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Sample records for air bearing table

  1. 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.

  2. The establish of the wireless air-bearing table

    NASA Astrophysics Data System (ADS)

    Li, Bin; Jin, Shengzhen

    2002-03-01

    This testing system has implemented the satellite high-attitude control simulated by the wireless air-bearing table. The system is the first attitude control of the two-grade image stable system composed by the wheel and the wheel controller. The attitude control computer on the table and the control computer under the table can communicate each other through the wireless cards. The units on the table are supplied by Uninterruptible Power Supply (UPS), so we can get the 1 arcsecond closed loop control accuracy of the air-bearing table.

  3. Parameter estimation of an air-bearing suspended test table

    NASA Astrophysics Data System (ADS)

    Fu, Zhenxian; Lin, Yurong; Liu, Yang; Chen, Xinglin; Chen, Fang

    2015-02-01

    A parameter estimation approach is proposed for parameter determination of a 3-axis air-bearing suspended test table. The table is to provide a balanced and frictionless environment for spacecraft ground test. To balance the suspension, the mechanical parameters of the table, including its angular inertias and centroid deviation from its rotating center, have to be determined first. Then sliding masses on the table can be adjusted by stepper motors to relocate the centroid of the table to its rotating center. Using the angular momentum theorem and the coriolis theorem, dynamic equations are derived describing the rotation of the table under the influence of gravity imbalance torque and activating torques. To generate the actuating torques, use of momentum wheels is proposed, whose virtue is that no active control is required to the momentum wheels, which merely have to spin at constant rates, thus avoiding the singularity problem and the difficulty of precisely adjusting the output torques, issues associated with control moment gyros. The gyroscopic torques generated by the momentum wheels, as they are forced by the table to precess, are sufficient to activate the table for parameter estimation. Then least-square estimation is be employed to calculate the desired parameters. The effectiveness of the method is validated by simulation.

  4. Air bearing provides friction-free support for shaker system slip table

    NASA Technical Reports Server (NTRS)

    Skoff, R. W.

    1966-01-01

    Air bearing system supports a shaker system slip table with minimum friction. At each corner of a square of grooves made on the table, a hole is drilled through the table and fitted with air connections. Air pressure is simultaneously fed to the four fittings forming an air bearing.

  5. Air bearing center cross gap of neutron stress spectrometer sample table support system

    NASA Astrophysics Data System (ADS)

    Li, Yang; Wu, Yunxin; Gong, Hai; Feng, Xiaolei

    2016-12-01

    A support system is the main load-bearing component of sample table for neutron stress spectrometer, and air bearing is an important element of a support system. The neutron stress spectrometer sample table was introduced, and the scheme for air bearing combination was selected. To study the performance of air bearing center cross gap, finite element models (FEMs) were established based on air motion and Reynolds equations, effects of air supply pressure, and gap parameters on the overturning moment and bearing capacity of air bearing center cross gap were analyzed. Results indicate that the width, depth, and height differences of the marble floor gap played important roles in the performance of the air bearing. When gap width is lesser than 1 mm and gap depth is lower than 0.4 mm, bearing capacity and overturning moment would vary rapidly with the variation of the width and depth. A gap height difference results in the bearing capacity dropping rapidly. The FEM results agree well with experimental results. Further, findings of the study could guide the design of the support system and marble floor.

  6. Tilted wheel satellite attitude control with air-bearing table experimental results

    NASA Astrophysics Data System (ADS)

    Inumoh, Lawrence O.; Forshaw, Jason L.; Horri, Nadjim M.

    2015-12-01

    Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

  7. Design, development and evaluation of a precision air bearing rotary table with large diameter through-hole

    SciTech Connect

    Accatino, M.R.

    1991-11-01

    A large diameter precision air bearing rotary table with a 16.0 inch diameter through-hole was designed, fabricated and tested in the course of this research. The rotary table will be used in conjunction with a specialized, computer controlled precision inspection machine being designed for the Department of Energy`s (DOE) Nuclear Weapons Complex (NWC). The design process included a complete engineering analysis to predict the final performance of the rotary table, and to ensure that the rotary table meets the required accuracy of 4.0 microinches of total radial (3.5 microinches average radial) and 4.0 microinches total axial (3.5 microinches average axial) errors. The engineering analysis included structural deformation, thermal sensitivity and dynamic analyses using finite element methods in some cases, as well as other analytic solutions. Comparisons are made between predicted and tested values, which are listed in the rotary table error budget. The rotary table performed as predicted with measured axial and radial stiffnesses of 1.1E06 lbf/inch and 2.9E06 lbf/inch, respectively, as well as average radial, axial and tilt errors of 2.5 microinches, 1.5 microinches, and less than 0.05 arcseconds, respectively.

  8. 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

  9. Performance testing of a magnetically suspended double gimbal control moment gyro based on the single axis air bearing table.

    PubMed

    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.

  10. 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.

  11. Precision Position Control of Pneumatic Servo Table Embedded with Aerostatic Bearing

    NASA Astrophysics Data System (ADS)

    Tsai, Ming-Hung; Hsu, Tzu-Yung; Pai, Kei-Ren; Shih, Ming-Chang

    This paper treats the control of a pneumatic servo table combining the air cylinders and sliding guides embedded with aerostatic bearing. Since compressed air flows into the small gap between the bearing and the sliding guide, the cylinder floats around the air film and on the guide surface of the table. The friction forces of the pneumatic servo table are measured, and the relation of frictional force and speed is plotted. The hybrid self-tuning fuzzy controller with the velocity compensators and dead-zone are proposed in this paper. From the experimental results, in case of different position, the positioning accuracy can reach the 0.04μm.

  12. Compressible Flow Tables for Air

    NASA Technical Reports Server (NTRS)

    Burcher, Marie A.

    1947-01-01

    This paper contains a tabulation of functions of the Mach number which are frequently used in high-speed aerodynamics. The tables extend from M = 0 to M = 10.0 in increments of 0.01 and are based on the assumption that air is a perfect gas having a specific heat ratio of 1.400.

  13. Pneumatic power is transmitted through air bearing

    NASA Technical Reports Server (NTRS)

    Johnson, H. I.; Wobig, O. A.

    1964-01-01

    A more efficient method for supplying high pressure air to an air bearing and pneumatic equipment mounted on it has been developed. The system uses a conventional air bearing and an air-supported sphere with a central passage. High pressure air is channeled through it into the pneumatic equipment on the sphere.

  14. Air-bearing spin facility for measuring energy dissipation

    NASA Technical Reports Server (NTRS)

    Peterson, R. L.

    1976-01-01

    The air-bearing spin facility was developed to determine experimentally the effect of energy dissipation upon the motion of spinning spacecraft. The facility consists of an air-bearing spin table, a telemetry system, a command system, and a ground control station. The air-bearing spin table was designed to operate in a vacuum chamber. Tests were run on spacecraft components such as fuel tanks, nutation dampers, reaction wheels, and active nutation damper systems. Each of these items affected the attitude of a spinning spacecraft. An experimental approach to determine these effects was required because the dissipation of these components could not be adequately analyzed. The results of these experiments have been used, with excellent results, to predict spacecraft motion.

  15. Apparatus for Teaching Physics: Air Table Experiments Without an Air Table.

    ERIC Educational Resources Information Center

    Minnix, Richard B.; Carpenter, D. Rae, Jr.

    1985-01-01

    Describes a new method and apparatus (consisting of a steel sheet, electromagnet, base, balls, and carbon paper) used to perform mechanics experiments which, until now, required use of an air table. Also compares the apparatus to an air table, explores its range of uses, and examines rotational dynamics. (DH)

  16. Apparatus for Teaching Physics: Air Table Experiments Without an Air Table.

    ERIC Educational Resources Information Center

    Minnix, Richard B.; Carpenter, D. Rae, Jr.

    1985-01-01

    Describes a new method and apparatus (consisting of a steel sheet, electromagnet, base, balls, and carbon paper) used to perform mechanics experiments which, until now, required use of an air table. Also compares the apparatus to an air table, explores its range of uses, and examines rotational dynamics. (DH)

  17. Least Action Principle on an Air Table

    ERIC Educational Resources Information Center

    Provost, J. P.

    1975-01-01

    Presents a mathematical demonstration that the least action principle enables both the trajectories and the conservation laws (of energy, momentum, and angular momentum) to be obtained without using Lagrange's equations. Discusses an experimental procedure which utilizes air tables to demonstrate the conservation laws and interactions at a…

  18. Least Action Principle on an Air Table

    ERIC Educational Resources Information Center

    Provost, J. P.

    1975-01-01

    Presents a mathematical demonstration that the least action principle enables both the trajectories and the conservation laws (of energy, momentum, and angular momentum) to be obtained without using Lagrange's equations. Discusses an experimental procedure which utilizes air tables to demonstrate the conservation laws and interactions at a…

  19. Bearings Only Air-to-Air Ranging

    DTIC Science & Technology

    1988-07-25

    sensor, observer and target parameters still remain. In order to reduce the number of cases to a manageable one, while preserving the geometric...perforance of variotu. ulro-air passive ranging tecnique has been examined as a fimn- tiam of uarget location andi motiom, observer motion. and length

  20. 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.

  1. Horizontal Air Bearing Experiment Number 1

    SciTech Connect

    Clauson, T.L.

    1999-08-31

    The Horizontal Air Bearing Experiment No.1 is a series of tests intended to further the understanding of rotational dynamics. A simple experimental assembly is rotated using the Horizontal Air Bearing and allowed to spin freely as the internal rotational damping is measured. The low friction of the bearing effectively isolates the test assembly, allowing the internal damping of the test object to be evaluated. The experimental assembly is composed of an aluminum ball within a spherical cavity. A flanged pipe section and an auxiliary adapter plate secure the assembly to the Air Bearing interface plate. Three aluminum balls are interchanged to vary test parameters. The aluminum balls are free to move independently as the entire assembly rotates. The aluminum balls vary in diameter and/or surface finish. While the diameter and surface finish is varied, the space between the ball and socket is dry. To examine the effect of viscosity, the space is filled with a lubricant while the ball diameter and surface finish is held constant.

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

    DTIC Science & Technology

    2010-07-01

    temperature, journal foil air bearing test rig . 3. Procedure Test preparation began by placing the bearing on the journal, attaching the air delivery...Lastly, foil thrust bearings use a number of individual, sector-shaped pads spaced evenly around a circular plate. With ample space between the...pads foil thrust bearings would likely benefit from this type of thermal management approach. 17 6. References 1. Blok, H.; van Rossum, J. J

  3. A microprocessor-based table lookup approach for magnetic bearing linearization

    NASA Technical Reports Server (NTRS)

    Groom, N. J.; Miller, J. B.

    1981-01-01

    An approach for producing a linear transfer characteristic between force command and force output of a magnetic bearing actuator without flux biasing is presented. The approach is microprocessor based and uses a table lookup to generate drive signals for the magnetic bearing power driver. An experimental test setup used to demonstrate the feasibility of the approach is described, and test results are presented. The test setup contains bearing elements similar to those used in a laboratory model annular momentum control device.

  4. Comparison of rotational speeds and torque properties between air-bearing and ball-bearing air-turbine handpieces.

    PubMed

    Taira, M; Wakasa, K; Yamaki, M; Matsui, A

    1989-06-01

    We examined the effects of air pressure on the free-running speed of air-bearing and torque-type ball-bearing air-turbine handpieces. The air pressure for the former should be kept at a certain high level to maintain the stable super-thin air-bearing film and to provide the quasi-constant speed of around 420,000 to 480,000 rpm. On the other hand, the air pressure for the latter could be adjusted to provide some varieties of speeds, ranging from about 150,000 to 320,000 rpm. Subsequently, to compare torque properties and cutting effectiveness between these two handpieces, weight-load cutting tests were conducted, using a glass-ceramic workpiece and a commercial diamond point. It was confirmed that the air-bearing handpiece had the lower torque power but exhibited better cutting effectiveness, compared with its counterpart.

  5. 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.

  6. 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.

  7. Spherical Air Bearing testbed for nanosatellite attitude control development

    NASA Astrophysics Data System (ADS)

    Ustrzycki, Tyler

    Spherical Air Bearing systems have been used as a test bed for attitude control systems for many decades. With the advancements of nanosatellite technologies as a platform for scientific missions, there is an increased demand for comprehensive, pre-launch testing of nanosatellites. Several spherical air bearing systems have been developed for larger satellite applications and add too much parasitic mass to be applicable for nanosatellite applications. This thesis details the design and validation of a Nanosatellite Three Axis Attitude Control Testbed. The testbed consists of the physical design of the system, a complete electronics system, and validation of the testbed using low-cost reaction wheels as actuators. The design of the air bearing platform includes a manual balancing system to align the centre of gravity with the centre of rotation. The electronics system is intended to measure the attitude of the platform and control the actuator system. Validation is achieved through a controlled slew maneuver of the air bearing platform.

  8. 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.

  9. 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.

  10. Flying height adjustment by slider's air bearing surface profile control

    NASA Astrophysics Data System (ADS)

    Zhang, Mingsheng; Yu, Shengkai; Liu, Jin; Liu, Bo

    2005-05-01

    A new active slider structure is proposed for the flying height adjustment. A bulk PZT ceramic is bonded onto the backside of slider directly. The PZT actuator adjusts the flying height by control of air bearing surface profile. The total thickness of the active slider is same as a standard pico slider. This structure is easy to fabricate and compatible with standard product, it also keeps the air bearing surface intact. The thicknesses of the PZT and the glue are optimized with numerical simulations. This active slider has been demonstrated and the observed flying height adjustment is 2.3nm.

  11. 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

  12. Transient Lift-Off Test Results for an Experimental Hybrid Bearing in Air

    DTIC Science & Technology

    2009-12-01

    distribution unlimited 4 DEDICATION To my parents , Gregg and Kathy Klooster, who taught me how to work hard, and gave me all their support and...test conditions were run four times. The silver plated NiCu bearing was tested using the higher peak load and the linear load profile an additional...60 times. Table 1 Bearing geometry from Scharrer et al. [3] Carbon P5N bearing NiCr alloy bearing, and Ag- plated NiCu alloy Bearing length

  13. 40 CFR Appendix: Table 1 to... - List of Hazardous Air Pollutants (HAP) for Subpart HHH

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false List of Hazardous Air Pollutants (HAP) for Subpart HHH Table Appendix: Table 1 to Subpart HHH of Part 63 Protection of Environment... Natural Gas Transmission and Storage Facilities Pt. 63, Subpt. HHH, Table 1 Appendix: Table 1 to Subpart...

  14. 40 CFR Appendix: Table 1 to... - List of Hazardous Air Pollutants (HAP) for Subpart HHH

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true List of Hazardous Air Pollutants (HAP) for Subpart HHH Table Appendix: Table 1 to Subpart HHH of Part 63 Protection of Environment... Natural Gas Transmission and Storage Facilities Pt. 63, Subpt. HHH, Table 1 Appendix: Table 1 to Subpart...

  15. 40 CFR Appendix: Table 1 to... - List of Hazardous Air Pollutants (HAP) for Subpart HHH

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true List of Hazardous Air Pollutants (HAP) for Subpart HHH Table Appendix: Table 1 to Subpart HHH of Part 63 Protection of Environment... Natural Gas Transmission and Storage Facilities Pt. 63, Subpt. HHH, Table 1 Appendix: Table 1 to Subpart...

  16. Recomputation of U. S. Navy Standard Air Decompression Tables,

    DTIC Science & Technology

    1982-01-31

    Contr-act #NOOQ(4-81-G-0216 with funds provided by the Naval Vedical Research and Development Comrmand. January 31, 1982 Appzavod fol Tru"-Ilc DL~trbuban...AO-AIII 991 SEA-SPACE RESEARCH . CO INC MARRERO LA F/6 6/19 RECOMPUTATZON F U. S. NAVY STANDARD AIR DECOMPRESSION TABLES, WI JAN 82 P 0 EDEL N0001-81...Peter 0. Edel SEA-SPACE RESEARCH COMPANY, INC. Marrero, Louisiana The research reported here has been supported under the Office of Naval Research

  17. Nanoscale air bearing modeling via lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Kim, Woo Tae; Jhon, Myung S.; Zhou, Yong; Staroselsky, Ilya; Chen, Hudong

    2005-05-01

    As spacing between the two solid surfaces in operating condition becomes much smaller than the mean free path of the air, continuum-based Navier-Stokes equation is no longer valid and one has to use a modified Reynolds equation (MRE) in simulating high Knudsen number air bearing. This MRE, which stems from the linearized Boltzmann transport equation with Bhatnagar-Gross-Krook approximation via the appropriate choice of the boundary condition, has the advantages of calculating the pressure distribution in a nanoscale confined gaseous system. In this paper, we provide a methodology based on the lattice Boltzmann method (LBM), which could enhance the computational capability of nanoscale confined gaseous system by calculating both velocity and pressure fields simultaneously. The advantage of transient and parallel nature makes this LBM an attractive tool for the next generation air bearing design. Furthermore, LBM is suitable for hybridization with lubricant morphology as well as multiscale modeling including entire disk flow analysis. We demonstrate the feasibility of this LBM by using first-order slip model as a case study. Hybridization with database established by Kang et al. [S.-C. Kang, R. M. Crone, and M. S. Jhon, J. Appl. Phys. 85, 5594 (1999)] can be performed via the similar procedure reported here to develop the state-of-the-art slider design software.

  18. 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.

  19. Low-friction coatings for air bearings in fuel cell air compressors

    SciTech Connect

    Ajayi, O. O.; Fenske, G. R.; Erdemir, A.; Woodford, J.; Sitts, J.; Elshot, K.; Griffey, K.

    2000-01-06

    In an effort to reduce fuel consumption and emissions, hybrid vehicles incorporating fuel cell systems are being developed by automotive manufacturers, their suppliers, federal agencies (specifically, the US Department of Energy) and national laboratories. The fuel cell system will require an air management subsystem that includes a compressor/expander. Certain components in the compressor will require innovative lubrication technology in order to reduce parasitic energy losses and improve their reliability and durability. One such component is the air bearing for air turbocompressors designed and fabricated by Meruit, Inc. Argonne National Laboratory recently developed a carbon-based coating with low friction and wear attributes; this near-frictionless-carbon (NFC) coating is a potential candidate for use in turbocompressor air bearings. The authors present here an evaluation of the Argonne coating for air compressor thrust bearings. With two parallel 440C stainless steel discs in unidirectional sliding contact, the NFC reduced the frictional force four times and the wear rate by more than two orders of magnitude. Wear mechanism on the uncoated surface involved oxidation and production of iron oxide debris. Wear occurred on the coated surfaces primarily by a polishing mechanism.

  20. Rotordynamic characteristics of a micro turbo generator supported by air foil bearings

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Bok; Park, Dong-Jin; Kim, Chang-Ho; Ryu, Keun

    2007-02-01

    The rotordynamic characteristics of a micro power system supported by air foil bearings were investigated. Stability analysis was performed by a finite element method with the predicted dynamic coefficients of the foil bearings. A preliminary test rig was developed to simulate the operating characteristics of the micro power system. It consisted of a rotor supported by two air foil journal bearings and two air foil thrust bearings, and an impulse driven turbine. The foil journal bearings had a diameter of 7 mm and a length of 7 mm (L/D = 1). The test rig was operated stably under various situations and speeded up to 300 000 rpm. The main portion of the rotor response was synchronous and the amplitude of synchronous vibration was about 5-20 µm. Further, theoretical and experimental results for the unbalance response were compared. From this study, we showed the possibility of stable performance for the micro power system supported by air foil bearings.

  1. An externally pressurized air bearing system, journals and thrust, for application to small turbomachinery

    NASA Astrophysics Data System (ADS)

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

    1992-06-01

    Experiments have been conducted to examine the feasibility of externally pressurized air bearings for possible utilization in small high-speed turbomachinery such as compressor and turbine test rigs. The bearing was designed employing a simplified theory that proved to be adequate, with the problem of thermal expansion solved using brass bearings sleeved with graphited bronze, up to a shaft/bearing temperature of 180 C. A new thrust bearing was demonstrated with a potential capacity greatly in excess of the conventional aerostatic, close contact, parallel disk type of thrust bearing.

  2. 40 CFR Table 1 to Subpart Xx of... - Hazardous Air Pollutants

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Hazardous Air Pollutants 1 Table 1 to Subpart XX of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

  3. 40 CFR Table 1 to Subpart Xx of... - Hazardous Air Pollutants

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Hazardous Air Pollutants 1 Table 1 to Subpart XX of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

  4. 40 CFR Table 1 to Subpart Xx of... - Hazardous Air Pollutants

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Hazardous Air Pollutants 1 Table 1 to Subpart XX of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED...

  5. 40 CFR Table 1 to Subpart Xx of... - Hazardous Air Pollutants

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Hazardous Air Pollutants 1 Table 1 to Subpart XX of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED...

  6. 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.

  7. Development of magnetically preloaded air bearings for a linear slide: active compensation of three degrees of freedom motion errors.

    PubMed

    Ro, Seung-Kook; Kim, Soohyun; Kwak, Yoonkeun; Park, Chun-Hong

    2008-03-01

    This article describes a linear air-bearing stage that uses active control to compensate for its motion errors. The active control is based on preloads generated by magnetic actuators, which were designed to generate nominal preloads for the air bearings using permanent magnets to maintain the desired stiffness while changing the air-bearing clearance by varying the magnetic flux generated by the current in electromagnetic coils. A single-axis linear stage with a linear motor and 240 mm of travel range was built to verify this design concept and used to test its performance. The motion of the table in three directions was controlled with four magnetic actuators driven by current amplifiers and a DSP (Digital Signal Processor)-based digital controller. The motion errors were measured using a laser interferometer combined with a two-probe method, and had 0.085 microm of repeatability for the straightness error. As a result of feed-forward active compensation, the errors were reduced from 1.09 to 0.11 microm for the vertical motion, from 9.42 to 0.18 arcsec for the pitch motion, and from 2.42 to 0.18 arcsec for the roll motion.

  8. 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.

  9. 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.

  10. Assessment of horizontal laminar air flow instrument table for additional ultraclean space during surgery.

    PubMed

    Nilsson, K-G; Lundholm, R; Friberg, S

    2010-11-01

    The area in a vertical ultraclean laminar air flow (LAF) theatre is usually too small to accommodate all the equipment needed for major surgery. We investigated the addition of an instrument table supplied with fixed ultraclean LAF and placed alongside the existing main LAF unit, to determine its physical and bacteriological effect on the main unit. In phase 1, with two investigators but without a patient, smoke tests showed no intrusion of air from the table into the main unit and particle counts did not show any adverse effect on the main LAF unit. In phase 2, during patients undergoing two total knee replacements, the LAF table and a table without LAF were placed alongside the main LAF unit. The tables were subjected to the activity of an extra operating room (OR) nurse working from inside the main LAF vigorously simulating handling of instruments. During this activity, the >5μm particle counts were 275/m(3) at the instrument table with LAF and 8550/m(3) at the table without LAF (P<0.0001). Also, without the OR nurse activity, the particle counts, just inside the main unit and adjacent to the LAF table, were significantly reduced (P<0.03-0.003). Sedimentation plates on the LAF table and in the main unit registered 22 and 25cfu/m(2)/h respectively compared with 45cfu/m(2)/h at the instrument table without LAF. In conclusion, the results from the smoke tests, particle counts and bacteriological evaluation showed that the additional instrument table supplied with LAF is efficient and can be safely used as an extension additional to a main OR LAF unit.

  11. 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

  12. 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

  13. 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

  14. Force versus current and air gap calibration of a double acting magnetic thrust bearing

    SciTech Connect

    Baun, D.O.; Fittro, R.L.; Maslen, E.H.

    1995-12-31

    Force versus current and air gap measurements were obtained for a double acting thrust bearing. Static force measurements were made for various air gap settings and bearing current combinations. The resulting data was reduced and an optimized expression representing the force versus current and air gap relationship of the bearing was found. In addition, a theoretical force model was developed using simple magnetic circuit theory and magnetic properties obtained from standard magnetic material tests. The theoretical and the experimentally derived force models were compared. Hysteresis tests were conducted with the thrust disk in the centered position for various current perturbation amplitudes about the design bias current. Hysteresis effects were shown to cause a difference between the measured force as the current was increasing as compared to when the current was decreasing. A second order polynomial expression was developed to express the coercive force as a function of the perturbation current amplitude. The bearing frequency response was examined by injecting sinusoidal currents of varying frequencies into the bearing. A maximum actuator bandwidth of approximately 700 Hz was determined. Above 700 Hz the bearing frequency response could not be distinguished from the test fixture frequency response.

  15. 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.

  16. Coordinated control of a space manipulator tested by means of an air bearing free floating platform

    NASA Astrophysics Data System (ADS)

    Sabatini, Marco; Gasbarri, Paolo; Palmerini, Giovanni B.

    2017-10-01

    A typical approach studied for the guidance of next generation space manipulators (satellites with robotic arms aimed at autonomously performing on-orbit operations) is to decouple the platform and the arm maneuvers, which are supposed to happen sequentially, mainly because of safety concerns. This control is implemented in this work as a two-stage Sequential control, where a first stage calls for the motion of the platform and the second stage calls for the motion of the manipulator. A second novel strategy is proposed, considering the platform and the manipulator as a single multibody system subject to a Coordinated control, with the goal of approaching and grasping a target spacecraft. At the scope, a region that the end effector can reach by means of the arm motion with limited reactions on the platform is identified (the so called Reaction Null workspace). The Coordinated control algorithm performs a gain modulation (finalized to a balanced contribution of the platform and arm motion) as a function of the target position within this Reaction Null map. The result is a coordinated maneuver in which the end effector moves thanks to the platform motion, predominant in a first phase, and to the arm motion, predominant when the Reaction-Null workspace is reached. In this way the collision avoidance and attitude over-control issues are automatically considered, without the need of splitting the mission in independent (and overall sub-optimal) segments. The guidance and control algorithms are first simulated by means of a multibody code, and successively tested in the lab by means of a free floating platform equipped with a robotic arm, moving frictionless on a flat granite table thanks to air bearings and on-off thrusters; the results will be discussed in terms of optimality of the fuel consumption and final accuracy.

  17. 40 CFR Table 2 to Subpart Jj of... - List of Volatile Hazardous Air Pollutants

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 11 2012-07-01 2012-07-01 false List of Volatile Hazardous Air Pollutants 2 Table 2 to Subpart JJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Wood Furniture Manufacturing Operations Pt. 63,...

  18. 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.

  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. An air bearing fan for EVA suit ventilation

    NASA Technical Reports Server (NTRS)

    Murry, Roger P.

    1990-01-01

    The portable life-support system (PLSS) ventilation requirements are outlined, along with the application of a high-speed axial fan technology for extravehicular-activity (EVA) space-suit ventilation. Focus is placed on a mechanical design employing high-speed gas bearings, permanent magnet rotor, and current-fed chopper/inverter electronics. The operational characteristics of the fan unit and its applicability for use in a pure-oxygen environment are discussed. It delivers a nominal 0.17 cu m/min at 1.24 kPa pressure rise using 13.8 w of input power. It is shown that the overall selection of materials for all major component meets the NASA requirements.

  1. An Experimental Investigation of Skin Friction on Smooth Surfaces Supporting Air Bearing Channels.

    DTIC Science & Technology

    1986-07-01

    EXPERIMENTAL INVESTIGATION OF SKIN FRICTION ON SMOOTH SURFACES SUPPORTING AIR BEARING CHANNELS ETUDE EXPERIMENTALE DU FROTTEMENT PELLICULAIRE SUR DES SURFACES...LISSES PORTEUSES DE CANAUX ANTI- FROTTEMENT by/par M. Khalid National Aeronautical Establishment AERONAUTICAL NOTE OTTAWA NAE-AN-39 JULY 1986 NRC NO...installant sur la surface des canaux qui agissent comme des valiers d’air. Les mesures ont &t prises A l’aide d’une balance de mesure du frottement

  2. 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.

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

    NASA Technical Reports Server (NTRS)

    1993-01-01

    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.

  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. Hypoxemia with air breathing periods in U.S. NAVY Treatment Table 6.

    PubMed

    Weaver, L K; Churchill, S K

    2006-01-01

    Air breathing is used to lessen hyperbaric oxygen (HBO2) toxicity. Hypoxemia could occur during hyperbaric air breathing in patients with lung dysfunction, although this has not been previously reported. We report two cases of hypoxemia during air breathing with two patients treated with the US Navy Table 6. Patient 1 was an 11-year-old male with cerebral gas embolism (during cardiac transplantation), patient 2 was a 66-year-old female with cerebral gas embolism from a central venous catheter accident. Both were mechanically ventilated. We monitored arterial blood gas (ABG) during therapy. In both patients, ABG measurements showed hypoxia during the first air breathing period at 1.9 atm abs (192.5 kPa). If patients require > or = 40% inspired oxygen before HBO2 therapy, oxygenation monitoring is advisable during air breathing periods, especially at lower chamber pressures (< or = 2.0 atm abs).

  7. 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

  8. Controlled-air incineration of alpha-bearing solid wastes

    SciTech Connect

    Koenig, R.A.; Draper, W.E.; Neuls, A.S.; Newmyer, J.M.

    1980-01-01

    The Los Alamos Scientific Laboratory is completing a study of controlled-air incineration (CAI) as a technique for volume reduction and stabilization of combustible transuranic-contaminated solid wastes. To demonstrate feasibility, a process has been assembled and operated on synthetic and contaminated combustibles. This paper summarizes the CAI project history, process design, provisions for radioactive operation, experimental results to date, and future plans. Achievements include operation at the design feed rate as well as combustion of separate feed compositions including cellulosics, polyethylene, polyvinyl chloride (PVC) and latex rubber. Refractory life has been satisfactory to date, with studies continuing. The offgas cleanup system has proven to be extremely effective; the final high-efficiency filters showing virtually no pressure drop increase. The ability of the system to process high concentrations of PVC has been demonstrated with no chloride-induced degradation detected. Chloride and sulfate removal from the offgas has been excellent with concentrations reaching 8 and 10 ppM maximum, respectively, in the process condensate.

  9. MACH NUMBER TABLES (GAMMA = 1.4) WITH CORRECTION FACTORS FOR REAL AIR.

    DTIC Science & Technology

    functions useful in flow analysis are tabulated over a wide range of Mach number values: O< or = M < or = 25. Both the isentropic and the normal shock...with the isentropic flow of real air. It covers the ranges: .1< or = P(atm)< or = 500; 900 < or = T(R)< or = 12,600; O2 or = M < or = (5-25). TABLE

  10. Performance and Durability of High Temperature Foil Air Bearing for Oil-Free Turbomachinery

    NASA Technical Reports Server (NTRS)

    DellaCorte, C.; Valco, M. J.; Radil, K. C.; Heshmat, H.

    1999-01-01

    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.

  11. 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.

  12. 40 CFR Table 1 to Subpart Vvvvvv... - Hazardous Air Pollutants Used To Determine Applicability of Chemical Manufacturing Operations

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Hazardous Air Pollutants Used To... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table...

  13. 40 CFR Table 1 to Subpart Vvvvvv... - Hazardous Air Pollutants Used To Determine Applicability of Chemical Manufacturing Operations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Hazardous Air Pollutants Used To... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table...

  14. 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.

  15. 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.

  16. 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

  17. Development of an air-bearing fan for space extravehicular activity (EVA) suit ventilation

    NASA Technical Reports Server (NTRS)

    Fukumoto, Paul; Allen, Norman; Stonesifer, Greg

    1992-01-01

    A high-speed/variable flow fan has been developed for EVA suit ventilation which combines air bearings with a two-pole, toothless permanent-magnet motor. The fan has demonstrated quiet and vibration-free operation and a 2:1 range in flow rate variation. System weight is 0.9 kg, and input powers range from 12.4 to 42 W.

  18. 40 CFR Table 2 to Subpart Ooo of... - Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (HAP) From the Manufacture of Amino/Phenolic Resins 2 Table 2 to Subpart OOO of Part 63 Protection of... Hazardous Air Pollutant Emissions: Manufacture of Amino/Phenolic Resins Pt. 63, Subpt. OOO, Table 2 Table 2 to Subpart OOO of Part 63—Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino...

  19. 40 CFR Table 2 to Subpart Ooo of... - Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (HAP) From the Manufacture of Amino/Phenolic Resins 2 Table 2 to Subpart OOO of Part 63 Protection of... Hazardous Air Pollutant Emissions: Manufacture of Amino/Phenolic Resins Pt. 63, Subpt. OOO, Table 2 Table 2 to Subpart OOO of Part 63—Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino...

  20. 40 CFR Table A-1 to Subpart A of... - Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants A Table A-1 to Subpart A of Part...) AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS General Provisions Pt. 53, Subpt. A, Table A-1 Table A-1 to Subpart A of Part 53—Summary of Applicable Requirements for Reference and Equivalent...

  1. 40 CFR Table A-1 to Subpart A of... - Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants A Table A-1 to Subpart A of Part...) AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS General Provisions Pt. 53, Subpt. A, Table A-1 Table A-1 to Subpart A of Part 53—Summary of Applicable Requirements for Reference and...

  2. 40 CFR Table A-1 to Subpart A of... - Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants A Table A-1 to Subpart A of Part...) AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS General Provisions Pt. 53, Subpt. A, Table A-1 Table A-1 to Subpart A of Part 53—Summary of Applicable Requirements for Reference and...

  3. 40 CFR Table A-1 to Subpart A of... - Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants A Table A-1 to Subpart A of Part...) AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS General Provisions Pt. 53, Subpt. A, Table A-1 Table A-1 to Subpart A of Part 53—Summary of Applicable Requirements for Reference and...

  4. 40 CFR Table A-1 to Subpart A of... - Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants A Table A-1 to Subpart A of Part...) AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS General Provisions Pt. 53, Subpt. A, Table A-1 Table A-1 to Subpart A of Part 53—Summary of Applicable Requirements for Reference and...

  5. 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.

  6. 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.

  7. Prediction of seasonal water-table fluctuations in La Pampa and Buenos Aires, Argentina

    NASA Astrophysics Data System (ADS)

    Tanco, Raúl; Kruse, Eduardo

    2001-07-01

    The fluctuation of the water table east of La Pampa province and northwest of Buenos Aires province, Argentina, influences agricultural production in the region because it is closely related to the alternation of dry and wet periods. Sea-surface temperature (SST) anomalies have been used as predictors to forecast atmospheric variables in different regions of the world. The objective of this work is to present a simple model to forecast seasonal rainfall using SST distribution in the Pacific Ocean as a predictor. Once the relationship between precipitation and water-table fluctuations was established, a methodology for the prediction of water-table fluctuations was developed. A good agreement between observed and predicted water-table fluctuations was found when estimating water-table fluctuations in the summer and autumn seasons. Résumé. Les fluctuations de la nappe à l'est de la province de La Pampa et au nord-ouest de la province de Buenos Aires (Argentine) influence la production agricole de la région parce qu'elle est étroitement liée à l'alternance de saisons sèches et humides. Les anomalies de la température de surface de l'océan (SST) ont été utilisées comme prédicteurs pour prévoir les variables atmosphériques dans différentes régions du monde. L'objectif de ce travail est de présenter un modèle simple de prévision des précipitations saisonnières en utilisant comme prédicteur la distribution des SST dans l'Océan Pacifique. Une fois que la relation entre les fluctuations des précipitations et celles de la nappe a été établie, une méthodologie de prédiction des variations de la nappe a été mise au point. Un bon accord entre les variations de la nappe observées et celles prédites a été trouvé pour les estimations des variations de nappe en été et en automne. Resumen. La fluctuación del nivel freático al este de la provincia de La Pampa y al nordeste de la de Buenos Aires (Argentina) repercute en la producción agr

  8. 40 CFR Table 2 to Subpart Ooo of... - Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (HAP) From the Manufacture of Amino/Phenolic Resins 2 Table 2 to Subpart OOO of Part 63 Protection of... Pollutant Emissions: Manufacture of Amino/Phenolic Resins Pt. 63, Subpt. OOO, Table 2 Table 2 to Subpart OOO of Part 63—Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins...

  9. 40 CFR Table 2 to Subpart Ooo of... - Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (HAP) From the Manufacture of Amino/Phenolic Resins 2 Table 2 to Subpart OOO of Part 63 Protection of... Pollutant Emissions: Manufacture of Amino/Phenolic Resins Pt. 63, Subpt. OOO, Table 2 Table 2 to Subpart OOO of Part 63—Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins...

  10. 40 CFR Table 2 to Subpart Ooo of... - Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (HAP) From the Manufacture of Amino/Phenolic Resins 2 Table 2 to Subpart OOO of Part 63 Protection of... Pollutant Emissions: Manufacture of Amino/Phenolic Resins Pt. 63, Subpt. OOO, Table 2 Table 2 to Subpart OOO of Part 63—Known Organic Hazardous Air Pollutants (HAP) From the Manufacture of Amino/Phenolic Resins...

  11. Table - Impacts of the Proposed Transport Rule on Counties with Monitors Projected to have Ozone and/or Fine Particle Air Quality Problems

    EPA Pesticide Factsheets

    This table shows the impacts of the proposed Transport Rule on Counties with Monitors Projected to have Ozone and/or Fine Particle Air Quality Problems, both with and without the Cross-State Air Pollution Rule.

  12. 40 CFR Table 1 to Subpart Vvvvvv... - Hazardous Air Pollutants Used To Determine Applicability of Chemical Manufacturing Operations

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Hazardous Air Pollutants Used To Determine Applicability of Chemical Manufacturing Operations 1 Table 1 to Subpart VVVVVV of Part 63... chloride 75092 h. Quinoline 91225 2. Metal compounds a. Arsenic compounds b. Cadmium compounds c....

  13. Tracking Phragmites Australis Expansion in Bear River Migratory Bird Refuge using AggieAir Aircraft Data

    NASA Astrophysics Data System (ADS)

    Zaman, B.; McKee, M.

    2010-12-01

    This research examines the use of unmanned air vehicles (UAV), a cutting edge technology developed at the Utah Water research lab for acquiring airborne imagery using drones for the assessment of abundance of an invasive species Phragmites australis in a wetland vegetation setup. These UAV’s acquire multispectral data in the visible and near-infrared bands with a spatial resolution of 0.5 meters. The study area is the Bear River Migratory Bird Refuge (MBR) which lies in northern Utah, where the Bear River flows into the northeast arm of the Great Salt Lake. The Refuge protects the marshes found at the mouth of the Bear River; these marshes are the largest freshwater component of the Great Salt Lake ecosystem. A common reed, Phragmites australis, is a tall (1.5-4.0 m) coarse perennial grass found primarily in brackish and freshwater wetlands, growing at or above mean high water. The methodology is to build Bayesian statistical supervised classification model using relevance vector machine (RVM) employing the inexpensive and readily available UAV data. The UAV images of the bird refuge are processed to obtain calibrated reflectance imagery. Thereafter, the isodata clustering algorithm is applied to classify the multispectral imagery into different classes. Using ground sampling of the species, pixels containing the Phragmites australis are deduced. The training set for the supervised RVM classification model is prepared using the deduced pixel values. A separate set of ground sampling points containing the Phragmites australis are kept aside for validation. The distribution of Phragmites australis in the study area as obtained from RVM classification model is compared to the validation set. The RVM model results for tracking of Phragmites are encouraging and the new technique has promising real-time implementation for similar applications.

  14. Dynamic Stiffness and Damping Characteristics of a High-Temperature Air Foil Journal Bearing

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; DellaCorte, Christopher; Valco, Mark J.; Prahl, Joseph M.; Heshmat, Hooshang

    2001-01-01

    Using a high-temperature optically based displacement measurement system, a foil air bearing's stiffness and damping characteristics were experimentally determined. Results were obtained over a range of modified Sommerfeld Number from 1.5E6 to 1.5E7, and at temperatures from 25 to 538 C. An Experimental procedure was developed comparing the error in two curve fitting functions to reveal different modes of physical behavior throughout the operating domain. The maximum change in dimensionless stiffness was 3.0E-2 to 6.5E-2 over the Sommerfeld Number range tested. Stiffness decreased with temperature by as much as a factor of two from 25 to 538 C. Dimensionless damping was a stronger function of Sommerfeld Number ranging from 20 to 300. The temperature effect on damping being more qualitative, showed the damping mechanism shifted from viscous type damping to frictional type as temperature increased.

  15. Stability of rigid rotors supported by air foil bearings: Comparison of two fundamental approaches

    NASA Astrophysics Data System (ADS)

    Larsen, Jon S.; Santos, Ilmar F.; von Osmanski, Sebastian

    2016-10-01

    High speed direct drive motors enable the use of Air Foil Bearings (AFB) in a wide range of applications due to the elimination of gear forces. Unfortunately, AFB supported rotors are lightly damped, and an accurate prediction of their Onset Speed of Instability (OSI) is therefore important. This paper compares two fundamental methods for predicting the OSI. One is based on a nonlinear time domain simulation and another is based on a linearised frequency domain method and a perturbation of the Reynolds equation. Both methods are based on equivalent models and should predict similar results. Significant discrepancies are observed leading to the question, is the classical frequency domain method sufficiently accurate? The discrepancies and possible explanations are discussed in detail.

  16. STS-64 SAFER exercise in bldg 9NW on the air-bearing floor

    NASA Image and Video Library

    1994-05-04

    S94-33357 (1994) --- Scott Bleiseth, top, prepares to spin Mike Hess, a fellow EVA engineer, during a test on the air-bearing floor in the Shuttle Mock-up and Integration Laboratory at NASA's Johnson Space Center. The hardware being tested is part of the Simplified Aid for EVA Rescue (SAFER). The pair was developing techniques by which the non-SAFER equipped spacewalker will impart a rotation to the SAFER-using spacewalker during the STS-64 mission. Once the SAFER astronaut is spinning, the device will be activated and its automatic attitude hold capability will be tested. SAFER is to fly on STS-76 as well. Photo credit: NASA or National Aeronautics and Space Administration

  17. Simulation of a tethered microgravity robot pair and validation on a planar air bearing

    NASA Astrophysics Data System (ADS)

    Mantellato, R.; Lorenzini, E. C.; Sternberg, D.; Roascio, D.; Saenz-Otero, A.; Zachrau, H. J.

    2017-09-01

    A software model has been developed to simulate the on-orbit dynamics of a dual-mass tethered system where one or both of the tethered spacecraft are able to produce propulsive thrust. The software simulates translations and rotations of both spacecraft, with the visco-elastic tether being simulated as a lumped-mass model. Thanks to this last feature, tether longitudinal and lateral modes of vibration and tether tension can be accurately assessed. Also, the way the spacecraft motion responds to sudden tether tension spikes can be studied in detail. The code enables the simulation of different scenarios, including space tug missions for deorbit maneuvers in a debris mitigation context and general-purpose tethered formation flight missions. This study aims to validate the software through a representative test campaign performed with the MIT Synchronized Position Hold Engage and Reorient Experimental Satellites (SPHERES) planar air bearing system. Results obtained with the numerical simulator are compared with data from direct measurements in different testing setups. The studied cases take into account different initial conditions of the spacecraft velocities and relative attitudes, and thrust forces. Data analysis is presented comparing the results of the simulations with direct measurements of acceleration and Azimuth rate of the two bodies in the planar air bearing test facility using a Nylon tether. Plans for conducting a microgravity test campaign using the SPHERES satellites aboard the International Space Station are also being scheduled in the near future in order to further validate the simulation using data from the relevant operational environment of extended microgravity with full six degree of freedom (per body) motion.

  18. Air-bearing-based satellite attitude dynamics simulator for control software research and development

    NASA Astrophysics Data System (ADS)

    Agrawal, Brij N.; Rasmussen, Richard E.

    2001-08-01

    A Satellite Attitude Dynamics Simulator (SADS) has been developed to facilitate the research and development of spacecraft flight attitude control software at the Naval Postgraduate School in Monterey, CA. The simulator provides a real-time 3 degree of freedom (3DOF) synthetic spacecraft hardware-in-the-loop environment, that includes realistic angular motions, sensor-effector delays, and control torque profiles. Control software, entered into a notebook PC mounted on the equipment platform, is input as high level object oriented code, allowing rapid code development and thorough post-test analysis. Three flight-like reaction wheels and eight cold-gas thrusters that are mounted to the SADS equipment platform provide motion simulation torque. The equipment platform is suspended in air by a spherical segment air bearing. This virtually frictionless suspension allows free rotation of the equipment platform about any rotation axis. Three separate sets of sensors, three single-axis rate gyros, a three-axis magnetometer, and a two-axis sun sensor monitor SADS platform motion. This paper discusses the SADS design, and the practical uses of this simulator for satellite attitude control system software research and development.

  19. The efficient computation of the nonlinear dynamic response of a foil-air bearing rotor system

    NASA Astrophysics Data System (ADS)

    Bonello, P.; Pham, H. M.

    2014-07-01

    The foil-air bearing (FAB) enables the emergence of oil-free turbomachinery. However, its potential to introduce undesirable nonlinear effects necessitates a reliable means for calculating the dynamic response. The computational burden has hitherto been alleviated by simplifications that compromised the true nature of the dynamic interaction between the rotor, air film and foil structure, introducing the potential for significant error. The overall novel contribution of this research is the development of efficient algorithms for the simultaneous solution of the state equations. The equations are extracted using two alternative transformations: (i) Finite Difference (FD); and (ii) a novel arbitrary-order Galerkin Reduction (GR) which does not use a grid, considerably reducing the number of state variables. A vectorized formulation facilitates the solution in two alternative ways: (i) in the time domain for arbitrary response via implicit integration using readily available routines; and (ii) in the frequency domain for the direct computation of self-excited periodic response via a novel Harmonic Balance (HB) method. GR and FD are cross-verified by time domain simulations which confirm that GR significantly reduces the computation time. Simulations also cross-verify the time and frequency domain solutions applied to the reference FD model and demonstrate the unique ability of HB to correctly accommodate structural damping.

  20. Liberation characteristics after cryogenic modification and air table separation of discarded printed circuit boards.

    PubMed

    Zhou, Cuihong; Pan, Yongtai; Lu, Maxi; Yang, Changshun

    2016-07-05

    Liberating useful materials from printed circuit boards (PCBs) is challenging because PCBs are flexible and complex in terms of materials and components. In this study, the crushing of PCBs at low-temperature was investigated. The results indicated that when the temperature was decreased to approximately -20 °C, the strength of PCBs decreased and their brittleness increased, making them easier to crush. A double roll crusher was selected to crush the PCBs. The particle size distribution and power consumption were studied under different working conditions. The results showed that the particle size of most of the lumps was in the range 15×20-25×20 mm, and that power consumption was minimal when the frequency of the crusher was 40-50 Hz. A small shredder was used for cryogenic grinding, and it was found that its power consumption strongly depended on the cooling temperature. An orthogonal experiment was conducted, which revealed that a smaller cutter gap and higher rotational speed could achieve higher yield. Furthermore, the results indicated that the air table developed to liberate PCB materials could effectively separate 2.8-0.5mm grade materials. Overall, the results of this study provide an experimental foundation for more effectively recycling discarded PCBs. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. A fully coupled air foil bearing model considering friction - Theory & experiment

    NASA Astrophysics Data System (ADS)

    von Osmanski, Sebastian; Larsen, Jon S.; Santos, Ilmar F.

    2017-07-01

    The dynamics of air foil bearings (AFBs) are not yet fully captured by any model. The recent years have, however, seen promising results from nonlinear time domain models, and simultaneously coupled formulations are now available, avoiding the previous requirements for undesirably small time steps and temporal convergence studies. In the present work, an alternative foil structure model is substituted for the simple elastic foundation model to avoid its inherent limitations. The new foil model is based on a truss representation from the literature, but incorporates the foil mass and a dynamic friction model. As a consequence of the friction model's velocity dependency, the foil mass is included to obtain a set of differential equations that can be coupled to the rotor and fluid domains while allowing a simultaneous solution. Considerations leading to a practically applicable implementation are discussed and numerical results are compared with experimental data. The model predicts natural frequencies and mode shapes well, but it is not yet capturing the unbalance response when friction is considered. Possible causes for this discrepancy are discussed and it is suggested that sticking is a more prevalent state than previously assumed.

  2. Contact sheet recording with a self-acting negative air bearing

    NASA Technical Reports Server (NTRS)

    Muftu , Sinan (Inventor); Hinteregger, Hans F (Inventor)

    2000-01-01

    A flat head and a tape transport arrangement impart a wrap angle to the tape at the upstream corner of the head. The wrap angle, corner sharpness and tape stiffness are sufficient to cause a moving tape to form a hollow bump at the upstream corner, thereby creating a hollow into which entrained air can expand, causing a subambient pressure within and downstream of the bump. This pressure keeps the tape in contact with the head. It is created without the need for a groove or complex pressure relief slot(s). No contact pressure arises at the signal exchange site due to media wrap. The highest contact pressures are developed at a wrapped upstream corner. For a tape drive, traveling in both forward and reverse, the wrap can be at both the upstream and downstream (which is the reverse upstream) corners. Heads that are not flat can also be used, if the wrap angle relative to a main surface is sufficient and not too large. The wrapped head can also be used with rotating media, such as disks (floppy and hard) and rotating heads, such as helical wound heads for video recording. Multiple flat tape bearing surfaces can be separated by grooves and/or angles. Each flat can carry heads along one or more gap lines. Multiple adjacent narrow tracks can thus be written for extreme high track density recording.

  3. Hydrodynamic air lubricated compliant surface bearing for an automotive gas turbine engine. 2: Materials and coatings

    NASA Technical Reports Server (NTRS)

    Bhushan, B.; Ruscitto, D.; Gray, S.

    1978-01-01

    Material coatings for an air-lubricated, compliant journal bearing for an automotive gas turbine engine were exposed to service test temperatures of 540 C or 650 C for 300 hours, and to 10 temperature cycles from room temperatures to the service test temperatures. Selected coatings were then put on journal and partial-arc foils and tested in start-stop cycle tests at 14 kPa (2 psi) loading for 2000 cycles. Half of the test cycles were performed at a test chamber service temperature of 540 C (1000 F) or 650 C (1200 F); the other half were performed at room temperature. Based on test results, the following combinations and their service temperature limitations are recommended: HL-800 TM (CdO and graphite) on foil versus chrome carbide on journal up to 370 C (700 F); NASA PS 120 (Tribaloy 400, silver and CaF2 on journal versus uncoated foil up to 540 C (1000 F); and Kaman DES on journal and foil up to 640 C (1200 F). Kaman DES coating system was further tested successfully at 35 kPa (5 psi) loading for 2000 start-stop cycles.

  4. Helical scan recording with a self-acting negative air bearing

    NASA Technical Reports Server (NTRS)

    Muftu , Sinan (Inventor); Hinteregger, Hans F (Inventor)

    2000-01-01

    A flat head and a tape transport arrangement impart a wrap angle to the tape at the upstream corner of the head. The wrap angle, corner sharpness and tape stiffness are sufficient to cause a moving tape to form a hollow bump at the upstream corner, thereby creating a hollow into which entrained air can expand, causing a subambient pressure within and downstream of the bump. This pressure keeps the tape in contact with the head. It is created without the need for a groove or complex pressure relief slot(s). No contact pressure arises at the signal exchange site due to media wrap. The highest contact pressures are developed at a wrapped upstream corner. For a tape drive, traveling in both forward and reverse, the wrap can be at both the upstream and downstream (which is the reverse upstream) corners. Heads that are not flat can also be used, if the wrap angle relative to a main surface is sufficient and not too large. The wrapped head can also be used with rotating media, such as disks (floppy and hard) and rotating heads, such as helical wound heads for video recording. Multiple flat tape bearing surfaces can be separated by grooves and/or angles. Each flat can carry heads along one or more gap lines. Multiple adjacent narrow tracks can thus be written for extreme high track density recording.

  5. A flexible tactile sensor calibration method based on an air-bearing six-dimensional force measurement platform

    NASA Astrophysics Data System (ADS)

    Huang, Bin

    2015-07-01

    A number of common issues related to the process of flexible tactile sensor calibration are discussed in this paper, and an estimate of the accuracy of classical calibration methods, as represented by a weight-pulley device, is presented. A flexible tactile sensor calibration method that is based on a six-dimensional force measurement is proposed on the basis of a theoretical analysis. A high-accuracy flexible tactile sensor calibration bench based on the air-bearing six-dimensional force measurement principle was developed to achieve a technically challenging measurement accuracy of 2% full scale (FS) for three-dimensional (3D) flexible tactile sensor calibration. The experimental results demonstrate that the accuracy of the air-bearing six-dimensional force measurement platform can reach 0.2% FS. Thus, the system satisfies the 3D flexible tactile sensor calibration requirement of 2% FS.

  6. A flexible tactile sensor calibration method based on an air-bearing six-dimensional force measurement platform.

    PubMed

    Huang, Bin

    2015-07-01

    A number of common issues related to the process of flexible tactile sensor calibration are discussed in this paper, and an estimate of the accuracy of classical calibration methods, as represented by a weight-pulley device, is presented. A flexible tactile sensor calibration method that is based on a six-dimensional force measurement is proposed on the basis of a theoretical analysis. A high-accuracy flexible tactile sensor calibration bench based on the air-bearing six-dimensional force measurement principle was developed to achieve a technically challenging measurement accuracy of 2% full scale (FS) for three-dimensional (3D) flexible tactile sensor calibration. The experimental results demonstrate that the accuracy of the air-bearing six-dimensional force measurement platform can reach 0.2% FS. Thus, the system satisfies the 3D flexible tactile sensor calibration requirement of 2% FS.

  7. 40 CFR Table 2 to Subpart F of... - Organic Hazardous Air Pollutants

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Organic Hazardous Air Pollutants 2...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic...

  8. 40 CFR Table 2 to Subpart F of... - Organic Hazardous Air Pollutants

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Organic Hazardous Air Pollutants 2...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic...

  9. 40 CFR Table 8 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 14 2012-07-01 2011-07-01 true Soluble Hazardous Air Pollutants 8...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous...

  10. 40 CFR Table 16 to Subpart Xxxx of... - Selected Hazardous Air Pollutants

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Selected Hazardous Air Pollutants 16...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire...

  11. 40 CFR Table 8 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 14 2013-07-01 2013-07-01 false Soluble Hazardous Air Pollutants 8...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous...

  12. 40 CFR Table 2 to Subpart F of... - Organic Hazardous Air Pollutants

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Organic Hazardous Air Pollutants 2...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic...

  13. 40 CFR Table 16 to Subpart Xxxx of... - Selected Hazardous Air Pollutants

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Selected Hazardous Air Pollutants 16...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63,...

  14. 40 CFR Table 2 to Subpart F of... - Organic Hazardous Air Pollutants

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Organic Hazardous Air Pollutants 2...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic...

  15. 40 CFR Table 16 to Subpart Xxxx of... - Selected Hazardous Air Pollutants

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Selected Hazardous Air Pollutants 16...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire...

  16. 40 CFR Table 9 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Soluble Hazardous Air Pollutants 9...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous...

  17. 40 CFR Table 8 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 13 2011-07-01 2011-07-01 false Soluble Hazardous Air Pollutants 8...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous...

  18. 40 CFR Table 2 to Subpart F of... - Organic Hazardous Air Pollutants

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Organic Hazardous Air Pollutants 2...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic...

  19. 40 CFR Table 9 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Soluble Hazardous Air Pollutants 9...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous...

  20. 40 CFR Table 8 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 14 2014-07-01 2014-07-01 false Soluble Hazardous Air Pollutants 8...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous Coating...

  1. 40 CFR Table 16 to Subpart Xxxx of... - Selected Hazardous Air Pollutants

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Selected Hazardous Air Pollutants 16...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing...

  2. 40 CFR Table 9 to Subpart Ffff of... - Soluble Hazardous Air Pollutants

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Soluble Hazardous Air Pollutants 9...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Miscellaneous Organic...

  3. Table of Historical Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS)

    EPA Pesticide Factsheets

    See the history of limits to the level of carbon monoxide (CO) in ambient air, set through the NAAQS review and rulemaking process under the Clean Air Act. This includes both primary and secondary standards.

  4. Table of Historical Nitrogen Dioxide National Ambient Air Quality Standards (NAAQS)

    EPA Pesticide Factsheets

    See the history of limits to the level of nitrogen dioxide (NO2) in ambient air, set through the NAAQS review and rulemaking process under the Clean Air Act. This includes both primary and secondary standards.

  5. Table of Historical Sulfur Dioxide National Ambient Air Quality Standards (NAAQS)

    EPA Pesticide Factsheets

    See the history of limits to the level of sulfur dioxide (SO2) in ambient air, set through the NAAQS review and rulemaking process under the Clean Air Act. This includes both primary and secondary standards.

  6. 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.

  7. VVal-79 Maximum Permissible Tissue Tension Table for Thalmann Algorithm Support of Air Diving

    DTIC Science & Technology

    2012-03-01

    22 Figure 18. Total decompression stop times (in-water and chamber ) in air SurDO2 schedules prescribed by the Thalmann Algorithm with VVal-77...Total decompression stop times (in-water and chamber ) in air SurDO2 schedules prescribed by the Thalmann Algorithm with VVal-77 and VVal-79, in...stop times (including both in-water and chamber stops) in air with surface decompression using oxygen (SurDO2) schedules prescribed by the Thalmann

  8. Preliminary Investigation of Molybdenum Disulfide-air-mist Lubrication for Roller Bearings Operating to DN Values of 1 x 10(exp 6) and Ball Bearings Operating to Temperatures of 1000 F

    NASA Technical Reports Server (NTRS)

    Macks, E F; Nemeth, Z N; Anderson, W J

    1951-01-01

    The effectiveness of molybdenum disulfide MoS2 as a bearing lubricant was determined at high temperature and at high speeds. A 1-inch-bore ball bearing operated at temperatures to 1000 F, a speed of 1725 rpm, and a thrust load of 20 pounds when lubricated only with MoS2-air mist. A 75-millimeter-bore cageless roller bearing, provided with a MoS2-syrup coating before operation, operated at DN values to 1 x 10(exp 6) with a load of 368 pounds.

  9. Backstepping sliding mode tracking control of a vane-type air motor X-Y table motion system.

    PubMed

    Lu, Chia-Hua; Hwang, Yean-Ren; Shen, Yu-Ta

    2011-04-01

    Air motors are increasingly being used in pneumatic related industries because of their advantages of low operating cost and low maintenance. The DSP controller and the backstepping sliding mode control method were utilized in this study to control an X-Y pneumatic table for tracking trajectory. Due to the effects of the compressibility of air, friction between the motor and ball screw table and the dead-zone effect caused by the proportional valve, the system will yield different responses even with the same inlet pressure and will chatter at low speed. Hence under certain conditions, this method of backstepping sliding mode control can be applied to achieve better results than with the PID controller, such as for tracking circle error and tracking error of the two axes. According to the results, a steady-state error of 0.5 μm can be achieved. The proposed method of backstepping sliding mode control can accomplish accurate tracking circle trajectory performance, offering an improvement in the tracking error of more than 50% over that of the PID controller.

  10. 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

  11. Compilation and application of Japanese inventories for energy consumption and air pollutant emissions using input-output tables.

    PubMed

    Nansai, Keisuke; Moriguchi, Yuichi; Tohno, Susumu

    2003-05-01

    Preparing emission inventories is essential to the assessment and management of our environment. In this study, Japanese air pollutant emissions, energy consumption, and CO2 emissions categorized by approximately 400 sectors (as classified by Japanese input-output tables in 1995) were estimated, and the contributions of each sector to the total amounts were analyzed. The air pollutants examined were nitrogen oxides (NOx), sulfur oxides (SOx), and suspended particulate matter (SPM). Consumptions of about 20 fossil fuels and five other fuels were estimated according to sector. Air pollutant emission factors for stationary sources were calculated from the results of a survey on air pollution prevention in Japan. Pollutant emissions from mobile sources were estimated taking into consideration vehicle types, traveling speeds, and distances. This work also counted energy supply and emissions from seven nonfossil fuel sources, including nonthermal electric power, and CO2 emissions from limestone (for example, during cement production). The total energy consumption in 1995 was concluded to be 18.3 EJ, and the annual total emissions of CO2, NOx, SOx, and SPM were, respectively, 343 Mt-C, 3.51 Mt, 1.87 Mt, and 0.32 Mt. An input-output analysis of the emission inventories was used to calculate the amounts of energy consumption and emissions induced in each sector by the economic final demand.

  12. Design for H type co-planar precision stage based on closed air bearing guideway with vacuum attraction force

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Shi, Zhaoyao; Lin, Jiachun; Zhang, Hua

    2011-12-01

    The accuracy of traditional two-dimensional precision stage is limited not only by the accuracy of each guideway but also by the configuration of the stage. It is not easy to calculate and compensate the total accuracy of the stage due to the complicated influence caused by the different position of the slides. An air bearing guideways with vacuum attraction forces has been designed with closed slide structure to enhance the stiffness and avoid the deformation caused by the weight of slide and workpieces. An H style two-dimension ultra-precision stage with co-planar structure has been developed based on the air bearing guideways to avoid the multi-influence by the axes. Driven by linear motors, the position of the workpiece is encoded by length scales with resolution of 50nm and thermal expansion of 0.6 μm/m/°C (0 °C to 30 °C). The travel span of the stage is 320x320mm, during which each axis has a positioning accuracy of +/-1μm, a repeatability of +/-0.3μm and a straightness of +/-0.5μm. The stage can be applied in precision manufacturing and measurement.

  13. [Studies on the performance of the dental air turbine handpieces. (Part 1). Air pressure and bur length to be influenced over the rotational performance of the air bearing type handpieces (author's transl)].

    PubMed

    Miyairi, H; Muramatsu, A

    1979-07-01

    Air turbine handpieces are used as the dental cutting instruments for the clinical use and many appliances. But, there are no studies on the performance of air turbine handpieces. So, this paper shows the rotational performance of air turbine handpieces which are influenced over the supplying air pressure and cutting bur length. Experimentally used air turbine handpieces is air bearing type and it's set up air pressure to be supplied is 3.5 kg/cm2. So, in this experiments, the range of air pressure is 1.8 approximately 3.5 kg/cm2, which is established five stages. And the bur length of the rotational parts is 5 approximately 9 mm with five steps. As the results, the rotational performance of air handpieces are influenced over these factors of the air pressure and the bur length. And air pressure to be supplied are influenced to be not only over the rotational speed but the load for the putting a stop to the revolutions.

  14. Environmental Assessment: 49th Materiel Maintenance Group BEAR Base Improvements Holloman Air Force Base, New Mexico

    DTIC Science & Technology

    2004-08-01

    buildings would provide 214,000 square feet of modular office and storage space. Construction of newT-storage units would provide an additional58,000...square ft of temporary storage for deployable assets. Additional area improvements would provide 1.2 million square feet of storage space, roads...jurisdictional wetland south ofBEAR Base, and Lake Stinky are noteworthy Waters of the US in the project area that receive Holloman AFB storm water

  15. Evaluation of Advanced Solid Lubricant Coatings for Foil Air Bearings Operating at 25 and 500 C

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Fellenstein, James A.; Benoy, Patricia A.

    1998-01-01

    The tribological properties of one chrome oxide and one chrome carbide based solid lubricant coating were evaluated in a partial-arc foil bearing at 25 and 500 C. Start/stop bearing operation up to 20,000 cycles were run under 10 kPa (1.5 psi) static deadweight load. Bearing friction (torque) was measured during the test. Specimen wear and SEM/EDS surface analyses were conducted after testing to understand and elucidate the tribological characteristics observed. The chrome oxide coating which contains both (Ag) and (BaF2/CaF2) for low and high temperature lubrication, exhibited low friction in sliding against Al2O3 coated foils at 25 and 500 C. The chrome carbide coating, which lacked a low temperature lubricant but contained BaF2/CaF2 as a high temperature lubricant, exhibited high friction at 25 C and low friction at 500 C against both bare and Al2O3 coated superalloy foil surfaces. Post test surface analyses suggest that improved tribological performance is exhibited when a lubricant film from the coating transfers to the foil surface.

  16. Evaluation of rotor-bearing system dynamic response to unbalance. [air conditioning equipment

    NASA Technical Reports Server (NTRS)

    Thaller, R. E.; Ozimek, D. W.

    1979-01-01

    The vibration environment within air conditioner rotating machinery referred to as an air cycle machine (ACM) was investigated to effectively increase ACM reliability. To assist in the selection of design changes which would result in improved ACM performance, various design modifications were incorporated into a baseline ACM configuration. For each design change, testing was conducted with the best balance achieveable (baseline) and with various degrees of unbalance. Relationships between unbalance (within the context of design changes) and the parameters associated with design goals were established. The results of rotor dynamics tests used to establish these relationships are presented.

  17. Evaluation of rotor-bearing system dynamic response to unbalance. [air conditioning equipment

    NASA Technical Reports Server (NTRS)

    Thaller, R. E.; Ozimek, D. W.

    1979-01-01

    The vibration environment within air conditioner rotating machinery referred to as an air cycle machine (ACM) was investigated to effectively increase ACM reliability. To assist in the selection of design changes which would result in improved ACM performance, various design modifications were incorporated into a baseline ACM configuration. For each design change, testing was conducted with the best balance achieveable (baseline) and with various degrees of unbalance. Relationships between unbalance (within the context of design changes) and the parameters associated with design goals were established. The results of rotor dynamics tests used to establish these relationships are presented.

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

    PubMed Central

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

    2016-01-01

    Background: 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. Methods: 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. Results: 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). Conclusion: 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. PMID:27390711

  19. 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.

  20. Wet air oxidation of table olive processing wastewater: determination of key operating parameters by factorial design.

    PubMed

    Katsoni, Athanasia; Frontistis, Zaharias; Xekoukoulotakis, Nikolaos P; Diamadopoulos, Evan; Mantzavinos, Dionissios

    2008-08-01

    The wet air oxidation of an effluent from edible olive processing was investigated. Semibatch experiments were conducted with 0.3L of effluent loaded into an autoclave and pure oxygen fed continuously to maintain an oxygen partial pressure of 2.5MPa. The effect of operating conditions, such as initial organic loading (from 1240 to 5150mg/L COD), reaction time (from 30 to 120min), temperature (from 140 to 180 degrees C), initial pH (from 3 to 7) and the use of 500mg/L H(2)O(2) as an additional oxidant, on treatment efficiency was assessed implementing a factorial experimental design. All five parameters had a statistically considerable effect on COD removal, alongside second order interactions of COD with reaction temperature, contact time and effluent pH. In most cases, high levels of phenols degradation (up to 100%) and decolorization (up to 90%) were achieved followed by low to moderate mineralization (up to 70%). The oxidation of phenols was affected to a considerable level by the initial COD, reaction temperature and contact time, as well as the second order interaction between COD and temperature, while all other effects were insignificant.

  1. Chronology of the US national ambient air quality standards. Supplemental tables to A&WMA 2007 Critical Review: Will the circle be unbroken: a history of the U.S. national ambient air quality standards

    SciTech Connect

    John Bachmann

    2007-06-15

    These tables summarize salient aspects of the chronology of the development and periodic revisions of the seven pollutants for which the US Environmental Protection Agency has produced air quality criteria and national ambient air quality standards (NAAAQS) since passage of the Clean Air Act Amendments of 1970. They are intended to provide reference and background to the main body of the 2007 Critical Review. They highlight when key steps in the criteria and NAAQS process occurred and highlight some of the key factors underlying the decisions. Particulates chronicled are: particulate matter, sulfur dioxide, carbon monoxide, ozone and photochemical oxidants, hydrocarbons, nitrogen dioxide, and lead. The tables are only available to subscribers of the Journal of the Air and Waste Management Association and were issued with the June 2007 issue, vol. 57, No. 6. 259 refs., 7 tabs.

  2. Foil bearings

    NASA Astrophysics Data System (ADS)

    Elrod, David A.

    1993-11-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  3. Foil bearings

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1993-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  4. Development of surface coatings for air-lubricated, compliant journal bearings to 650 C

    NASA Technical Reports Server (NTRS)

    Bhushan, B.; Gray, S.

    1978-01-01

    Surface coatings for an air-lubricated, compliant journal for an automotive gas turbine engine were tested to find those capable of withstanding temperatures of either 540 C (1000 F) or 650 C (1200 F). Also, the coatings have to be capable of surviving the start-stop sliding contact cycles prior to rotor lift-off and at touchdown. Selected coating combinations were tested in start-stop tests at 14 kPa (2 psi) loading for 2000 cycles at room and maximum temperatures. Specific coating recommendations are: Cdo and graphite on foil versus chrome carbide on journal up to 370 C (700 F); NASA PS-120 (Tribaloy 400, silver, and CaF2) on journal versus uncoated foil up to 540 C (1000 F); and chemically adherent Cr2O3 on journal and foil up to 650 C (1200 F). The chemically adherent Cr2O3 coating system was further tested successfully at 35 kPa (5 psi) loading for 2000 start-stop cycles.

  5. An Investigation of Applications for Thermodynamic Work Potential Methods: Working Tables and Charts for Estimation of Thermodynamic Work Potential in Equilibrium Mixtures of Jet-A and Air

    NASA Technical Reports Server (NTRS)

    Mavris, Dimitri; Roth, Bryce; McDonald, Rob

    2002-01-01

    The objective of this report is to provide a tool to facilitate the application of thermodynamic work potential methods to aircraft and engine analysis. This starts with a discussion of the theoretical background underlying these methods, which is then used to derive various equations useful for thermodynamic analysis of aircraft engines. The work potential analysis method is implemented in the form of a set of working charts and tables that can be used to graphically evaluate work potential stored in high-enthalpy gas. The range of validity for these tables is 300 to 36,000 R, pressures between between 0.01 atm and 100 atm, and fuel-air ratios from zero to stoichiometric. The derivations and charts assume mixtures of Jet-A and air as the working fluid. The thermodynamic properties presented in these charts were calculated based upon standard thermodynamic curve fits.

  6. Dynamic behavior of air lubricated pivoted-pad journal-bearing, rotor system. 2: Pivot consideration and pad mass

    NASA Technical Reports Server (NTRS)

    Nemeth, Z. N.

    1972-01-01

    Rotor bearing dynamic tests were conducted with tilting-pad journal bearings having three different pad masses and two different pivot geometries. The rotor was vertically mounted and supported by two three-pad tilting-pad gas journal bearings and a simple externally pressurized thrust bearing. The bearing pads were 5.1 cm (2.02 in.) in diameter and 2.8 cm (1.5 in.) long. The length to diameter ratio was 0.75. One pad was mounted on a flexible diaphragm. The bearing supply pressure ranged from 0 to 690 kilonewtons per square meter (0 to 100 psig), and speeds ranged to 38,500 rpm. Heavy mass pad tilting-pad assemblies produced three rotor-bearing resonances above the first two rotor critical speeds. Lower supply pressure eliminated the resonances. The resonances were oriented primarily in the direction normal to the diaphragm.

  7. Gas bearing operates in vacuum

    NASA Technical Reports Server (NTRS)

    Perkins, G. S.

    1975-01-01

    Bearing has restrictions to reduce air leaks and is connected to external pumpout facility which removes exhausted air. Token amount of air which is lost to vacuum is easily removed by conventional vacuum pump.

  8. Analysis and experimental verification of the nutation of a satellite equipped with magnetic bearing momentum wheels

    NASA Astrophysics Data System (ADS)

    Rouyer, C.; Heimbolt, G.; Lange, T.

    1981-11-01

    The problem of the nutation divergence of a 3 axis stablized satellite equipped with hydrodynamic bearing momentum wheels is discussed. The magnetic bearing momentum wheels, having a relatively low transverse rigidity and dissipating energy in the rotor (due to eddy currents), are likely to present an inconvenience of the same nature, if not of the same magnitude. A physical explanation of the phenomenon is given. The results of tests carried out on an air-bearing table are presented and it is shown that phenomenon cannot be detected on a satellite of the INTELSAT size.

  9. Identification of water-bearing fractures by the use of geophysical logs, May to July 1998, former Naval Air Warfare Center, Bucks County, Pennsylvania

    USGS Publications Warehouse

    Conger, Randall W.; Bird, Philip H.

    1999-01-01

    Between May and July 1998, 10 monitor wells were drilled near the site of the former Naval Air Warfare Center (NAWC), Warminster, Bucks County, Pa., to monitor water levels and sample ground water in shallow and intermediate water-bearing fractures. The sampling will determine the horizontal and vertical distribution of contaminated ground water migrating from known or suspected sources. Three boreholes were drilled on the property at 960 Jacksonville Road, at the northwestern side of NAWC, along strike from Area A; seven boreholes were drilled in Area B in the southeastern corner of NAWC. Depths range from 40.5 to 150 feet below land surface. Borehole geophysical logging and video surveys were used to identify water-bearing fractures so that appropriate intervals could be screened in each monitor well. Geophysical logs were obtained at the 10 monitor wells. Video surveys were obtained at three monitor wells in the southeastern corner of the NAWC property. Caliper logs and video surveys were used to locate fractures. Inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-bearing fractures. Heatpulse-flowmeter measurements verified these locations. Natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller?s logs, all wells were screened such that water-level fluctuations could be monitored and water samples collected from discrete water-bearing fractures in each monitor well.

  10. Identification of water-bearing fractures by the use of geophysical logs, May to July 1998, former Naval Air Warfare Center, Bucks County, Pennsylvania

    USGS Publications Warehouse

    Conger, Randall W.; Bird, Philip H.

    1999-01-01

    Between May and July 1998, 10 monitor wells were drilled near the site of the former Naval Air Warfare Center (NAWC), Warminster, Bucks County, Pa., to monitor water levels and sample ground water in shallow and intermediate water-bearing fractures. The sampling will determine the horizontal and vertical distribution of contaminated ground water migrating from known or suspected sources. Three boreholes were drilled on the property at 960 Jacksonville Road, at the northwestern side of NAWC, along strike from Area A; seven boreholes were drilled in Area B in the southeastern corner of NAWC. Depths range from 40.5 to 150 feet below land surface. Borehole geophysical logging and video surveys were used to identify water-bearing fractures so that appropriate intervals could be screened in each monitor well. Geophysical logs were obtained at the 10 monitor wells. Video surveys were obtained at three monitor wells in the southeastern corner of the NAWC property. Caliper logs and video surveys were used to locate fractures. Inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-bearing fractures. Heatpulse-flowmeter measurements verified these locations. Natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller?s logs, all wells were screened such that water-level fluctuations could be monitored and water samples collected from discrete water-bearing fractures in each monitor well.

  11. KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility settle into place one of two rudder speed brake actuators onto a table to measure the alignment of its bearings. The actuators move an orbiter’s rudder, speed brake, elevons and main engines during flight.

    NASA Image and Video Library

    2004-01-22

    KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility settle into place one of two rudder speed brake actuators onto a table to measure the alignment of its bearings. The actuators move an orbiter’s rudder, speed brake, elevons and main engines during flight.

  12. KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility stand by while another guides the lifting of one of two rudder speed brake actuators onto a table to measure the alignment of its bearings. The actuators move an orbiter’s rudder, speed brake, elevons and main engines during flight.

    NASA Image and Video Library

    2004-01-22

    KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility stand by while another guides the lifting of one of two rudder speed brake actuators onto a table to measure the alignment of its bearings. The actuators move an orbiter’s rudder, speed brake, elevons and main engines during flight.

  13. Bending fatigue of electron-beam-welded foils. Application to a hydrodynamic air bearing in the Chrysler/DOE upgraded automotive gas tubine engine

    NASA Technical Reports Server (NTRS)

    Saltsman, J. F.; Halford, G. R.

    1984-01-01

    A hydrodynamic air bearing with a compliment surface is used in the gas generator of an upgraded automotive gas turbine engine. In the prototype design, the compliant surface is a thin foil spot welded at one end to the bearing cartridge. During operation, the foil failed along the line of spot welds which acted as a series of stress concentrators. Because of its higher degree of geometric uniformity, electron beam welding of the foil was selected as an alternative to spot welding. Room temperature bending fatigue tests were conducted to determine the fatigue resistance of the electron beam welded foils. Equations were determined relating cycles to crack initiation and cycles to failure to nominal total strain range. A scaling procedure is presented for estimating the reduction in cyclic life when the foil is at its normal operating temperature of 260 C (500 F).

  14. Fixture design for seismometer testing on the shake table

    NASA Astrophysics Data System (ADS)

    Ma, J.

    2013-12-01

    Using shake table is one of the effective measures for calibration and testing of seismometer. Ultra-low frequency shake table equipped with laser vibrometer adopts air-bearing slider and displacement-based feedback in China Earthquake Networks Seismometer Testing Center. This essential equipment possesses the characteristics of low frequency, long stroke and low distortion, whereas the resonance and the angular deviation strongly influence the measurement results. The former is generated from the loose couple between the seismometer and table board and the latter from the difference between motion direction and sensitive axis of the seismometer when shake table moves in the horizontal directions. This study aims to design a fixture for testing to improve the measuring accuracy and meet the testing requirement for the seismometer of jumbo size. Three-dimensional solid modeling software of Pro/Engineer Wildfire is used to build the model of vibration fixture. The model is imported into ANSYS with seamless interface between Pro/E and ANSYS and analyzed with finite element method. After multiple calculation and calibration, optimization models are finalized for the vibration fixtures on horizontal and vertical table boards. Material objects are manufactured based on the models. Shake table testing suggests the fixtures effectively satisfy the requirements of inherent frequency over 160Hz, degree of displacement distortion lower than 1% and lateral acceleration ratio less than 3%. In practical testing, accurate azimuth angle is obtained reliably and close coupling is realized between the seismometer and the table board, which provides better testing data.

  15. Generalized water-table and water-level data at the US Air Force plant 42 and vicinity, Palmdale, California, March-April, 1997

    USGS Publications Warehouse

    Christensen, Allen H.

    1999-01-01

    The U.S. Air Force Plant 42 (Plant 42) which is in the Antelope Valley about 1.5 miles northeast of Palmdale and 3 miles southeast of Lancaster in Los Angeles County. Historically, ground water has been the primary source of water owing, in large part, to the scarcity of surface water in the region. Since 1972, supplemental surface water has been imported from the California Water Project to help meet the demand for water. Despite the importation of surface water, ground-water withdrawal for both municipal and agricultural uses is affecting ground-water levels in the vicinity of Plant 42. To better understand the effects of ground-water withdrawal on ground-water levels and movement in the area, the U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force, constructed a generalized water-table-contour map of the aquifer system underlying Plant 42 and the surrounding area.

  16. Teddy Bear Still Lifes.

    ERIC Educational Resources Information Center

    Mannlein, Sally

    2001-01-01

    Describes an art activity for first-grade students in which the students draw their own still-life pictures, using teddy bears and balls as the subject matter. Explains that the students must include three objects, a line for the table, and overlap the shapes. (CMK)

  17. Bearing system

    DOEpatents

    Kapich, Davorin D.

    1987-01-01

    A bearing system includes backup bearings for supporting a rotating shaft upon failure of primary bearings. In the preferred embodiment, the backup bearings are rolling element bearings having their rolling elements disposed out of contact with their associated respective inner races during normal functioning of the primary bearings. Displacement detection sensors are provided for detecting displacement of the shaft upon failure of the primary bearings. Upon detection of the failure of the primary bearings, the rolling elements and inner races of the backup bearings are brought into mutual contact by axial displacement of the shaft.

  18. Control of a Thrust Alignment Table for Modeling the Coning Dynamics of a Spinning Spacecraft with a Follower Force

    NASA Technical Reports Server (NTRS)

    Halsmer, Dominic; Bennett, J. Damon; DeHaven, Max; Ligard, Vidar

    1999-01-01

    This document presents a system controlling the motion of a spherical air bearing used in the modeling of spacecraft dynamics and controls in a laboratory environment. The system is part of the Spinning Rocket Simulator (SRS), used to simulate the coning of spacecraft during a thrusting stage. The reaction force at the spherical air bearing supporting the spacecraft model must coincide with the thrust axis of the model for proper simulation. Therefore, the bearing is translated in a circular path to introduce a centrifugal force. This horizontal force along with the gravitational reaction force at the bearing combines to simulate the direction of the spacecraft's thrust force. The control system receives attitude information from the spacecraft model via a laser beam embedded in the model that impinges on a photosensitive array. The non-linear system is controlled using high-speed lookup tables and digital techniques. A vector-controlled motor and a stepper motor are given the necessary signals to accurately control the turntable and platform supporting the air bearing. Preliminary performance data is presented. Mechanical elements of the table and platform are described in detail. A wireless (RF) data path for all devices on the spacecraft model to an off-table command computer is also described.

  19. Control of a Thrust Alignment Table for Modeling the Coning Dynamics of a Spinning Spacecraft with a Follower Force

    NASA Technical Reports Server (NTRS)

    Halsmer, Dominic; Bennett, J. Damon; DeHaven, Max; Ligard, Vidar

    1999-01-01

    This document presents a system controlling the motion of a spherical air bearing used in the modeling of spacecraft dynamics and controls in a laboratory environment. The system is part of the Spinning Rocket Simulator (SRS), used to simulate the coning of spacecraft during a thrusting stage. The reaction force at the spherical air bearing supporting the spacecraft model must coincide with the thrust axis of the model for proper simulation. Therefore, the bearing is translated in a circular path to introduce a centrifugal force. This horizontal force along with the gravitational reaction force at the bearing combines to simulate the direction of the spacecraft's thrust force. The control system receives attitude information from the spacecraft model via a laser beam embedded in the model that impinges on a photosensitive array. The non-linear system is controlled using high-speed lookup tables and digital techniques. A vector-controlled motor and a stepper motor are given the necessary signals to accurately control the turntable and platform supporting the air bearing. Preliminary performance data is presented. Mechanical elements of the table and platform are described in detail. A wireless (RF) data path for all devices on the spacecraft model to an off-table command computer is also described.

  20. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  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. Approximations for Estimating Change in Life Expectancy Attributable to Air Pollution in Relation to Multiple Causes of Death Using a Cause Modified Life Table.

    PubMed

    Stieb, David M; Judek, Stan; Brand, Kevin; Burnett, Richard T; Shin, Hwashin H

    2015-08-01

    There is considerable debate as to the most appropriate metric for characterizing the mortality impacts of air pollution. Life expectancy has been advocated as an informative measure. Although the life-table calculus is relatively straightforward, it becomes increasingly cumbersome when repeated over large numbers of geographic areas and for multiple causes of death. Two simplifying assumptions were evaluated: linearity of the relation between excess rate ratio and change in life expectancy, and additivity of cause-specific life-table calculations. We employed excess rate ratios linking PM2.5 and mortality from cerebrovascular disease, chronic obstructive pulmonary disease, ischemic heart disease, and lung cancer derived from a meta-analysis of worldwide cohort studies. As a sensitivity analysis, we employed an integrated exposure response function based on the observed risk of PM2.5 over a wide range of concentrations from ambient exposure, indoor exposure, second-hand smoke, and personal smoking. Impacts were estimated in relation to a change in PM2.5 from 19.5 μg/m(3) estimated for Toronto to an estimated natural background concentration of 1.8 μg/m(3) . Estimated changes in life expectancy varied linearly with excess rate ratios, but at higher values the relationship was more accurately represented as a nonlinear function. Changes in life expectancy attributed to specific causes of death were additive with maximum error of 10%. Results were sensitive to assumptions about the air pollution concentration below which effects on mortality were not quantified. We have demonstrated valid approximations comprising expression of change in life expectancy as a function of excess mortality and summation across multiple causes of death.

  3. CAR SHOP TRANSFER TABLE, IN STORAGE AT WEST SIDE OF ...

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

    CAR SHOP TRANSFER TABLE, IN STORAGE AT WEST SIDE OF SHOPS, WEST END JOURNAL BEARING AND WHEELSET DETAIL, LOOKING NORTHEAST. - Southern Pacific, Sacramento Shops, Pitless Transfer Table, 111 I Street, Sacramento, Sacramento County, CA

  4. [COSMOS motion design optimization in the CT table].

    PubMed

    Shang, Hong; Huang, Jian; Ren, Chao

    2013-03-01

    Through the CT Table dynamic simulation by COSMOS Motion, analysis the hinge of table and the motor force, then optimize the position of the hinge of table, provide the evidence of selecting bearing and motor, meanwhile enhance the design quality of the CT table and reduce the product design cost.

  5. Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China.

    PubMed

    Song, Gang; Wang, Xinming; Chen, Diyun; Chen, Yongheng

    2011-04-01

    This study investigates the contribution of radon ((222)Rn)-bearing water to indoor (222)Rn in thermal baths. The (222)Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM(10) and PM(2.5)) and carbon dioxide (CO(2)) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m(-3) of (222)Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which (222)Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average (222)Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor (222)Rn levels were influenced by the (222)Rn concentrations in the hot spring water and the bathing times. The average (222)Rn transfer coefficients from water to air were 6.2 × 10(-4)-4.1 × 10(-3). The 24-h average levels of CO(2) and PM(10) in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM(2.5). Radon and PM(10) levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants.

  6. Development of a structurally integrated conformal load-bearing multifunction antenna: overview of the Air Force Smart Skin Structures Technology Demonstration Program

    NASA Astrophysics Data System (ADS)

    Lockyer, Allen J.; Alt, Kevin H.; Kinslow, Robert W.; Kan, Han-Pin; Kudva, Jayanth N.; Tuss, James; Goetz, Allan C.

    1996-05-01

    The Structures Division of the Air Force's Wright Laboratory is sponsoring the development and demonstration of a new high pay-off technology termed CLAS--Conformal Load Bearing Antenna Structures. Northrop Grumman Corporation and TRW/ASD are developing the technology under the `Smart-Skin Structure Technology Demonstration (S3D)' program, contract, No. F33615-93-C-3200. The program goal is to design, develop, fabricate, and test a CLAS component and lay the foundation for future work where potential benefits from structurally integrated antennas may be realized. Key issues will focus but are not limited to the design, structures, and manufacturing aspects of antenna embedment into load bearing aircraft structures. Results from Phase I of the program have been previously reported, where initial pay-offs in reducing overall airframe acquisition and support cost, weight, signature, and drag were quantitatively and qualitatively identified. A full-sized CLAS component, featuring a broadband multi-arm spiral embedded in sandwich stiffened structure, will be fabricated and tested for static strength, durability, and damage tolerance. Basic electrical performance, (e.g. radiation patterns, gain, and impedance) will also be verified; however, extensive electrical validation will be the subject of further work. Key aspects of the work and progress to date are detailed below.

  7. A new modal-based approach for modelling the bump foil structure in the simultaneous solution of foil-air bearing rotor dynamic problems

    NASA Astrophysics Data System (ADS)

    Bin Hassan, M. F.; Bonello, P.

    2017-05-01

    Recently-proposed techniques for the simultaneous solution of foil-air bearing (FAB) rotor dynamic problems have been limited to a simple bump foil model in which the individual bumps were modelled as independent spring-damper (ISD) subsystems. The present paper addresses this limitation by introducing a modal model of the bump foil structure into the simultaneous solution scheme. The dynamics of the corrugated bump foil structure are first studied using the finite element (FE) technique. This study is experimentally validated using a purpose-made corrugated foil structure. Based on the findings of this study, it is proposed that the dynamics of the full foil structure, including bump interaction and foil inertia, can be represented by a modal model comprising a limited number of modes. This full foil structure modal model (FFSMM) is then adapted into the rotordynamic FAB problem solution scheme, instead of the ISD model. Preliminary results using the FFSMM under static and unbalance excitation conditions are proven to be reliable by comparison against the corresponding ISD foil model results and by cross-correlating different methods for computing the deflection of the full foil structure. The rotor-bearing model is also validated against experimental and theoretical results in the literature.

  8. Compressor ported shroud for foil bearing cooling

    DOEpatents

    Elpern, David G.; McCabe, Niall; Gee, Mark

    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.

  9. OTV bearing deflection investigation

    NASA Technical Reports Server (NTRS)

    Reimer, B. L.; Diepenbrock, R. T.; Millis, M. G.

    1993-01-01

    The primary goal of the Bearing Deflectometer Investigation was to gain experience in the use of fiber optic displacement probe technology for bearing health monitoring in a liquid hydrogen turbo pump. The work specified in this Task Order was conducted in conjunction with Air Force Rocket Propulsion Laboratory Contract F04611-86-C-0010. APD conducted the analysis and design coordination to provide a displacement probe design compatible with the XLR-134 liquid hydrogen turbo pump assembly (TPA). Specifications and requirements of the bearing deflectometer were established working with Mechanical Technology Instruments, Inc. (MTI). The TPA design accommodated positioning of the probe to measure outer race cyclic deflections of the pump inlet bearing. The fiber optic sensor was installed as required in the TPA and sensor output was recorded during the TPA testing. Data review indicated that no bearing deflection signature could be differentiated from the inherent system noise. Alternate sensor installations were not investigated, but might yield different results.

  10. High temperature self-lubricating coatings for air lubricated foil bearings for the automotive gas turbine engine

    NASA Technical Reports Server (NTRS)

    Bhushan, B.

    1980-01-01

    coating combinations were developed for compliant surface bearings and journals to be used in an automotive gas turbine engine. The coatings were able to withstand the sliding start/stops during rotor liftoff and touchdown and occasional short time, high speed rubs under representative loading of the engine. Some dozen coating variations of CdO-graphite, Cr2O3 (by sputtering) and CaF2 (plasma sprayed) were identified. The coatings were optimized and they were examined for stoichiometry, metallurgical condition, and adhesion. Sputtered Cr2O3 was most adherent when optimum parameters were used and it was applied on an annealed (soft) substrate. Metallic binders and interlayers were used to improve the ductility and the adherence.

  11. Environmental Assessment to Replace Utility Poles at Bear Creek and Coast Road, Vandenberg Air Force Base, California

    DTIC Science & Technology

    2009-02-01

    Surveys by VAFB biologists did not find tarplant near the project area, but did find habitat for beach layia approximately 4,600 feet from the project ...affect, but is not likely to adversely affect, the federally endangered beach layia ( Layia carnosa ) and the federally tlrreatened California red-legged...habitat occurs onsite. In addition, the Air Force proposed to have qualified biologists conduct pre- project surveys for the beach layia and California red

  12. THRUST BEARING

    DOEpatents

    Heller, P.R.

    1958-09-16

    A thrust bearing suitable for use with a rotor or blower that is to rotate about a vertical axis is descrihed. A centrifagal jack is provided so thnt the device may opernte on one hearing at starting and lower speeds, and transfer the load to another bearing at higher speeds. A low viscosity fluid is used to lubricate the higher speed operation bearing, in connection with broad hearing -surfaces, the ability to withstand great loads, and a relatively high friction loss, as contraated to the lower speed operatio;n bearing which will withstand only light thrust loads but is sufficiently frictionfree to avoid bearing seizure during slow speed or startup operation. An axially aligned shaft pin provides the bearing surface for low rotational speeds, but at higher speed, weights operating against spring tension withdraw nthe shaft pin into the bearing proper and the rotor shaft comes in contact with the large bearing surfaces.

  13. Some economic tables for airships

    NASA Technical Reports Server (NTRS)

    Neumann, R. D.

    1975-01-01

    During the course of the Southern California Aviation Council study on lighter than air it was determined that some form of economic base must be developed for estimation of costs of the airship. The tables are presented.

  14. Bearing fatigue investigation 3

    NASA Technical Reports Server (NTRS)

    Nahm, A. H.; Bamberger, E. N.; Signer, H. R.

    1982-01-01

    The operating characteristics of large diameter rolling-element bearings in the ultra high speed regimes expected in advanced turbine engines for high performance aircraft were investigated. A high temperature lubricant, DuPont Krytox 143 AC, was evaluated at bearing speeds to 3 million DN. Compared to the results of earlier, similar tests using a MIL-L-23699 (Type II) lubricant, bearings lubricated with the high density Krytox fluid showed significantly higher power requirements. Additionally, short bearing lives were observed when this fluid was used with AISI M50 bearings in an air atmosphere. The primary mode of failure was corrosion initiated surface distress (fatigue) on the raceways. The potential of a case-carburized bearing to sustain a combination of high-tangential and hertzian stresses without experiencing race fracture was also investigated. Limited full scale bearing tests of a 120 mm bore ball bearing at a speed of 25,000 rpm (3 million DN) indicated that a carburized material could sustain spalling fatigue without subsequent propagation to fracture. Planned life tests of the carburized material had to be aborted, however, because of apparent processing-induced material defects.

  15. Gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2003-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission.

  16. The dynamic characteristics of a turbo-rotor simulator supported on gas-lubricated foil bearings. Part 1: Response to rotating imbalance and unidirectional excitation

    NASA Technical Reports Server (NTRS)

    Licht, L.

    1970-01-01

    A sixteen-inch rotor, weighing approximately twenty-one pounds, was supported by air-lubricated foil bearings. In physical size and in mass distribution, the rotor closely matched that of an experimental Brayton cycle turboalternator unit. The rotor was stable in both vertical horizontal attitudes at speeds up to 50,000 rpm. A detailed description of the experimental apparatus and of the foil bearing design are given. The paper contains data on response of the rotor to rotating imbalance, symmetric and asymmetric, and to excitation by means of a vibrator (shake table). It is concluded that the gas-lubricated foil bearing suspension is free from fractional frequency whirl and suffers no loss of load capacity when excited at frequency equal to half the rotational speed. In contrast to rigid gas bearings, the foil bearing imposes no stringent requirements with respect to dimensional tolerances, cleanliness, or limitations of journal motion within the narrow confines of bearing clearance.

  17. Helium tables.

    NASA Technical Reports Server (NTRS)

    Havill, Clinton H

    1928-01-01

    These tables are intended to provide a standard method and to facilitate the calculation of the quantity of "Standard Helium" in high pressure containers. The research data and the formulas used in the preparation of the tables were furnished by the Research Laboratory of Physical Chemistry, of the Massachusetts Institute of Technology.

  18. Journal bearing

    DOEpatents

    Menke, John R.; Boeker, Gilbert F.

    1976-05-11

    1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

  19. High Temperature Bearing and Dry - Lubrication Concepts

    DTIC Science & Technology

    1982-09-01

    Ball and Sleeve Bearing / Mounting Techniques 52 6.5 Phase II and Interim Work 53 7.0 Appendixes A. Summary 54 B. Solar Turbines Inc / Facilities and...Measurement Methods 46 20 Test-Rig / SOLAR TURBINE Inc. 56 * ’I List of Tables Table Page 1. Properties of selected Ceramic Materials 7 2. Commercial... SOLAR TURBINES INC., in San Diego, California. Their expertise in turbine technology makes the company an attractive choice. Bearing investigations have

  20. A Table! (At the Table).

    ERIC Educational Resources Information Center

    Terry, Robert M.

    A review of French dining habits and table manners outlines: elements of the place setting, courtesies used at the table, serving conventions, restaurant tipping, the size and content of the different meals of the day, subtle differences in common foods, restaurant types, menu types, general wine and cheese choices, waiter-client communication,…

  1. GAS BEARING

    DOEpatents

    Skarstrom, C.W.

    1960-09-01

    A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

  2. Grizzly bear

    USGS Publications Warehouse

    Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

    2003-01-01

    The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

  3. Integrated use of air sparging, soil vapor extraction and pump and treat technologies to remediate chlorinated hydrocarbon contaminated water-bearing units at a HDPE facility

    SciTech Connect

    Sturdivant, R. Jr.; Schramm, W.H.; Bains, F.E.

    1996-09-01

    Disposal practices prior to RCRA caused the release of chlorinated hydrocarbons (CHCs) into the shallow ground water under a temporary pond at the facility. This impact was discovered through a due diligence survey and properly reported to the Louisiana Department of Environmental Quality (LDEQ). Through a phased investigation the company, in cooperation with LDEQ, has determined that the upper three water bearing units have been affected by multiple contaminants forming a DNAPL plume. Remedial actions were proposed to the Agency and implemented with approval during 1994-95. The remedial system includes soil vapor extraction and air sparging for the uppermost zone and pump and treat for contaminated water removal in the second zone. Throughout 1995, the systems efficiency was evaluated and continuous adjustments were made to improve the recovery. A balanced approach to minimize downward movement of contaminants and achieve optimum recovery included: startup of system components, manipulation of recovery rates and installation of additional equipment. Data assimilated over the past year of operation suggests the effective recovery of CHCs. Monitoring of the impacted zones shows a downward trend in contamination levels, however it is evident that control of the impacted zones is incomplete. Proposed alterations to the system include additional recovery wells, pump tests, and continued evaluations to improve the system. Further efforts will be required by the Agency to address the remaining contaminants. This paper will address the implementation of the Corrective Action Program and present the current state of operations and proposed augmentations to improve the system.

  4. Structural finite-element modeling strategies for conformal load-bearing antenna structure (CLAS) (Air Force contract F33615-C-93-3200)

    NASA Astrophysics Data System (ADS)

    Lockyer, Allen J.; Alt, Kevin H.; Kudva, Jayanth N.; Kinslow, Robert W.; Goetz, Allan C.

    1997-06-01

    As the Wright Lab Air Force military contrast `Smart Skin Structures Technology Demonstration' (S3TD) Contract No. F33615-C-93-3200 draws toward conclusion, pertinent features of the program finite element modeling are presented. Analysis was performed to predict the structural performance of a complex multilayered composite panel that will be tested structurally (and electrically) for the final program deliverable. Application of finite element modeling to predict component load path and strain distribution in sandwich panel construction has been reported elsewhere in the literature for more standard applications. However, the unauthordox sandwich configuration lay-up posed by the quite revolutionary S3TD CLAS aircraft fuselage panel demonstration article merits further discussion. Difficulties with material selection, the stumbling block for many programs, are further exacerbated by conflicting material properties required to support simultaneous electrical and structural performance roles. The structural analysis challenge derives from S3TD's unique program goal, namely, to investigate load bearing antennas structural configurations, rather than conventional structurally inefficient `bolt in' installations, that have been the modus operandi for tactical aircraft antenna installations to date. Discussed below is a cost saving strategy where use of linear finite element analysis has been employed in the prediction of key structural parameters, and validated with risk reduction sub panel measurements, before proceeding to the final fabrication of a full scale 36 by 36 inch CLAS panel demonstration article.

  5. Accession Medical Standards Analysis and Research Activity (AMSARA) 2015, Annual Report, and four Supplemental Applicants and Accessions Tables for: Army, Air Force, Marine, and Navy

    DTIC Science & Technology

    2016-03-11

    and gender identity disorders disqualification and waiver ICD-9 code categories...19 Table 1.12: Medical disqualifications for sexual and gender identity disorders ...Table 1.13: Accession Medical Waivers for sexual and gender identity disorders in first-time active component Applicants 2008-2013 by service

  6. Polar Bears

    USGS Publications Warehouse

    Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

  7. Polar Bear

    USGS Publications Warehouse

    Amstrup, S.D.; ,; Lentfer, J.W.

    1988-01-01

    Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout the Arctic for thousands of years.

  8. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A magnetic bearing for passively suspending a rotatable element subjected to axial and radial thrust forces is disclosed. The magnetic bearing employs a taut wire stretched along the longitudinal axis of the bearing between opposed end pieces and an intermediate magnetic section. The intermediate section is segmented to provide oppositely directed magnetic flux paths between the end pieces and may include either an axially polarized magnets interposed between the segments. The end pieces, separated from the intermediate section by air gaps, control distribution of magnetic flux between the intermediate section segments. Coaxial alignment of the end pieces with the intermediate section minimizes magnetic reluctance in the flux paths endowing the bearing with self-centering characteristics when subjected to radial loads. In an alternative embodiment, pairs of oppositely wound armature coils are concentrically interposed between segments of the intermediate section in concentric arcs adjacent to radially polarized magnets to equip a magnetic bearing as a torsion drive motor. The magnetic suspension bearing disclosed provides long term reliability without maintenance with application to long term space missions such as the VISSR/VAS scanning mirror instrument in the GOES program.

  9. Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    AVCON, Inc. produces advanced magnetic bearing systems for industrial use, offering a unique technological approach based on contract work done at Marshall Space Flight Center and Lewis Research Center. Designed for the turbopump of the Space Shuttle main engine, they are now used in applications such as electric power generation, petroleum refining, machine tool operation and natural gas pipelines. Magnetic bearings support moving machinery without physical contact; AVCON's homopolar approach is a hybrid of permanent and electromagnets which are one-third the weight, smaller and more power- efficient than previous magnetic bearings.

  10. 40 CFR Table 2 to Subpart Ooo - Stack Emission Limits for Affected Facilities With Capture Systems

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Nonmetallic Mineral Processing Plants Subpt. OOO, Table 2 Table 2 to Subpart...

  11. 24 CFR 3285.202 - Soil classifications and bearing capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... bearing capacity must be determined by one or more of the following methods, unless the soil bearing... in accordance with generally accepted engineering practice; or (b) Soil records. Soil records of the...; or (e) In lieu of determining the soil bearing capacity by use of the methods shown in the table, an...

  12. 42 CFR Appendix - Table to Subpart J of Part 84

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Table to Subpart J of Part 84 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND.... 84, Subpt. J, Table Table to Subpart J of Part 84 Table 8—Air-Supply-Line Requirements and...

  13. 40 CFR Appendix to Subpart Cc of... - Tables

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Tables Appendix to Subpart CC of Part... to Subpart CC of Part 63—Tables Table 1—Hazardous Air Pollutants Chemical name CAS No.a Benzene 71432... salts, esters, or derivatives. Table 2—Leak Definitions for Pumps and Valves Standard a Phase Leak...

  14. 40 CFR Appendix to Subpart Cc of... - Tables

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Tables Appendix to Subpart CC of Part... to Subpart CC of Part 63—Tables Table 1—Hazardous Air Pollutants Chemical name CAS No.a Benzene 71432... salts, esters, or derivatives. Table 2—Leak Definitions for Pumps and Valves Standard a Phase Leak...

  15. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

  16. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

  17. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

  18. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

  19. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

  20. Enrollment Tables.

    ERIC Educational Resources Information Center

    University System of Georgia, Atlanta.

    A set of tables is provided summarizing fall enrollment from 1979 through 1988 in the university system of Georgia. The following types of data are provided: headcount enrollment; joint enrollment; developmental studies, freshmen, sophomores, juniors, seniors, graduate students, professional enrollment, transients, others, EFT enrollment, entering…

  1. Enrollment Tables.

    ERIC Educational Resources Information Center

    University System of Georgia, Atlanta.

    A set of tables is provided summarizing fall enrollment from 1979 through 1988 in the university system of Georgia. The following types of data are provided: headcount enrollment; joint enrollment; developmental studies, freshmen, sophomores, juniors, seniors, graduate students, professional enrollment, transients, others, EFT enrollment, entering…

  2. 32 CFR Table 3 to Part 855 - Landing Fees

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Landing Fees 3 Table 3 to Part 855 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 3 Table 3 to Part 855—Landing Fees Aircraft...

  3. Model input and output files for the simulation of time of arrival of landfill leachate at the water table, Municipal Solid Waste Landfill Facility, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    USGS Publications Warehouse

    Abeyta, Cynthia G.; Frenzel, Peter F.

    1999-01-01

    This report contains listings of model input and output files for the simulation of the time of arrival of landfill leachate at the water table from the Municipal Solid Waste Landfill Facility (MSWLF), about 10 miles northeast of downtown El Paso, Texas. This simulation was done by the U.S. Geological Survey in cooperation with the U.S. Department of the Army, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso, Texas. The U.S. Environmental Protection Agency-developed Hydrologic Evaluation of Landfill Performance (HELP) and Multimedia Exposure Assessment (MULTIMED) computer models were used to simulate the production of leachate by a landfill and transport of landfill leachate to the water table. Model input data files used with and output files generated by the HELP and MULTIMED models are provided in ASCII format on a 3.5-inch 1.44-megabyte IBM-PC compatible floppy disk.

  4. Seismic bearing

    NASA Astrophysics Data System (ADS)

    Power, Dennis

    2009-05-01

    Textron Systems (Textron) has been using geophones for target detection for many years. This sensing capability was utilized for detection and classification purposes only. Recently Textron has been evaluating multiaxis geophones to calculate bearings and track targets more specifically personnel. This capability will not only aid the system in locating personnel in bearing space or cartesian space but also enhance detection and reduce false alarms. Textron has been involved in the testing and evaluation of several sensors at multiple sites. One of the challenges of calculating seismic bearing is an adequate signal to noise ratio. The sensor signal to noise ratio is a function of sensor coupling to the ground, seismic propagation and range to target. The goals of testing at multiple sites are to gain a good understanding of the maximum and minimum ranges for bearing and detection and to exploit that information to tailor sensor system emplacement to achieve desired performance. Test sites include 10A Site Devens, MA, McKenna Airfield Ft. Benning, GA and Yuma Proving Ground Yuma, AZ. Geophone sensors evaluated include a 28 Hz triax spike, a 15 Hz triax spike and a hybrid triax spike consisting of a 10 Hz vertical geophone and two 28 Hz horizontal geophones. The algorithm uses raw seismic data to calculate the bearings. All evaluated sensors have triaxial geophone configuration mounted to a spike housing/fixture. The suite of sensors also compares various types of geophones to evaluate benefits in lower bandwidth. The data products of these tests include raw geophone signals, seismic features, seismic bearings, seismic detection and GPS position truth data. The analyses produce Probability of Detection vs range, bearing accuracy vs range, and seismic feature level vs range. These analysis products are compared across test sites and sensor types.

  5. Identification of water-bearing zones by the use of geophysical logs and borehole television surveys, collected February to September 1997, at the Former Naval Air Warfare Center, Warminster, Bucks County, Pennsylvania

    USGS Publications Warehouse

    Conger, Randall W.

    1998-01-01

    Between February 1997 and September 1997, 10 monitor wells were drilled near the site of the former Naval Air Warfare Center, Warminster, Bucks County, Pa., to monitor water levels and sample ground-water contaminants in the shallow, intermediate, and deep water-bearing zones. The sampling will determine the horizontal and vertical distribution of contaminated ground water migrating from known or suspected contaminant sources. Four wells were drilled north of the property adjacent to Area A, three wells along strike located on Lewis Drive, and three wells directly down dip on Ivyland Road. Well depths range from 69 feet to 300 feet below land surface. Borehole-geophysical logging and television surveys were used to identify water-bearing zones so that appropriate intervals could be screened in each monitor well. Geophysical logs were obtained at the 10 monitor wells. Borehole television surveys were obtained at the four monitor wells adjacent to Area A. Caliper and borehole television surveys were used to locate fractures, inflections on fluidtemperature and fluid-resistivity logs were used to locate possible water-bearing fractures, and heatpulse- flowmeter measurements verified these locations. Natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, borehole television surveys, and driller?s logs, all wells were screened such that water-level fluctuations could be monitored and water samples collected from discrete water-bearing zones in each borehole.

  6. Interference Fit Life Factors for Roller Bearings

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2008-01-01

    The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner ring interference fit. Calculations were performed for up to seven interference fit classes for each of ten bearing sizes. Each fit was taken at tightest, average and loosest values within the fit class for RBEC-5 tolerance, thus requiring 486 separate analyses. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. The method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings based on interference fit. All calculated lives are for zero initial bearing internal clearance. Any reduction in bearing clearance due to interference fit was compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate and heavy loads and interference fits ranging from extremely light to extremely heavy and for bearing accuracy class RBEC 5 (ISO class 5). Interference fits on the inner bearing ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference fit life factors for a particular fit. The tightest fit at the high end of the RBEC-5 tolerance band defined in ANSI/ABMA shaft fit tables produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

  7. 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.

  8. 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.

  9. Wave Journal Bearing. Part 1: Analysis

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin

    1995-01-01

    A wave journal bearing concept features a waved inner bearing diameter of the non-rotating bearing side and it is an alternative to the plain journal bearing. The wave journal bearing has a significantly increased load capacity in comparison to the plain journal bearing operating at the same eccentricity. It also offers greater stability than the plain circular bearing under all operating conditions. The wave bearing's design is relatively simple and allows the shaft to rotate in either direction. Three wave bearings are sensitive to the direction of an applied stationary side load. Increasing the number of waves reduces the wave 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 wave bearing design for a specific application. It is concluded that the stiffness of an air journal bearing, due to 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.

  10. Exceptional Events Submissions Table (2016 Rule)

    EPA Pesticide Factsheets

    This table contains examples of air agency submitted exceptional events demonstrations and responsive EPA decision documents that have been prepared and/or acted upon under the 2016 Exceptional Events Rule

  11. System for testing bearings

    NASA Technical Reports Server (NTRS)

    Gibson, John C. (Inventor)

    1993-01-01

    Disclosed here is a system for testing bearings wherein a pair of spaced bearings provides support for a shaft on which is mounted a bearing to be tested, this bearing being mounted in a bearing holder spaced from and in alignment with the pair of bearings. The bearing holder is provided with an annular collar positioned in an opening in the bearing holder for holding the bearing to be tested. A screw threaded through the bearing holder into engagement with the annular collar can be turned to force the collar radially out of alignment with the pair of bearings to apply a radial load to the bearing.

  12. CUSHIONED BEARING

    DOEpatents

    Rushing, F.C.

    1960-09-01

    A vibration damping device effective to dampen vibrations occurring at the several critical speeds encountered in the operation of a high-speed centrifuge is described. A self-centering bearing mechanism is used to protect both the centrifuge shaft and the damping mechanism. The damping mechanism comprises spaced-apant, movable, and stationary sleeve members arranged concentrically of a rotating shaft with a fluid maintained between the members. The movable sleeve member is connected to the shaft for radial movement therewith.

  13. Camshaft bearing arrangement

    SciTech Connect

    Aoi, K.; Ozawa, T.

    1986-06-10

    A bearing arrangement is described for the camshaft of an internal combustion engine or the like which camshaft is formed along its length in axial order with a first bearing surface, a first cam lobe, a second bearing surface, a second cam lobe, a third bearing surface, a third cam lobe and a fourth bearing surface, the improvement comprising first bearing means extending around substantially the full circumference of the first bearing surface and journaling the first bearing surface, second bearing means extending around substantially less than the circumference of the second bearing surface and journaling the second bearing surface, third bearing means extending around substantially less than the circumference of the third bearing surface and journaling the third bearing surface, and fourth bearing means extending around substantially the full circumference of the fourth bearing surface and journaling the first bearing surface.

  14. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, Philip A. (Inventor)

    1983-01-01

    A magnetic bearing assembly (10) has an intermediate rotatable section (33) having an outer cylindrical member (30) coaxially suspended by a torsion wire (72) around an axially polarized cylindrical magnet (32). Axial alignment between the pole faces (40-43) of the intermediate section (33) and end surfaces (50-53) of opposed end bells (20, 22) provides a path of least reluctance across intervening air gaps (60-63) for the magnetic flux emanating from magnet (32). Radial dislocation increases the reluctance and creates a radial restoring force. Substitution of radially polarized magnets 107 fixed to a magnetically permeable cylinder (32') and insertion of pairs of armature coil windings (109-112) between the cylinder pair (33') provides an integral magnetic bearing and torsion motor (100) able to provide arcuately limited rotational drive.

  15. Mesa = Table

    NASA Technical Reports Server (NTRS)

    2006-01-01

    10 August 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two mesas on the northern plains of Mars. 'Mesa' is the Spanish word for 'table,' and that is a very good description of the two elliptical features captured in this MOC image. In both cases, the mesa tops and the material beneath them, down to the level of the surrounding, rugged plain, are remnants of a once more extensive layer (or layers) of material that has been largely eroded away. The circular feature near the center of the larger mesa is the site of a filled and buried impact crater.

    Location near: 53.5oN, 153.5oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

  16. Mesa = Table

    NASA Technical Reports Server (NTRS)

    2006-01-01

    10 August 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two mesas on the northern plains of Mars. 'Mesa' is the Spanish word for 'table,' and that is a very good description of the two elliptical features captured in this MOC image. In both cases, the mesa tops and the material beneath them, down to the level of the surrounding, rugged plain, are remnants of a once more extensive layer (or layers) of material that has been largely eroded away. The circular feature near the center of the larger mesa is the site of a filled and buried impact crater.

    Location near: 53.5oN, 153.5oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

  17. 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.

  18. Advances In Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1994-01-01

    NASA technical memorandum reviews state of technology of magnetic bearings, focusing mainly on attractive bearings rather than repulsive, eddy-current, or Lorentz bearings. Attractive bearings offer greater load capacities and preferred for aerospace machinery.

  19. Links between climate change, water-table depth, and water chemistry in a mineralized mountain watershed

    USGS Publications Warehouse

    Manning, Andrew H.; Verplanck, Philip L.; Caine, Jonathan S.; Todd, Andrew S.

    2013-01-01

    Recent studies suggest that climate change is causing rising solute concentrations in mountain lakes and streams. These changes may be more pronounced in mineralized watersheds due to the sensitivity of sulfide weathering to changes in subsurface oxygen transport. Specific causal mechanisms linking climate change and accelerated weathering rates have been proposed, but in general remain entirely hypothetical. For mineralized watersheds, a favored hypothesis is that falling water tables caused by declining recharge rates allow an increasing volume of sulfide-bearing rock to become exposed to air, thus oxygen. Here, we test the hypothesis that falling water tables are the primary cause of an increase in metals and SO4 (100-400%) observed since 1980 in the Upper Snake River (USR), Colorado. The USR drains an alpine watershed geologically and climatologically representative of many others in mineralized areas of the western U.S. Hydrologic and chemical data collected from 2005 to 2011 in a deep monitoring well (WP1) at the top of the USR watershed are utilized. During this period, both water table depths and groundwater SO4 concentrations have generally increased in the well. A numerical model was constructed using TOUGHREACT that simulates pyrite oxidation near WP1, including groundwater flow and oxygen transport in both saturated and unsaturated zones. The modeling suggests that a falling water table could produce an increase in metals and SO4 of a magnitude similar to that observed in the USR (up to 300%). Future water table declines may produce limited increases in sulfide weathering high in the watershed because of the water table dropping below the depth of oxygen penetration, but may continue to enhance sulfide weathering lower in the watershed where water tables are shallower. Advective air (oxygen) transport in the unsaturated zone caused by seasonally variable recharge and associated water table fluctuations was found to have little influence on pyrite

  20. Site Investigation Report. 161st Air Refueling Group, Arizona National Guard, Sky Harbor International Airport and Papago Military Reservation, Phoenix, Arizona. Volume 1. Report, Tables and Figures

    DTIC Science & Technology

    1992-11-01

    Site 5. Ammunition Dumo SI activities consisted of conducting geophysical surveys to ascertain the location of suspected historical ammunition disposal...the Toxic Substances Control Act (TSCA), the Safe Drinking Water Act (SDWA) , the Clean Air Act (CAA), the Clean Water Act (CV;7A), and the Marine ...Treaty Acv Federal Insecticide, Fungi’:ide, 3nd Rodenticide Acc Wild and Scenic Rivers Act Clean Air Act M4arine Mammal Protection Act Marine

  1. Numerical investigation of the performance of aerostatic journal bearings

    NASA Astrophysics Data System (ADS)

    Wang, Xinkuan; Xu, Qiao; Wang, Baorui; Zhang, Lianxin; Peng, Zhike

    2016-10-01

    The current study presents a detailed theoretical analysis on the performance of aerostatic journal bearings. The dimensionless Reynolds equation is derived and discretized by the finite difference method. An iterative procedure is adopted to get the air film pressure distribution. The bearing characteristics such as load capacity, stiffness and air flow rate under various bearing operating and geometric parameters are investigated. The numerical results show that the journal rotation plays an important role on the bearing characteristics, and the rotating speeds must be taken into consideration. The proposed method provides a valuable approach for analyzing the performance of aerostatic journal bearings, and can be used for the bearing optimizing design.

  2. A Passive Magnetic Bearing Flywheel

    NASA Technical Reports Server (NTRS)

    Siebert, Mark; Ebihara, Ben; Jansen, Ralph; Fusaro, Robert L.; Morales, Wilfredo; Kascak, Albert; Kenny, Andrew

    2002-01-01

    A 100 percent passive magnetic bearing flywheel rig employing no active control components was designed, constructed, and tested. The suspension clothe rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm, which is 65 percent above the first critical speed of 3336 rpm. Operation was not continued beyond this point because of the excessive noise generated by the air impeller and because of inadequate containment in case of failure. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

  3. 40 CFR Appendix B to Subpart E of... - Tables

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Tables B Appendix B to Subpart E of Part 89 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Procedures Pt. 89, Subpt. E, App. B Appendix B to Subpart E of Part 89—Tables Table 1—8-Mode Test Cycle...

  4. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of Par...

  5. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpart B, Tables Tables to Subpart B of Part 88...

  6. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpart B, Tables Tables to Subpart B of Part 88...

  7. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of Par...

  8. 40 CFR Appendix to Subpart Cc of... - Tables

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Tables Appendix to Subpart CC of Part... to Subpart CC of Part 63—Tables Link to an amendment published at 75 FR 37731, June 30, 2010. Link to an amendment published at 75 FR 37731, June 30, 2010. Table 1—Hazardous Air Pollutants Chemical name...

  9. 40 CFR Table 1 to Subpart H of... - Batch Processes

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch Processes 1 Table 1 to Subpart H... Standards for Organic Hazardous Air Pollutants for Equipment Leaks Pt. 63, Subpt. H, Table 1 Table 1 to Subpart H of Part 63—Batch Processes Monitoring Frequency for Equipment Other than Connectors Operating...

  10. 40 CFR Table 1 to Subpart H of... - Batch Processes

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Batch Processes 1 Table 1 to Subpart H... Standards for Organic Hazardous Air Pollutants for Equipment Leaks Pt. 63, Subpt. H, Table 1 Table 1 to Subpart H of Part 63—Batch Processes Monitoring Frequency for Equipment Other than Connectors Operating...

  11. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of Part...

  12. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of Par...

  13. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of Par...

  14. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpt. B, Tables Tables to Subpart B of Part 88...

  15. 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.

  16. Ceramic Bearings For Gas-Turbine Engines

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1989-01-01

    Report reviews data from three decades of research on bearings containing rolling elements and possibly other components made of ceramics. Ceramic bearings attractive for use in gas-turbine engines because ceramics generally retain strengths and resistances to corrosion over range of temperatures greater than typical steels used in rolling-element bearings. Text begins with brief description of historical developments in field. Followed by discussion of effects of contact stress on fatigue life of rolling element. Supplemented by figures and tables giving data on fatigue lives of rolling elements made of various materials. Analyzes data on effects of temperature and speed on fatigue lives for several materials and operating conditions. Followed by discussion of related topic of generation of heat in bearings, with consideration of effects of bearing materials, lubrication, speeds, and loads.

  17. Ceramic Bearings For Gas-Turbine Engines

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1989-01-01

    Report reviews data from three decades of research on bearings containing rolling elements and possibly other components made of ceramics. Ceramic bearings attractive for use in gas-turbine engines because ceramics generally retain strengths and resistances to corrosion over range of temperatures greater than typical steels used in rolling-element bearings. Text begins with brief description of historical developments in field. Followed by discussion of effects of contact stress on fatigue life of rolling element. Supplemented by figures and tables giving data on fatigue lives of rolling elements made of various materials. Analyzes data on effects of temperature and speed on fatigue lives for several materials and operating conditions. Followed by discussion of related topic of generation of heat in bearings, with consideration of effects of bearing materials, lubrication, speeds, and loads.

  18. Turbocharger bearing retention and lubrication system

    SciTech Connect

    Gutknecht, D.A.

    1991-12-31

    This patent describes exhausts gas driven turbocharger. It comprises a housing, a shaft within the housing having a longitudinal axis of rotation and a pair of ends, a compressor wheel mounted within the housing on one end of the shaft for rotation therewith, a turbine wheel mounted within the housing on the other end of the shaft for rotation therewith, means for communicating air to the compressor wheel, means for communicating exhaust gas to the turbine wheel to cause the latter to rotate the shaft and the compressor wheel mounted thereon to compress the air communicated to the compressor wheel, and bearing means mounting the shaft for rotation relative to the housing, the bearing means including a bearing outer ring, a bearing inner ring, and ball bearing elements supporting the bearing outer ring on the bearing inner ring, a bearing locating aperture in the bearing outer ring, and an elongated bearing location pin having a longitudinal axis of symmetry extending transversely to the longitudinal axis of the shaft.

  19. Human impacts on bear habitat use

    USGS Publications Warehouse

    Mattson, David J.

    1990-01-01

    : Human effects on bear habitat use are mediated through food biomass changes, bear tolerance of humans and their impacts, and human tolerance of bears. Large-scale changes in bear food biomass have been caused by conversion of wildlands and waterways to intensive human use, and by the introduction of exotic pathogens. Bears consume virtually all human foods that have been established in former wildlands, but bear use has been limited by access. Air pollution has also affected bear food biomass on a small scale and is likely to have major future impacts on bear habitat through climatic warming. Major changes in disturbance cycles and landscape mosaics wrought by humans have further altered temporal and spatial pulses of bear food production. These changes have brought short-term benefits in places, but have also added long-term stresses to most bear populations. Although bears tend to avoid humans, they will also use exotic and native foods in close proximity to humans. Subadult males and adult females are more often impelled to forage closer to humans because of their energetic predicament and because more secure sites are often preempted by adult males. Although male bears are typically responsible for most livestock predation, adult females and subadult males are more likely to be habituated to humans because they tend to forage closer to humans. Elimination of human-habituated bears predictably reduces effective carrying capacity and is more likely to be a factor in preserving bear populations where humans are present in moderate-to-high densities. If humans desire to preserve viable bear populations, they will either have to accept increased risk of injury associated with preserving habituated animals, or continue to crop habituated bears while at the same time preserving large tracts of wildlands free from significant human intrusion.

  20. Fluid lubricated bearing construction

    DOEpatents

    Dunning, John R.; Boorse, Henry A.; Boeker, Gilbert F.

    1976-01-01

    1. A fluid lubricated thrust bearing assembly comprising, in combination, a first bearing member having a plain bearing surface, a second bearing member having a bearing surface confronting the bearing surface of said first bearing member and provided with at least one spiral groove extending inwardly from the periphery of said second bearing member, one of said bearing members having an axial fluid-tight well, a source of fluid lubricant adjacent to the periphery of said second bearing member, and means for relatively rotating said bearing members to cause said lubricant to be drawn through said groove and to flow between said bearing surfaces, whereby a sufficient pressure is built up between said bearing surfaces and in said well to tend to separate said bearing surfaces.

  1. Fluid Film Bearing Code Development

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The next generation of rocket engine turbopumps is being developed by industry through Government-directed contracts. These turbopumps will use fluid film bearings because they eliminate the life and shaft-speed limitations of rolling-element bearings, increase turbopump design flexibility, and reduce the need for turbopump overhauls and maintenance. The design of the fluid film bearings for these turbopumps, however, requires sophisticated analysis tools to model the complex physical behavior characteristic of fluid film bearings operating at high speeds with low viscosity fluids. State-of-the-art analysis and design tools are being developed at the Texas A&M University under a grant guided by the NASA Lewis Research Center. The latest version of the code, HYDROFLEXT, is a thermohydrodynamic bulk flow analysis with fluid compressibility, full inertia, and fully developed turbulence models. It can predict the static and dynamic force response of rigid and flexible pad hydrodynamic bearings and of rigid and tilting pad hydrostatic bearings. The Texas A&M code is a comprehensive analysis tool, incorporating key fluid phenomenon pertinent to bearings that operate at high speeds with low-viscosity fluids typical of those used in rocket engine turbopumps. Specifically, the energy equation was implemented into the code to enable fluid properties to vary with temperature and pressure. This is particularly important for cryogenic fluids because their properties are sensitive to temperature as well as pressure. As shown in the figure, predicted bearing mass flow rates vary significantly depending on the fluid model used. Because cryogens are semicompressible fluids and the bearing dynamic characteristics are highly sensitive to fluid compressibility, fluid compressibility effects are also modeled. The code contains fluid properties for liquid hydrogen, liquid oxygen, and liquid nitrogen as well as for water and air. Other fluids can be handled by the code provided that the

  2. Permanent Magnetic Bearing for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Morales, Winfredo; Fusaro, Robert; Kascak, Albert

    2008-01-01

    A permanent, totally passive magnetic bearing rig was designed, constructed, and tested. The suspension of the rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm using an air impeller. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

  3. Technical Development Path for Gas Foil Bearings

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher

    2016-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  4. Technical Development Path for Foil Gas Bearings

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher

    2008-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  5. Tables for technical writers

    Treesearch

    E. vH. Larson

    1947-01-01

    Practically every publication we issue contains tables of some sort. Tables offer a convenient way of presenting many kinds of information. And tables are badly abused. There are few places a writer can go to find out how to construct clear, compact, easy-to-read tables, and how to use them.

  6. Data for Figures and Tables in Journal Article Assessment of the Effects of Horizontal Grid Resolution on Long-Term Air Quality Trends using Coupled WRF-CMAQ Simulations, doi:10.1016/j.atmosenv.2016.02.036

    EPA Pesticide Factsheets

    The dataset represents the data depicted in the Figures and Tables of a Journal Manuscript with the following abstract: The objective of this study is to determine the adequacy of using a relatively coarse horizontal resolution (i.e. 36 km) to simulate long-term trends of pollutant concentrations and radiation variables with the coupled WRF-CMAQ model. WRF-CMAQ simulations over the continental United State are performed over the 2001 to 2010 time period at two different horizontal resolutions of 12 and 36 km. Both simulations used the same emission inventory and model configurations. Model results are compared both in space and time to assess the potential weaknesses and strengths of using coarse resolution in long-term air quality applications. The results show that the 36 km and 12 km simulations are comparable in terms of trends analysis for both pollutant concentrations and radiation variables. The advantage of using the coarser 36 km resolution is a significant reduction of computational cost, time and storage requirement which are key considerations when performing multiple years of simulations for trend analysis. However, if such simulations are to be used for local air quality analysis, finer horizontal resolution may be beneficial since it can provide information on local gradients. In particular, divergences between the two simulations are noticeable in urban, complex terrain and coastal regions.This dataset is associated with the following publication

  7. Behaviour of volcanogenic S-bearing compounds (H2S and SO2) in air at Vulcano Island (Aeolian Archipelago, southern Italy)

    NASA Astrophysics Data System (ADS)

    Caponi, Chiara; Tassi, Franco; Ricci, Andrea; Capecchiacci, Francesco; Venturi, Stefania; Cabassi, Jacopo; Vaselli, Orlando

    2017-04-01

    The main sources of SO2 and H2S in air consist of both natural fluid emissions related to active/quiescent volcanoes and hydrothermal systems, and anthropogenic activities (e.g. gas and oil refineries, steel industries, urban traffic). These gas compounds have a strong impact on air quality, since they are strong toxic and climate forcing agents. Notwithstanding, the behaviour of these S-compounds in air once they are released from the contaminant source(s) is poorly known, due to the scarce available data from thermodynamics and direct measurements. Hydrogen sulfide is considered to be relatively reactive in the atmosphere, being easily oxidized to SO2 by photochemical reactions, even though the efficiency of the H2S to SO2 conversion is significantly lowered under dark, dry and relatively cold conditions, leading to a residence time of H2S in air up to 42 days in winter. In this work, H2S and SO2 measurements in air carried out at the Levante beach (Vulcano Island, Aeolian Archipelago), where a number of hydrothermal fluid discharges consisting of fumaroles and submarine emissions occur, are presented and discussed. These volcanic fluids, characterized by an H2S-rich chemical composition, are released in a close proximity to the touristic village of Vulcano Porto. The measurements were carried out using a Thermo Scientific™ Model 450i Analyzer coupled with a Davis® Vantage Vue weather station (air humidity and temperature, wind direction and speed) in 34 fixed spots and along 8 pathways, selected according to: (i) distance from the contaminant source, (ii) wind direction and (iii) accessibility by car (where the instrument was installed). The main aim was to provide empirical insights on the behavior of these air pollutants in relation to the physical and chemical processes controlling their spatial distribution. The measured data were elaborated using a statistical approach to construct spatial distribution maps and conceptual models able to forecast the

  8. KENNEDY SPACE CENTER, FLA. - Employees file around table displays under a tent near the Operations and Checkout Building. Many vendors and organizations displayed their products during the Spaceport Super Safety and Health Day at KSC and Cape Canaveral Air Force Station, an annual event dedicated to reinforcing safe and healthful behaviors in the workforce.

    NASA Image and Video Library

    2003-10-15

    KENNEDY SPACE CENTER, FLA. - Employees file around table displays under a tent near the Operations and Checkout Building. Many vendors and organizations displayed their products during the Spaceport Super Safety and Health Day at KSC and Cape Canaveral Air Force Station, an annual event dedicated to reinforcing safe and healthful behaviors in the workforce.

  9. Wave Journal Bearing. Part 2: Experimental Pressure Measurements and Fractional Frequency Whirl Threshold for Wave and Plain Journal Bearings

    NASA Technical Reports Server (NTRS)

    Walker, James F.; Dimofte, Florin; Addy, Harold E., Jr.

    1995-01-01

    A new hydrodynamic bearing concept, the wave journal bearing, is being developed because it has better stability characteristics than plain journal bearings while maintaining similar load capacity. An analysis code to predict the steady state and dynamic performance of the wave journal bearing is also part of the development. To verify numerical predictions and contrast the wave journal bearing's stability characteristics to a plain journal bearing, tests were conducted at NASA Lewis Research Center using an air bearing test rig. Bearing film pressures were measured at 16 ports located around the bearing circumference at the middle of the bearing length. The pressure measurements for both a plain journal bearing and a wave journal bearing compared favorably with numerical predictions. Both bearings were tested with no radial load to determine the speed threshold for self-excited fractional frequency whirl. The plain journal bearing started to whirl immediately upon shaft start-up. The wave journal did not incur self-excited whirl until 800 to 900 rpm as predicted by the analysis. Furthermore, the wave bearing's geometry limited the whirl orbit to less than the bearing's clearance. In contrast, the plain journal bearing did not limit the whirl orbit, causing it to rub.

  10. 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.

  11. Characterisation of tissue factor-bearing extracellular vesicles with AFM: comparison of air-tapping-mode AFM and liquid Peak Force AFM.

    PubMed

    Hardij, Julie; Cecchet, Francesca; Berquand, Alexandre; Gheldof, Damien; Chatelain, Christian; Mullier, François; Chatelain, Bernard; Dogné, Jean-Michel

    2013-01-01

    Extracellular vesicles (EVs) are shed from cells and carry markers of the parent cells. Vesicles derived from cancer cells reach the bloodstream and locally influence important physiological processes. It has been previously shown that procoagulant vesicles are circulating in patients' fluids. These EVs are therefore considered as promising biomarkers for the thrombotic risk. Because of their small size, classical methods such as flow cytometry suffer from limitation for their characterisation. Atomic force microscopy (AFM) has been proposed as a promising complementary method for the characterisation of EVs. THE OBJECTIVES OF THIS STUDY ARE: (a) to develop and validate AFM with specific antibodies (anti-TF) and (b) to compare air and liquid modes for EVs' size and number determination as potential biomarkers of the prothrombotic risk. AFM multimode nanoscope III was used for air tapping mode (TM). AFM catalyst was used for liquid Peak Force Tapping (PFT) mode. Vesicles are generated according to Davila et al.'s protocol. Substrates are coated with various concentrations of antibodies, thanks to ethanolamine and glutaraldehyde. Vesicles were immobilised on antibody-coated surfaces to select tissue factor (TF)-positive vesicles. The size range of vesicles observed in liquid PFT mode is 6-10 times higher than in air mode. This corresponds to the data found in the literature. We recommend liquid PFT mode to analyse vesicles on 5 µg/ml antibody-coated substrates.

  12. Fatigue life and performance testing of hybrid ceramic ball bearings

    SciTech Connect

    Chiu, Y.P.; Prason, P.K.; Dezzani, M.

    1996-03-01

    Hybrid ceramic ball bearings are finding increased applications in machine tool spindles and aerospace vehicles. Results of three types of testing hybrid ceramic ball bearing are presented and discussed. The first is the classical endurance testing of highly loaded hybrid bearings with good lubrication. The second is the endurance test of hybrid nitrided bearings after running in a contaminated lubricant which caused dented raceways. The third is the high-speed performance testing of spindle bearings lubricated with grease or an oil-air mixture. Recent material development, bearing temperature at high-speed and reliability considerations are discussed. 14 refs., 9 fig., 4 tab.

  13. 32 CFR Table 4 to Part 855 - Parking and Storage Fees

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Parking and Storage Fees 4 Table 4 to Part 855 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 4 Table 4 to Part 855—Parking and Storage Fees...

  14. 32 CFR Table 4 to Part 855 - Parking and Storage Fees

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Parking and Storage Fees 4 Table 4 to Part 855 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 4 Table 4 to Part 855—Parking and Storage Fees...

  15. 32 CFR Table 2 to Part 855 - Aircraft Liability Coverage Requirements

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Aircraft Liability Coverage Requirements 2 Table 2 to Part 855 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 2 Table 2 to Part 855...

  16. 40 CFR Table 10 to Subpart Ffff of... - Work Practice Standards for Heat Exchange Systems

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Exchange Systems 10 Table 10 to Subpart FFFF of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants: Miscellaneous Organic...

  17. Passive magnetic bearing configurations

    DOEpatents

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  18. Restoration of bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.; Zaretsky, E. V.; Hanau, H.

    1977-01-01

    Process consisting of grinding raceways to oversize but original quality condition and installing new oversize balls or bearings restores wornout ball and roller bearings to original quality, thereby doubling their operating life. Evaluations reveal process results in restoration of 90% of replaced bearings at less than 50% of new-bearing costs.

  19. Tabled Execution in Scheme

    SciTech Connect

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  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. Cryogenic foil bearing turbopumps

    NASA Technical Reports Server (NTRS)

    Gu, Alston L.

    1993-01-01

    Cryogenic foil bearing turbopumps offer high reliability and low cost. The fundamental cryogenic foil bearing technology has been validated in both liquid hydrogen and liquid oxygen. High load capacity, excellent rotor dynamics, and negligible bearing wear after over 100 starts and stops, and over many hours of testing, were observed in both fluids. An experimental liquid hydrogen foil bearing turbopump was also successfully demonstrated. The results indicate excellent stability, high reliability, wide throttle-ability, low bearing cooling flow, and two-phase bearing operability. A liquid oxygen foil bearing turbopump has been built and is being tested at NASA MSFC.

  2. Introduction to ball bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    The purpose of a ball bearing is to provide a relative positioning and rotational freedom while transmitting a load between two structures, usually a shaft and a housing. For high rotational speeds (e.g., in gyroscope ball bearings) the purpose can be expanded to include rotational freedom with practically no wear in the bearing. This condition can be achieved by separating the bearing parts with a coherent film of fluid known as an elastohydrodynamic film. This film can be maintained not only when the bearing carries the load on a shaft, but also when the bearing is preloaded to position the shaft to within micro- or nano-inch accuracy and stability. Background information on ball bearings is provided, different types of ball bearings and their geometry and kinematics are defined, bearing materials, manufacturing processes, and separators are discussed. It is assumed, for the purposes of analysis, that the bearing carries no load.

  3. Periodic Table of Students.

    ERIC Educational Resources Information Center

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  4. Periodic Table of Students.

    ERIC Educational Resources Information Center

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  5. High efficiency magnetic bearings

    NASA Technical Reports Server (NTRS)

    Studer, Philip A.; Jayaraman, Chaitanya P.; Anand, Davinder K.; Kirk, James A.

    1993-01-01

    Research activities concerning high efficiency permanent magnet plus electromagnet (PM/EM) pancake magnetic bearings at the University of Maryland are reported. A description of the construction and working of the magnetic bearing is provided. Next, parameters needed to describe the bearing are explained. Then, methods developed for the design and testing of magnetic bearings are summarized. Finally, a new magnetic bearing which allows active torque control in the off axes directions is discussed.

  6. 40 CFR Table 5 to Subpart Lllll of... - Continuous Compliance With Operating Limits a

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Asphalt Processing and Asphalt Roofing Manufacturing Pt. 63, Subpt. LLLLL, Table 5 Table 5 to Subpart LLLLL of Part 63—Continuous...

  7. 40 CFR Table 3 to Subpart Zzzz of... - Subsequent Performance Tests

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Pt. 63, Subpt. ZZZZ, Table 3 Table 3 to Subpart ZZZZ of Part 63—Subsequent...

  8. 40 CFR Table 3 to Subpart Zzzz of... - Subsequent Performance Tests

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Pt. 63, Subpt. ZZZZ, Table 3 Table 3 to Subpart ZZZZ of Part 63—Subsequent...

  9. 40 CFR Table 3 to Subpart Zzzz of... - Subsequent Performance Tests

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Pt. 63, Subpt. ZZZZ, Table 3 Table 3 to Subpart ZZZZ of Part 63—Subsequent...

  10. 40 CFR Table 3 to Subpart Zzzz of... - Subsequent Performance Tests

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Pt. 63, Subpt. ZZZZ, Table 3 Table 3 to Subpart ZZZZ of Part 63—Subsequent...

  11. 40 CFR Table 6 to Subpart Zzzz of... - Continuous Compliance With Emission Limitations and Operating Limitations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Pollutants for Stationary Reciprocating Internal Combustion Engines Pt. 63, Subpt. ZZZZ, Table 6 Table 6 to... maintenance and operation of the engine in a manner consistent with good air pollution control practice...

  12. 40 CFR Table 3 to Subpart Zzzz of... - Subsequent Performance Tests

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Pt. 63, Subpt. ZZZZ, Table 3 Table 3 to Subpart ZZZZ of Part 63—Subsequent...

  13. 40 CFR Table 1 to Subpart Ooo - Exceptions to Applicability of Subpart A to Subpart OOO

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Nonmetallic Mineral Processing Plants Subpt. OOO, Table 1 Table 1 to Subpart OOO—Exceptions...

  14. 40 CFR Table 2 to Subpart Nnnnnn... - Applicability of General Provisions to Subpart NNNNNN

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium Compounds Pt. 63, Subpt. NNNNNN, Table 2 Table 2 to Subpart NNNNNN of...

  15. 40 CFR Table 2 to Subpart Nnnnnn... - Applicability of General Provisions to Subpart NNNNNN

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium Compounds Pt. 63, Subpt. NNNNNN, Table 2 Table 2 to Subpart NNNNNN of...

  16. Hot cell examination table

    DOEpatents

    Gaal, Peter S.; Ebejer, Lino P.; Kareis, James H.; Schlegel, Gary L.

    1991-01-01

    A table for use in a hot cell or similar controlled environment for use in examining specimens. The table has a movable table top that can be moved relative to a table frame. A shaft is fixedly mounted to the frame for axial rotation. A shaft traveler having a plurality of tilted rollers biased against the shaft is connected to the table top such that rotation of the shaft causes the shaft traveler to roll along the shaft. An electromagnetic drive is connected to the shaft and the frame for controllably rotating the shaft.

  17. Mortality table construction

    NASA Astrophysics Data System (ADS)

    Sutawanir

    2015-12-01

    Mortality tables play important role in actuarial studies such as life annuities, premium determination, premium reserve, valuation pension plan, pension funding. Some known mortality tables are CSO mortality table, Indonesian Mortality Table, Bowers mortality table, Japan Mortality table. For actuary applications some tables are constructed with different environment such as single decrement, double decrement, and multiple decrement. There exist two approaches in mortality table construction : mathematics approach and statistical approach. Distribution model and estimation theory are the statistical concepts that are used in mortality table construction. This article aims to discuss the statistical approach in mortality table construction. The distributional assumptions are uniform death distribution (UDD) and constant force (exponential). Moment estimation and maximum likelihood are used to estimate the mortality parameter. Moment estimation methods are easier to manipulate compared to maximum likelihood estimation (mle). However, the complete mortality data are not used in moment estimation method. Maximum likelihood exploited all available information in mortality estimation. Some mle equations are complicated and solved using numerical methods. The article focus on single decrement estimation using moment and maximum likelihood estimation. Some extension to double decrement will introduced. Simple dataset will be used to illustrated the mortality estimation, and mortality table.

  18. Turbocharger with improved roller bearing shaft support

    SciTech Connect

    Gutknecht, D.A.

    1991-10-08

    This paper describes an exhaust gas driven turbocharger. It comprises: a housing, a shaft within the housing having a pair of ends, a compressor wheel mounted within the housing on one end of the shaft for rotation therewith, a turbine wheel mounted within the housing on the other end of the shaft for rotation therewith, means for communicating air through the compressor wheel, means for communicating exhaust gas through the turbine wheel to cause the latter to rotate the shaft and the compressor wheel mounted thereon to compress the air communicated through the compressor wheel, and bearing means mounting the shaft for rotation relative to the housing, the bearing means including a bearing outer ring, a bearing inner ring, and ball bearing elements supporting the bearing outer ring on the bearing inner ring, the ball bearing elements includes a first set of the elements and a second set of the elements spaced axially from the first set, the bearing outer ring being a rigid, uninterrupted member providing an uninterrupted structural link between the first and second sets to establish the axial spacing between the sets, a pair of axially spaced faying surfaces on the inner ring engaging corresponding faying surfaces on the shaft to support the inner ring on the shaft, the shaft defining a circumferentially extending surface between the faying surfaces on the inner ring cooperating with the shaft to define an air gap therebetween, one of the faying surfaces on the inner ring having a diameter greater than the diameter of the other of the faying surfaces on the inner ring.

  19. Microeconomic analysis of military aircraft bearing restoration

    NASA Technical Reports Server (NTRS)

    Hein, G. F.

    1976-01-01

    The risk and cost of a bearing restoration by grinding program was analyzed. A microeconomic impact analysis was performed. The annual cost savings to U.S. Army aviation is approximately $950,000.00 for three engines and three transmissions. The capital value over an indefinite life is approximately ten million dollars. The annual cost savings for U.S. Air Force engines is approximately $313,000.00 with a capital value of approximately 3.1 million dollars. The program will result in the government obtaining bearings at lower costs at equivalent reliability. The bearing industry can recover lost profits during a period of reduced demand and higher costs.

  20. Investigating Science through Bears (and Teddy Bears).

    ERIC Educational Resources Information Center

    Smith, Karlene Ray

    1997-01-01

    Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear…

  1. Investigating Science through Bears (and Teddy Bears).

    ERIC Educational Resources Information Center

    Smith, Karlene Ray

    1997-01-01

    Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear…

  2. 40 CFR Table 7 to Subpart Ppppp of... - Applicability of General Provisions to Subpart PPPPP

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Engine Test Cells/Stands Pt. 63, Subpt. PPPPP, Table 7 Table 7 to Subpart PPPPP of Part 63—Applicability of...

  3. 40 CFR Table 2 to Subpart Nnnnnn... - Applicability of General Provisions to Subpart NNNNNN

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium Compounds Pt. 63, Subpt. NNNNNN, Table 2 Table 2 to Subpart NNNNNN of Part...

  4. 40 CFR Table 2 to Subpart Nnnnnn... - Applicability of General Provisions to Subpart NNNNNN

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium Compounds Pt. 63, Subpt. NNNNNN, Table 2 Table 2 to Subpart NNNNNN of Part...

  5. 40 CFR Table 2 to Subpart Nnnnnn... - Applicability of General Provisions to Subpart NNNNNN

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium Compounds Pt. 63, Subpt. NNNNNN, Table 2 Table 2 to Subpart NNNNNN of Part...

  6. Experiments with needle bearings

    NASA Technical Reports Server (NTRS)

    Ferretti, Pericle

    1933-01-01

    Experiments and results are presented in testing needle bearings, especially in comparison with roller bearings. Reduction in coefficient of friction is discussed as well as experimental methods and recording devices.

  7. Mechanical spin bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1998-01-01

    A spin bearing assembly including, a pair of mutually opposing complementary bearing support members having mutually spaced apart bearing support surfaces which may be, for example, bearing races and a set of spin bearings located therebetween. Each spin bearing includes a pair of end faces, a central rotational axis passing through the end faces, a waist region substantially mid-way between the end faces and having a first thickness dimension, and discrete side surface regions located between the waist region and the end faces and having a second thickness dimension different from the first thickness dimension of the waist region and wherein the side surface regions further have respective curvilinear contact surfaces adapted to provide a plurality of bearing contact points on the bearing support members.

  8. Precision instrumentation for rolling element bearing characterization

    SciTech Connect

    Marsh, Eric R.; Vigliano, Vincent C.; Weiss, Jeffrey R.; Moerlein, Alex W.; Vallance, R. Ryan

    2007-03-15

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings.

  9. Precision instrumentation for rolling element bearing characterization.

    PubMed

    Marsh, Eric R; Vigliano, Vincent C; Weiss, Jeffrey R; Moerlein, Alex W; Vallance, R Ryan

    2007-03-01

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings.

  10. Axial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2008-01-01

    Axial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control.

  11. 40 CFR Appendix to Subpart III of... - Tables: Note

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Tables: Note Appendix to Subpart III of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., Subpt. III, App. Appendix to Subpart III of Part 63—Tables: Note For the convenience of the readers of...

  12. 40 CFR Appendix to Subpart III of... - Tables: Note

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Tables: Note Appendix to Subpart III of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., Subpt. III, App. Appendix to Subpart III of Part 63—Tables: Note For the convenience of the readers of...

  13. 40 CFR Table 1 to Subpart Cccc of... - Emission Limitations

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standards for Hazardous Air Pollutants: Manufacturing of Nutritional Yeast Part 63, Subpt. CCCC, Table 1... emission limitations in the following table: For each fed-batch fermenter producing yeast in the following... limitation does not apply during the production of specialty yeast....

  14. 40 CFR Table 1 to Subpart Cccc of... - Emission Limitations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Standards for Hazardous Air Pollutants: Manufacturing of Nutritional Yeast Part 63, Subpt. CCCC, Table 1... emission limitations in the following table: For each fed-batch fermenter producing yeast in the following... limitation does not apply during the production of specialty yeast....

  15. 40 CFR Table 16 to Subpart G of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false 16 Table 16 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Vents, Storage Vessels, Transfer Operations, and Wastewater Table 16 to Subpart G of Part 63 ...

  16. 40 CFR Table 16 to Subpart G of... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false 16 Table 16 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Vents, Storage Vessels, Transfer Operations, and Wastewater Table 16 to Subpart G of Part 63 ...

  17. 40 CFR Table 16 to Subpart G of... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false 16 Table 16 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Vents, Storage Vessels, Transfer Operations, and Wastewater Table 16 to Subpart G of Part 63 ...

  18. 40 CFR Table 16 to Subpart G of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false 16 Table 16 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Vents, Storage Vessels, Transfer Operations, and Wastewater Table 16 to Subpart G of Part 63 ...

  19. 40 CFR Table 16 to Subpart G of... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false 16 Table 16 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Vents, Storage Vessels, Transfer Operations, and Wastewater Table 16 to Subpart G of Part 63 ...

  20. Table of radioactive elements

    SciTech Connect

    Holden, N.E.

    1985-01-01

    As has been the custom in the past, the Commission publishes a table of relative atomic masses and halflives of selected radionuclides. The information contained in this table will enable the user to calculate the atomic weight for radioactive materials with a variety of isotopic compositions. The atomic masses have been taken from the 1984 Atomic Mass Table. Some of the halflives have already been documented.

  1. 1-Way Bearing

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2003-01-01

    A one-way bearing is provided having sprags and rolling bearings both disposed between an inner and an outer race. The sprags may comprise three-dimensional sprags for preventing rotation in a non-preferential direction. The roll- ing bearings may comprise thrust rollers for transmitting axial, tilt, and radial loads between the inner and outer races.

  2. Supertough Stainless Bearing Steel

    NASA Technical Reports Server (NTRS)

    Olson, Gregory B.

    1995-01-01

    Composition and processing of supertough stainless bearing steel designed with help of computer-aided thermodynamic modeling. Fracture toughness and hardness of steel exceeds those of other bearing steels like 440C stainless bearing steel. Developed for service in fuel and oxidizer turbopumps on Space Shuttle main engine. Because of strength and toughness, also proves useful in other applications like gears and surgical knives.

  3. Cryogenic Hybrid Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  4. Cryogenic Hybrid Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  5. TOPICAL REVIEW: Superconducting bearings

    NASA Astrophysics Data System (ADS)

    Hull, John R.

    2000-02-01

    The physics and technology of superconducting bearings is reviewed. Particular attention is given to the use of high-temperature superconductors (HTSs) in rotating bearings. The basic phenomenology of levitational forces is presented, followed by a brief discussion of the theoretical models that can be used for conceptual understanding and calculations. The merits of various HTS bearing designs are presented, and the behaviour of HTS bearings in typical situations is discussed. The article concludes with a brief survey of various proposed applications for HTS bearings.

  6. The Viability of the Air Mobility Command Pure Pallet Program for US Army Reparable Retrograde Shipments

    DTIC Science & Technology

    2007-03-01

    Level .......................................................................................................101 Customer Satisfaction ...Transportation Service............................................................116 Table 6. Customer Satisfaction -Use of Express Air...117 Table 7. Customer Satisfaction -Level of Satisfaction ..................................................118

  7. The Ratio Table.

    ERIC Educational Resources Information Center

    Middleton, James A.; Heuvel-Panhuizen, Marja van den

    1995-01-01

    Examines the use of a ratio table for developing students' conceptual understanding of rational number. The ratio table is an alternative to cross-multiplication and can utilize both additive and multiplicative strategies. It organizes numbers and keeps track of operations and results, which aids the teacher in assessment. (MLB)

  8. The Living Periodic Table

    ERIC Educational Resources Information Center

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  9. The Living Periodic Table

    ERIC Educational Resources Information Center

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  10. 1992 tubing tables

    SciTech Connect

    Not Available

    1992-01-01

    This paper is helpful to those designing oil well completions or purchasing tubing with proprietary or premium connections. Tables contain specifications and application data for over 100 different tubing joints, including those used with fiberglass pipe. The tables this year contain dimensional and performance data for coiled tubing.

  11. Equations, tables, and charts for compressible flow

    NASA Technical Reports Server (NTRS)

    1953-01-01

    This report, which is a revision and extension of NACA-TN-1428, presents a compilation of equations, tables, and charts useful in the analysis of high-speed flow of a compressible fluid. The equations provide relations for continuous one-dimensional flow, normal and oblique shock waves, and Prandtl-Meyer expansions for both perfect and imperfect gases. The tables present useful dimensionless ratios for continuous one-dimensional flow and for normal shock waves as functions of Mach number for air considered as a perfect gas. One series of charts presents the characteristics of the flow of air (considered a perfect gas) for oblique shock waves and for cones in a supersonic air stream. A second series shows the effects of caloric imperfections on continuous one-dimensional flow and on the flow through normal and oblique shock waves. (author)

  12. Problems with Approximate Bearing Capacity of Gravel Soils

    NASA Astrophysics Data System (ADS)

    Plachý, Jan; Weiss, Viktorie; Bartuška, Ladislav

    2016-10-01

    The publication aims to bring undoubted importance approximate table bearing capacity of gravel soils, which are used in the new constructions. Tabulated values enable to determine the estimated bearing capacity of foundation soil for a simple and inexpensive construction to a depth of 1 meter. In the publication there are compares particular class of gravel soils in depending on the width of the base and ingredients of fine-grained soil. Gravelly soils are the best foundation soil in terms of bearing capacity, but the amount of fine-grained soils or poorly grained gravel, or gravel with a low value of relative density can greatly reduce this value.

  13. Geohydrology of the unsaturated zone and simulated time of arrival of landfill leachate at the water table, municipal solid waste landfill facility, US Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    USGS Publications Warehouse

    Frenzel, Peter F.; Abeyta, Cynthia G.

    1999-01-01

    The U.S. Air Defense Artillery Center and Fort Bliss Municipal Solid Waste Landfill Facility (MSWLF) is located about 10 miles northeast of downtown El Paso, Texas. The landfill is built on the Hueco Bolson, a deposit that yields water to five public-supply wells within 1.1 miles of the landfill boundary on all sides. The bolson deposits consist of lenses and mixtures of sand, clay, silt, gravel, and caliche. The unsaturated zone at the landfill is about 300 feet thick. The Hydrologic Evaluation of Landfill Performance (HELP) and the Multimedia Exposure Assessment Model for Evaluating the Land Disposal of Wastes (MULTIMED) computer models were used to simulate the time of first arrival of landfill leachate at the water table. Site-specific data were collected for model input. At five sites on the landfill cover, hydraulic conductivity was measured by an in situ method; in addition, laboratory values were obtained for porosity, moisture content at field capacity, and moisture content at wilting point. Twenty-seven sediment samples were collected from two adjacent boreholes drilled near the southwest corner of the landfill. Of these, 23 samples were assumed to represent the unsaturated zone beneath the landfill. The core samples were analyzed in the laboratory for various characteristics required for the HELP and MULTIMED models: initial moisture content, dry bulk density, porosity, saturated hydraulic conductivity, moisture retention percentages at various suction values, total organic carbon, and pH. Parameters were calculated for the van Genuchten and Brooks-Corey equations that relate hydraulic conductivity to saturation. A reported recharge value of 0.008 inch per year was estimated on the basis of soil- water chloride concentration. The HELP model was implemented using input values that were based mostly on site-specific data or assumed in a conservative manner. Exceptions were the default values used for waste characteristics. Flow through the landfill was

  14. Grease selection for sealed roll neck bearings

    SciTech Connect

    Schrama, R.C.; Vickerman, R.T.; Bender, C.P.

    1995-09-01

    During the 1990`s, a revolution took place in the steel industry with respect to lubricant usage, maintenance costs and the environment. The 4-row taper roller bearings that are used in rolling mills on the work roll necks have been historically lubricated with grease from a centralized grease system, pre-packed with grease at each roll change, or fed with oil from mist or air-oil system. Steel mills are being forced to reduce lubricant consumption to reduce maintenance costs, decrease the costs for the disposal of sludges created from the spent greases and reduce the amount of sludge that was created. The sealed bearing became an avenue for accomplishing these objectives. The open 4-row taper roller bearing was redesigned to accommodate seals. The bearing was pre-packed with grease and put into service without any grease replenishment for up to 22 months operation time. The selection of the grease to provide optimum operating characteristics for the lubricant and the bearing is one of the critical elements to the success of the bearing design. This paper reviews the critical properties that are necessary in the grease for the lubricant to provide the correct tribological functions in the bearing. This includes wear of the rollers and raceways, seal lip and surface wear, heat generation during rotation and under load, corrosion resistance, resistance to shearing during the working life of the grease and resistance to water contamination.

  15. 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.

  16. Empirical field tables for Michigan.

    Treesearch

    Jerold T. Hahn; Joan M. Stelman

    1984-01-01

    Describes the tables derived from the 1980 Forest Survey of Michigan and presents ways the tables can be used. These tables are broken down according to Michigan's four Forest Survey Units, 14 forest types, and 5 site-index classes.

  17. 40 CFR Table 3 to Subpart Dddd of... - Work Practice Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Work Practice Requirements 3 Table 3 to Subpart DDDD of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS.... DDDD, Table 3 Table 3 to Subpart DDDD of Part 63—Work Practice Requirements For the following process...

  18. 40 CFR Table B-5 to Subpart B of... - Symbols and Abbreviations

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Symbols and Abbreviations B Table B-5 to Subpart B of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Performance Characteristics of Automated Methods for SO2, CO, O3, and NO2 Pt. 53, Subpt. B, Table B-5 Table...

  19. 40 CFR Table B-5 to Subpart B of... - Symbols and Abbreviations

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Symbols and Abbreviations B Table B-5 to Subpart B of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Performance Characteristics of Automated Methods for SO2, CO, O3, and NO2 Pt. 53, Subpt. B, Table B-5 Table...

  20. 40 CFR Table B-5 to Subpart B of... - Symbols and Abbreviations

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Symbols and Abbreviations B Table B-5 to Subpart B of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Performance Characteristics of Automated Methods for SO2, CO, O3, and NO2 Pt. 53, Subpt. B, Table B-5 Table...

  1. 40 CFR Table 5 of Subpart Aaaa to... - Requirements for Stack Tests

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Pt. 60, Subpt. AAAA, Table 5 Table 5 of Subpart AAAA to Part...

  2. 40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart...

  3. 32 CFR Table 2 to Part 855 - Aircraft Liability Coverage Requirements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Aircraft Liability Coverage Requirements 2 Table... AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 2 Table 2 to Part 855—Aircraft Liability Coverage Requirements Aircraft maximum gross takeoff weight(MGTOW) Coverage for...

  4. 32 CFR Table 2 to Part 855 - Aircraft Liability Coverage Requirements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Aircraft Liability Coverage Requirements 2 Table... AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 2 Table 2 to Part 855—Aircraft Liability Coverage Requirements Aircraft maximum gross takeoff weight(MGTOW) Coverage for...

  5. 40 CFR Table 43 to Subpart Uuu of... - Requirements for Reports

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Requirements for Reports 43 Table 43 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Reforming Units, and Sulfur Recovery Units Pt. 63, Subpt. UUU, Table 43 Table 43 to Subpart UUU of Part 63...

  6. 40 CFR Table 2 of Subpart Ec of... - Toxic Equivalency Factors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Toxic Equivalency Factors 2 Table 2 of Subpart Ec of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., Subpt. Ec, Table 2 Table 2 of Subpart Ec of Part 60—Toxic Equivalency Factors Dioxin/furan...

  7. 40 CFR Table 2 of Subpart Ec of... - Toxic Equivalency Factors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Toxic Equivalency Factors 2 Table 2 of Subpart Ec of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., Subpt. Ec, Table 2 Table 2 of Subpart Ec of Part 60—Toxic Equivalency Factors Dioxin/furan...

  8. 32 CFR Table 2 to Part 855 - Aircraft Liability Coverage Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Aircraft Liability Coverage Requirements 2 Table... AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 2 Table 2 to Part 855—Aircraft Liability Coverage Requirements Aircraft maximum gross takeoff weight(MGTOW) Coverage for...

  9. 40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

  10. 40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

  11. 40 CFR Table 6 to Subpart Jj of... - VHAP of Potential Concern

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 10 2011-07-01 2011-07-01 false VHAP of Potential Concern 6 Table 6 to Subpart JJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Wood Furniture Manufacturing Operations Pt. 63, Subpt. JJ, Table 6 Table...

  12. 40 CFR Table 6 to Subpart Jj of... - VHAP of Potential Concern

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 11 2012-07-01 2012-07-01 false VHAP of Potential Concern 6 Table 6 to Subpart JJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Wood Furniture Manufacturing Operations Pt. 63, Subpt. JJ, Table 6 Table...

  13. 40 CFR Table 2 to Subpart Hhh of... - Toxic Equivalency Factors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Toxic Equivalency Factors 2 Table 2 to Subpart HHH of Part 62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS.... 62, Subpt. HHH, Table 2 Table 2 to Subpart HHH of Part 62—Toxic Equivalency Factors...

  14. 40 CFR Table 5 of Subpart Aaaa to... - Requirements for Stack Tests

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Pt. 60, Subpt. AAAA, Table 5 Table 5 of Subpart AAAA to Part...

  15. 40 CFR Table 5 of Subpart Aaaa to... - Requirements for Stack Tests

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Pt. 60, Subpt. AAAA, Table 5 Table 5 of Subpart AAAA to Part...

  16. 32 CFR Table 2 to Part 855 - Aircraft Liability Coverage Requirements

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Aircraft Liability Coverage Requirements 2 Table... AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Pt. 855, Table 2 Table 2 to Part 855—Aircraft Liability Coverage Requirements Aircraft maximum gross takeoff weight (MGTOW) Coverage for Bodily...

  17. 40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart...

  18. 40 CFR Table 29 to Subpart Uuu of... - HAP Emission Limits for Sulfur Recovery Units

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Recovery Units 29 Table 29 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION..., Table 29 Table 29 to Subpart UUU of Part 63—HAP Emission Limits for Sulfur Recovery Units As stated in... ppmv of reduced sulfur compounds calculated as ppmv SO2 (dry basis) at zero percent excess air if...

  19. 40 CFR Table 29 to Subpart Uuu of... - HAP Emission Limits for Sulfur Recovery Units

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Units 29 Table 29 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units Pt. 63, Subpt. UUU, Table 29 Table 29... sulfur compounds calculated as ppmv SO2 (dry basis) at zero percent excess air if you use a...

  20. 40 CFR Table 29 to Subpart Uuu of... - HAP Emission Limits for Sulfur Recovery Units

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Units 29 Table 29 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units Pt. 63, Subpt. UUU, Table 29 Table 29... sulfur compounds calculated as ppmv SO2 (dry basis) at zero percent excess air if you use a...

  1. Bearings: Technology and needs

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1982-01-01

    A brief status report on bearing technology and present and near-term future problems that warrant research support is presented. For rolling element bearings a material with improved fracture toughness, life data in the low Lambda region, a comprehensive failure theory verified by life data and incorporated into dynamic analyses, and an improved corrosion resistant alloy are perceived as important needs. For hydrodynamic bearings better definition of cavitation boundaries and pressure distributions for squeeze film dampers, and geometry optimization for minimum power loss in turbulent film bearings are needed. For gas film bearings, foil bearing geometries that form more nearly optimum film shapes for maximum load capacity, and more effective surface protective coatings for high temperature operation are needed.

  2. 9. LOOKING SOUTH AT BEARING AND LOCKING MECHANISM ON EASTERN ...

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

    9. LOOKING SOUTH AT BEARING AND LOCKING MECHANISM ON EASTERN END OF BASCULE LEAF. - St. Charles Air Line Bridge, Spanning South Branch of Chicago River, north of Sixteenth Street, Chicago, Cook County, IL

  3. 36 CFR 7.80 - Sleeping Bear Dunes National Lakeshore.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.80 Sleeping Bear Dunes National Lakeshore. (a) Powerless flight. The use of devices designed to carry persons through the air in powerless...

  4. Bear Spray Safety Program

    USGS Publications Warehouse

    Blome, C.D.; Kuzniar, R.L.

    2009-01-01

    A bear spray safety program for the U.S. Geological Survey (USGS) was officially initiated by the Firearms Safety Committee to address accident prevention and to promote personnel training in bear spray and its transportation, storage, and use for defense against wild animals. Used as part of a system including firearms, or used alone for those who choose not to carry a firearm, bear spray is recognized as an effective tool that can prevent injury in a wild animal attack.

  5. Comparison of predicted and experimental thermal performance of angular-contact ball bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1984-01-01

    Predicted bearing heat generation and bearing temperature were verified by experimental data for ball bearings over a range of sizes, shaft speeds, and lubricant flow rates. The computer program Shaberth requires, as input, a factor which describes the air-oil mixture in the bearing cavity for calculation of the ball drag contribution to bearing heat generation. An equation for this lubricant percent volume in the bearing cavity was derived and appears to be valid over the range of test conditions including bearing bore sizes from 35 to 167 mm and shaft speeds from 1.0 to 3.0 million DN.

  6. Bearing restoration by grinding

    NASA Technical Reports Server (NTRS)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  7. Linear magnetic bearing

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A linear magnetic bearing system having electromagnetic vernier flux paths in shunt relation with permanent magnets, so that the vernier flux does not traverse the permanent magnet, is described. Novelty is believed to reside in providing a linear magnetic bearing having electromagnetic flux paths that bypass high reluctance permanent magnets. Particular novelty is believed to reside in providing a linear magnetic bearing with a pair of axially spaced elements having electromagnets for establishing vernier x and y axis control. The magnetic bearing system has possible use in connection with a long life reciprocating cryogenic refrigerator that may be used on the space shuttle.

  8. Extending bearing life

    SciTech Connect

    Boyer, D.

    1997-08-01

    Long-term bearing operation cannot be achieved unless proper handling, storage, installation, and maintenance procedures are followed. These factors can shorten--sometimes drastically--expected bearing service life. Failures are generally related to improper lubrication or installation and induced conditions. Most major bearing manufacturers offer technical assistance in inspection, evaluation, and reporting on bearings which have failed in service. Actual percentages associated with each failure category vary, depending on the source, but generally they are 70% from lubrication and installation, 20% from induced factors, and 10% from reaching their fatigue limit or design life. The paper describes lubricant-related failures and procedures for the correct handling, storage, installation, and maintenance.

  9. 40 CFR Table Nn-2 to Subpart Hh of... - Lookup Default Values for Calculation Methodology 2 of This Subpart

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. NN, Table NN-2 Table NN-2 to Subpart HH of Part 98—Lookup Default...

  10. 40 CFR Table Nn-1 to Subpart Hh of... - Default Factors for Calculation Methodology 1 of This Subpart

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. NN, Table NN-1 Table NN-1 to Subpart HH of Part 98—Default Factors...

  11. 40 CFR Table Nn-1 to Subpart Hh of... - Default Factors for Calculation Methodology 1 of This Subpart

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. NN, Table NN-1 Table NN-1 to Subpart HH of Part 98—Default Factors...

  12. 40 CFR Table Nn-2 to Subpart Hh of... - Lookup Default Values for Calculation Methodology 2 of This Subpart

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. NN, Table NN-2 Table NN-2 to Subpart HH of Part 98—Lookup Default...

  13. 40 CFR Table Nn-1 to Subpart Hh of... - Default Factors for Calculation Methodology 1 of This Subpart

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. NN, Table NN-1 Table NN-1 to Subpart HH of Part 98—Default Factors...

  14. 40 CFR Table 6 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Production Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of... monthly period that no cements and solvents were purchased and used at the affected source containing...

  15. 40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 10 Table 10 to Subpart XXXX... each monthly period that no cements and solvents were purchased and used at the affected...

  16. 40 CFR Table 40 to Subpart Uuu of... - Requirements for Installation, Operation, and Maintenance of Continuous Opacity Monitoring...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutants for Petroleum Refineries: Catalytic Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units Pt. 63, Subpt. UUU, Table 40 Table 40...

  17. Setting the Periodic Table.

    ERIC Educational Resources Information Center

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  18. The Periodic Table CD.

    ERIC Educational Resources Information Center

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  19. The Periodic Table CD.

    ERIC Educational Resources Information Center

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  20. Setting the Periodic Table.

    ERIC Educational Resources Information Center

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  1. Building Materials Property Table

    SciTech Connect

    2010-04-16

    This information sheet describes a table of some of the key technical properties of many of the most common building materials taken from ASHRAE Fundamentals - 2001, Moisture Control in Buildings, CMHC, NRC/IRC, IEA Annex 24, and manufacturer data.

  2. Fee Reduction Tables

    EPA Pesticide Factsheets

    Under PRIA 3, refunds for a portion of the registration service fee are provided following the withdrawal of a PRIA covered application and at the request of an applicant. These tables provide the information for each registering division.

  3. Food table on ISS

    NASA Image and Video Library

    2015-04-08

    ISS043E091650 (04/08/2015) --- A view of the food table located in the Russian Zvezda service module on the International Space Station taken by Expedition 43 Flight Engineer Scott Kelly. Assorted food, drink and condiment packets are visible. Kelly tweeted this image along with the comment: ""Looks messy, but it's functional. Our #food table on the @space station. What's for breakfast? #YearInSpace".

  4. Identifying lubricant options for compressor bearing designs

    NASA Astrophysics Data System (ADS)

    Karnaz, J.; Seeton, C.; Dixon, L.

    2017-08-01

    Today’s refrigeration and air conditioning market is not only driven by the environmental aspects of the refrigerants, but also by the energy efficiency and reliability of system operation. Numerous types of compressor designs are used in refrigeration and air conditioning applications which means that different bearings are used; and in some cases, multiple bearing types within a single compressor. Since only one lubricant is used, it is important to try to optimize the lubricant to meet the various demands and requirements for operation. This optimization entails investigating different types of lubricant chemistries, viscosities, and various formulation options. What makes evaluating these options more challenging is the refrigerant which changes the properties of the lubricant delivered to the bearing. Once the lubricant and refrigerant interaction are understood, through various test methods, then work can start on collaborating with compressor engineers on identifying the lubricant chemistry and formulation options. These interaction properties are important to the design engineer to make decisions on the adequacy of the lubricant before compressor tests are started. This paper will discuss the process to evaluate lubricants for various types of compressors and bearing design with focus on what’s needed for current refrigerant trends. In addition, the paper will show how the lubricant chemistry choice can be manipulated through understanding of the bearing design and knowledge of interaction with the refrigerant to maximize performance. Emphasis will be placed on evaluation of synthetic lubricants for both natural and synthetic low GWP refrigerants.

  5. 40 CFR Table 10 to Subpart Sssss... - Requirements for Reports

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Requirements for Reports 10 Table 10 to Subpart SSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  6. 40 CFR Table 10 to Subpart Sssss... - Requirements for Reports

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Requirements for Reports 10 Table 10 to Subpart SSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  7. 40 CFR Table 10 to Subpart Sssss... - Requirements for Reports

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Requirements for Reports 10 Table 10 to Subpart SSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  8. 40 CFR Table 10 to Subpart Sssss... - Requirements for Reports

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Requirements for Reports 10 Table 10 to Subpart SSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  9. 40 CFR Table 10 to Subpart Sssss... - Requirements for Reports

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Requirements for Reports 10 Table 10 to Subpart SSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for...

  10. 40 CFR Table 33 to Subpart G of... - Saturation Factors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Saturation Factors 33 Table 33 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission...

  11. 40 CFR Table 33 to Subpart G of... - Saturation Factors

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Saturation Factors 33 Table 33 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission...

  12. 40 CFR Table 1 to Subpart Mmmmm of... - Emission Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 14 2014-07-01 2014-07-01 false Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication...

  13. 40 CFR Table 1 to Subpart Ssssss... - Emission Limits

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63,...

  14. 40 CFR Table 1 to Subpart Jjjjjj... - Emission Limits

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and...

  15. 40 CFR Table 2 to Subpart Eeee of... - Emission Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Emission Limits 2 Table 2 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Organic Liquids Distribution (Non-Gasoline)...

  16. 40 CFR Table 1 to Subpart Mmmmm of... - Emission Limits

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 14 2012-07-01 2011-07-01 true Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication...

  17. 40 CFR Table 2 to Subpart Eeee of... - Emission Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Emission Limits 2 Table 2 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Organic Liquids Distribution (Non-Gasoline)...

  18. 40 CFR Table 1 to Subpart Jjjjjj... - Emission Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and...

  19. 40 CFR Table 1 to Subpart Mmmmm of... - Emission Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 14 2013-07-01 2013-07-01 false Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication...

  20. 40 CFR Table 1 to Subpart Ssssss... - Emission Limits

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Emission Limits 1 Table 1 to Subpart... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63,...

  1. 40 CFR Table 5 of Subpart Bbbbbbb... - Reporting Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Reporting Requirements 5 Table 5 of Subpart BBBBBBB of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  2. 40 CFR Table 5 of Subpart Bbbbbbb... - Reporting Requirements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Reporting Requirements 5 Table 5 of Subpart BBBBBBB of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  3. 40 CFR Table 5 of Subpart Bbbbbbb... - Reporting Requirements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Reporting Requirements 5 Table 5 of Subpart BBBBBBB of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  4. 40 CFR Table 5 of Subpart Bbbbbbb... - Reporting Requirements

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Reporting Requirements 5 Table 5 of Subpart BBBBBBB of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards...

  5. 40 CFR Table 33 to Subpart G of... - Saturation Factors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Saturation Factors 33 Table 33 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing...

  6. 40 CFR Table 33 to Subpart G of... - Saturation Factors

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Saturation Factors 33 Table 33 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing...

  7. Damper bearing rotordynamics

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1990-01-01

    High side loads reduce the life of the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP) bearings. High stiffness damper seals were recommended to reduce the loads on the pump and turbine end bearings in the HPOTP. The seals designed for use on the pump end are expected to adequately reduce the bearing loads; the predicted performance of the planned turbine end seal is marginal. An alternative to the suggested turbine end seal design is a damper bearing with radial holes from the pressurized center of the turbopump rotor, feeding a smooth land region between two rough-stator/smooth-rotor annular seals. An analysis was prepared to predict the leakage and rotor dynamic coefficients (stiffness, damping, and added mass) of the damper bearing. Governing equations of the seal analysis modified to model the damper bearing; differences between the upstream conditions of the damper bearing and a typical annular seal; prediction of the damper bearing analysis; and assumptions of the analysis which require further investigation are described.

  8. Cylindrical bearing analysis

    NASA Technical Reports Server (NTRS)

    Kleckner, R. J.; Pirvics, J.

    1981-01-01

    Program CYBEAN computes behavior of rolling-element bearings including effects of bearing geometry, shaft misalinement, and temperature. Accurate assessment is possible for various outer-ring and housing configurations. CYBEAN is structured for coordinated execution of modules that perform specific analytical tasks. It is written in FORTRAN IV for use on the UNIVAC 1100/40 computer.

  9. Low cost lobed bearing

    NASA Technical Reports Server (NTRS)

    Schuller, F. T.

    1970-01-01

    Separate sectors for each lobed area of the bearing are assembled into the bearing housing individually and bolted tightly against the housing inside diameter. The center of a grinding wheel and the center of the housing are offset, resulting in the desired inner radius and tilt of the sector.

  10. Passive Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1983-01-01

    Magnetic bearing for limited rotation devices requires no feedback control system to sense and correct shaft position. Passive Magnetic Torsion Bearing requires no power supply and has no rubbing parts. Torsion wire restrains against axial instability. Magnetic flux geometry chosen to assure lateral stability with radial restoring force that maintains alignment.

  11. 40 CFR Table 3 to Subpart X of... - Toxic Equivalency Factors

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Subpart X of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards For Hazardous Air Pollutants From Secondary Lead Smelting Pt. 63, Subpt. X, Table 3 Table 3 to Subpart X of Part 63—Toxic Equivalency Factors Dioxin/furan congener Toxic equivalency factor...

  12. 40 CFR Table 3 to Subpart X of... - Toxic Equivalency Factors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Subpart X of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards For Hazardous Air Pollutants From Secondary Lead Smelting Pt. 63, Subpt. X, Table 3 Table 3 to Subpart X of Part 63—Toxic Equivalency Factors Dioxin/furan congener Toxic equivalency factor...

  13. 40 CFR Table 3 to Subpart X of... - Toxic Equivalency Factors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Subpart X of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards For Hazardous Air Pollutants From Secondary Lead Smelting Pt. 63, Subpt. X, Table 3 Table 3 to Subpart X of Part 63—Toxic Equivalency Factors Dioxin/furan congener Toxicequivalency factor...

  14. 40 CFR Table 2 to Subpart A of... - Applicable Referencing Subpart Provisions

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Applicable Referencing Subpart Provisions 2 Table 2 to Subpart A of Part 65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions Pt. 65, Subpt. A, Table...

  15. Arcturus and the Bears

    NASA Astrophysics Data System (ADS)

    Antonello, E.

    2009-08-01

    Arcturus is the brightest star in Bootes. The ancient Greek name Arktouros means Bear Guard. The star, however, is not close to Ursa Maior (Big She-Bear) and Ursa Minor (Little She-Bear), as the name would suggest. This curious discrepancy could be explained by the star proper motion, assuming the name Bear Guard is a remote cultural heritage. The proper motion analysis could allow us to get an insight also into an ancient myth regarding Ursa Maior. Though we cannot explain scientifically such a myth, some interesting suggestions can be obtained about its possible origin, in the context of the present knowledge of the importance of the cult of the bear both during the Palaeolithic times and for several primitive populations of modern times, as shown by the ethnological studies.

  16. Permeability of stylolite-bearing chalk

    SciTech Connect

    Lind, I.; Nykjaer, O.; Priisholm, S. ); Springer, N.

    1994-11-01

    Permeabilities were measured on core plugs from stylolite-bearing chalk of the Gorm field in the Danish North Sea. Air and liquid permeabilities were measured in directions parallel to and perpendicular to the stylolite surface. Permeability was measured with sleeve pressure equal to in-situ reservoir stress. Permeabilities of plugs with stylolites but without stylolite-associated fractures were equal in the two directions. The permeability is equal to the matrix permeability of non-stylolite-bearing chalk. In contrast, when fractures were associated with the stylolites, permeability was enhanced. The enhancement was most significant in the horizontal direction parallel to the stylolites.

  17. 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.

  18. Touchdown Ball-Bearing System for Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Kingsbury, Edward P.; Price, Robert; Gelotte, Erik; Singer, Herbert B.

    2003-01-01

    The torque-limited touchdown bearing system (TLTBS) is a backup mechanical-bearing system for a high-speed rotary machine in which the rotor shaft is supported by magnetic bearings in steady-state normal operation. The TLTBS provides ball-bearing support to augment or supplant the magnetic bearings during startup, shutdown, or failure of the magnetic bearings. The TLTBS also provides support in the presence of conditions (in particular, rotational acceleration) that make it difficult or impossible to control the magnetic bearings or in which the magnetic bearings are not strong enough (e.g., when the side load against the rotor exceeds the available lateral magnetic force).

  19. Good bearings reduce downtime

    SciTech Connect

    Kinney, J.; Foster, J.

    1982-12-01

    Points out that a poorly maintained $100 bearing can hold up the operation of a $1-million conveyor. Of all the moving parts in a coal conveyor system, few cost less or last longer than anti-friction bearings. Most modern conveyor systems are equipped with 2 types of bearings: troughing idlers, spaced at regular intervals to support the conveyor belt as it travels throughout the system, and the adaptermounted spherical roller bearing pillow blocks that are used in the head, tail, bend and takeup pulleys that drive, alter the direction of, or regulate tension in the belt to allow for repairs or splicing. Explains how pillow blocks should handle radial or axial loads, how to mount bearings correctly, and how rings prevent infiltration. Concludes that by making certain that the proper bearing types are built into the system initially, or used as replacements in case of failures, paying close attention to installation procedures and devoting adequate time to maintenance, conveyor system bearings can provide decades of problem-free service.

  20. HTS magnetic bearings

    NASA Astrophysics Data System (ADS)

    Werfel, Frank N.; Flögel-Delor, Uta; Rothfeld, Rolf; Wippich, Dieter; Riedel, Thomas

    2002-08-01

    Radial HTS magnetic bearings (SMB) up to 200 mm size are developed and tested in prototype fast rotating machines to demonstrate the potential to replace conventional bearings. The individual rotational bearing components HTS and PM, their physical interaction and technology is reviewed. Characterisation experiments are conducted to understand the rotor dynamic behaviour. In terms of unbalance and critical speeds the suspended wheels and rotors compare favourably with conventional bearing devices. The rationale of our present bearing technology lies in the assembling of both low-speed magnetic bearings for centrifugal and wafer processing units up to 20,000 rpm as well as a high-speed optical mirror accelerated to rim speed of more than 500 m/s (174,000 rpm) confirming stable low-drag and low energy operation. Two new-type U shaped semicircle HTS bearings coupled each with a 6 W/80 K cryocooler of the Stirling type allow the contact-free operation of a Si wafer carrier in semiconductor wet processes.

  1. 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.

  2. Magnetically-controlled bearing lubrication

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F.

    1977-01-01

    Proposed magnetic-lubricant ball-bearing assembly has permanently-magnetized bearing retainer fabricated of porous material. Pores of retainer are filled with ferrolubricant. Surface tension causes retainer to deliver sufficient lubricant to nonmagnetic ball bearings.

  3. Ball Bearing Mechanics

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    Load-deflection relationships for different types of elliptical contacts such as those found in a ball bearing are developed. Simplified expressions that allow quick calculations of deformation to be made simply from a knowledge of the applied load, the material properties, and the geometry of the contacting elements are presented. Ball bearings subjected to radial, thrust and combined ball loads are analyzed. A design criterion for fatigue life of ball bearings is developed. The section of a satisfactory lubricant, as well as describing systems that provide a constant flow of lubricant to the contact, is considered.

  4. Vibration Transmission through Bearings with Application to Gearboxes

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    2007-01-01

    Cabin noise has become a major concern to manufacturers and users of helicopters. Gear noise is the largest part of this unwanted sound. The crucial noise path is generally considered to be from the gears through the gear-supporting shafts and bearings into the gearbox case, and from there either through the gearbox mounts or the surrounding air to the helicopter cabin. If the noise, that is, the gear and shaft vibration, can be prevented from traveling through the gearbox bearings, then the noise cannot make its way into the helicopter cabin. Thus the vibration-transmitting properties of bearings are of paramount importance. This paper surveys the literature concerning evaluation of properties for the types of bearings used in helicopter gearboxes. A simple model is proposed to evaluate vibration transmission, using measured or calculated bearing stiffness and damping. Less-commonly used types of gearbox bearings (e.g., fluid film) are evaluated for their potential in reducing vibration transmission.

  5. Ball and Roller Bearings. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The manual provides a subject reference for ball and roller bearings. The following topics are included: (1) bearing nomenclature, (2) bearing uses, (3) bearing capacities, (4) shop area working conditions, (5) bearing removal, (6) bearing cleaning and inspection, (7) bearing replacement, (8) bearing lubrication, (9) bearing installation, (10)…

  6. Arkansas black bear hunter survey

    USGS Publications Warehouse

    Pharris, Larry D.; Clark, Joseph D.

    1987-01-01

    Questionnaires were mailed to black bear (Ursus americanus) hunters in Arkansas following the 1980-84 bear seasons to determine participation, hunter success, and number of bears observed by hunters. Man-days of hunting to harvest a bear ranged from 148 to 671 and hunter success ranged from 0.4% to 2.2%. With the exception of 1980, number of permits issued, man-days of bear hunting, and bears harvested appear affected by hunting permit cost. 

  7. Relative-Motion Sensors and Actuators for Two Optical Tables

    NASA Technical Reports Server (NTRS)

    Gursel, Yekta; McKenney, Elizabeth

    2004-01-01

    Optoelectronic sensors and magnetic actuators have been developed as parts of a system for controlling the relative position and attitude of two massive optical tables that float on separate standard air suspensions that attenuate ground vibrations. In the specific application for which these sensors and actuators were developed, one of the optical tables holds an optical system that mimics distant stars, while the other optical table holds a test article that simulates a spaceborne stellar interferometer that would be used to observe the stars. The control system is designed to suppress relative motion of the tables or, on demand, to impose controlled relative motion between the tables. The control system includes a sensor system that detects relative motion of the tables in six independent degrees of freedom and a drive system that can apply force to the star-simulator table in the six degrees of freedom. The sensor system includes (1) a set of laser heterodyne gauges and (2) a set of four diode lasers on the star-simulator table, each aimed at one of four quadrant photodiodes at nominal corresponding positions on the test-article table. The heterodyne gauges are used to measure relative displacements along the x axis.

  8. Space station wardroom table

    NASA Technical Reports Server (NTRS)

    Cohen, Marc M. (Inventor); Kaplicky, Jan (Inventor); Nixon, David A. (Inventor)

    1989-01-01

    A table top for use in constricted areas has a plurality of support arms abutting at one end to form a hub. The support arms are arranged in equidistant, spaced-apart relation to each other at the ends distal to the hub. A plurality of work surface leaf sections mounted between the support arms are individually pivotable through 360 degrees about their longitudinal axes. The table top additionally has a plurality of distal leaves, each distal leaf being attached to the distal end of one of the arms. The distal leaves are pivotable between an upright position level with the support arms and a stored position below the support arms.

  9. Process for depositing Cr-bearing layer

    DOEpatents

    Ellis, Timothy W.; Lograsso, Thomas A.; Eshelman, Mark A.

    1995-05-09

    A method of applying a Cr-bearing layer to a substrate, comprises introducing an organometallic compound, in vapor or solid powder form entrained in a carrier gas to a plasma of an inductively coupled plasma torch or device to thermally decompose the organometallic compound and contacting the plasma and the substrate to be coated so as to deposit the Cr-bearing layer on the substrate. A metallic Cr, Cr alloy or Cr compound such as chromium oxide, nitride and carbide can be provided on the substrate. Typically, the organometallic compound is introduced to an inductively coupled plasma torch that is disposed in ambient air so to thermally decompose the organometallic compound in the plasma. The plasma is directed at the substrate to deposit the Cr-bearing layer or coating on the substrate.

  10. Process for depositing Cr-bearing layer

    DOEpatents

    Ellis, T.W.; Lograsso, T.A.; Eshelman, M.A.

    1995-05-09

    A method of applying a Cr-bearing layer to a substrate, comprises introducing an organometallic compound, in vapor or solid powder form entrained in a carrier gas to a plasma of an inductively coupled plasma torch or device to thermally decompose the organometallic compound and contacting the plasma and the substrate to be coated so as to deposit the Cr-bearing layer on the substrate. A metallic Cr, Cr alloy or Cr compound such as chromium oxide, nitride and carbide can be provided on the substrate. Typically, the organometallic compound is introduced to an inductively coupled plasma torch that is disposed in ambient air so to thermally decompose the organometallic compound in the plasma. The plasma is directed at the substrate to deposit the Cr-bearing layer or coating on the substrate. 7 figs.

  11. The dynamic characteristics of hydrostatic bearings

    NASA Astrophysics Data System (ADS)

    Pang, Zhicheng; Sun, Jingwu; Zhai, Wenjie; Liu, Qingming; Chi, Wei

    1993-07-01

    Results of a theoretical study of the characteristics of hydrostatic bearings performed in terms of the compressibility of the air-contained oil are presented. A formula for the stability criterion of a hydrostatic bearing system and a dynamic stiffness formula is derived. It is found that, under the sinusoidal load, each of the pressure compensation systems has its own load frequency-film characteristics. The greater that compressible volume, V(oa), of oil, the smaller the dynamic stiffness. V(oa) must be reduced in the design of high-precision hydrostatic bearings. If the load frequency is in the low-stiffness area, the dynamic stiffness is small. Methods to enhance the dynamic stiffness are discussed.

  12. Roller bearing geometry design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Pinkston, B. H. W.

    1976-01-01

    A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

  13. Interference-Fit Life Factors for Roller Bearings

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2009-01-01

    The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner-ring interference fit. Calculations were performed for up to 7 fit classes for each of 10 bearing sizes. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. A method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings. All calculated lives are for zero initial internal clearance. Any reduction in bearing clearance due to interference fit would be compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate, and heavy loads and interference fits ranging from extremely light to extremely heavy for bearing accuracy class RBEC-5 (ISO class 5). Interference fits on the inner ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference-fit life factors for a particular fit. The tightest fit at the high end of the tolerance band produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

  14. Gear bearing drive

    NASA Technical Reports Server (NTRS)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  15. Surface Analysis of Bearings,

    DTIC Science & Technology

    1993-03-31

    standards, applied laser spectroscopy, laser chemistry, laser optoelectronics, phase conjugation and coherent imaging, solar cell physics, battery...of a thrust bearing raceway lubricated with sputter-deposited MoS2 (1 pim thick) after testing and failure, defined as a significant torque rise...200 gim 100 jgm Figure 3. SEM micrographs of a 440C steel thrust bearing raceway lubricated with sputter-deposited MoS2 (1 pum thick) after testing

  16. High speed hybrid bearing comprising a fluid bearing and a rolling bearing convected in series

    NASA Technical Reports Server (NTRS)

    Anderson, W. J. (Inventor)

    1973-01-01

    A description is given of an antifriction bearing and a process by which its fatigue life may be extended. The method involves a rotating shaft supported by a fluid bearing and a rolling element bearing coupled in series. Each bearing turns at a fraction of the rotational speed of the shaft. The fluid bearing is preferably conical, thereby providing thrust and radial load support in a single bearing structure.

  17. Load responsive hydrodynamic bearing

    DOEpatents

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  18. 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.

  19. 40 CFR Table 3 to Subpart G of... - Process Vents-Monitoring, Recordkeeping, and Reporting Requirements for Complying With 98 Weight...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Hazardous Air Pollutants Emissions or a Limit of 20 Parts Per Million by Volume 3 Table 3 to Subpart G of... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 3 Table 3 to... flare are absent—PR. Recapture devices The appropriate monitoring device identified in table 4 when, in...

  20. 40 CFR Table 3 to Subpart G of... - Process Vents-Monitoring, Recordkeeping, and Reporting Requirements for Complying With 98 Weight...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Air Pollutants Emissions or a Limit of 20 Parts Per Million by Volume 3 Table 3 to Subpart G of Part... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 3 Table 3 to... flare are absent—PR. Recapture devices The appropriate monitoring device identified in table 4 when, in...

  1. Conduction and Utilization of Research: The Relationship Between Air Force Nurses’ Attitudes, Levels of Education, and Rank

    DTIC Science & Technology

    1999-05-01

    Respondents 22 Table 5. Highest Level of Non- Nursing Education of the Air Force Nurse Respondents 23 Table 6. Overall Highest Level of Education...Force Rank (Good Attitude vs Bad Attitude 41 Table 13. Air Force Nurse Respondents’ Attitudes by Highest Level of Nursing Education 44 Table 14. Air...Figure 2. Research Experience of Air Force Nurse Respondents by Highest Level of Nursing Education (Excellent, Fair or Poor Experience 38 Figure 3. Air

  2. The Dynamic Force Table

    ERIC Educational Resources Information Center

    Geddes, John B.; Black, Kelly

    2008-01-01

    We examine an experimental apparatus that is used to motivate the connections between the basic properties of vectors, potential functions, systems of nonlinear equations, and Newton's method for nonlinear systems of equations. The apparatus is an adaptation of a force table where we remove the center-pin and allow the center-ring to move freely.…

  3. NEW APPROACHES: Pool table

    NASA Astrophysics Data System (ADS)

    Parry, Malcolm

    1998-05-01

    This article explains a novel way of demonstrating the principle of conservation of energy. This can be difficult to demonstrate in the laboratory, but if students have been convinced of the conservation of momentum, two-dimensional collisions on a pool table may be used.

  4. A Modern Periodic Table.

    ERIC Educational Resources Information Center

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  5. Guide to the Table

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2010

    2010-01-01

    This article presents a table that provides a snapshot of how employment is expected to change in 289 occupations. For each occupation, it shows estimated employment in 2008, the projected numeric change in employment (that is, how many jobs are expected to be gained or lost) over the 2008-18 decade, and the projected percent change in employment…

  6. A Modern Periodic Table.

    ERIC Educational Resources Information Center

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  7. The Aerodynamic Plane Table

    NASA Technical Reports Server (NTRS)

    Zahm, A F

    1924-01-01

    This report gives the description and the use of a specially designed aerodynamic plane table. For the accurate and expeditious geometrical measurement of models in an aerodynamic laboratory, and for miscellaneous truing operations, there is frequent need for a specially equipped plan table. For example, one may have to measure truly to 0.001 inch the offsets of an airfoil at many parts of its surface. Or the offsets of a strut, airship hull, or other carefully formed figure may require exact calipering. Again, a complete airplane model may have to be adjusted for correct incidence at all parts of its surfaces or verified in those parts for conformance to specifications. Such work, if but occasional, may be done on a planing or milling machine; but if frequent, justifies the provision of a special table. For this reason it was found desirable in 1918 to make the table described in this report and to equip it with such gauges and measures as the work should require.

  8. The Dynamic Force Table

    ERIC Educational Resources Information Center

    Geddes, John B.; Black, Kelly

    2008-01-01

    We examine an experimental apparatus that is used to motivate the connections between the basic properties of vectors, potential functions, systems of nonlinear equations, and Newton's method for nonlinear systems of equations. The apparatus is an adaptation of a force table where we remove the center-pin and allow the center-ring to move freely.…

  9. 14. VIEW OF DOWNDRAFT TABLES IN THE SUPER DRY ROOM ...

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

    14. VIEW OF DOWNDRAFT TABLES IN THE SUPER DRY ROOM OF MODULE F. AIR IS DRAWN TOWARD THE DOWNDRAFT TABLE, THROUGH THE MESH-SCREEN WORK SURFACE, AND OUT OF THE BUILDING THROUGH A BANK OF FILTERS. AT THE DOWNDRAFT TABLE, UNCOATED PLUTONIUM PARTS AND OTHER PARTS FROM PREVIOUS GLOVE BOX OPERATIONS WERE ASSEMBLED INTO UNITS THAT COULD BE SAFELY TRANSPORTED, PROCESSED, AND STORED OUTSIDE THE PROTECTION OF A GLOVE BOX. (11/6/73) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  10. Three years of experience with a dissection table ventilation system.

    PubMed

    Martin, W D; Nemitz, J W; Hendley, A; Fisk, R M; Wells, J P

    1995-01-01

    A dissection table ventilation system that draws air across the cadaver and away from the table top was designed to fit the Shandon-Lipshaw AN-52 dissection table. Each U-shaped unit consists of a pair of hollow collection arms that attach to a collecting manifold at one end. During dissection the manifold is coupled to a central ventilation system through a flexible duct. The air from the table ventilation system is exhausted after passing through a heat recovery system. The unit is raised from the table surface during dissection of the body cavities to increase the efficiency of fume/odor removal. Eight hour exposure data for formaldehyde concentrations are presented. Data were collected from detectors positioned at selected levels above the cadaver during dissection, and above a tray on the table top containing a known volume of 4% formaldehyde or the West Virginia School of Osteopathic Medicine embalming fluid under varying airflow conditions. The results demonstrate that the table ventilation system is effective in reducing exposure to formaldehyde in the dissection laboratory.

  11. DEVELOPMENT OF A HYDROSTATIC JOURNAL BEARING WITH SLIT-STEP COMPENSATION

    SciTech Connect

    Hale, L C; Donaldson, R R; Castro, C; Chung, C A; Hopkins, D J

    2006-07-28

    This paper describes the mathematical modeling and initial testing of an oil-hydrostatic bearing that derives compensation from both a central radial slit where fluid enters and stepped clearances near each end. Bearings using either a radial slit or stepped clearances for compensation were well studied over forty years ago by Donaldson. These bearings have smooth bores uninterrupted with multiple recesses around the circumference. The present slit-step bearing achieves the best of both types with somewhat higher hydrostatic stiffness than the slit bearing and fluid shear drag lower than the step bearing. This is apparent in TABLE 1, which compares calculated values of initial (i.e., centered) hydrostatic stiffness for each type. The slit-step bearing is one of several types being studied at Lawrence Livermore National Laboratory for possible use on the Precision Optical Grinder and Lathe (POGAL).

  12. Microeconomic analysis of military aircraft bearing restoration

    NASA Technical Reports Server (NTRS)

    Hein, G. F.

    1976-01-01

    The risk and cost of a bearing restoration by grinding program was analyzed. A microeconomic impact analysis was performed. The annual cost savings to U.S. Army aviation is approximately $950,000.00 for three engines and three transmissions. The capital value over an indefinite life is approximately ten million dollars. The annual cost savings for U.S. Air Force engines are approximately $313,000.00 with a capital value of approximately 3.1 million dollars.

  13. Measuring Micro-Friction Torque in MEMS Gas Bearings.

    PubMed

    Fang, Xudong; Liu, Huan

    2016-05-18

    An in situ measurement of micro-friction torque in MEMS gas bearings, which has been a challenging research topic for years, is realized by a system designed in this paper. In the system, a high accuracy micro-force sensor and an electronically-driven table are designed, fabricated and utilized. With appropriate installation of the sensor and bearings on the table, the engine rotor can be driven to rotate with the sensor using a silicon lever beam. One end of the beam is fixed to the shaft of the gas bearing, while the other end is free and in contact with the sensor probe tip. When the sensor begins to rotate with the table, the beam is pushed by the sensor probe to rotate in the same direction. For the beam, the friction torque from the gas bearing is balanced by the torque induced by pushing force from the sensor probe. Thus, the friction torque can be calculated as a product of the pushing force measured by the sensor and the lever arm, which is defined as the distance from the sensor probe tip to the centerline of the bearing. Experimental results demonstrate the feasibility of this system, with a sensitivity of 1.285 mV/μN·m in a range of 0 to 11.76 μN·m when the lever arm is 20 mm long. The measuring range can be modified by varying the length of the lever arm. Thus, this system has wide potential applications in measuring the micro-friction torque of gas bearings in rotating MEMS machines.

  14. Measuring Micro-Friction Torque in MEMS Gas Bearings

    PubMed Central

    Fang, Xudong; Liu, Huan

    2016-01-01

    An in situ measurement of micro-friction torque in MEMS gas bearings, which has been a challenging research topic for years, is realized by a system designed in this paper. In the system, a high accuracy micro-force sensor and an electronically-driven table are designed, fabricated and utilized. With appropriate installation of the sensor and bearings on the table, the engine rotor can be driven to rotate with the sensor using a silicon lever beam. One end of the beam is fixed to the shaft of the gas bearing, while the other end is free and in contact with the sensor probe tip. When the sensor begins to rotate with the table, the beam is pushed by the sensor probe to rotate in the same direction. For the beam, the friction torque from the gas bearing is balanced by the torque induced by pushing force from the sensor probe. Thus, the friction torque can be calculated as a product of the pushing force measured by the sensor and the lever arm, which is defined as the distance from the sensor probe tip to the centerline of the bearing. Experimental results demonstrate the feasibility of this system, with a sensitivity of 1.285 mV/μN·m in a range of 0 to 11.76 μN·m when the lever arm is 20 mm long. The measuring range can be modified by varying the length of the lever arm. Thus, this system has wide potential applications in measuring the micro-friction torque of gas bearings in rotating MEMS machines. PMID:27213377

  15. Climate Drives Polar Bear Origins

    USDA-ARS?s Scientific Manuscript database

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  16. Watchable Wildlife: The Black Bear

    Treesearch

    Lynn L. Rogers

    1992-01-01

    Black bears are the bears people most often encounter. Black bears live in forests over much of North America, unlike grizzlies that live only in Alaska, northern and western Canada, and the northern Rocky Mountains. This brochure presents the latest information on black bear life and how this species responds to an ever-increasing number of campers, hikers, and...

  17. Measured force/current relations in solid magnetic thrust bearings

    SciTech Connect

    Allaire, P.E.; Fittro, R.L.; Maslen, E.H.; Wakefield, W.C.

    1997-01-01

    When magnetic bearings are employed in a pump, compressor, turbine, or other rotating machine, measurement of the current in the bearing coils provides knowledge of the forces imposed on the bearings. This can be a significant indicator of machine problems. Additionally, magnetic bearings can be utilized as a load cell for measuring impeller forces in test rigs. The forces supported by magnetic bearings are directly related to the currents, air gaps, and other parameters in the bearings. This paper discusses the current/force relation for magnetic thrust bearings. Force versus current measurements were made on a particular magnetic bearing in a test rig as the bearing coil currents were cycled at various time rates of change.d the quasi-static force versus current relations were measured for a variety of air gaps and currents. The thrust bearing exhibits a hysteresis effect, which creates a significant difference between the measured force when the current is increasing as compared to that when the current is decreasing. For design current loops, 0.95 A to 2.55 A, at the time rate of change of 0.1 A/s, the difference between increasing and decreasing current curves due to hysteresis ranged from 4 to 8%. If the bearing is operated in small trajectories about a fixed (nonzero) operation point on the F/I (force/current) curve, the scatter in the measurement error could be expected to be on the order of 4%. A quasi-static nonlinear current/force equation was developed to model the data and curve-fit parameters established for the measured data. The effects of coercive force and iron reluctance, obtained from conventional magnetic materials tests, were included to improve the model, but theoretically calculated values from simple magnetic circuit theory do not produce accurate results. Magnetic fringing, leakage, and other effects must be included.

  18. Rolling-element bearings. [contact sliding friction study of solid bodies

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1980-01-01

    In contrast to hydrodynamic bearings, which depend for low-friction characteristics on a fluid film between the journal and the bearing surfaces, roller-element bearings employ a number of balls or rollers that roll in an annular space. The paper briefly outlines the advantages and disadvantages of roller-element bearings as compared to hydrodynamic bearings. The discussion covers bearing types, rolling friction, friction losses in rolling bearings, contact stresses, deformations, kinematics (normal and high speeds), bearing dynamics including elastohydrodynamics, load distribution, lubrication (grease, solid oil, oil-air mist), specific dynamic capacity and life, specific static capacity, and fatigue or wearout (elastohydrodynamics, wear). Rolling bearing wear factor as a function of operating environment is plotted and discussed.

  19. Rolling-element bearings. [contact sliding friction study of solid bodies

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1980-01-01

    In contrast to hydrodynamic bearings, which depend for low-friction characteristics on a fluid film between the journal and the bearing surfaces, roller-element bearings employ a number of balls or rollers that roll in an annular space. The paper briefly outlines the advantages and disadvantages of roller-element bearings as compared to hydrodynamic bearings. The discussion covers bearing types, rolling friction, friction losses in rolling bearings, contact stresses, deformations, kinematics (normal and high speeds), bearing dynamics including elastohydrodynamics, load distribution, lubrication (grease, solid oil, oil-air mist), specific dynamic capacity and life, specific static capacity, and fatigue or wearout (elastohydrodynamics, wear). Rolling bearing wear factor as a function of operating environment is plotted and discussed.

  20. Fault tolerant magnetic bearings

    SciTech Connect

    Maslen, E.H.; Sortore, C.K.; Gillies, G.T.; Williams, R.D.; Fedigan, S.J.; Aimone, R.J.

    1999-07-01

    A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

  1. Fluid lubricated bearing assembly

    DOEpatents

    Boorse, Henry A.; Boeker, Gilbert F.; Menke, John R.

    1976-01-01

    1. A support for a loaded rotatable shaft comprising in combination on a housing having a fluid-tight cavity encasing an end portion of said shaft, a thrust bearing near the open end of said cavity for supporting the axial thrust of said shaft, said thrust bearing comprising a thrust plate mounted in said housing and a thrust collar mounted on said shaft, said thrust plate having a central opening the peripheral portion of which is hermetically sealed to said housing at the open end of said cavity, and means for supplying a fluid lubricant to said thrust bearing, said thrust bearing having a lubricant-conducting path connecting said lubricant supplying means with the space between said thrust plate and collar intermediate the peripheries thereof, the surfaces of said plate and collar being constructed and arranged to inhibit radial flow of lubricant and, on rotation of said thrust collar, to draw lubricant through said path between the bearing surfaces and to increase the pressure therebetween and in said cavity and thereby exert a supporting force on said end portion of said shaft.

  2. Tribology of alternative bearings.

    PubMed

    Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

    2006-12-01

    The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

  3. Polar bear management in Alaska 1997-2000

    USGS Publications Warehouse

    Schliebe, Scott L.; Bridges, John W.; Evans, Thomas J.; Fischbach, Anthony S.; Kalxdorff, Susanne B.; Lierheimer, Lisa J.; Lunn, Nicholas J.; Schliebe, Scott L.; Born, Erik W.; Lunn, Nicholas J.; Schliebe, Scott L.; Born, Erik W.

    2002-01-01

    Since the Twelfth Working Meeting of the IUCN/SSC Polar Bear Specialist Group in 1997, a number of changes in the management of polar bears have occurred in Alaska. On October 16, 2000, the governments of the United States and the Russian Federation signed the “Agreement on the Conservation and Management of the Alaska-Chukotka Polar Bear Population.” This agreement provides substantial benefits for the effective conservation of polar bears shared between the U.S. and Russia. It will require enactment of enabling legislation by the U.S. Congress and other steps by Russia before the agreement has the force of law. A copy of the agreement is included as Appendix 1 to this report. Also, during this period, regulations were developed to implement 1994 amendments to the Marine Mammal Protection Act (MMPA), which allow polar bear trophies taken in approved Canadian populations by U.S. citizens to be imported into the U.S. A summary of the regulatory actions and a table listing populations approved for importation and the number of polar bears imported into the U.S. since 1997 is included in this report. Regarding oil and gas activities in polar bear habitat, three sets of regulations were published authorizing the incidental, non-intentional, taking of small numbers of polar bears concurrent to oil and gas activities.Cooperation continued with the Alaska Nanuuq Commission, representing the polar bear hunting communities in Alaska, as well as with the North Slope Borough and the Inuvialuit Game Council in their agreement for the management of the Southern Beaufort Sea polar bear population. Harvest summaries and technical assistance in designing and assistance in conducting a National Park Service/Alaska Nanuuq Commission study to collect traditional ecological knowledge of polar bear habitat use in Chukotka were provided. In addition, a long-range plan was developed to address and minimize polar bear-human conflicts in North Slope communities.We continued to monitor

  4. Radial Clearance of Antifriction Bearings,

    DTIC Science & Technology

    The article concerns in detail the radial clearance of different antifriction bearings which belong to important parameters which influence the...longevity of the bearing to a certain extent. The effect of the influence of assembly and the wear on the radial clearance of different bearings, the...antifriction bearings operate and their respect in clearance and assembly can contribute substantially to decreasing the daily disproportionate bearing consumption for the repair and maintenance of different machines. (Author)

  5. 40 CFR Table 4 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the Source...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Foam Production Affected Sources Complying With the Source-Wide Emission Limitation 4 Table 4 to... Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 4 Table 4 to Subpart III of Part 63—Compliance Requirements for Slabstock Foam Production Affected...

  6. 40 CFR Table 6 to Subpart Ppp of... - Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Operations-Monitoring, Recordkeeping, and Reporting Requirements 6 Table 6 to Subpart PPP of Part 63... Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production Pt. 63, Subpt. PPP, Table 6 Table 6 to Subpart PPP of Part 63—Process Vents From Continuous Unit Operations—Monitoring...

  7. 40 CFR Table 7 to Subpart G of... - Transfer Operations-Monitoring, Recordkeeping, and Reporting Requirements for Complying With 98...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Hazardous Air Pollutants Emissions or a Limit of 20 Parts Per Million by Volume 7 Table 7 to Subpart G of... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 7 Table 7 to... recorded instead of the daily average. f The periodic reports shall include the duration of periods when...

  8. 40 CFR Table 6 to Subpart Aaaaa of... - Periodic Monitoring for Compliance With Opacity and Visible Emissions Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 14 2013-07-01 2013-07-01 false Periodic Monitoring for Compliance With Opacity and Visible Emissions Limits 6 Table 6 to Subpart AAAAA of Part 63 Protection of... Hazardous Air Pollutants for Lime Manufacturing Plants Pt. 63, Subpt. AAAAA, Table 6 Table 6 to Subpart...

  9. 40 CFR Table 7 to Subpart G of... - Transfer Operations-Monitoring, Recordkeeping, and Reporting Requirements for Complying With 98...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Hazardous Air Pollutants Emissions or a Limit of 20 Parts Per Million by Volume 7 Table 7 to Subpart G of... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 7 Table 7 to... recorded instead of the daily average. f The periodic reports shall include the duration of periods when...

  10. 40 CFR Table 1 to Subpart Ccccccc... - Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Paints and Allied Products Manufacturing Area Sources 1 Table 1 to Subpart CCCCCCC of Part 63 Protection... Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing Pt. 63, Subpt. CCCCCCC, Table 1 Table 1 to Subpart CCCCCCC of Part 63—Applicability of General Provisions to Paints and...

  11. 40 CFR Table 1 to Subpart Ccccccc... - Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Paints and Allied Products Manufacturing Area Sources 1 Table 1 to Subpart CCCCCCC of Part 63 Protection... Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing Pt. 63, Subpt. CCCCCCC, Table 1 Table 1 to Subpart CCCCCCC of Part 63—Applicability of General Provisions to Paints and...

  12. 40 CFR Table 1 to Subpart Ccccccc... - Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Paints and Allied Products Manufacturing Area Sources 1 Table 1 to Subpart CCCCCCC of Part 63 Protection... Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing Pt. 63, Subpt. CCCCCCC, Table 1 Table 1 to Subpart CCCCCCC of Part 63—Applicability of General Provisions to Paints and...

  13. 40 CFR Table 1 to Subpart Ccccccc... - Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Paints and Allied Products Manufacturing Area Sources 1 Table 1 to Subpart CCCCCCC of Part 63 Protection... Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing Pt. 63, Subpt. CCCCCCC, Table 1 Table 1 to Subpart CCCCCCC of Part 63—Applicability of General Provisions to Paints and...

  14. 40 CFR Table 1 to Subpart Ccccccc... - Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Paints and Allied Products Manufacturing Area Sources 1 Table 1 to Subpart CCCCCCC of Part 63 Protection... Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing Pt. 63, Subpt. CCCCCCC, Table 1 Table 1 to Subpart CCCCCCC of Part 63—Applicability of General Provisions to Paints and...

  15. 40 CFR Table 2-to Subpart Xxxxxx... - Applicability of General Provisions to Metal Fabrication or Finishing Area Sources

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Metal Fabrication or Finishing Area Sources 2 Table 2-to Subpart XXXXXX of Part 63 Protection of... Hazardous Air Pollutants Area Source Standards for Nine Metal Fabrication and Finishing Source Categories..., Table 2 Table 2—to Subpart XXXXXX of Part 63—Applicability of General Provisions to Metal Fabrication...

  16. 40 CFR Table 7 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Limits for Tire Cord Production Affected Sources 7 Table 7 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 7 Table 7 to Subpart XXXX of Part 63—Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources As stated...

  17. 40 CFR Table 6 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Production Affected Sources

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial Compliance With the Emission Limits for Tire Production Affected Sources As stated in...

  18. 40 CFR Table 12 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Emission Limits for Tire Cord Production Affected Sources 12 Table 12 to Subpart XXXX of Part 63 Protection... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 12 Table 12 to Subpart XXXX of Part 63—Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources...

  19. 40 CFR Table 12 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Emission Limits for Tire Cord Production Affected Sources 12 Table 12 to Subpart XXXX of Part 63 Protection... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 12 Table 12 to Subpart XXXX of Part 63—Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources...

  20. 40 CFR Table 7 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Limits for Tire Cord Production Affected Sources 7 Table 7 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 7 Table 7 to Subpart XXXX of Part 63—Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources As stated...

  1. 40 CFR Table 3 to Subpart Llll of... - Operating Parameters for New Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Sludge Incineration Units a 3 Table 3 to Subpart LLLL of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for New Sewage Sludge Incineration Units Pt. 60, Subpt. LLLL, Table 3 Table 3...

  2. 40 CFR Table 3 to Subpart Llll of... - Operating Parameters for New Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Sludge Incineration Units a 3 Table 3 to Subpart LLLL of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for New Sewage Sludge Incineration Units Pt. 60, Subpt. LLLL, Table 3 Table 3...

  3. 40 CFR Table 7 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Limits for Tire Cord Production Affected Sources 7 Table 7 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 7 Table 7 to Subpart XXXX of Part 63—Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources As stated...

  4. 40 CFR Table 12 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Limits for Tire Cord Production Affected Sources 12 Table 12 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 12 Table 12 to Subpart XXXX of Part 63—Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources...

  5. 40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Limits for Tire Production Affected Sources 10 Table 10 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 10 Table 10 to Subpart XXXX of Part 63—Continuous Compliance With the Emission Limits for Tire Production Affected Sources As...

  6. 40 CFR Table 6 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Production Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of... Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial Compliance With the Emission Limits for Tire Production Affected Sources As stated in...

  7. Radial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2009-01-01

    Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Radial Halbach magnetic bearings are based on the same principle as that of axial Halbach magnetic bearings, differing in geometry as the names of these two types of bearings suggest. Both radial and axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control. Axial Halbach magnetic bearings were described in Axial Halbach Magnetic Bearings (LEW-18066-1), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 85. In the remainder of this article, the description of the principle of operation from the cited prior article is recapitulated and updated to incorporate the present radial geometry. In simplest terms, the basic principle of levitation in an axial or radial Halbach magnetic bearing is that of the repulsive electromagnetic force between (1) a moving permanent magnet and (2) an electric current induced in a stationary electrical conductor by the motion of the magnetic field. An axial or radial Halbach bearing includes multiple permanent magnets arranged in a Halbach array ("Halbach array" is defined below) in a rotor and multiple conductors in the form of wire coils in a stator, all arranged so the rotary motion produces an axial or radial repulsion that is sufficient to levitate the rotor. A basic Halbach array (see Figure 1) consists of a row of permanent magnets, each oriented so that its magnetic field is at a right angle to that of the adjacent magnet, and the right-angle turns are sequenced so as to maximize the magnitude of the magnetic flux density on one side of the row while

  8. Turbogear bearing analysis

    SciTech Connect

    Cassolato, B.M.

    1997-04-01

    To optimize process energy efficiency, many plants are considering variable-speed electric motor drives with speed-increasing gears for centrifugal compressors. Variable-speed systems are much more complex than fixed-speed systems, especially when power and speed change independently across the compressor performance map, for example, from start-of-run to end-of-run. There are more mechanical design issues that impact reliable operation. Bearing analysis of turbogears subjected to these conditions is an important consideration. Many turbomachines have a simple bearing load characteristic comprised principally of the rotating assembly weight. Helical gear loads are more complex because of the influence of tooth geometry and torque magnitude. A force analysis is required to define parameters for a meaningful rotordynamic study, and evaluate tooth integrity and bearing performance.

  9. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  10. Solving bearing overheating problems

    SciTech Connect

    Jendzurski, T.

    1995-05-08

    Overheating is a major indicator, along with vibration and noise, of an underlying problem affecting a bearing or related components. Because normal operating temperatures vary widely from one application to another, no single temperature is a reliable sign of overheating in every situation. By observing an application when it is running smoothly, a technician can establish a benchmark temperature for a particular bearing arrangement. Wide deviations from this accepted norm generally indicate troublesome overheating. The list of possible causes of over-heating ranges from out-of-round housings and oversize shaft diameters to excessive lubrication and bearing preloading. These causes fall into two major categories: improper or faulty lubrication and mechanical problems, such as incorrect fits and tolerances. These are discussed along with solutions.

  11. Taper tables for western hemlock.

    Treesearch

    Floyd A. Johnson; Wilbur. Engstrom

    1949-01-01

    In 1947 the West Coast Forestry procedures Committee recommended several mensuration projects, one of which called for the construction of taper tables for Western hemlock. In response the present tables were prepared. Basic data for these tables consist of measurements of 912 trees taken a number of years ago by members of the Pacific Northwest Forest & Range...

  12. Large deflection analysis of a tension-foil bearing

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1996-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are as follows: rolling or sliding contact within the bearing has life-limiting consequences; and REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's. CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contacts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exist for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. Recently, a new tension-foil bearing configuration has been proposed for turbomachinery applications.

  13. Modular gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  14. Pyrolysis of Table Sugar

    PubMed Central

    Karagöz, Selhan

    2013-01-01

    Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52 wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance (1H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro-α-d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C. PMID:24223500

  15. Pyrolysis of table sugar.

    PubMed

    Bulut, Adnan; Karagöz, Selhan

    2013-01-01

    Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52 wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance ((1)H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro- α -d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C.

  16. League tables for orthodontists

    PubMed Central

    Richmond, Stephen; Phillips, Ceri; Durning, Peter

    2008-01-01

    The aim of this study was to explore the complexities in constructing league tables purporting to measure orthodontic clinical outcomes. Eighteen orthodontists were invited to participate in a cost-effectiveness study. Each orthodontist was asked to provide information on 100 consecutively treated patients. The Index of Complexity, Outcome, and Need (ICON) was used to assess treatment need, complexity, and outcome prior to, and on completion of, orthodontic treatment. The 18 orthodontists were ranked based on achieving a successful orthodontic outcome (ICON score less than or equal to 30) and the uncertainty in both the success rates and rankings was also quantified using confidence intervals. Successful outcomes were achieved in 62 per cent of the sample (range 19–94 per cent); four of the 18 orthodontists failed to achieve more than a 50 per cent success rate. In developing league tables, it is imperative that factors such as case mix are identified and accounted for in producing rankings. Bayesian hierarchical modelling was used to achieve this and to quantify uncertainty in the rankings produced. When case mix was taken into account, the four with low success rates were clearly not as good as the top four performing orthodontists. League tables can be valuable for the individual orthodontist, groups of orthodontists, payment/insurance agencies, and the public to enable informed choice for orthodontic provision but must be correctly constructed so that users can have confidence in them. PMID:18687990

  17. Design and Analysis of an Electromagnetic Thrust Bearing

    NASA Technical Reports Server (NTRS)

    Banerjee, Bibhuti; Rao, Dantam K.

    1996-01-01

    A double-acting electromagnetic thrust bearing is normally used to counter the axial loads in many rotating machines that employ magnetic bearings. It essentially consists of an actuator and drive electronics. Existing thrust bearing design programs are based on several assumptions. These assumptions, however, are often violated in practice. For example, no distinction is made between maximum external loads and maximum bearing forces, which are assumed to be identical. Furthermore, it is assumed that the maximum flux density in the air gap occurs at the nominal gap position of the thrust runner. The purpose of this paper is to present a clear theoretical basis for the design of the electromagnetic thrust bearing which obviates such assumptions.

  18. Active Control of Fan Noise in Ducts Using Magnetic Bearings

    DTIC Science & Technology

    2007-11-02

    of magnetic bearings. An axial flow fan creates tonal noise related to its rotational rate. Additional noise exists due to harmonics of this frequency...magnetic bearings. An axial flow fan creates tonal noise related to its rotational rate. Additional noise exists due to harmonics of this frequency as well...systems typically have fans that will move air from the heating or cooling system to any desired space. Fan noise is characterized first by tonal

  19. Kepler Certified False Positive Table

    NASA Technical Reports Server (NTRS)

    Bryson, Stephen T.; Batalha, Natalie Marie; Colon, Knicole Dawn; Coughlin, Jeffrey Langer; Haas, Michael R.; Henze, Chris; Huber, Daniel; Morton, Tim; Rowe, Jason Frank; Mullally, Susan Elizabeth; hide

    2017-01-01

    This document describes the Kepler Certied False Positive table hosted at the Exoplanet Archive1, herein referred to as the CFP table. This table is the result of detailed examination by the Kepler False Positive Working Group (FPWG) of declared false positives in the Kepler Object of Interest (KOI) tables (see, for example, Batalha et al. (2012); Burke et al.(2014); Rowe et al. (2015); Mullally et al. (2015); Coughlin et al. (2015b)) at the Exoplanet Archive. A KOI is considered a false positive if it is not due to a planet orbiting the KOI's target star. The CFP table contains all KOIs in the Exoplanet Archive cumulative KOI table. The purpose of the CFP table is to provide a list of certified false positive KOIs. A KOI is certified as a false positive when, in the judgement of the FPWG, there is no plausible planetary interpretation of the observational evidence, which we summarize by saying that the evidence for a false positive is compelling. This certification process involves detailed examination using all available data for each KOI, establishing a high-reliability ground truth set. The CFP table can be used to estimate the reliability of, for example, the KOI tables which are created using only Kepler photometric data, so the disposition of individual KOIs may differ in the KOI and CFP tables. Follow-up observers may find the CFP table useful to avoid observing false positives.

  20. Improvement of the Corrosion Resistance of Turbine Engine Bearings

    DTIC Science & Technology

    1984-02-01

    also explored. A galvanic cell could greatly increase the rate ol corrosion. It consists of two dissimilar metals immersed in a conductive solution. To...are more significant contributors to the water content of the oil than the water washing procedure (Table 3). 4. Galvanic Cell Tests Galvanic...and water contamination of preservatives and oils, all of the elements required for galvanic corrosion are present. In a bearing, a local galvanic

  1. Hybrid superconductor magnet bearings

    SciTech Connect

    Chu, W.

    1995-04-01

    Hybrid superconductor magnet bearings (HSMB`s) utilize high temperature superconductors (HTS`s) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS`s, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, the authors present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  2. Composite Bear Canister

    NASA Technical Reports Server (NTRS)

    Chung, W. Richard; Jara, Steve; Suffel, Susan

    2003-01-01

    To many national park campers and mountain climbers saving their foods in a safe and unbreakable storage container without worrying being attacked by a bear is a challenging task. In some parks, the park rangers have mandated that park visitors rent a bear canister for their food storage. Commercially available bear canisters are made of ABS plastic, weigh 2.8 pounds, and have a 180 cubic inch capacity for food storage. A new design with similar capacity was conducted in this study to reduce its weight and make it a stiffer and stronger canister. Two prototypes incorporating carbon prepreg with and without honeycomb constructions were manufactured using hand lay-up and vacuum bag forming techniques. A 6061-T6-aluminum ring was machined to dimensions in order to reinforce the opening area of the canister. Physical properties (weight and volume) along with mechanical properties (flexural strength and specific allowable moment) of the newly fabricated canisters are compared against the commercial ones. The composite canister weighs only 56% of the ABS one can withstand 9 times of the force greater. The advantages and limitations of using composite bear canisters will be discussed in the presentation.

  3. 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.

  4. The Teddy Bears' Disc.

    ERIC Educational Resources Information Center

    Laurillard, Diana

    1985-01-01

    Reports an evaluation of the Teddy Bear disc, an interactive videodisc developed at the Open University for a second-level course in metallurgy and materials technology. Findings from observation of students utilizing the videodisc are reviewed; successful design features and design problems are considered; and development costs are outlined. (MBR)

  5. Hybrid superconductor magnet bearings

    NASA Astrophysics Data System (ADS)

    Chu, Wei-Kan

    1995-04-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  6. Magnetically leviated superconducting bearing

    DOEpatents

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  7. Bearings Incorporating Deadband Rollers

    NASA Technical Reports Server (NTRS)

    Gualtieri, Guy V.

    1996-01-01

    Bearings in high-pressure turbopump redesigned to incorporate rollers allowing limited axial motion within small deadband. Does not permit radial deadband motion. Axial deadband motion used for rotor-thrust-balance control. Design eliminates some nonlinearities in dynamics of pump rotor and assists in suppressing vibrations at harmonics of frequency of rotation.

  8. Hybrid superconductor magnet bearings

    NASA Technical Reports Server (NTRS)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  9. Teddy bear clinic.

    PubMed

    Creedon, C M

    1989-02-01

    1. The Shriners Institute in Boston developed a day to educate children about hospitals and the OR environment. 2. OR nurses have instituted extensive procedures and policies to allow potential patients the information they need to know their rights. 3. The most important instruction was for the children to ask those questions that they thought their teddy bears might ask.

  10. The Teddy Bears' Disc.

    ERIC Educational Resources Information Center

    Laurillard, Diana

    1985-01-01

    Reports an evaluation of the Teddy Bear disc, an interactive videodisc developed at the Open University for a second-level course in metallurgy and materials technology. Findings from observation of students utilizing the videodisc are reviewed; successful design features and design problems are considered; and development costs are outlined. (MBR)

  11. Optimal Synchronizability of Bearings

    NASA Astrophysics Data System (ADS)

    Araújo, N. A. M.; Seybold, H.; Baram, R. M.; Herrmann, H. J.; Andrade, J. S., Jr.

    2013-02-01

    Bearings are mechanical dissipative systems that, when perturbed, relax toward a synchronized (bearing) state. Here we find that bearings can be perceived as physical realizations of complex networks of oscillators with asymmetrically weighted couplings. Accordingly, these networks can exhibit optimal synchronization properties through fine-tuning of the local interaction strength as a function of node degree [Motter, Zhou, and Kurths, Phys. Rev. E 71, 016116 (2005)PLEEE81539-3755]. We show that, in analogy, the synchronizability of bearings can be maximized by counterbalancing the number of contacts and the inertia of their constituting rotor disks through the mass-radius relation, m˜rα, with an optimal exponent α=α× which converges to unity for a large number of rotors. Under this condition, and regardless of the presence of a long-tailed distribution of disk radii composing the mechanical system, the average participation per disk is maximized and the energy dissipation rate is homogeneously distributed among elementary rotors.

  12. Magnetic Bearings For Turbopumps

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Mendez, Antonio J.

    1995-01-01

    Report presents study of feasibility of magnetic bearings in turbopumps. Liquid-oxygen turbopump in space shuttle main engine selected for study. Other potential applications include manned and unmanned spacecraft, gas turbines for commercial and military aircraft, turbomachinery for petro-chemical and gas operations, suspension systems for precise machinery, and precise pointing and tracking systems.

  13. Hybrid superconductor magnet bearings

    NASA Technical Reports Server (NTRS)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  14. Prototype ventricular assist device supported on magnetic bearings

    SciTech Connect

    Allaire, P.E.; Maslen, E.H.; Kim, H.C.; Olsen, D.B.; Bearnson, G.D.

    1995-12-31

    Mechanical artificial hearts are now expected to be used as assist or total replacements for failing human hearts, if a reliable, anatomically appropriate design is developed. Initially, ventricular assist or total replacement devices were pulsatile air driven units containing a flexing polymeric diaphragm and two valves for each ventricle. Many reliability problems were encountered. Recently, attention has been focused on axial or centrifugal continuous flow blood pumps. Magnetic bearings employed in such devices offer the advantages of no required lubrication and large operating clearances. This paper describes a prototype continuous flow pump supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. It delivered 6 liters/min of flow at 100 mm Hg differential head operating at 2,400 rpm in water. The pump is totally magnetically supported in four magnetic bearings - two radial and two thrust. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity, current gains, and open loop stiffness 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.

  15. Magnetic-Bearing Test Fixture

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.; Poole, William L.

    1991-01-01

    Microcomputer-controlled magnetic-bearing test fixture used to develop approaches to design of controls for magnetic bearing actuators designed and constructed. Includes load cells connected to bar, in turn, connected through screw positioners to geared drive motors. Position of equivalent suspended element sensed by position sensors and controlled by drive motors. Provides control of gap in magnetic bearing and of current in electromagnet coil. Measurements made include magnetic-bearing gaps, magnetic flux in bearing gaps, and bearing forces. Approaches to linearization and control developed by use of fixture applicable to wide range of small-gap suspension systems.

  16. Flexure Bearing Reduces Startup Friction

    NASA Technical Reports Server (NTRS)

    Clingman, W. Dean

    1991-01-01

    Design concept for ball bearing incorporates small pieces of shim stock, wire spokes like those in bicycle wheels, or other flexing elements to reduce both stiction and friction slope. In flexure bearing, flexing elements placed between outer race of ball bearing and outer ring. Elements flex when ball bearings encounter small frictional-torque "bumps" or even larger ones when bearing balls encounter buildups of grease on inner or outer race. Flexure of elements reduce high friction slopes of "bumps", helping to keep torque between outer ring and inner race low and more nearly constant. Concept intended for bearings in gimbals on laser and/or antenna mirrors.

  17. Bearing-Cartridge Damping Seal

    NASA Technical Reports Server (NTRS)

    Goggins, David G.; Scharrer, Joseph K.; Chen, Wei C.

    1991-01-01

    In proposed design for improved ball-bearing cartridge, damping seal in form of thin-layer fluid journal bearing incorporated into cartridge. Damping seal acts as auxiliary bearing, relieving bearing balls of significant portions of both static and dynamic bearing loads. Damping from seal reduces dynamic loads even further by reducing amplitude of vibrations in second vibrational mode of rotor, which mode occurs when rotor turning at nearly full operating speed. Intended for use in high-pressure-oxygen turbopump of Space Shuttle main engine, also applicable to other turbomachinery bearings.

  18. Lubricant effects on bearing life

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1986-01-01

    Lubricant considerations for rolling-element bearings have within the last two decades taken on added importance in the design and operation of mechanical systems. The phenomenon which limits the useful life of bearings is rolling-element or surface pitting fatigue. The elastohydrodynamic (EHD) film thickness which separates the ball or roller surface from those of the raceways of the bearing directly affects bearing life. Chemical additives added to the lubricant can also significantly affect bearings life and reliability. The interaction of these physical and chemical effects is important to the design engineer and user of these systems. Design methods and lubricant selection for rolling-element bearings are presented and discussed.

  19. 40 CFR Table 5 to Subpart Dddd of... - Performance Testing and Initial Compliance Demonstrations for the Compliance Options and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Performance Testing and Initial... Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... for Hazardous Air Pollutants: Plywood and Composite Wood Products Pt. 63, Subpt. DDDD, Table 5 Table...

  20. 40 CFR Table 11 to Subpart Ffff of... - Requirements for Reports

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Requirements for Reports 11 Table 11 to Subpart FFFF of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air...