid lubricant coatings for foil gas bearings at temperatures to 650 C

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher

    1988-01-01

    The determination of the tribilogically optimum composition of chromium-carbide-based solid lubricant coatings using a foil gas bearing test apparatus is described. The coatings contain a wear resistant chromium carbide `base stock' with the lubricant additives silver and BaF2-CaF2 eutectic. The coating composition is optimized for air-lubricated foil gas bearings at temperatures ranging from 25 to 650 C. The various compositions were prepared by powder blending, then plasma sprayed onto Inconel 718 test journals and diamond ground to the desired coating thickness and surface finish. The journals were operated against preoxidized Ni-Cr alloy foils, and the test bearings were subjected to repeated start-stop cycles under a bearing unit of 14 kPa. Sliding contact between the coated journal and the smooth foil occurs during bearing start-up before lift-off or hydrodynamic lubrication by the air film and during bearing coast-down. The bearings were tested for 9000 start-stop cycles or until specimen reached a predetermined failure level.

  8. The accuracy of ultrasound for measurement of mobile- bearing motion.

    PubMed

    Aigner, Christian; Radl, Roman; Pechmann, Michael; Rehak, Peter; Stacher, Rudolf; Windhager, Reinhard

    2004-04-01

    After anterior cruciate ligament-sacrificing total knee replacement, mobile bearings sometimes have paradoxic movement but the implications of such movement on function, wear, and implant survival are not known. To study this potential problem accurate, reliable, and widely available inexpensive tools for in vivo mobile-bearing motion analyses are needed. We developed a method using an 8-MHz ultrasound to analyze mobile-bearing motion and ascertained accuracy, precision, and reliability compared with plain and standard digital radiographs. The anterior rim of the mobile bearing was the target for all methods. The radiographs were taken in a horizontal plane at neutral rotation and incremental external and internal rotations. Five investigators examined four positions of the mobile bearing with all three methods. The accuracy and precision were: ultrasound, 0.7 mm and 0.2 mm; digital radiograph, 0.4 mm and 0.2 mm; and plain radiographs, 0.7 mm and 0.3 mm. The interrater and intrarater reliability ranged between 0.3 to 0.4 mm and 0.1 to 0.2 mm, respectively. The difference between the methods was not significant for neutral rotation but ultrasound was significantly more accurate than any one degree of rotation or higher. Ultrasound of 8 MHz provides an accuracy and reliability that is suitable for evaluation of in vivo meniscal bearing motion. Whether this method or others are sufficiently accurate to detect motion leading to abnormal wear is not known.

  9. 95. View of transmitter building no. 102 second floor view ...

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

    95. View of transmitter building no. 102 second floor view of capacitor vaults, waveguides and combiner bifurcation, Official photograph BMEWS Project by C. Henry, 6 January 1962, Photographic Services, Riverton, NJ, BMEWS, clear as negative no. A-3541. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  10. [Ceramic-on-ceramic bearings in total hip arthroplasty (THA)].

    PubMed

    Sentürk, U; Perka, C

    2015-04-01

    The main reason for total hip arthroplasty (THA) revision is the wear-related aseptic loosening. Younger and active patients after total joint replacement create high demands, in particular, on the bearings. The progress, especially for alumina ceramic-on-ceramic bearings and mixed ceramics have solved many problems of the past and lead to good in vitro results. Modern ceramics (alumina or mixed ceramics containing alumina) are extremely hard, scratch-resistant, biocompatible, offer a low coefficient of friction, superior lubrication and have the lowest wear rates in comparison to all other bearings in THA. The disadvantage of ceramic is the risk of material failure, i.e., of ceramic fracture. The new generation of mixed ceramics (delta ceramic), has reduced the risk of head fractures to 0.03-0.05 %, but the risk for liner fractures remains unchanged at about 0.02 %. Assuming a non-impinging component implantation, ceramic-on-ceramic bearings have substantial advantages over all other bearings in THA. Due to the superior hardness, ceramic bearings produce less third body wear and are virtually impervious to damage from instruments during the implantation process. A specific complication for ceramic-on-ceramic bearings is "squeaking". The high rate of reported squeaking (0.45 to 10.7 %) highlights the importance of precise implant positioning and the stem and patient selection. With precise implant positioning this problem is rare with many implant designs and without clinical relevance. The improved tribology and the presumable resulting implant longevity make ceramic-on-ceramic the bearing of choice for young and active patients. Georg Thieme Verlag KG Stuttgart · New York.

  11. Forced-air warming and ultra-clean ventilation do not mix: an investigation of theatre ventilation, patient warming and joint replacement infection in orthopaedics.

    PubMed

    McGovern, P D; Albrecht, M; Belani, K G; Nachtsheim, C; Partington, P F; Carluke, I; Reed, M R

    2011-11-01

    We investigated the capacity of patient warming devices to disrupt the ultra-clean airflow system. We compared the effects of two patient warming technologies, forced-air and conductive fabric, on operating theatre ventilation during simulated hip replacement and lumbar spinal procedures using a mannequin as a patient. Infection data were reviewed to determine whether joint infection rates were associated with the type of patient warming device that was used. Neutral-buoyancy detergent bubbles were released adjacent to the mannequin's head and at floor level to assess the movement of non-sterile air into the clean airflow over the surgical site. During simulated hip replacement, bubble counts over the surgical site were greater for forced-air than for conductive fabric warming when the anaesthesia/surgery drape was laid down (p = 0.010) and at half-height (p < 0.001). For lumbar surgery, forced-air warming generated convection currents that mobilised floor air into the surgical site area. Conductive fabric warming had no such effect. A significant increase in deep joint infection, as demonstrated by an elevated infection odds ratio (3.8, p = 0.024), was identified during a period when forced-air warming was used compared to a period when conductive fabric warming was used. Air-free warming is, therefore, recommended over forced-air warming for orthopaedic procedures.

  12. Variability of indoor fungal microbiome of green and non-green low-income homes in Cincinnati, Ohio.

    PubMed

    Coombs, Kanistha; Taft, Diana; Ward, Doyle V; Green, Brett J; Chew, Ginger L; Shamsaei, Behrouz; Meller, Jaroslaw; Indugula, Reshmi; Reponen, Tiina

    2018-01-01

    "Green" housing is designed to use low-impact materials, increase energy efficiency and improve occupant health. However, little is known about the indoor mycobiome of green homes. The current study is a subset of a multicenter study that aims to investigate the indoor environment of green homes and the respiratory health of asthmatic children. In the current study, the mycobiome in air, bed dust and floor dust was compared between green (study site) and non-green (control site), low-income homes in Cincinnati, Ohio. The samples were collected at baseline (within four months following renovation), and 12months after the baseline at the study site. Parallel sample collection was conducted in non-green control homes. Air samples were collected by PM2.5 samplers over 5-days. Bed and floor dust samples were vacuumed after the air sampling was completed. The DNA sample extracts were analyzed using ITS amplicon sequencing. Analysis indicated that there was no clear trend in the fungal communities between green and non-green homes. Instead, fungal community differences were greatest between sample types - air, bed, and floor. Microbial communities also changed substantially between sampling intervals in both green and non-green homes for all sample types, potentially indicating that there was very little stability in the mycobiomes. Research gaps remain regarding how indoor mycobiome fluctuates over time. Longer follow-up periods might elucidate the effect of green renovation on microbial load in buildings. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Lubricant distribution and its effect on slider air bearing performance over bit patterned media disk of disk drives

    NASA Astrophysics Data System (ADS)

    Wu, Lin

    2011-04-01

    The distribution dynamics of a thin lubricant film on a bit-patterned media disk and its effect on the performance of the ultralow flying air bearing slider of disk drives are studied by direct numerical simulations. Our analysis shows that the physics governing lubricant distribution dynamics changes when deep enough sub-100-nm nanostructures are patterned on the disk surface. Air shearing under the slider that dominates lubricant flow on a flat disk may become negligible on a bit-patterned media disk. Surface tension and disjoining pressure become dominant factors instead. Our results show that disks with nanoscale patterns/roughness may no longer be treated as flat, and the air bearing load may strongly depend not only on the geometric detail of disk patterns but also on how lubricants are distributed on the patterns when slider-disk clearance is reduced to sub-10-nm. Air bearing load and consequently the slider's flying attitude are affected by disk pattern geometry, average lubricant thickness, and material properties of lubricant such as the surface tension coefficient and Hamaker constant. The significantly expanded parameter space, upon which ultralow flying slider's dynamics depends, has to be seriously considered in evaluating the head/disk interface tribology performance of next generation patterned media magnetic recording systems.

  14. Mineral abundances at the final four curiosity study sites and implications for their formation

    NASA Astrophysics Data System (ADS)

    Poulet, F.; Carter, J.; Bishop, J. L.; Loizeau, D.; Murchie, S. M.

    2014-03-01

    A component of the landing site selection process for the Mars Science Laboratory (MSL) involved the presence of phyllosilicates as the main astrobiological targets. Gale crater was selected as the MSL landing site from among 4 down selected study sites (Gale, Eberswalde and Holden craters, Mawrth Vallis) that addressed the primary scientific goal of assessing the past habitability of Mars. A key constraint on the formation process of these phyllosilicate-bearing deposits is in the precise mineralogical composition. We present a reassessment of the mineralogy of the sites combined with a determination of the modal mineralogy of the major phyllosilicate-bearing deposits of the four final study sites from the modeling of near-infrared spectra using a radiative transfer model. The largest abundance of phyllosilicates (30-70%) is found in Mawrth Vallis, the lowest one in Eberswalde (<25%). Except for Mawrth Vallis, the anhydrous phases (plagioclase, pyroxenes and martian dust) are the dominant phases, suggesting formation conditions with a lower alteration grade and/or a post-formation mixing with anhydrous phases. The composition of Holden layered deposits (mixture of saponite and micas with a total abundance in the range of 25-45%) suggests transport and deposition of altered basalts of the Noachian crust without major chemical transformation. For Eberswalde, the modal mineralogy is also consistent with detrital clays, but the presence of opaline silica indicates that an authigenic formation occurred during the deposition. The overall composition including approximately 20-30% smectite detected by MSL in the rocks of Yellow-knife Bay area interpreted to be material deposited on the floor of Gale crater by channels (http://www.nasa.gov/mission_pages/msl/news/msl20130312.html).

  15. This photographic copy of an engineering drawing shows floor plans, ...

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

    This photographic copy of an engineering drawing shows floor plans, sections and elevations of Building E-86, with details typical of the steel frame and "Transite" building construction at JPL Edwards Facility. California Institute of Technology, Jet Propulsion Laboratory, Facilities Engineering and Construction Office: "Casting & Curing, Building E-86, Floor Plan, Elevations & Section," drawing no. E86/6, 25 February 1977. California Institute of Technology, Jet Propulsion Laboratory, Plant Engineering: engineering drawings of structures at JPL Edwards Facility. Drawings on file at JPL Plant Engineering, Pasadena, California - Jet Propulsion Laboratory Edwards Facility, Casting & Curing Building, Edwards Air Force Base, Boron, Kern County, CA

  16. Sub-sampling genetic data to estimate black bear population size: A case study

    USGS Publications Warehouse

    Tredick, C.A.; Vaughan, M.R.; Stauffer, D.F.; Simek, S.L.; Eason, T.

    2007-01-01

    Costs for genetic analysis of hair samples collected for individual identification of bears average approximately US$50 [2004] per sample. This can easily exceed budgetary allowances for large-scale studies or studies of high-density bear populations. We used 2 genetic datasets from 2 areas in the southeastern United States to explore how reducing costs of analysis by sub-sampling affected precision and accuracy of resulting population estimates. We used several sub-sampling scenarios to create subsets of the full datasets and compared summary statistics, population estimates, and precision of estimates generated from these subsets to estimates generated from the complete datasets. Our results suggested that bias and precision of estimates improved as the proportion of total samples used increased, and heterogeneity models (e.g., Mh[CHAO]) were more robust to reduced sample sizes than other models (e.g., behavior models). We recommend that only high-quality samples (>5 hair follicles) be used when budgets are constrained, and efforts should be made to maximize capture and recapture rates in the field.

  17. Comparison of indoor air sampling and dust collection methods for fungal exposure assessment using quantitative PCR.

    PubMed

    Cox, Jennie; Indugula, Reshmi; Vesper, Stephen; Zhu, Zheng; Jandarov, Roman; Reponen, Tiina

    2017-10-18

    Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample collected with a Button™ inhalable aerosol sampler and four types of dust samples: a vacuumed floor dust sample, newly settled dust collected for four weeks onto two types of electrostatic dust cloths (EDCs) in trays, and a wipe sample of dust from above floor surfaces. The samples were obtained in the bedrooms of asthmatic children (n = 14). Quantitative polymerase chain reaction (qPCR) was used to analyze the dust and air samples for the 36 fungal species that make up the Environmental Relative Moldiness Index (ERMI). The results from the samples were compared by four matrices: total concentration of fungal cells, concentration of fungal species associated with indoor environments, concentration of fungal species associated with outdoor environments, and ERMI values (or ERMI-like values for air samples). The ERMI values for the dust samples and the ERMI-like values for the 48 hour air samples were not significantly different. The total cell concentrations of the 36 species obtained with the four dust collection methods correlated significantly (r = 0.64-0.79, p < 0.05), with the exception of the vacuumed floor dust and newly settled dust. In addition, fungal cell concentrations of indoor associated species correlated well between all four dust sampling methods (r = 0.68-0.86, p < 0.01). No correlation was found between the fungal concentrations in the air and dust samples primarily because of differences in concentrations of Cladosporium cladosporioides Type 1 and Epicoccum nigrum. A representative type of dust sample and a 48 hour air sample might both provide useful information about fungal exposures.

  18. A Monocular Vision Sensor-Based Obstacle Detection Algorithm for Autonomous Robots.

    PubMed

    Lee, Tae-Jae; Yi, Dong-Hoon; Cho, Dong-Il Dan

    2016-03-01

    This paper presents a monocular vision sensor-based obstacle detection algorithm for autonomous robots. Each individual image pixel at the bottom region of interest is labeled as belonging either to an obstacle or the floor. While conventional methods depend on point tracking for geometric cues for obstacle detection, the proposed algorithm uses the inverse perspective mapping (IPM) method. This method is much more advantageous when the camera is not high off the floor, which makes point tracking near the floor difficult. Markov random field-based obstacle segmentation is then performed using the IPM results and a floor appearance model. Next, the shortest distance between the robot and the obstacle is calculated. The algorithm is tested by applying it to 70 datasets, 20 of which include nonobstacle images where considerable changes in floor appearance occur. The obstacle segmentation accuracies and the distance estimation error are quantitatively analyzed. For obstacle datasets, the segmentation precision and the average distance estimation error of the proposed method are 81.4% and 1.6 cm, respectively, whereas those for a conventional method are 57.5% and 9.9 cm, respectively. For nonobstacle datasets, the proposed method gives 0.0% false positive rates, while the conventional method gives 17.6%.

  19. VOCS IN AMBIENT AIR NEAR WORLD TRADE CENTER SITE

    EPA Science Inventory

    Beginning on September 22, 2001 and continuing through February 2002, ambient air samples were collected at three sites within a block of ground zero and at a fourth site on the 16th floor of a building at 290 Broadway. Grab samples were collected in evacuated, electro-polished...

  20. Photocopy of print (original sepia print is backward and in ...

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

    Photocopy of print (original sepia print is backward and in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1953 architectural drawings by Horowick & Lee, Architects, Jacksonville, Florida) FLOOR PLAN AND SCHEDULES - MacDill Air Force Base, Photography Laboratory, 2617 Florida Keys Avenue, Tampa, Hillsborough County, FL

  1. Poster Puzzler Solution: Taking in Air | Poster

    Cancer.gov

    The current Poster Puzzler image shows the top of Building 560, where a new supply air handler was recently installed by Facilities Maintenance and Engineering (FME) staff, as part of lab renovations in wing 1, floor 1. FME staff enlarged the attic of the building to make space for the air handler. Building 560, the largest building at the NCI at Frederick campus, houses about

  2. CATALOG OF MATERIALS AS POTENTIAL SOURCES OF INDOOR AIR EMISSIONS - VOLUME 1. INSULATION, WALLCOVERINGS, RESI- LIENT FLOOR COVERINGS, CARPET, ADHESIVES, SEALANTS AND CAULKS, AND PESTICIDES

    EPA Science Inventory

    The report discusses and presents data on constituents and emissions from products that have the potential to impact the indoor air environment. t is a tool to be used by researchers to help organize the study of materials as potential sources of indoor air emissions. ncluded are...

  3. High efficiency machining technology and equipment for edge chamfer of KDP crystals

    NASA Astrophysics Data System (ADS)

    Chen, Dongsheng; Wang, Baorui; Chen, Jihong

    2016-10-01

    Potassium dihydrogen phosphate (KDP) is a type of nonlinear optical crystal material. To Inhibit the transverse stimulated Raman scattering of laser beam and then enhance the optical performance of the optics, the edges of the large-sized KDP crystal needs to be removed to form chamfered faces with high surface quality (RMS<5 nm). However, as the depth of cut (DOC) of fly cutting is usually several, its machining efficiency is too low to be accepted for chamfering of the KDP crystal as the amount of materials to be removed is in the order of millimeter. This paper proposes a novel hybrid machining method, which combines precision grinding with fly cutting, for crackless and high efficiency chamfer of KDP crystal. A specialized machine tool, which adopts aerostatic bearing linear slide and aerostatic bearing spindle, was developed for chamfer of the KDP crystal. The aerostatic bearing linear slide consists of an aerostatic bearing guide with linearity of 0.1 μm/100mm and a linear motor to achieve linear feeding with high precision and high dynamic performance. The vertical spindle consists of an aerostatic bearing spindle with the rotation accuracy (axial) of 0.05 microns and Fork type flexible connection precision driving mechanism. The machining experiment on flying and grinding was carried out, the optimize machining parameters was gained by a series of experiment. Surface roughness of 2.4 nm has been obtained. The machining efficiency can be improved by six times using the combined method to produce the same machined surface quality.

  4. Oil-Free Turbomachinery Team Passed Milestone on Path to the First Oil-Free Turbine Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Bream, Bruce L.

    2002-01-01

    The Oil-Free Turbine Engine Technology Project team successfully demonstrated a foil-air bearing designed for the core rotor shaft of a turbine engine. The bearings were subjected to test conditions representative of the engine core environment through a combination of high speeds, sustained loads, and elevated temperatures. The operational test envelope was defined during conceptual design studies completed earlier this year by bearing manufacturer Mohawk Innovative Technologies and the turbine engine company Williams International. The prototype journal foil-air bearings were tested at the NASA Glenn Research Center. Glenn is working with Williams and Mohawk to create a revolution in turbomachinery by developing the world's first Oil-Free turbine aircraft engine. NASA's General Aviation Propulsion project and Williams International recently developed the FJX-2 turbofan engine that is being commercialized as the EJ-22. This core bearing milestone is a first step toward a future version of the EJ-22 that will take advantage of recent advances in foil-air bearings by eliminating the need for oil lubrication systems and rolling element bearings. Oil-Free technology can reduce engine weight by 15 percent and let engines operate at very high speeds, yielding power density improvements of 20 percent, and reducing engine maintenance costs. In addition, with NASA coating technology, engines can operate at temperatures up to 1200 F. Although the project is still a couple of years from a full engine test of the bearings, this milestone shows that the bearing design exceeds the expected environment, thus providing confidence that an Oil-Free turbine aircraft engine will be attained. The Oil-Free Turbomachinery Project is supported through the Aeropropulsion Base Research Program.

  5. Use of negative air pressure by nasal suction during maxillary sinus floor lift: audit of 13 consecutive sinus grafts.

    PubMed

    Ucer, T C

    2009-03-01

    A common and serious intraoperative complication of sinus floor lift is perforation of the sinus lining. Several strategies to prevent or treat it have had varying results. We report the results of an audit of 13 consecutive sinus grafts in 11 patients in which nasal suction was used to facilitate raising the sinus lining, and to reduce the risk of perforation.

  6. Sudden transient complete loss of vision caused by nose blowing after a fracture of the orbital floor.

    PubMed

    Harmer, S G; Ethunandan, M; Zaki, G A; Brennan, P A

    2007-03-01

    A 52-year-old man was being attended to in a hospital for a fracture of the right zygoma and orbital floor, after being struck on the right upper face. After blowing his nose, he immediately lost vision in the right eye, and an urgent CT scan showed extensive retrobulbar air. Vision was regained within an hour. The management of this rare condition is discussed.

  7. NASA PS304 Lubricant Tested in World's First Commercial Oil-Free Gas Turbine

    NASA Technical Reports Server (NTRS)

    Weaver, Harold F.

    2003-01-01

    In a marriage of research and commercial technology, a 30-kW Oil-Free Capstone microturbine electrical generator unit has been installed and is serving as a test bed for long-term life-cycle testing of NASA-developed PS304 shaft coatings. The coatings are used to reduce friction and wear of the turbine engine s foil air bearings during startup and shut down when sliding occurs, prior to the formation of a lubricating air film. This testing supports NASA Glenn Research Center s effort to develop Oil-Free gas turbine aircraft propulsion systems, which will employ advanced foil air bearings and NASA s PS304 high temperature solid lubricant to replace the ball bearings and lubricating oil found in conventional engines. Glenn s Oil-Free Turbomachinery team s current project is the demonstration of an Oil-Free business jet engine. In anticipation of future flight certification of Oil-Free aircraft engines, long-term endurance and durability tests are being conducted in a relevant gas turbine environment using the Capstone microturbine engine. By operating the engine now, valuable performance data for PS304 shaft coatings and for industry s foil air bearings are being accumulated.

  8. An Autonomous, Low Cost Platform for Seafloor Geodetic Observations

    NASA Astrophysics Data System (ADS)

    Ericksen, T.; Foster, J. H.; Bingham, B. S.

    2013-12-01

    The high cost of acquiring geodetic data from the sea floor has limited the observations available to help us understand and model the behavior of seafloor geodetic processes. To address this problem, the Pacific GPS Facility at the University of Hawaii is developing a cost effective approach for accurately measuring short-term vertical motions of the seafloor and maintaining a continuous long-term record of seafloor pressure without the requirement for costly ship time. There is a recognized need to vastly increase our underwater geodetic observing capacity. Most of the largest recorded earthquakes and most devastating tsunamis are generated at subduction zones underwater. Similarly, many volcanoes are partly (e.g. Santorini) or completely (e.g. Loihi) submerged, and are not well observed and understood. Furthermore, landslide features ring many ocean basins, and huge debris deposits surround many volcanic oceanic islands. Our approach will lower the cost of collecting sea-floor geodetic data, reducing the barriers preventing us from acquiring the information we need to observe and understand these types of structures and provide a direct societal benefit in improving hazard assessment. The capability is being developed by equipping one of the University of Hawaii Wave Gliders with an integrated acoustic telemetry package, a dual frequency geodetic-grade Global Positioning System (GPS) receiver, processing unit, and cellular communications. The Wave Glider will interrogate high accuracy pressure sensors on the sea floor to maintain a near-continuous stream of pressure and temperature data, but seafloor pressure data includes contribution from a variety of sources and on its own may not provide the accuracy required for geodetic investigations. Independent measurements of sea surface pressure and sea surface height can be used to remove these contributions from the observed sea floor pressure timeseries. We will integrate our seafloor pressure measurements with air pressure data, and precise vertical measurements of the sea surface from kinematic positioning of the Wave Glider over the bottom sensor, to determine cm-scale vertical seafloor motions. The seafloor package will consist of a simple tripod frame that seats the pressure sensor unit, and includes an attachment onto which an ROV can install a mobile pressure recorder (MPR) should ship and ROV time be available. Two visits with an MPR would allow calibration of the linear drift of the continuous sensor, further enhancing the value of the timeseries. The pressure sensor is recoverable and serviceable and using the MPR calibration will enable the seafloor monument to be re-occupied to extend the pressure record beyond a single 5+ year deployment. We are currently focused on retrieving high accuracy vertical sea floor motions, but, importantly, we have chosen a development approach that provides a simple upgrade path for incorporating the Wave Glider GPS-Acoustic (GPS/A) measurement system under development at SIO. With this upgrade, Wave Gliders could also acquire accurate horizontal motions of the sea floor sensors, and provide a cost-effective way of performing full, 3-dimensional, surveys of sea-floor motions.

  9. Sea Legs

    NASA Astrophysics Data System (ADS)

    Macdonald, Kenneth C.

    Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

  10. Flux density measurement of radial magnetic bearing with a rotating rotor based on fiber Bragg grating-giant magnetostrictive material sensors.

    PubMed

    Ding, Guoping; Zhang, Songchao; Cao, Hao; Gao, Bin; Zhang, Biyun

    2017-06-10

    The rotational magnetic field of radial magnetic bearings characterizes remarkable time and spatial nonlinearity due to the eddy current and induced electromagnetic field. It is significant to experimentally obtain the features of the rotational magnetic field of the radial magnetic bearings to validate the theoretical analysis and reveal the discipline of a rotational magnetic field. This paper developed thin-slice fiber Bragg grating-giant magnetostrictive material (FBG-GMM) magnetic sensors to measure air-gap flux density of a radial magnetic bearing with a rotating rotor; a radial magnetic bearing test rig was constructed and the rotational magnetic field with different rotation speed was measured. Moreover, the finite element method (FEM) was used to simulate the rotational magnetic field; the measurement results and FEM results were investigated, and it was concluded that the FBG-GMM sensors were capable of measuring the radial magnetic bearing's air gap flux density with a rotating rotor, and the measurement results showed a certain degree of accuracy.

  11. Precision measurement and modeling of superconducting magnetic bearings for the satellite test of the equivalence principle

    NASA Astrophysics Data System (ADS)

    Sapilewski, Glen Alan

    The Satellite Test of the Equivalence Principle (STEP) is a modern version of Galileo's experiment of dropping two objects from the leaning tower of Pisa. The Equivalence Principle states that all objects fall with the same acceleration, independent of their composition. The primary scientific objective of STEP is to measure a possible violation of the Equivalence Principle one million times better than the best ground based tests. This extraordinary sensitivity is made possible by using cryogenic differential accelerometers in the space environment. Critical to the STEP experiment is a sound fundamental understanding of the behavior of the superconducting magnetic linear bearings used in the accelerometers. We have developed a theoretical bearing model and a precision measuring system with which to validate the model. The accelerometers contain two concentric hollow cylindrical test masses, of different materials, each levitated and constrained to axial motion by a superconducting magnetic bearing. Ensuring that the bearings satisfy the stringent mission specifications requires developing new testing apparatus and methods. The bearing is tested using an actively-controlled table which tips it relative to gravity. This balances the magnetic forces from the bearing against a component of gravity. The magnetic force profile of the bearing can be mapped by measuring the tilt necessary to position the test mass at various locations. An operational bearing has been built and is being used to verify the theoretical levitation models. The experimental results obtained from the bearing test apparatus were inconsistent with the previous models used for STEP bearings. This led to the development of a new bearing model that includes the influence of surface current variations in the bearing wires and the effect of the superconducting transformer. The new model, which has been experimentally verified, significantly improves the prediction of levitation current, accurately estimates the relationship between tilting and translational modes, and predicts the dependence of radial mode frequencies on the bearing current. In addition, we developed a new model for the forces produced by trapped magnetic fluxons, a potential source of imperfections in the bearing. This model estimates the forces between magnetic fluxons trapped in separate superconducting objects.

  12. Prototype continuous flow ventricular assist device supported on magnetic bearings.

    PubMed

    Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

    1996-06-01

    This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells.

  13. The argonaut shell: gas-mediated buoyancy control in a pelagic octopus

    PubMed Central

    Finn, Julian K.; Norman, Mark D.

    2010-01-01

    Argonauts (Cephalopoda: Argonautidae) are a group of rarely encountered open-ocean pelagic octopuses with benthic ancestry. Female argonauts inhabit a brittle ‘paper nautilus’ shell, the role of which has puzzled naturalists for millennia. The primary role attributed to the shell has been as a receptacle for egg deposition and brooding. Our observations of wild argonauts have revealed that the thin calcareous shell also functions as a hydrostatic structure, employed by the female argonaut to precisely control buoyancy at varying depths. Female argonauts use the shell to ‘gulp’ a measured volume of air at the sea surface, seal off the captured gas using flanged arms and forcefully dive to a depth where the compressed gas buoyancy counteracts body weight. This process allows the female argonaut to attain neutral buoyancy at depth and potentially adjust buoyancy to counter the increased (and significant) weight of eggs during reproductive periods. Evolution of this air-capture strategy enables this negatively buoyant octopus to survive free of the sea floor. This major shift in life mode from benthic to pelagic shows strong evolutionary parallels with the origins of all cephalopods, which attained gas-mediated buoyancy via the closed-chambered shells of the true nautiluses and their relatives. PMID:20484241

  14. Commercialization of NASA PS304 Solid Lubricant Coating Enhanced by Fundamental Powder Flow Research

    NASA Technical Reports Server (NTRS)

    Stanford, Malcolm K.

    2003-01-01

    The NASA Glenn Research Center has developed a patented high-temperature solid lubricant coating, designated PS304, for reducing friction and wear in bearing systems. The material used to produce the coating is initially a blend of metallic and ceramic powders that are deposited on the bearing surface by the plasma spray process. PS304 was developed to lubricate foil air bearings in Oil-Free turbomachinery, where the moving surfaces are coated with a hydrodynamic air film except at the beginning and end of an operation cycle when the air film is not present. The coating has been successful in several applications including turbochargers, land-based turbines, and industrial drying furnace conveyor components, with current development activities directed at implementation in Oil-Free aeropropulsion engines.

  15. Mineralogy and stratigraphy of the Gale crater rim, wall, and floor units

    NASA Astrophysics Data System (ADS)

    Buz, Jennifer; Ehlmann, Bethany L.; Pan, Lu; Grotzinger, John P.

    2017-05-01

    The Curiosity rover has detected diverse lithologies in float rocks and sedimentary units on the Gale crater floor, interpreted to have been transported from the rim. To understand their provenance, we examine the mineralogy and geology of Gale's rim, walls, and floor, using high-resolution imagery and infrared spectra. While no significant differences in bedrock spectral properties were observed within most Thermal Emission Imaging System and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) scenes, some CRISM scenes of rim and wall rocks showed olivine-bearing bedrock accompanied by Fe/Mg phyllosilicates. Hydrated materials with 2.48 μm absorptions in Gale's eastern walls are spectrally similar to the sulfate unit in Mount Sharp (Aeolis Mons). Sedimentary strata on the Gale floor southwest of the landing site, likely coeval with the Bradbury units explored by Curiosity, also are hydrated and/or have Fe/Mg phyllosilicates. Spectral properties of these phyllosilicates differ from the Al-substituted nontronite detected by CRISM in Mount Sharp, suggesting formation by fluids of different composition. Geologic mapping of the crater floor shows that the hydrated or hydroxylated materials are typically overlain by spectrally undistinctive, erosionally resistant, cliff-forming units. Additionally, a 4 km impact crater exposes >250 m of the Gale floor, including finely layered units. No basement rocks are exposed, thus indicating sedimentary deposits ≥250 m beneath strata studied by Curiosity. Collectively, the data indicate substantial sedimentary infill of Gale crater, including some materials derived from the crater rim. Lowermost thin layers are consistent with deposition in a lacustrine environment; interbedded hydrated/hydroxylated units may signify changing environmental conditions, perhaps in a drying or episodically dry lake bed.

  16. Case Study of Envelope Sealing in Existing Multiunit Structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dentz, J.; Conlin, F.; Podorson, D.

    2012-10-01

    Envelope air sealing was included in the retrofit of a 244 unit low-rise multifamily housing complex in Durham, N.C. Pre- and post-retrofit enclosure leakage tests were conducted on 51 units and detailed diagnostics were performed on 16. On average, total leakage was reduced by nearly half, from 19.7 ACH50 to 9.4 ACH50. Costs for air sealing were $0.31 per square foot of conditioned floor area, lower than estimates found in the National Residential Efficiency Measures Database (NREMD) and other sources, perhaps due in part to the large-scale production nature of the project. Modeling with BEopt software -- using an estimatemore » of 85% of the envelope air leakage going to the outside (based on guarded tests performed at the site) -- calculated a space conditioning energy cost savings of 15% to 21% due to the air sealing retrofit. Important air leakage locations identified included plumbing and electrical penetrations, dropped ceilings/soffits, windows, ducts and wall-to-floor intersections. Previous repair activity had created significant leakage locations as well. Specifications and a pictorial guide were developed for contractors performing the work.« less

  17. Study design and sampling intensity for demographic analyses of bear populations

    USGS Publications Warehouse

    Harris, R.B.; Schwartz, C.C.; Mace, R.D.; Haroldson, M.A.

    2011-01-01

    The rate of population change through time (??) is a fundamental element of a wildlife population's conservation status, yet estimating it with acceptable precision for bears is difficult. For studies that follow known (usually marked) bears, ?? can be estimated during some defined time by applying either life-table or matrix projection methods to estimates of individual vital rates. Usually however, confidence intervals surrounding the estimate are broader than one would like. Using an estimator suggested by Doak et al. (2005), we explored the precision to be expected in ?? from demographic analyses of typical grizzly (Ursus arctos) and American black (U. americanus) bear data sets. We also evaluated some trade-offs among vital rates in sampling strategies. Confidence intervals around ?? were more sensitive to adding to the duration of a short (e.g., 3 yrs) than a long (e.g., 10 yrs) study, and more sensitive to adding additional bears to studies with small (e.g., 10 adult females/yr) than large (e.g., 30 adult females/yr) sample sizes. Confidence intervals of ?? projected using process-only variance of vital rates were only slightly smaller than those projected using total variances of vital rates. Under sampling constraints typical of most bear studies, it may be more efficient to invest additional resources into monitoring recruitment and juvenile survival rates of females already a part of the study, than to simply increase the sample size of study females. ?? 2011 International Association for Bear Research and Management.

  18. 5. Photographic copy of construction drawing, dated March (?), 1959, ...

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

    5. Photographic copy of construction drawing, dated March (?), 1959, Department of the Air Force Air Defense Command Installations, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. FLOOR PLAN, SHEET 1 OF 1, DRAWING SLF-440-022. - Selfridge Field, Building No. 101, Supply Street east of Maple Street, Mount Clemens, Macomb County, MI

  19. 18. Interior view of large unoccupied meeting/gathering room looking towards ...

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

    18. Interior view of large unoccupied meeting/gathering room looking towards small stage and opened doorway to exterior vestibule; showing through wall air conditioning unit; north end of east wing on main floor; view to southwest. - Ellsworth Air Force Base, Group Administration & Secure Storage Building, 2372 Westover Avenue, Blackhawk, Meade County, SD

  20. 15. DETAIL OF UNDERSIDE OF BRIDGE, SHOWING LONGITUDINAL STRINGERS SUPPORTING ...

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

    15. DETAIL OF UNDERSIDE OF BRIDGE, SHOWING LONGITUDINAL STRINGERS SUPPORTING WOODEN DECK AND RESTING ON TRANSVERSE FLOOR BEAMS. DIAGONAL EYE BARS FOR REINFORCEMENT ARE SEEN AT CENTER; VIEW FROM SOUTH BANK. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  1. 61. Upper panel in cornerpower panel lcpa lower panel in ...

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

    61. Upper panel in corner-power panel lcpa lower panel in corner-oxygen regeneration unit, at right-air conditioner control panel, on floor-bio-pack 45 for emergency breathing, looking northwest - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

  2. 29. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    29. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. 19508 RENOVATION OF FIRST FLOOR, CENTRAL PORTION. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  3. 26 CFR 52.4682-4 - Floor stocks tax.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-conditioning system are not used as materials in the manufacture of articles produced in the factory. (v... conditioners. Example 4. D operates an air-conditioning repair service and holds an ODC for use in repairing... sale. However, the tax is imposed on a can of ODC used to recharge an air conditioning unit because the...

  4. Carpet and Indoor Air Quality in Schools. Technical Bulletin.

    ERIC Educational Resources Information Center

    Maryland State Dept. of Education, Baltimore.

    Ways in which carpeting can affect a school's indoor air quality (IAQ) are discussed. Carpeting is defined as a system of components that includes pads, adhesives, floor preparation compounds, and seam sealers. For the last several years, these products have been increasingly scrutinized as to how they affect IAQ. Carpeting gives off volatile…

  5. Photocopy of drawing (original drawing of War Department Theater in ...

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

    Photocopy of drawing (original drawing of War Department Theater in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1940 architectural drawings by Construction Division, Office of the Quartermaster General) FIRST FLOOR AND CEILING PLAN - MacDill Air Force Base, Base Theater, 2420 Florida Keys Avenue, Tampa, Hillsborough County, FL

  6. Photocopy of drawing (original drawing of War Department Theater in ...

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

    Photocopy of drawing (original drawing of War Department Theater in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1940 architectural drawings by Construction Division, Office of the Quartermaster General) FLOOR PLAN AND BENCH DETAILS - MacDill Air Force Base, Base Theater, 2420 Florida Keys Avenue, Tampa, Hillsborough County, FL

  7. KENNEDY SPACE CENTER, FLA. - A KSC employee uses a clean-air shower before entering a clean room. Streams of pressurized air directed at the occupant from nozzles in the chamber's ceiling and walls are designed to dislodge particulate matter from hair, clothing and shoes. The adhesive mat on the floor captures soil from shoe soles, as well as particles that fall on its surface. Particulate matter has the potential to contaminate the space flight hardware being stored or processed in the clean room. The shower is part of KSC's Foreign Object Debris (FOD) control program, an important safety initiative.

    NASA Image and Video Library

    2003-08-29

    KENNEDY SPACE CENTER, FLA. - A KSC employee uses a clean-air shower before entering a clean room. Streams of pressurized air directed at the occupant from nozzles in the chamber's ceiling and walls are designed to dislodge particulate matter from hair, clothing and shoes. The adhesive mat on the floor captures soil from shoe soles, as well as particles that fall on its surface. Particulate matter has the potential to contaminate the space flight hardware being stored or processed in the clean room. The shower is part of KSC's Foreign Object Debris (FOD) control program, an important safety initiative.

  8. Accuracy improvement of the H-drive air-levitating wafer inspection stage based on error analysis and compensation

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Liu, Pinkuan

    2018-04-01

    In order to improve the inspection precision of the H-drive air-bearing stage for wafer inspection, in this paper the geometric error of the stage is analyzed and compensated. The relationship between the positioning errors and error sources are initially modeled, and seven error components are identified that are closely related to the inspection accuracy. The most effective factor that affects the geometric error is identified by error sensitivity analysis. Then, the Spearman rank correlation method is applied to find the correlation between different error components, aiming at guiding the accuracy design and error compensation of the stage. Finally, different compensation methods, including the three-error curve interpolation method, the polynomial interpolation method, the Chebyshev polynomial interpolation method, and the B-spline interpolation method, are employed within the full range of the stage, and their results are compared. Simulation and experiment show that the B-spline interpolation method based on the error model has better compensation results. In addition, the research result is valuable for promoting wafer inspection accuracy and will greatly benefit the semiconductor industry.

  9. Design and manufacturing considerations for high-performance gimbals used for land, sea, air, and space

    NASA Astrophysics Data System (ADS)

    Sweeney, Mike; Redd, Lafe; Vettese, Tom; Myatt, Ray; Uchida, David; Sellers, Del

    2015-09-01

    High performance stabilized EO/IR surveillance and targeting systems are in demand for a wide variety of military, law enforcement, and commercial assets for land, sea, air, and space. Operating ranges, wavelengths, and angular resolution capabilities define the requirements for EO/IR optics and sensors, and line of sight stabilization. Many materials and design configurations are available for EO/IR pointing gimbals depending on trade-offs of size, weight, power (SWaP), performance, and cost. Space and high performance military aircraft applications are often driven toward expensive but exceptionally performing beryllium and aluminum beryllium components. Commercial applications often rely on aluminum and composite materials. Gimbal design considerations include achieving minimized mass and inertia simultaneous with demanding structural, thermal, optical, and scene stabilization requirements when operating in dynamic operational environments. Manufacturing considerations include precision lapping and honing of ball bearing interfaces, brazing, welding, and casting of complex aluminum and beryllium alloy structures, and molding of composite structures. Several notional and previously developed EO/IR gimbal platforms are profiled that exemplify applicable design and manufacturing technologies.

  10. Installation Restoration Program Phase 1 - Records Search, O’Hare Air Reserve Forces Facility, Illinois

    DTIC Science & Technology

    1983-12-01

    clarifiers, activated sludge units, trickling filters, aerobic and anaerobic digesters, and various dowatering devices and recommendations for...for locations of water- bearing fractures. Additional responsibilities included drilling with mud and air rotary drilling rigs as well as bucket auger...interpretation. Also conducted earth resistivity surveys in Georgia and Alabama Piedmont Provinces for locations of water- bearing fractures. Additional

  11. Environmental Assessment for Installation of a New Jet Engine Test Cell, Edwards Air Force Base, California

    DTIC Science & Technology

    2012-09-01

    suspended in the runoff waters around the lakebeds, sealing lakebed surface cracks and filling fissures. Shallow flooding along with consistent winds are...of the recorded specimens consist of isolated fragments of tooth enamel or bone that are not securely dated. Irvingtonian fossil localities have...require frequent repair as well. Concrete floors are cracking throughout all four test cells. Entry doors sag and drag on buckled floors. One-half

  12. Foundation Design against Frost Action in Europe.

    DTIC Science & Technology

    1988-03-01

    the inside of the foundation wall and consisted of 50mm of ’Rockwool’ (a mineral wool ). This insulation guides heat from the house down toward the...Separation of the floor slab from the inner part of the foundation wall by introducing mineral wool (Fig. 49c) gives a further slight reduction in...construction consisting, for example, of wood and mineral wool and including air spaces. Rt is the thermal resistance of the composite floor from surface to

  13. Emission of di-2-ethylhexyl phthalate from PVC flooring into air and uptake in dust: emission and sorption experiments in FLEC and CLIMPAQ.

    PubMed

    Clausen, Per Axel; Hansen, Vivi; Gunnarsen, Lars; Afshari, Alireza; Wolkoff, Peder

    2004-05-01

    The emission of di-2-ethylhexyl phthalate (DEHP) from a PVC flooring was studied for up to 472 days in both the FLEC (Field and Laboratory Emission Cell) and the CLIMPAQ (Chamberfor Laboratory Investigations of Materials, Pollution, and Air Quality). The loading of the CLIMPAQs was varied but was constant in the FLECs. The sorption properties of FLEC and CLIMPAQ were investigated using different methods. In addition, the uptake of DEHP by office floor dust on the PVC flooring was studied in CLIMPAQ experiments. The concentration versus time curves in both FLECs and CLIMPAQs increased slowly over about 150 days and reached a quasi-static equilibrium at 1 microg m(-3). The main conclusions were that (i) the emission rate of DEHP was limited by gas-phase mass transport and (ii) the dust layer increased the emission rate by increasing the external concentration gradient above the surface of the PVC. These conclusions were based on the facts that the specific emission rate was inversely proportional to the loading and that the dust had sorbed about four times as much DEHP over a 68-day period as emitted in the gas-phase experiments. About one-half of the emitted DEHP was deposited on the internal surfaces of both the FLEC and the CLIMPAQ.

  14. Oil-air mist lubrication as an emergency system and as a primary lubrication system. [for helicopter engines

    NASA Technical Reports Server (NTRS)

    Loomis, W. R.

    1976-01-01

    The feasibility of an emergency aspirator once-through lubrication system was demonstrated as a viable survivability concept for Army helicopter mainshaft engine bearings for periods as long as 30 minutes. It was also shown in an experimental study using a 46-mm bore bearing test machine that an oil-air mist once-through system with auxiliary air cooling is an effective primary lubrication system at speeds up to 2,500,000 DN for extended operating periods of at least 50 hours.

  15. EPHECT III: Health risk assessment of exposure to household consumer products.

    PubMed

    Trantallidi, M; Dimitroulopoulou, C; Wolkoff, P; Kephalopoulos, S; Carrer, P

    2015-12-01

    In the framework of the EU EPHECT project (Emissions, Exposure Patterns and Health Effects of Consumer Products in the EU), irritative and respiratory effects were assessed in relation to acute (30-min) and long-term (24-h) inhalation exposure to key and emerging indoor air pollutants emitted during household use of selected consumer products. A detailed Health Risk Assessment (HRA) was performed for five selected pollutants of respiratory health relevance, namely acrolein, formaldehyde, naphthalene, d-limonene and α-pinene. For each pollutant, the Critical Exposure Limit (CEL) was compared to indoor air concentrations and exposure estimates for the use of 15 selected consumer products by two population groups (housekeepers and retired people) in the four geographical regions of Europe (North, West, South, East), which were derived previously based on microenvironmental modelling. For the present HRA, health-based CELs were derived for certain compounds in case indoor air quality guidelines were not available by the World Health Organization for end-points relevant to the current study. For each pollutant, the highest indoor air concentrations in each microenvironment and exposure estimates across home microenvironments during the day were lower than the corresponding acute and long-term CELs. However, considerable contributions, especially to acute exposures, were obtained in some cases, such as formaldehyde emissions resulting from single product use of a floor cleaning agent (82% CEL), a candle (10% CEL) and an electric air freshener (17% CEL). Regarding multiple product use, the case of 30-min formaldehyde exposure reaching 34% CEL when eight product classes were used across home microenvironments, i.e. all-purpose/kitchen/floor cleaning agents, furniture/floor polish, combustible/electric air fresheners, and perfume, needs to be highlighted. Such estimated values should be evaluated with caution, as these may be attributed to the exposure scenarios specifically constructed for the present study, following a 'most-representative worst-case scenario' approach for exposure and health risk assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Measurement of shallow sea floor motion with GPS on a rigid buoy: system design and synthetic analysis

    NASA Astrophysics Data System (ADS)

    Dixon, T. H.; Xie, S.; Malservisi, R.; Lembke, C.; Iannaccone, G.; Law, J.; Rodgers, M.; Russell, R.; Voss, N. K.

    2017-12-01

    A GPS-buoy system has been built and is currently undergoing test to measure precise 3D sea floor motion in the shallow (less than 200 m) continental shelf environment. Offshore deformation is undersampled in most subduction zones. In Cascadia, the shallow shelf environment constitutes roughly 20%-25% of the offshore area between the coastline and the trench. In the system being tested, the GPS receiver at the top of the buoy is connected to the sea floor through a rigid structure supported by a float. A similar design has been used by INGV (Italy) to measure vertical deformation on the sea floor near the Campi Flegrei caldera. Synthetic analysis shows that by adding a 3-axis digital compass to measure heading and tilt, along with kinematic GPS measurements, position of the anchor can be recovered to an accuracy of several centimeters or better, depending on water depth and GPS baseline length. Synthetic resolution tests show that our ability to detect shallow slow slip events on subduction plate boundaries can be greatly improved by adding offshore GPS-buoy sites.

  17. Model estimation and measurement of ammonia emission from naturally ventilated dairy cattle buildings with slatted floor designs.

    PubMed

    Wang, Chaoyuan; Li, Baoming; Zhang, Guoqiang; Rom, Hans Benny; Strøom, Jan S

    2006-09-01

    Laboratory experiments were carried out in a wind tunnel with a model of a slurry pit to investigate the characteristics of ammonia emission from dairy cattle buildings with slatted floor designs. Ammonia emission at different temperatures and air velocities over the floor surface above the slurry pit was measured with uniform feces spreading and urine sprinkling on the surface daily. The data were used to improve a model for estimation of ammonia emission from dairy cattle buildings. Estimates from the updated emission model were compared with measured data from five naturally ventilated dairy cattle buildings. The overall measured ammonia emission rates were in the range of 11-88 g per cow per day at air temperatures of 2.3-22.4 degrees C. Ammonia emission rates estimated by the model were in the range of 19-107 g per cow per day for the surveyed buildings. The average ammonia emission estimated by the model was 11% higher than the mean measured value. The results show that predicted emission patterns generally agree with the measured one, but the prediction has less variation. The model performance may be improved if the influence of animal activity and management strategy on ammonia emission could be estimated and more reliable data of air velocities of the buildings could be obtained.

  18. Polybrominated diphenyl ether (PBDE) concentrations and resulting exposure in homes in California: relationships among passive air, surface wipe and dust concentrations, and temporal variability

    PubMed Central

    Bennett, D. H.; Moran, R. E.; Wu, X. (May); Tulve, N. S.; Clifton, M. S.; Colón, M.; Weathers, W.; Sjödin, A.; Jones, R.; Hertz-Picciotto, I.

    2016-01-01

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam, electronics, and other home furnishings. A field study was conducted that enrolled 139 households from California, which has had more stringent flame retardant requirements than other countries and areas. The study collected passive air, floor and indoor window surface wipes, and dust samples (investigator collected using an HVS3 and vacuum cleaner) in each home. PentaBDE and BDE209 were detected in the majority of the dust samples and many floor wipe samples, but the detection in air and window wipe samples was relatively low. Concentrations of each PBDE congener in different indoor environmental media were moderately correlated, with correlation coefficients ranging between 0.42 and 0.68. Correlation coefficients with blood levels were up to 0.65 and varied between environmental media and age group. Both investigator-collected dust and floor wipes were correlated with serum levels for a wide range of congeners. These two sample types also had a relatively high fraction of samples with adequate mass for reliable quantification. In 42 homes, PBDE levels measured in the same environmental media in the same home 1 year apart were statistically correlated (correlation coefficients: 0.57–0.90), with the exception of BDE209 which was not well correlated longitudinally. PMID:24832910

  19. Tool holder for preparation and inspection of a radiused edge cutting tool

    DOEpatents

    Asmanes, Charles

    1979-01-01

    A tool holding fixture is provided for removably holding a radiused edge cutting tool in a tool edge lapping apparatus. The fixture allows the operator to preset the lapping radius and angle before the tool holder is placed in the fixture and the holder may be removed from the lapping apparatus to inspect the tool and simply replaced in the fixture to continue lapping in accordance with a precise alignment without realignment of the tool relative to the lap. The tool holder includes a pair of self aligning bearings in the form of precision formed steel balls connected together by a rigid shaft. The tool is held by an arm extending from the shaft and the balls set in fixed position bearing cups and the holder is oscillated back and forth about a fixed axis of rotation to lap the tool radius by means of a reversibly driven belt-pulley arrangement coupled to the shaft between the bearings. To temporarily remove the holder, the drive belt is slipped over the rearward end of the holder and the holder is lifted out of the bearing cups.

  20. FEASIBILITY STUDY OF AIR BEARING ROCKET SLED SLIPPERS

    DTIC Science & Technology

    a simple self-acting type of bearing can support a typical monorail rocket sled, without contact between the slipper and the rail, at speeds between...slipper bearing is capable of preventing slipper-rail contact over the entire speed range of typical monorail and dual rail sleds. However, the weight and

  1. Compliant hydrodynamic fluid journal bearing

    NASA Technical Reports Server (NTRS)

    Warren, E. L. (Inventor)

    1985-01-01

    An air bearing structure is described that prevents destructive bending moments within the top foil. Welds are eliminated by mounting the top bearing foil in the bearing cartridge sleeve without using a space block. Tabs or pins at the end of the top bearing foil are restrained by slots or stops formed in the cartridge sleeve. These structural members are free to move in a direction normal to the shaft while being restrained from movement in the direction of shaft rotation.

  2. Mobile bearing medial unicompartmental knee arthroplasty in patients whose lifestyles involve high degrees of knee flexion: A 10-14year follow-up study.

    PubMed

    Choy, Won Sik; Lee, Kwang Won; Kim, Ha Yong; Kim, Kap Jung; Chun, Young Sub; Yang, Dae Suk

    2017-08-01

    Because Asian populations have different lifestyles, such as squatting and sitting on the floor, from those of Western populations, it is possible that the clinical results and survival rate of unicompartmental knee arthroplasty (UKA) for Asian patients may be different. This study described outcomes of mobile bearing medial UKA for Korean patients. A total of the 164 knees treated with mobile bearing UKAs in 147 patients (14 males and 133 females) were reviewed. The mean follow-up period was 12.1years (range 10.1-14). The clinical outcomes, such as the Hospital for Special Surgery Knee score, the Oxford Knee Score and the Knee Society rating system, showed statistically significant improvement from pre-operative to final follow-up (P<0.05). A total of 26 UKAs (15.8%) required revision; the most common reason was bearing dislocation. The 95% confidence interval of survival rate at 12years was 84.1%, with revision for any reason as the end point. Minimally invasive mobile bearing UKA in Asian patients who required high degrees of knee flexion showed rapid recovery and good clinical outcome. However, they also showed relatively high rates of bearing dislocation and aseptic loosening. Therefore, mobile bearing UKA should only be performed in patients whose lifestyle involves high flexions after carefully considering these risks and benefits. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Rolling-Bearing Service Life Based on Probable Cause for Removal: A Tutorial

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.; Branzai, Emanuel V.

    2017-01-01

    In 1947 and 1952, Gustaf Lundberg and Arvid Palmgren developed what is now referred to as the Lundberg-Palmgren Model for Rolling Bearing Life Prediction based on classical rolling-element fatigue. Today, bearing fatigue probably accounts for less than 5 percent of bearings removed from service for cause. A bearing service life prediction methodology and tutorial indexed to eight probable causes for bearing removal, including fatigue, are presented, which incorporate strict series reliability; Weibull statistical analysis; available published field data from the Naval Air Rework Facility; and 224,000 rolling-element bearings removed for rework from commercial aircraft engines.

  4. Movement of a female polar bear (Ursus maritimus) in the Kara Sea during the summer sea-ice break-up.

    PubMed

    Rozhnov, V V; Platonov, N G; Naidenko, S V; Mordvintsev, I N; Ivanov, E A

    2017-01-01

    The polar bear movement trajectory in relation to onset date of the sea-ice break-up was studied in the coastal zone of the Taimyr Peninsula, eastern part of the Kara Sea, using as an example a female polar bear tagged by a radio collar with an Argos satellite transmitter. Analysis of the long-term pattern of ice melting and tracking, by means of satellite telemetry, of the female polar bear who followed the ice-edge outgoing in the north-eastern direction (in summer 2012) suggests that direction of the polar bear movement depends precisely on the direction of the sea-ice cover break-up.

  5. A Natural Application for High Temperature Superconductors: a Bearing for the Azimuth Mount of a Lunar Telescope

    NASA Technical Reports Server (NTRS)

    Ma, Ki; Lamb, Mark; Chen, Peter; Wilson, Thomas; Cooley, Rodger; Xia, Harold; Fowler, Clay; Chen, Quark; Chu, Wei-Kan

    1995-01-01

    A bearing for telescope mounts on the moon has to function in a cold dusty vacuum environment that impairs the operation of almost all traditional bearings, but it is a natural environment for bearings constructed out of magnets and high temperature superconductors. The challenge lies not so much in the weight of the telescope that has to be supported, but in the smoothness of forces required for precision positioning control over a long stretch of time without human intervention. In this paper, we present a design of hybrid superconductor magnet bearings intended for use on the azimuth mount of an altitude-azimuth telescope mount system. In addition to the general features of hybrid super conducting magnet bearings, we will address particular issues connected with the application of these bearings on a telescope mount.

  6. Industry Needs Fulfilled by Patented NASA PS300 Solid Lubricant Technology

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher

    2003-01-01

    In 1999, the NASA Glenn Research Center was awarded a patent (#5866518) for a new high-temperature solid lubricant coating material, PS300. A combination of wear-resistant metals and ceramics with solid lubricant additives, PS300 reduces friction and wear in sliding contacts from below ambient to over 650 C. This lubricant is an outgrowth of over three decades of high-temperature tribological research and was specifically developed as a shaft lubricant to protect foil air bearings used in Oil-Free turbomachinery, like gas turbines. Foil bearings are lubricated by air at high speeds but experience sliding and wear during initial startup and shut down when a lubricating film of air has not yet developed. PS300 shaft coatings have successfully lubricated foil bearings for over 100 000 cycles without wearing out.

  7. Microinterferometer transducer

    DOEpatents

    Corey, III, Harry S.

    1979-01-01

    An air-bearing microinterferometer transducer is provided for increased accuracy, range and linearity over conventional displacement transducers. A microinterferometer system is housed within a small compartment of an air-bearing displacement transducer housing. A movable cube corner reflector of the interferometer is mounted to move with the displacement gauging probe of the transducer. The probe is disposed for axial displacement by means of an air-bearing. Light from a single frequency laser is directed into an interferometer system within the transducer housing by means of a self-focusing fiber optic cable to maintain light coherency. Separate fringe patterns are monitored by a pair of fiber optic cables which transmit the patterns to a detecting system. The detecting system includes a bidirectional counter which counts the light pattern fringes according to the direction of movement of the probe during a displacement gauging operation.

  8. Correlated carbon and oxygen isotope signatures in eclogitic diamonds with coesite inclusions: A SIMS investigation of diamonds from Guaniamo, Argyle and Orapa mines

    NASA Astrophysics Data System (ADS)

    Schulze, D. J.; Page, Z.; Harte, B.; Valley, J.; Channer, D.; Jaques, L.

    2006-12-01

    Using ion microprobes and secondary-ion mass spectrometry we have analyzed the carbon and oxygen isotopic composition of eclogite-suite diamonds and their coesite inclusions, respectively, from three suites of diamonds of Proterozoic age. Extremely high (for the mantle) oxygen isotope values (delta 18O of +10.2 to +16.9 per mil VSMOW) are preserved in coesites included in eclogitic diamonds from Guaniamo, Venezuela (Schulze et al., Nature, 2003), providing compelling evidence for an origin of their eclogite hosts by subduction of sea water altered ocean floor basalts. In situ SIMS analyses of their host diamonds yield carbon isotope values (delta 13C) of -12 to -18 per mil PDB. SIMS analyses of coesite inclusions from Argyle, Australia diamonds previously analyzed by combustion methods for d13C composition (Jaques et al., Proc. 4th Kimb. Conf, 1989), also yield anomalously high d18O values (+6.8 to +16.0 per mil VSMOW), that correlate with the anomalously low carbon isotope values (-10.3 to -14.1 per mil PDB). One coesite-bearing diamond from Orapa, Botswana analyzed in situ by SIMS has a d18O value of the coesite of +8.5 per mil VSMOW and a d13C value of the adjacent diamond host of -9.0 per mil PDB. A second Orapa stone has a SIMS carbon isotope compositional range of d13C = -14 to -16 per mil PDB, but the coesite is too small for ion probe analysis. At each of these localities, carbon isotope values of coesite-bearing diamonds that are lower than typical of mantle carbon are correlated with oxygen isotope compositions of included coesites that are substantially above the common mantle oxygen isotope range. Such results are not in accord with diamond genesis models involving formation of eclogitic diamonds from igneous melts undergoing fractionation in the mantle or by crystallization from primordial inhomogeneities in Earth's mantle. By analogy with the oxygen isotope compositions of altered ocean floor basalts and Alpine (subduction zone) eclogites they are, however, consistent with a subduction origin for these eclogite assemblages from altered ocean floor basaltic protoliths, and thus the simplest explanation for the source of the low carbon isotope values of these diamonds is formation from biogenic carbon accumulated on or near the ocean floor and subducted to the depths of eclogite and diamond stability with the altered basalts. Significantly these results, which were not predicted from studies of diamond-bearing eclogites, apply to the mantle beneath three different continental crustal blocks of both Proterozoic (Guaniamo and Argyle) and Archean/Proterozoic (Orapa) age.

  9. A Monocular Vision Sensor-Based Obstacle Detection Algorithm for Autonomous Robots

    PubMed Central

    Lee, Tae-Jae; Yi, Dong-Hoon; Cho, Dong-Il “Dan”

    2016-01-01

    This paper presents a monocular vision sensor-based obstacle detection algorithm for autonomous robots. Each individual image pixel at the bottom region of interest is labeled as belonging either to an obstacle or the floor. While conventional methods depend on point tracking for geometric cues for obstacle detection, the proposed algorithm uses the inverse perspective mapping (IPM) method. This method is much more advantageous when the camera is not high off the floor, which makes point tracking near the floor difficult. Markov random field-based obstacle segmentation is then performed using the IPM results and a floor appearance model. Next, the shortest distance between the robot and the obstacle is calculated. The algorithm is tested by applying it to 70 datasets, 20 of which include nonobstacle images where considerable changes in floor appearance occur. The obstacle segmentation accuracies and the distance estimation error are quantitatively analyzed. For obstacle datasets, the segmentation precision and the average distance estimation error of the proposed method are 81.4% and 1.6 cm, respectively, whereas those for a conventional method are 57.5% and 9.9 cm, respectively. For nonobstacle datasets, the proposed method gives 0.0% false positive rates, while the conventional method gives 17.6%. PMID:26938540

  10. Longitudinal axons are guided by Slit/Robo signals from the floor plate.

    PubMed

    Mastick, Grant S; Farmer, W Todd; Altick, Amy L; Nural, Hikmet Feyza; Dugan, James P; Kidd, Thomas; Charron, Frederic

    2010-01-01

    Longitudinal axons grow long distances along precise pathways to connect major CNS regions. However, during embryonic development, it remains largely undefined how the first longitudinal axons choose specific positions and grow along them. Here, we review recent evidence identifying a critical role for Slit/Robo signals to guide pioneer longitudinal axons in the embryonic brain stem. These studies indicate that Slit/Robo signals from the floor plate have dual functions: to repel longitudinal axons away from the ventral midline, and also to maintain straight longitudinal growth. These dual functions likely cooperate with other guidance cues to establish the major longitudinal tracts in the brain.

  11. Photographic copy of construction drawing, dated November 17, 1961, Department ...

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

    Photographic copy of construction drawing, dated November 17, 1961, Department of the Air Force, Air Defense Command Installations, in possession of Selfridge Base Museum, Mt. Clemens, Michigan. FLOOR PLAN, EQUIPMENT LAYOUT, SITE PLAN, DRAWING NO. P20-130-002 - Selfridge Field, Building No. 1025, Doolittle Drive north of D Street, Mount Clemens, Macomb County, MI

  12. 53. Photocopy of Structural drawing, dated August 6, 1976 by ...

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

    53. Photocopy of Structural drawing, dated August 6, 1976 by Raytheon Company. Original drawing property of United States Air Force, 21" Space Command. S-4 - PAVE PAWS TECHNICAL FACILITY - OTIS AFB - FIRST FLOOR PLAN. DRAWING NO. AW35-46-06 - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  13. 9. DETAIL OF ONE OF THE TWO CENTER PANELS IN ...

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

    9. DETAIL OF ONE OF THE TWO CENTER PANELS IN THE WEST TRUSS, SEEN FROM THE WEST, SHOWING POSTS, RIVETED PLATES, LOWER CHORDS, DIAGONAL EYE BARS WITH TURNBUCKLES, AND ENDS OF FLOOR BEAMS SUSPENDED FROM POSTS. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  14. 21. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    21. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. SECOND FLOOR PLAN, RIGHT AND LEFT END PORTIONS, TEST CELLS 5-12. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  15. 18. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    18. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. FIRST FLOOR PLAN, CENTRAL PORTION AND TEST CELLS 1-4. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  16. 22. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    22. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. THIRD FLOOR AND ROOF PLAN, CENTRAL PORTION AND TEST CELLS 1-4. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  17. 16. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    16. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. BASEMENT FLOOR PLAN, CENTRAL PORTION AND TEST CELLS 1-4. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  18. 17. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    17. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. BASEMENT FLOOR PLAN, RIGHT AND LEFT END PORTIONS, TEST CELLS 5-12. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  19. 20. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    20. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. SECOND FLOOR PLAN, CENTRAL PORTION AND TEST CELLS 1-4. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  20. 19. Photocopy of engineering drawing, May, 1941 (original drawing located ...

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

    19. Photocopy of engineering drawing, May, 1941 (original drawing located at Fairchild Air Force Base, Civil Engineering Building, Civil Engineering vault). ENGINE TEST CELL BUILDING. FIRST FLOOR PLAN, RIGHT AND LEFT END PORTIONS, TEST CELLS 5-12. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  1. DETAIL VIEW ON THE MAIN ASSEMBLY LEVEL OF A LADDER ...

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

    DETAIL VIEW ON THE MAIN ASSEMBLY LEVEL OF A LADDER TO THE CATWALK AT COLUMN LINE AA-28 SHOWING VERTICAL MECHANICAL DUCT, RETURN AIR FLOOR GRILLE, STEEL INDUSTRIAL SASH WINDOWS AND CROSS BRACING OF SOUTH WALL. - Offutt Air Force Base, Glenn L. Martin-Nebraska Bomber Plant, Building D, Peacekeeper Drive, Bellevue, Sarpy County, NE

  2. Photocopy of drawing (original drawing of Q.M. Warehouse & Commissary ...

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

    Photocopy of drawing (original drawing of Q.M. Warehouse & Commissary in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1940 architectural drawings by Construction Division, Office of the Quartermaster General) FIRST FLOOR PLAN AND DOOR DETAILS - MacDill Air Force Base, Quartermaster Warehouse & Commissary, 7621 Hillsborough Loop Drive, Tampa, Hillsborough County, FL

  3. Photocopy of drawing (original drawing of Sewage Treatment Plant ...

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

    Photocopy of drawing (original drawing of Sewage Treatment Plant - No. 1 Pump House in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1940 architectural drawings by Construction Division, Office of the Quartermaster General) FLOOR PLANS AND SECTIONS - MacDill Air Force Base, Pump House No. 1, Hillsborough Garden Drive & Tampa Boulevard, Tampa, Hillsborough County, FL

  4. Measurements of air dose rates in and around houses in the Fukushima Prefecture in Japan after the Fukushima accident.

    PubMed

    Matsuda, Norihiro; Mikami, Satoshi; Sato, Tetsuro; Saito, Kimiaki

    2017-01-01

    Measurements of air dose rates for 192 houses in a less contaminated area (<0.5 μSv h -1 ) of the Fukushima Prefecture in Japan were conducted in both living rooms and/or bedrooms using optically stimulated luminescence (OSL) dosimeters and around the houses via a man-borne survey at intervals of several meters. The relation of the two air dose rates (inside and outside) for each house, including the background from natural radionuclides, was divided into several categories, determined by construction materials (light and heavy) and floor number, with the dose reduction factors being expressed as the ratio of the dose inside to that outside the house. For wooden and lightweight steel houses (classed as light), the dose rates inside and outside the houses showed a positive correlation and linear regression with a slope-intercept form due to the natural background, although the degree of correlation was not very high. The regression coefficient, i.e., the average dose reduction factor, was 0.38 on the first floor and 0.49 on the second floor. It was found that the contribution of natural radiation cannot be neglected when we consider dose reduction factors in less contaminated areas. The reductions in indoor dose rates are observed because a patch of ground under each house is not contaminated (this is the so-called uncontaminated effect) since the shielding capability of light construction materials is typically low. For reinforced steel-framed concrete houses (classed as heavy), the dose rates inside the houses did not show a correlation with those outside the houses due to the substantial shielding capability of these materials. The average indoor dose rates were slightly higher than the arithmetic mean value of the outdoor dose rates from the natural background because concrete acts as a source of natural radionuclides. The characteristics of the uncontaminated effect were clarified through Monte Carlo simulations. It was found that there is a great variation in air dose rates even within one house, depending on the height of the area and its closeness to the outside boundary. Measurements of outdoor dose rates required consideration of local variations depending on the environment surrounding each house. The representative value was obtained from detailed distributions of air dose rates around the house, as measured by a man-borne survey. Therefore, it is imperative to recognize that dose reduction factors fluctuate in response to various factors such as the size and shape of a house, construction materials acting as a shield and as sources, position (including height) within a room, floor number, total number of floors, and surrounding environment. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Radon and thoron concentrations in public workplaces in Brisbane, Australia.

    PubMed

    Alharbi, Sami H; Akber, Riaz A

    2015-06-01

    Radon and thoron are radioactive gases that can emanate from soil and building materials, and it can accumulate in indoor environments. The concentrations of radon and thoron in the air from various workplace categories in Brisbane, Australia were measured using an active method. The average radon and thoron concentrations for all workplace categories were 10.5 ± 11.3 and 8.2 ± 1.4 Bq m(-3), respectively. The highest radon concentration was detected in a confined area, 86.6 ± 6.0 Bq m(-3), while the maximum thoron level was found in a storage room, 78.1 ± 14.0 Bq m(-3). At each site, the concentrations of radon and thoron were measured at two heights, 5 cm and 120 cm above the floor. The effect of the measurement heights on the concentration level was significant in the case of thoron. The monitoring of radon and thoron concentrations showed a lower radon concentration during work hours than at other times of the day. This can be attributed to the ventilation systems, including the air conditioner and natural ventilation, which normally operate during work hours. The diurnal variation was less observed in the case of thoron, as the change in its concentration during and after the working hours was insignificant. The study also investigated the influence of the floor level and flooring type on indoor radon and thoron concentrations. The elevated levels of radon and thoron were largely found in basements and ground floor levels and in rooms with concrete flooring. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Prototype Continuous Flow Ventricular Assist Device Supported on Magnetic Bearings.

    PubMed

    Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

    1996-05-01

    This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells. © 1996 International Society for Artificial Organs.

  7. 92. View of transmitter building no. 102 first floor coolant ...

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

    92. View of transmitter building no. 102 first floor coolant process water tanks (sodium bisulfate solution), stainless steel, for electronic systems cooling in transmitter and MIP rooms. RCA Services Company 29 September, 1960, official photograph BMEWS Project by unknown photograph, Photographic Services, Riverton, NJ, BMEWS, clear as negative no. A-1226 - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  8. Using simulation to evaluate wildlife survey designs: polar bears and seals in the Chukchi Sea.

    PubMed

    Conn, Paul B; Moreland, Erin E; Regehr, Eric V; Richmond, Erin L; Cameron, Michael F; Boveng, Peter L

    2016-01-01

    Logistically demanding and expensive wildlife surveys should ideally yield defensible estimates. Here, we show how simulation can be used to evaluate alternative survey designs for estimating wildlife abundance. Specifically, we evaluate the potential of instrument-based aerial surveys (combining infrared imagery with high-resolution digital photography to detect and identify species) for estimating abundance of polar bears and seals in the Chukchi Sea. We investigate the consequences of different levels of survey effort, flight track allocation and model configuration on bias and precision of abundance estimators. For bearded seals (0.07 animals km(-2)) and ringed seals (1.29 animals km(-2)), we find that eight flights traversing ≈7840 km are sufficient to achieve target precision levels (coefficient of variation (CV)<20%) for a 2.94×10(5) km(2) study area. For polar bears (provisionally, 0.003 animals km(-2)), 12 flights traversing ≈11 760 km resulted in CVs ranging from 28 to 35%. Estimators were relatively unbiased with similar precision over different flight track allocation strategies and estimation models, although some combinations had superior performance. These findings suggest that instrument-based aerial surveys may provide a viable means for monitoring seal and polar bear populations on the surface of the sea ice over large Arctic regions. More broadly, our simulation-based approach to evaluating survey designs can serve as a template for biologists designing their own surveys.

  9. Using simulation to evaluate wildlife survey designs: polar bears and seals in the Chukchi Sea

    PubMed Central

    Conn, Paul B.; Moreland, Erin E.; Regehr, Eric V.; Richmond, Erin L.; Cameron, Michael F.; Boveng, Peter L.

    2016-01-01

    Logistically demanding and expensive wildlife surveys should ideally yield defensible estimates. Here, we show how simulation can be used to evaluate alternative survey designs for estimating wildlife abundance. Specifically, we evaluate the potential of instrument-based aerial surveys (combining infrared imagery with high-resolution digital photography to detect and identify species) for estimating abundance of polar bears and seals in the Chukchi Sea. We investigate the consequences of different levels of survey effort, flight track allocation and model configuration on bias and precision of abundance estimators. For bearded seals (0.07 animals km−2) and ringed seals (1.29 animals km−2), we find that eight flights traversing ≈7840 km are sufficient to achieve target precision levels (coefficient of variation (CV)<20%) for a 2.94×105 km2 study area. For polar bears (provisionally, 0.003 animals km−2), 12 flights traversing ≈11 760 km resulted in CVs ranging from 28 to 35%. Estimators were relatively unbiased with similar precision over different flight track allocation strategies and estimation models, although some combinations had superior performance. These findings suggest that instrument-based aerial surveys may provide a viable means for monitoring seal and polar bear populations on the surface of the sea ice over large Arctic regions. More broadly, our simulation-based approach to evaluating survey designs can serve as a template for biologists designing their own surveys. PMID:26909183

  10. The Complexity-Adaptability Paradox: Issues for Combat Aircraft Development

    DTIC Science & Technology

    2011-02-16

    to Darwin in many sources, including being engraved in stone on the floor of the California Academy of Science, it is most widely attributed to...showing laser -guided bombs guiding down elevator shafts. Observers have described this combination of precision and stealth as having a ―revolutionary

  11. Multi-functional Extreme Environment Surfaces: Nanotribology for Air and Space

    DTIC Science & Technology

    2010-09-14

    SPANNING THE PHYSICAL SCALES OF MODERN TRIBOLOGY ( QCM ) (STM) Fundamental Challenges and Unsolved Issues How do adsorbed and tribo-generated films impact...Space Applications Satellite bearings, InfraRed sensor mechanisms Jet engine bearings 2 mm NCD MCD 300 mm Thrust II: Cryotribology and...Nanocrystalline Diamond for Space Applications Satellite bearings, InfraRed sensor mechanisms Jet engine bearings 2 mm NCD MCD 300 mm Five Years ago: Three

  12. Regular exercisers have stronger pelvic floor muscles than nonregular exercisers at midpregnancy.

    PubMed

    Bø, Kari; Ellstrøm Engh, Marie; Hilde, Gunvor

    2018-04-01

    Today all healthy pregnant women are encouraged to be physically active throughout pregnancy, with recommendations to participate in at least 30 minutes of aerobic activity on most days of the week in addition to performing strength training of the major muscle groups 2-3 days per week and also pelvic floor muscle training. There is, however, an ongoing debate whether general physical activity enhances or declines pelvic floor muscle function. The objectives of the study were to compare vaginal resting pressure, pelvic floor muscle strength, and endurance in regular exercisers (exercise ≥30 minutes 3 or more times per week) and nonexercisers at midpregnancy. Furthermore, another objective was to assess whether regular general exercise or pelvic floor muscle strength was associated with urinary incontinence. This was a cross-sectional study at mean gestational week 20.9 (±1.4) including 218 nulliparous pregnant women, with a mean age of 28.6 years (range, 19-40 years) and prepregnancy body mass index of 23.9 kg/m 2 (SD, 4.0). Vaginal resting pressure, pelvic floor muscle strength, and pelvic floor muscle endurance were measured by a high-precision pressure transducer connected to a vaginal balloon. The International Consultation on Incontinence Questionnaire Urinary Incontinence Short Form was used to assess urinary incontinence. Differences between groups were analyzed using an independent-sample Student t test. Linear regression analysis was conducted to adjust for prepregnancy body mass index, age, smoking during pregnancy, and regular pelvic floor muscle training during pregnancy. The significance value was set to P ≤ .05. Regular exercisers had statistically significant stronger (mean 6.4 cm H 2 O [95% confidence interval, 1.7-11.2]) and more enduring (mean 39.9 cm H 2 Osec [95% confidence interval, 42.2-75.7]) pelvic floor muscles. Only pelvic floor muscle strength remained statistically significant, when adjusting for possible confounders. Pelvic floor muscle strength and not regular general exercise was associated with urinary continence (adjusted B, -6.4 [95% confidence interval, -11.5 to -1.4]). Regular exercisers at midpregnancy have stronger pelvic floor muscles than their sedentary counterparts. However, pelvic floor muscle strength and not regular general exercise was associated with urinary incontinence. There is a need for additional studies in elite athletes and women performing more strenuous exercise regimens. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Emission of volatile organic compounds (VOCs) from PVC floor coverings.

    PubMed

    Wiglusz, R; Igielska, B; Sitko, E; Nikel, G; Jarnuszkiewicz, I

    1998-01-01

    In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination.

  14. System considerations favoring rotary artificial hearts with blood-immersed bearings.

    PubMed

    Jarvik, R K

    1995-07-01

    Hydrodynamic blood pumps provide such advantages as not requiring an air vent or compliance chamber as well as a great reduction in mechanical complexity with the potential for very long durability. The detailed design of their bearings is emerging as the single most important determinant of long-term success. Three categories of bearings include remote force, such as magnetic suspension; blood-isolated, which require a shaft seal; and blood-immersed using either mechanical or hydrodynamic support. Blood-immersed bearings permit maximum simplification and miniaturization of the entire system, require no flush fluid, and require no electronics as with magnetic suspension. The Jarvik 2000 heart represents an example of their potential. The intraventricular titanium pump (25 mm diameter, 25 cc, 85 g), uses blood flow through the motor air gap with blood-immersed bearings. The longest in vitro bearing durability test is ongoing at 20,000,000,000 revolutions with minimal wear (3 years at 15,000 rpm). In vivo results include 5-month calf survival, no thromboembolism, plasma Hb 2-5 mg%, and power under 10 W.

  15. Investigation of dairy cattle ease of movement on new methyl methacrylate resin aggregate floorings.

    PubMed

    Franco-Gendron, N; Bergeron, R; Curilla, W; Conte, S; DeVries, T; Vasseur, E

    2016-10-01

    Freestall dairy farms commonly present issues with cattle slips and falls caused by smooth flooring and manure slurry. This study examined the effect of 4 new methyl methacrylate (MMA) resin aggregate flooring types (1-4) compared with rubber (positive) and concrete (negative control) on dairy cow (n=18) ease of movement when walking on straight and right-angled corridors. Our hypothesis was that cow ease of movement when walking on the MMA surfaces would be better than when walking on traction milled concrete, and at least as good as when walking on rubber. Cattle ease of movement was measured using kinematics, accelerometers, and visual observation of gait and associated behaviors. Stride length, swing time, stance time, and hoof height were obtained from kinematic evaluation. Acceleration and asymmetry of variance were measured with accelerometers. Locomotion score and behaviors associated with lameness, such as arch back, head bob, tracking up, step asymmetry, and reluctance to bear weight were visually observed. Stride length, swing time, stance time, and the number of steps taken were the only variables affected by flooring type. Differences between flooring types for these variables were tested using a generalized linear mixed model with cow as a random effect, week as a random block factor, and flooring type as a fixed effect. Multiple comparisons with a Scheffé adjustment were done to analyze differences among flooring types. Stride length was 0.14 m longer (better) on rubber when compared with concrete, and 0.11 and 0.17 m shorter on MMA 1 and 2 compared with rubber. On MMA 3 and 4, stride length did not differ from either rubber or concrete. Swing time was 0.04 s shorter (worse) on MMA 1 than on rubber, but did not differ from any other flooring. Stance time was 0.18 s longer (worse) on MMA 2 when compared with rubber, but it did not differ from any other treatment. The number of steps was higher on MMA 4 compared with rubber (4.57 vs. 3.95 steps), but did not differ from any other treatment. Of all the MMA floors tested, MMA 3 was the only one that was consistently as good as rubber (positive control). All 4 MMA floors never differed from concrete (negative control) in any of the ease of movement variables measured. These results suggest that MMA 3 may improve cow ease of movement, compared with the other MMA floors, but more research is required to confirm these findings. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Kinematically aligned TKA can align knee joint line to horizontal.

    PubMed

    Ji, Hyung-Min; Han, Jun; Jin, Dong San; Seo, Hyunseok; Won, Ye-Yeon

    2016-08-01

    The joint line of the native knee is horizontal to the floor and perpendicular to the vertical weight-bearing axis of the patient in a bipedal stance. The purposes of this study were as follows: (1) to find out the distribution of the native joint line in a population of normal patients with normal knees; (2) to compare the native joint line orientation between patients receiving conventional mechanically aligned total knee arthroplasty (TKA), navigated mechanically aligned TKA, and kinematically aligned TKA; and (3) to determine which of the three TKA methods aligns the postoperative knee joint perpendicular to the weight-bearing axis of the limb in bipedal stance. To determine the joint line orientation of a native knee, 50 full-length standing hip-to-ankle digital radiographs were obtained in 50 young, healthy individuals. The angle between knee joint line and the line parallel to the floor was measured and defined as joint line orientation angle (JLOA). JLOA was also measured prior to and after conventional mechanically aligned TKA (65 knees), mechanically aligned TKA using imageless navigation (65 knees), and kinematically aligned TKA (65 knees). The proportion of the knees similar to the native joint line was calculated for each group. The mean JLOA in healthy individuals was parallel to the floor (0.2° ± 1.1°). The pre-operative JLOA of all treatment groups slanted down to the lateral side. Postoperative JLOA slanted down to the lateral side in conventional mechanically aligned TKA (-3.3° ± 2.2°) and in navigation mechanically aligned TKA (-2.6° ± 1.8°), while it was horizontal to the floor in kinematically aligned TKA (0.6° ± 1.7°). Only 6.9 % of the conventional mechanically aligned TKA and 16.9 % of the navigation mechanically aligned TKA were within one SD of the mean JLOA of the native knee, while the proportion was significantly higher (50.8 %) in kinematically aligned TKA. The portion was statistically greater in mechanically aligned TKA group than the other two. Postoperative joint line orientation after kinematically aligned TKA was more similar to that of native knees than that of mechanically aligned TKA and horizontal to the floor. Kinematically aligned TKA can restore pre-arthritic knee joint line orientation, while mechanically aligned TKA is inefficient in achieving the purpose even if navigation TKA is employed. III.

  17. Two High-Temperature Foil Journal Bearings

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2006-01-01

    An enlarged, high-temperature-compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. Foil bearings are attractive for use in some machines in which (1) speeds of rotation, temperatures, or both exceed maximum allowable values for rolling-element bearings; (2) conventional lubricants decompose at high operating temperatures; and/or (3) it is necessary or desirable not to rely on conventional lubrication systems. In a foil bearing, the lubricant is the working fluid (e.g., air or a mixture of combustion gases) in the space between the journal and the shaft in the machine in which the bearing is installed.

  18. Emergency and microfog lubrication and cooling of bearings for Army helicopters

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1978-01-01

    An analysis and system study was performed to provide design information regarding lubricant and coolant flow rates and flow paths for effective utilization of the lubricant and coolant in a once-through oil-mist (microfog) and coolant air system. A system was designed, manufactured, coupled with an existing rig and evaluation tests were performed using 46 mm bore split-inner angular-contact ball bearings under 1779N (400 lb.) thrust load. An emergency lubrication aspirator system was also manufactured and tested under lost lubricant conditions. The testing demonstrated the feasibility of using a mist oil and cooling air system to lubricate and cool a high speed helicopter engine mainshaft bearing. The testing also demonstrated the feasibility of using an emergency aspirator lubrication system as a viable survivability concept for helicopter mainshaft engine bearing for periods as long as 30 minutes.

  19. Solid Lubricants for Oil-Free Turbomachinery

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher

    2005-01-01

    Recent breakthroughs in gas foil bearing solid lubricants and computer based modeling has enabled the development of revolulionary Oil-Free turbomachinery systems. These innovative new and solid lubricants at low speeds (start-up and shut down). Foil bearings are hydrodynamic, self acting fluid film bearings made from thin, flexible sheet metal foils. These thin foils trap a hydrodynamic lubricating air film between their surfaces and moving shaft surface. For low temperature applications, like ainrafl air cycle machines (ACM's), polymer coatings provide important solid lubrication during start-up and shut down prior to the development of the lubricating fluid film. The successful development of Oil-Free gas turbine engines requires bearings which can operate at much higher temperatures (greater than 300 C). To address this extreme solid lubrication need, NASA has invented a new family of compostie solid lubricant coatings, NASA PS300.

  20. Influence of number of dental autoclave treatment cycles on rotational performance of commercially available air-turbine handpieces.

    PubMed

    Nagai, Masahiro; Takakuda, Kazuo

    2006-06-01

    The influence of number of autoclave treatment cycles (N) on rotational speed and total indicated run-out of commercially available air-turbine handpieces from five manufacturers was investigated at N=0, 50, 100, 150, 200, 250 and 300 cycles, and the significance in the test results was assessed by Dunnett's multiple comparison test. Some air-turbine handpieces showed the significant differences in rotational speed at N=300 cycles, however, the decreases of the rotational speeds were only 1 to 3.5 percent. Some air-turbine handpieces showed the significant differences in total indicated run-out, however, the respective values were smaller than that at N=0 cycle. Accordingly, it can be considered that the ball bearing in the air-turbine handpieces is not affected significantly by autoclave. To further evaluate rotational performance, this study focused on the rotational vibration of the ball bearing components of the air-turbine, as measured by Fast Fourier Transform (FFT) analysis; the power spectra of frequency of the ball's revolution, frequency of the cage's rotation and frequency of the ball's rotation were comparatively investigated at N=0, 150 and 300 cycles, and the influence of autoclave was evaluated qualitatively. No abnormalities in the ball bearings were recognized.

  1. Vibration transmission through rolling element bearings in geared rotor system, part 1. Ph.D. Thesis Final Report

    NASA Technical Reports Server (NTRS)

    Singh, Rajendra; Lim, Teik Chin

    1989-01-01

    A mathematical model is proposed to examine the vibration transmission through rolling element bearings in geared rotor systems. Current bearing models, based on either ideal boundary conditions for the shaft or purely translational stiffness element description, cannot explain how the vibratory motion may be transmitted from the rotating shaft to the casing. This study clarifies this issue qualitatively and quantitatively by developing a comprehensive bearing stiffness matrix of dimension 6 model for the precision rolling element bearings from basic principles. The proposed bearing formulation is extended to analyze the overall geared rotor system dynamics including casing and mounts. The bearing stiffness matrix is included in discrete system models using lumped parameter and/or dynamic finite element techniques. Eigensolution and forced harmonic response due to rotating mass unbalance or kinematic transmission error excitation for a number of examples are computed.

  2. A Waved Journal Bearing Concept-Evaluating Steady-State and Dynamic Performance with a Potential Active Control Alternative

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin

    1993-01-01

    Analysis of the waved journal bearing concept featuring a waved inner bearing diameter for use with a compressible lubricant (gas) is presented. The performance of generic waved bearings having either three or four waves is predicted for air lubricated bearings. Steady-state performance is discussed in terms of bearing load capacity, while the dynamic performance is discussed in terms of fluid film stability and dynamic coefficients. It was found that the bearing wave amplitude has an important influence on both the steady-state and the dynamic performance of the waved journal bearing. For a fixed eccentricity ratio, the bearing steady-state load capacity and direct dynamic stiffness coefficient increase as the wave amplitude increases.

  3. Turbo test rig with hydroinertia air bearings for a palmtop gas turbine

    NASA Astrophysics Data System (ADS)

    Tanaka, Shuji; Isomura, Kousuke; Togo, Shin-ichi; Esashi, Masayoshi

    2004-11-01

    This paper describes a turbo test rig to test the compressor of a palmtop gas turbine generator at low temperature (<100 °C). Impellers are 10 mm in diameter and have three-dimensional blades machined using a five-axis NC milling machine. Hydroinertia bearings are employed in both radial and axial directions. The performance of the compressor was measured at 50% (435 000 rpm) and 60% (530 000 rpm) of the rated rotational speed (870 000 rpm) by driving a turbine using compressed air at room temperature. The measured pressure ratio is lower than the predicted value. This could be mainly because impeller tip clearance was larger than the designed value. The measured adiabatic efficiency is unrealistically high due to heat dissipation from compressed air. During acceleration toward the rated rotational speed, a shaft crashed to the bearing at 566 000 rpm due to whirl. At that time, the whirl ratio was 8.

  4. Technology evaluation of man-rated acceleration test equipment for vestibular research

    NASA Technical Reports Server (NTRS)

    Taback, I.; Kenimer, R. L.; Butterfield, A. J.

    1983-01-01

    The considerations for eliminating acceleration noise cues in horizontal, linear, cyclic-motion sleds intended for both ground and shuttle-flight applications are addressed. the principal concerns are the acceleration transients associated with change in direction-of-motion for the carriage. The study presents a design limit for acceleration cues or transients based upon published measurements for thresholds of human perception to linear cyclic motion. The sources and levels for motion transients are presented based upon measurements obtained from existing sled systems. The approaches to a noise-free system recommends the use of air bearings for the carriage support and moving-coil linear induction motors operating at low frequency as the drive system. Metal belts running on air bearing pulleys provide an alternate approach to the driving system. The appendix presents a discussion of alternate testing techniques intended to provide preliminary type data by means of pendulums, linear motion devices and commercial air bearing tables.

  5. Neural Network Control of a Magnetically Suspended Rotor System

    NASA Technical Reports Server (NTRS)

    Choi, Benjamin; Brown, Gerald; Johnson, Dexter

    1997-01-01

    Abstract Magnetic bearings offer significant advantages because of their noncontact operation, which can reduce maintenance. Higher speeds, no friction, no lubrication, weight reduction, precise position control, and active damping make them far superior to conventional contact bearings. However, there are technical barriers that limit the application of this technology in industry. One of them is the need for a nonlinear controller that can overcome the system nonlinearity and uncertainty inherent in magnetic bearings. This paper discusses the use of a neural network as a nonlinear controller that circumvents system nonlinearity. A neural network controller was well trained and successfully demonstrated on a small magnetic bearing rig. This work demonstrated the feasibility of using a neural network to control nonlinear magnetic bearings and systems with unknown dynamics.

  6. Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method

    PubMed Central

    Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J

    2015-01-01

    Residential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER1z). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER2z). In total, 287 daily pairs of AER2z and AER1z estimates were made from 35 homes across three cities. In 87% of the cases, AER2z was higher than AER1z. Overall, the AER1z estimates underestimated AER2z by approximately 16% (IQR: 5–32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. PMID:25399878

  7. A new method for measuring the rotational accuracy of rolling element bearings

    NASA Astrophysics Data System (ADS)

    Chen, Ye; Zhao, Xiangsong; Gao, Weiguo; Hu, Gaofeng; Zhang, Shizhen; Zhang, Dawei

    2016-12-01

    The rotational accuracy of a machine tool spindle has critical influence upon the geometric shape and surface roughness of finished workpiece. The rotational performance of the rolling element bearings is a main factor which affects the spindle accuracy, especially in the ultra-precision machining. In this paper, a new method is developed to measure the rotational accuracy of rolling element bearings of machine tool spindles. Variable and measurable axial preload is applied to seat the rolling elements in the bearing races, which is used to simulate the operating conditions. A high-precision (radial error is less than 300 nm) and high-stiffness (radial stiffness is 600 N/μm) hydrostatic reference spindle is adopted to rotate the inner race of the test bearing. To prevent the outer race from rotating, a 2-degrees of freedom flexure hinge mechanism (2-DOF FHM) is designed. Correction factors by using stiffness analysis are adopted to eliminate the influences of 2-DOF FHM in the radial direction. Two capacitive displacement sensors with nano-resolution (the highest resolution is 9 nm) are used to measure the radial error motion of the rolling element bearing, without separating the profile error as the traditional rotational accuracy metrology of the spindle. Finally, experimental measurements are performed at different spindle speeds (100-4000 rpm) and axial preloads (75-780 N). Synchronous and asynchronous error motion values are evaluated to demonstrate the feasibility and repeatability of the developed method and instrument.

  8. University of Hull Library

    ERIC Educational Resources Information Center

    Architect Design, 1970

    1970-01-01

    The problems of enlarging the existing library facilities are described. The requirement for complete air-conditioning of the extension caused special design of the external cladding system. Detailed floor plans and photographs are provided. (JW)

  9. Department of the Navy. FY 1994/FY 1995 Biennial Budget Estimates. Military Construction Program. FY 1994

    DTIC Science & Technology

    1992-01-01

    3 are severely deteriorated. The concrete deck and supporting wood -pile structure are nearing the end of their life cycle. Both piers are to be...PROPOSED CONSTRUCTION One-story building with concrete foundation walls, load bearing masonry walls, and concrete floors; roof with wood truss framing...concrete building addition; concrete foundation and slab on grade; wood truss roof; 750 KVA. 3 phase transformer; utilities; concrete and storm drain. 11

  10. Constructive systems, load-bearing and enclosing structures of high-rise buildings

    NASA Astrophysics Data System (ADS)

    Anatol'evna Korol', Elena; Olegovna Kustikova, Yuliya

    2018-03-01

    As the height of the building increases, loads on load-carrying structures increase dramatically, and as a result of the development of high-rise construction, several structural systems of such buildings have been developed: frame, frame-frame, cross-wall, barrel, box-type, box-to-wall ("pipe in pipe", "Trumpet in the farm"), etc. In turn, the barrel systems have their own versions: cantilever support of the ceilings on the trunk, suspension of the outer part of the overlap to the upper carrying console "hanging house" or its support by means of the walls on the lower bearing cantilever, intermediate position of the supporting cantilevers in height to the floor, from a part of floors. The object of the study are the structural solutions of high-rise buildings. The subject of the study is the layout of structural schemes of high-rise buildings, taking into account the main parameters - altitude (height), natural climatic conditions of construction, materials of structural elements and their physical and mechanical characteristics. The purpose of the study is to identify the features and systematization of structural systems of high-rise buildings and the corresponding structural elements. The results of the research make it possible, at the stage of making design decisions, to establish rational parameters for the correspondence between the structural systems of high-rise buildings and their individual elements.

  11. An assessment of formaldehyde emissions from laminate flooring manufactured in China.

    PubMed

    Pierce, Jennifer S; Abelmann, Anders; Lotter, Jason T; Ruestow, Peter S; Unice, Kenneth M; Beckett, Evan M; Fritz, Heidi A; Bare, Jennifer L; Finley, Brent L

    2016-11-01

    Formaldehyde emissions from two laminate flooring products, labeled as California Air Resources Board (CARB) compliant, were evaluated. Passive 24-hr samples (n = 79) and real-time measurements were collected following installation and removal of the products in two rooms of similar size. Mean formaldehyde concentrations following installation were 0.038 and 0.022 ppm for Products 1 and 2 respectively, and 7 days after flooring removal the concentrations returned to background pre-installation levels. Both products were also evaluated in a small chamber (ASTM D6007) using Deconstructive (de-laminated product) and Non-Deconstructive (intact product) methods. Deconstructive testing showed that Product 1 exceeded the applicable CARB emission standard by 4-fold, while Product 2 was equivalent to the standard. Non-Deconstructive measurements were far below the Deconstructive results and were used to predict 24-hr steady-state room air concentrations. Based on the products that we tested (one of which was found to not be compliant with the CARB standard), the airborne formaldehyde concentrations measured following installation in a real-world setting would not be expected to elicit adverse acute health effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Saltstone SDU6 Modeling Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Si Y.; Hyun, Sinjae

    2013-01-10

    A new disposal unit, designated as Saltstone Disposal Unit 6 (SDU6), is being designed for support of site accelerated closure goals and salt waste projections identified in the new Liquid Waste System Plan. The unit is a cylindrical disposal cell of 375 ft in diameter and 43 ft in height, and it has a minimum 30 million gallons of capacity. SRNL was requested to evaluate the impact of an increased grout placement height on the flow patterns radially spread on the floor and to determine whether grout quality is impacted by the height. The primary goals of the work aremore » to develop the baseline Computational Fluid Dynamics (CFD) model and to perform the evaluations for the flow patterns of grout material in SDU6 as a function of elevation of grout discharge port and grout rheology. Two transient grout models have been developed by taking a three-dimensional multiphase CFD approach to estimate the domain size of the grout materials radially spread on the facility floor and to perform the sensitivity analysis with respect to the baseline design and operating conditions such as elevation height of the discharge port and fresh grout properties. For the CFD modeling calculations, air-grout Volume of Fluid (VOF) method combined with Bingham plastic and time-dependent grout models were used for examining the impact of fluid spread performance for the initial baseline configurations and to evaluate the impact of grout pouring height on grout quality. The grout quality was estimated in terms of the air volume fraction for the grout layer formed on the SDU6 floor, resulting in the change of grout density. The study results should be considered as preliminary scoping analyses since benchmarking analysis is not included in this task scope. Transient analyses with the Bingham plastic model were performed with the FLUENTTM code on the high performance parallel computing platform in SRNL. The analysis coupled with a transient grout aging model was performed by using ANSYS-CFX code in the parallel computing platform in Mercer University. Recommended operational guidance was developed assuming that local shear rates and flow patterns related to radial spread along the SDU floor can be used as a measure of grout performance and spatial dispersion affected by the grout height and viscosity. The 5 ft height baseline results show that when the 150 gpm grout flow with a 5 Pa yield stress and a 60 cp viscosity is poured down through a 3 inch discharge port, the grout is spread radially up to about 64 ft distance from the pouring center after 2 hours' pouring time. The air volume fraction of the grout layer is about 29% at 5 minutes' transient time, and it is reduced by about 9% in 2 hours' pouring time, resulting in the grout density consisting of about 80% grout and 20% air volume fractions. The sensitivity results show that when the discharge port is located at a higher position, a larger amount of air is trapped inside the layer formed below the discharge port at the early transient time of less than 30 minutes because of the higher impinging momentum of the grout flow on the floor, resulting in the formation of less smooth layer. The results clearly indicate that the radial spread for the 43 ft discharge port is about 10% faster than that of the 5 ft discharge port for the early transient period of 5 minutes. However, for the pouring time longer than half an hour, the discharge port height does not affect the radial distance spread on the disposal floor. When grout quality is related to grout volume fraction, the grout volume fraction for the 43 ft discharge port has lower volume fraction than the 5 ft discharge port for the transient period of the first 5 minutes. However, for the pouring time longer than half an hour, the discharge port height does not affect the grout volume fraction for the layer accumulated on the disposal floor. A modified Bingham plastic model coupled with time-dependent viscosity behavior was developed for conducting the initial scoping calculations to assess the impact of fluid residence time on radial spreading and basic flow patterns. The results for the transient viscosity model show that when grout material becomes more viscous, the thickness of the grout layer accumulated on the floor becomes higher, but the radial distance spread on the horizontal floor becomes smaller. The early transient results for the grout density with about 32% air volume fractions are in reasonable agreement with those of the idealized Bingham plastic model. It is recommended that the current models developed here be benchmarked against the experimental results for critical applications of the modeling results.« less

  13. 50. Photocopy of Architectural drawing, dated August 6, 1976 by ...

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

    50. Photocopy of Architectural drawing, dated August 6, 1976 by Raytheon Company. Original drawing property of United States Air Force, 21" Space Command. A-5 - PAVE PAWS TECHNICAL FACILITY - OTIS AFB - FOURTH FLOOR AND PLATFORM 4A. DRAWING NO. AW35-46-06 - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  14. 51. Photocopy of Architectural drawing, dated August 6, 1976 by ...

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

    51. Photocopy of Architectural drawing, dated August 6, 1976 by Raytheon Company. Original drawing property of United States Air Force, 21" Space Command. A-6 - PAVE PAWS TECHNICAL FACILITY - OTIS AFB - FIFTH FLOOR AND PLATFORM 5A. DRAWING NO. AW35-46-06 - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  15. 49. Photocopy of Architectural drawing, dated August 6, 1976 by ...

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

    49. Photocopy of Architectural drawing, dated August 6, 1976 by Raytheon Company. Original drawing property of United States Air Force, 21" Space Command. A-4 - PAVE PAWS TECHNICAL FACILITY - OTIS AFB - THIRD FLOOR AND PLATFORM 3A. DRAWING NO. AW35-46-06 - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  16. 1. Photocopy of drawing 1958 architectural drawing by the Ralph ...

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

    1. Photocopy of drawing 1958 architectural drawing by the Ralph Parsons Company in possession of Vandenberg Air Force Base Civil Engineering Office) FLOOR PLANS, ELEVATIONS, AND DETAILS FOR TRAFFIC CHECK HOUSE (BLDG. 759), AND THEODOLITE SHELTERS, SHEET A9 - Vandenberg Air Force Base, Space Launch Complex 3, Traffic Check House, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  17. 17. Interior view of courtroom looking towards judge's bench; showing ...

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

    17. Interior view of courtroom looking towards judge's bench; showing built in linear seating on both ends of room, clerical desk and equipment, through wall air conditioning units, exterior windows and door; north end of west wing on top floor; view to northwest. - Ellsworth Air Force Base, Group Administration & Secure Storage Building, 2372 Westover Avenue, Blackhawk, Meade County, SD

  18. 14. DETAIL OF CONNECTIONS AT THE BOTTOM OF A POST ...

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

    14. DETAIL OF CONNECTIONS AT THE BOTTOM OF A POST IN THE WEST TRUSS, SHOWING THE ASSEMBLY OF LOWER CHORD AND DIAGONAL EYE BOLTS AND THE SUSPENSION OF A FLOOR BEAM FROM THE POST BY A U-BOLT; VIEW FROM SOUTH BANK. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  19. Photocopy of drawing (original drawing of Armament & Instrument Inspection ...

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

    Photocopy of drawing (original drawing of Armament & Instrument Inspection and Adjustment Bldg. in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1941 architectural drawings by Construction Division, Office of the Quartermaster General) FIRST FLOOR PLAN, SECTIONS, AND DETAILS - MacDill Air Force Base, Armament & Instrument Inspection & Adjustment Building, 7807 Hanger Loop Drive, Tampa, Hillsborough County, FL

  20. Photocopy of drawing (original drawing of Double N.C.O. Quarters in ...

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

    Photocopy of drawing (original drawing of Double N.C.O. Quarters in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1939 architectural drawings by Construction Division, Office of the Quartermaster General) FIRST AND SECOND FLOOR PLANS - MacDill Air Force Base, Double Non-Commissioned Officers' Quarters, 7418 Hanger Loop Drive, Tampa, Hillsborough County, FL

Some links on this page may take you to non-federal websites. Their policies may differ from this site.
Top