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Sample records for air brake tests

  1. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  2. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  3. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  4. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  5. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  6. 78 FR 44189 - Petition for Modification of Single Car Air Brake Test Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... Federal Railroad Administration Petition for Modification of Single Car Air Brake Test Procedures In... the Federal Railroad Administration (FRA) per 49 CFR 232.307 to modify the single car air brake test procedures located in AAR Standard S-486, Code of Air Brake System Tests for Freight Equipment-- Single...

  7. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  8. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  9. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  10. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... source, an engineer's brake valve or a suitable test device shall be used to provide any increase or reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... calibrated every 92 days. Electronic yard test devices and gauges shall be calibrated annually....

  11. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... source, an engineer's brake valve or a suitable test device shall be used to provide any increase or reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... calibrated every 92 days. Electronic yard test devices and gauges shall be calibrated annually....

  12. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... source, an engineer's brake valve or a suitable test device shall be used to provide any increase or reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... calibrated every 92 days. Electronic yard test devices and gauges shall be calibrated annually....

  13. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... source, an engineer's brake valve or a suitable test device shall be used to provide any increase or reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... calibrated every 92 days. Electronic yard test devices and gauges shall be calibrated annually....

  14. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... source, an engineer's brake valve or a suitable test device shall be used to provide any increase or reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... calibrated every 92 days. Electronic yard test devices and gauges shall be calibrated annually....

  15. 76 FR 34801 - Petition for Modification of Single Car Air Brake Test Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... Federal Railroad Administration Petition for Modification of Single Car Air Brake Test Procedures In... (PATH) has requested the Federal Railroad Administration (FRA) grant a modification of the single car... FRA-2010-0174. PATH operates a fleet of 25 flat cars in consist with revenue cars utilized...

  16. Deployable Engine Air Brake

    NASA Technical Reports Server (NTRS)

    2014-01-01

    On approach, next-generation aircraft are likely to have airframe noise levels that are comparable to or in excess of engine noise. ATA Engineering, Inc. (ATA) is developing a novel quiet engine air brake (EAB), a device that generates "equivalent drag" within the engine through stream thrust reduction by creating a swirling outflow in the turbofan exhaust nozzle. Two Phase II projects were conducted to mature this technology: (1) a concept development program (CDP) and (2) a system development program (SDP).

  17. Vehicle brake testing system

    SciTech Connect

    Stevens, Samuel S; Hodgson, Jeffrey W

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  18. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  19. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  20. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  1. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  2. 49 CFR 229.29 - Air brake system calibration, maintenance, and testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... maintained in accordance with paragraph (g) of this section. (b) Except for DMU or MU locomotives covered... prescribed paragraph (g)(1) of this section. (c) Except for DMU or MU locomotives covered under § 238.309 of... system; and all air brake related filters and dirt collectors. (d) Except for MU locomotives...

  3. 49 CFR 229.29 - Air brake system calibration, maintenance, and testing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... maintained in accordance with paragraph (g) of this section. (b) Except for DMU or MU locomotives covered... prescribed paragraph (g)(1) of this section. (c) Except for DMU or MU locomotives covered under § 238.309 of... system; and all air brake related filters and dirt collectors. (d) Except for MU locomotives...

  4. 49 CFR 229.29 - Air brake system calibration, maintenance, and testing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... maintained in accordance with paragraph (g) of this section. (b) Except for DMU or MU locomotives covered... prescribed paragraph (g)(1) of this section. (c) Except for DMU or MU locomotives covered under § 238.309 of... system; and all air brake related filters and dirt collectors. (d) Except for MU locomotives...

  5. Air brake-dynamometer accurately measures torque

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  6. Braking and cornering studies on an air cushion landing system

    NASA Technical Reports Server (NTRS)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

  7. Braking, Wheeled Vehicles. Test Operations Procedure (TOP)

    DTIC Science & Technology

    2008-05-20

    are as follows: a. Micrometer calipers (inside, outside, and dial types). b. Surface finish gauges. c. Torque wrench. d. Brake shoe...is imminent. 11. Front Disc Brakes Procedure: Step 1: Visually inspect and measure rotors, calipers , and pads. Equipment needed...4. TITLE AND SUBTITLE Test Operations Procedure (TOP) 2-2-608 Braking , Wheeled Vehicles 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e

  8. NAC Off-Vehicle Brake Testing Project

    DTIC Science & Technology

    2007-05-01

    Supporting the Objective Force – NAC Off-vehicle Brake Testing Project -Version: 01 May 2007 FinalR1 UNCLAS: Dist A. Approved for public release NAC ...Project Officer (TIPO) US Army National Automotive Center ( NAC ) Warren, MI Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden... NAC Off-vehicle Brake Testing Project 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Miller, Leo 5d. PROJECT NUMBER

  9. Mountain Braking Test Venue Study

    DTIC Science & Technology

    2013-12-12

    estimates used in this analysis are based upon engine friction measurements measured by TARDEC on a Caterpillar 3116 Diesel engine as shown in Figure 1...This engine is the predecessor of and similar to the Caterpillar C7 engine used in some MRAP vehicles. The engine braking horsepower based on a...5 UNCLASSIFIED Figure 1: Caterpillar 3116 Diesel Engine Horsepower and Torque Seventy-five to eighty percent of the power absorbed by

  10. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  11. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  12. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  13. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  14. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  15. 22. General view inside air brake shop section of roundhouse. ...

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

    22. General view inside air brake shop section of roundhouse. View to west. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

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

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

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

  17. 6. North wall and east end of air brake shop ...

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

    6. North wall and east end of air brake shop section of roundhouse at center. East end of boiler shop section of roundhouse to the right of air brake shop. East end of blacksmith shop section of roundhouse at far right. View to southeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  18. 5. Machine shop and air brake shop sections of roundhouse ...

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

    5. Machine shop and air brake shop sections of roundhouse in background. Foundry (MN-99-B) in foreground. View to south. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  19. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets...

  20. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets...

  1. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....315(a)(1); (3) When previously tested units (i.e., cars that received a Class I brake test within the... hours) are added to the train; (4) When cars or equipment are removed from the train; and (5) When an... locomotives that utilize an electric signal to communicate a service brake application and only a...

  2. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....315(a)(1); (3) When previously tested units (i.e., cars that received a Class I brake test within the... hours) are added to the train; (4) When cars or equipment are removed from the train; and (5) When an... locomotives that utilize an electric signal to communicate a service brake application and only a...

  3. A Comparative Study on Automotive Brake Testing Standards

    NASA Astrophysics Data System (ADS)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  4. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the terminal complex with passengers; (2) Prior to the first morning departure of each commuter or... operator first takes charge of the train, except for face-to-face relief. (b) A Class II brake test shall... locomotives that utilize an electric signal to communicate a service brake application and only a...

  5. 49. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST ...

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

    49. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST EQUIPMENT, BAYS 50-51/6 NORTH, TO EAST - Ford Motor Company Edgewater Assembly Plant, Assembly Building, 309 River Road, Edgewater, Bergen County, NJ

  6. 50. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST ...

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

    50. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST EQUIPMENT, BAYS 52-53/3 NORTH, TO NORTHWEST - Ford Motor Company Edgewater Assembly Plant, Assembly Building, 309 River Road, Edgewater, Bergen County, NJ

  7. 49 CFR 232.211 - Class III brake tests-trainline continuity inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class III brake tests-trainline continuity... § 232.211 Class III brake tests-trainline continuity inspection. (a) A Class III brake test shall be... configuration of the train has changed in certain ways. In particular, a Class III brake test shall be...

  8. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cars en route.); (3) A location where the train is off air for a period of more than four hours; (4) A location where a unit or cycle train has traveled 3,000 miles since its last Class I brake test; and (5) A... of not less than 20 degrees Fahrenheit. AFM indicators shall be accurate to within ±3 standard...

  9. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... first morning departure of each commuter or short-distance intercity passenger train, unless all of the... repeated at the first passenger terminal if the train remains on a source of compressed air and: (1) The... that utilize an electric signal to communicate a service brake application and only a pneumatic...

  10. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK62 Federal Motor Vehicle Safety... that amended the Federal motor vehicle safety standard for air brake systems by requiring substantial... 37122) amending Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to...

  11. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... Administration 49 CFR Part 571 [Docket No. NHTSA-2009-0175] RIN 2127-AK84 Federal Motor Vehicle Safety Standards... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to require improved...

  12. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is... the case of tread or disc brakes by determining that the brake shoe or pad provides pressure to the... of the clearance between the brake shoe and the wheel or between the brake pad and the brake disc....

  13. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is... the case of tread or disc brakes by determining that the brake shoe or pad provides pressure to the... of the clearance between the brake shoe and the wheel or between the brake pad and the brake disc....

  14. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is... the case of tread or disc brakes by determining that the brake shoe or pad provides pressure to the... of the clearance between the brake shoe and the wheel or between the brake pad and the brake disc....

  15. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic.... (3) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets this requirement. [64 FR 25660, May 12, 1999, as amended at 65 FR...

  16. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic.... (3) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets this requirement....

  17. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... correctly aligned in relation to the wheel or to the disc; (6) The engineer's brake valve or controller will..., provided FRA has access to the record upon request. (2) The written or electronic record must contain the...; (iv) The total number of cars inspected during the test; and (v) The signature or...

  18. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... correctly aligned in relation to the wheel or to the disc; (6) The engineer's brake valve or controller will..., provided FRA has access to the record upon request. (2) The written or electronic record must contain the...; (iv) The total number of cars inspected during the test; and (v) The signature or...

  19. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ...; Technical Report on the Effectiveness of Antilock Braking Systems in Heavy Truck Tractors and Trailers...: Request for comments on technical report. SUMMARY: This notice announces NHTSA's publication of a Technical Report its existing Safety Standard 121, Air Brake Systems. The report's title is:...

  20. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  1. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  2. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  3. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  4. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  5. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  6. Design and testing of a rotational brake with shear thickening fluids

    NASA Astrophysics Data System (ADS)

    Tian, Tongfei; Nakano, Masami

    2017-03-01

    A rotational brake working with shear thickening fluid (STF) was designed and tested in this study. With the optimisation in design, most of the STF in the brake can receive the same shear rate when the brake rotates. The parts of this brake were fabricated with a 3D printer and then assembled manually. Three types of STFs with various carrier fluids and different particles were fabricated and tested with a rheometer. Then the brake with each STF was separately tested with the rheometer. The estimated and measured torques as a function of the angular velocity fit each other well. The stability of the rotational STF brake was investigated in repeated tests, which proved the function of the brake for a long time.

  7. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    SciTech Connect

    Lascurain, Mary Beth; Capps, Gary J; Franzese, Oscar

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

  8. Automotive Brake Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

  9. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL11 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... published a final rule in the Federal Register amending Federal Motor Vehicle Safety Standard (FMVSS)...

  10. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the...

  11. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the...

  12. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    SciTech Connect

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  13. ATPD-2354 Revision 10 Verification Test, Disc Brake Version Only (16 NOV 06) Article Test of High Mobility Multipurpose Wheeled Vehicle (HMMWV-ECV)

    DTIC Science & Technology

    2007-05-23

    standard measuring caliper . Close brake pad dimension tolerances are critical to ensuring proper brake operation. 4.1.5.1. The analysis of results...070169 ATPD-2354 REVISION 10 VERIFICATION TEST, DISC BRAKE VERSION ONLY (16 NOV 06) ARTICLE TEST OF HIGH MOBILITY MULTIPURPOSE WHEELED...Verification Test, Disc Brake Verson Only (16 NOV 06) Article Test of High Mobility Multipurpose Wheeled Vehicle (HMMWV-ECV) 5a. CONTRACT NUMBER

  14. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    NASA Astrophysics Data System (ADS)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  15. Atmospheric testing of wind turbine trailing edge aerodynamic brakes

    SciTech Connect

    Miller, L.S.; Migliore, P.G.; Quandt, G.A.

    1997-12-31

    An experimental investigation was conducted using an instrumented horizontal-axis wind turbine that incorporated variable span trailing-edge aerodynamic brakes. A primary goal was to directly compare study results with (infinite-span) wind tunnel data and to provide information on how to account for device span effects during turbine design or analysis. Comprehensive measurements were utilized to define effective changes in the aerodynamic coefficients, as a function of angle of attack and control deflection, for three device spans and configurations. Differences in the lift and drag behavior are most pronounced near stall and for device spans of less than 15%. Drag performance is affected only minimally (<70%) for 15% or larger span devices. Interestingly, aerodynamic controls with characteristic vents or openings appear most affected by span reductions and three-dimensional flow.

  16. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... engineer by any means determined appropriate by the railroad; however, a written or electronic record of... engineer that the Class I brake test was satisfactorily performed and provide the information required in this paragraph to the locomotive engineer or place the information in the cab of the...

  17. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... engineer by any means determined appropriate by the railroad; however, a written or electronic record of... engineer that the Class I brake test was satisfactorily performed and provide the information required in this paragraph to the locomotive engineer or place the information in the cab of the...

  18. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... § 232.205 Class I brake test-initial terminal inspection. (a) Each train and each car in the train shall... car or a solid block of cars, except as provided in paragraph (b)(2) of this section; (ii) Removing a single car or a solid block of cars; (iii) Removing cars determined to be defective under this...

  19. Test Results for Rotordynamic Coefficients of the SSME HPOTP Turbine Interstage Seal with Two Swirl Brakes

    NASA Technical Reports Server (NTRS)

    Childs, Dara W.; Baskharone, Erian; Ramsey, Christopher

    1991-01-01

    Test results are presented for the HPOTP Turbine Interstage Seal with both the current and an alternate, aerodynamically designed, swirl brake. Tests were conducted at speeds out to 16,000 rpm, supply pressures up to 18.3 bars, and the following three inlet tangential velocity conditions: (1) no preswirl; (2) intermediate preswirl in the direction of rotation; and (3) high preswirl in the direction of rotation. The back pressure can be controlled independently and was varied to yield the following four pressure ratios: 0.4, 0.45, 0.56, and 0.67. The central and simplest conclusion to be obtained from the test series is that the alternate swirl brake consistently outperforms the current swirl brake in terms of stability performance. The alternate swirl brake's whirl frequency ratio was generally about one half or less than corresponding values for the current design. In many cases, the alternate design yielded negative whirl frequency ratio values in comparison to positive values for the current design. The alternate design can be directly substituted into the space currently occupied by the current design. There is no change in leakage performance.

  20. Sensor configuration and test for fault diagnoses of subway braking system based on signed digraph method

    NASA Astrophysics Data System (ADS)

    Zuo, Jianyong; Chen, Zhongkai

    2014-05-01

    Fault diagnosis of various systems on rolling stock has drawn the attention of many researchers. However, obtaining an optimized sensor set of these systems, which is a prerequisite for fault diagnosis, remains a major challenge. Available literature suggests that the configuration of sensors in these systems is presently dependent on the knowledge and engineering experiences of designers, which may lead to insufficient or redundant development of various sensors. In this paper, the optimization of sensor sets is addressed by using the signed digraph (SDG) method. The method is modified for use in braking systems by the introduction of an effect-function method to replace the traditional quantitative methods. Two criteria are adopted to evaluate the capability of the sensor sets, namely, observability and resolution. The sensors configuration method of braking system is proposed. It consists of generating bipartite graphs from SDG models and then solving the set cover problem using a greedy algorithm. To demonstrate the improvement, the sensor configuration of the HP2008 braking system is investigated and fault diagnosis on a test bench is performed. The test results show that SDG algorithm can improve single-fault resolution from 6 faults to 10 faults, and with additional four brake cylinder pressure (BCP) sensors it can cover up to 67 double faults which were not considered by traditional fault diagnosis system. SDG methods are suitable for reducing redundant sensors and that the sensor sets thereby obtained are capable of detecting typical faults, such as the failure of a release valve. This study investigates the formal extension of the SDG method to the sensor configuration of braking system, as well as the adaptation supported by the effect-function method.

  1. Quantification of brake creep groan in vehicle tests and its relation with stick-slip obtained in laboratory tests

    NASA Astrophysics Data System (ADS)

    Neis, P. D.; Ferreira, N. F.; Poletto, J. C.; Matozo, L. T.; Masotti, D.

    2016-05-01

    This paper describes the development of a methodology for assessing and correlating stick-slip and brake creep groan. For doing that, results of tribotests are compared to data obtained in vehicle tests. A low velocity and a linear reduction in normal force were set for the tribotests. The vehicle tests consisted of subjecting a sport utility vehicle to three different ramp slopes. Creep groan events were measured by accelerometers placed on the brake calipers. The root mean square of the acceleration signal (QRMS parameter) was shown to be able to measure the creep groan severity resulting from the vehicle tests. Differences in QRMS were observed between front-rear and left-right wheels for all tested materials. Frequency spectrum analysis of the acceleration revealed that the wheel side and material type do not cause any significant shift in the creep groan frequency. QRMS measured in the vehicle tests presented good correlation with slip power (SP) summation. For this reason, SP summation may represent the "creep groan propensity" of brake materials. Thus, the proposed tribotest method can be utilized to predict the creep groan severity of brake materials in service.

  2. Airborne brake wear debris: size distributions, composition, and a comparison of dynamometer and vehicle tests.

    PubMed

    Sanders, Paul G; Xu, Ning; Dalka, Tom M; Maricq, M Matti

    2003-09-15

    Particle size distributions of light-duty vehicle brake wear debris are reported with careful attention paid to avoid sampling biases. Electrical low-pressure impactor and micro-orifice uniform deposit impactor measurements yield consistent size distributions, and the net particulate matter mass from each method is in good agreement with gravimetric filter measurements. The mass mean diameter of wear debris from braking events representative of urban driving is 6 microm, and the number-weighted mean is 1-2 microm for three currently used classes of lining materials: low metallic, semimetallic, and non-asbestos organic (NAO). In contrast, the wear rates are very material dependent, both in number and mass of particles, with 3-4 times higher emissions observed from the low metallic linings as compared to the semimetallic and NAO linings. Wind tunnel and test track measurements demonstrate the appearance of micron size particles that correlate with braking events, with approximately 50% of the wear debris being airborne for the test vehicle in this study. Elemental analysis of the wear debris reveals a consistent presence of the elements Fe, Cu, and Ba in both dynamometer and test track samples.

  3. The design of aircraft brake systems, employing cooling to increase brake life

    NASA Technical Reports Server (NTRS)

    Scaringe, R. P.; Ho, T. L.; Peterson, M. B.

    1975-01-01

    A research program was initiated to determine the feasibility of using cooling to increase brake life. An air cooling scheme was proposed, constructed and tested with various designs. Straight and curved slotting of the friction material was tested. A water cooling technique, similar to the air cooling procedure, was evaluated on a curved slotted rotor. Also investigated was the possibility of using a phase-change material within the rotor to absorb heat during braking. Various phase-changing materials were tabulated and a 50%, (by weight) LiF - BeF2 mixing was chosen. It was shown that corrosion was not a problem with this mixture. A preliminary design was evaluated on an actual brake. Results showed that significant improvements in lowering the surface temperature of the brake occurred when air or water cooling was used in conjunction with curved slotted rotors.

  4. Mechanical testing and modelling of carbon-carbon composites for aircraft disc brakes

    NASA Astrophysics Data System (ADS)

    Bradley, Luke R.

    The objective of this study is to improve the understanding of the stress distributions and failure mechanisms experienced by carbon-carbon composite aircraft brake discs using finite element (FE) analyses. The project has been carried out in association with Dunlop Aerospace as an EPSRC CASE studentship. It therefore focuses on the carbon-carbon composite brake disc material produced by Dunlop Aerospace, although it is envisaged that the approach will have broader applications for modelling and mechanical testing of carbon-carbon composites in general. The disc brake material is a laminated carbon-carbon composite comprised of poly(acrylonitrile) (PAN) derived carbon fibres in a chemical vapour infiltration (CVI) deposited matrix, in which the reinforcement is present in both continuous fibre and chopped fibre forms. To pave the way for the finite element analysis, a comprehensive study of the mechanical properties of the carbon-carbon composite material was carried out. This focused largely, but not entirely, on model composite materials formulated using structural elements of the disc brake material. The strengths and moduli of these materials were measured in tension, compression and shear in several orientations. It was found that the stress-strain behaviour of the materials were linear in directions where there was some continuous fibre reinforcement, but non-linear when this was not the case. In all orientations, some degree of non-linearity was observed in the shear stress-strain response of the materials. However, this non-linearity was generally not large enough to pose a problem for the estimation of elastic moduli. Evidence was found for negative Poisson's ratio behaviour in some orientations of the material in tension. Additionally, the through-thickness properties of the composite, including interlaminar shear strength, were shown to be positively related to bulk density. The in-plane properties were mostly unrelated to bulk density over the range of

  5. A high performance pneumatic braking system for heavy vehicles

    NASA Astrophysics Data System (ADS)

    Miller, Jonathan I.; Cebon, David

    2010-12-01

    Current research into reducing actuator delays in pneumatic brake systems is opening the door for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, these algorithms require the knowledge of variables that are impractical to measure directly. This paper introduces a sliding mode braking force observer to support a sliding mode controller for air-braked heavy vehicles. The performance of the observer is examined through simulations and field testing of an articulated heavy vehicle. The observer operated robustly during single-wheel vehicle simulations, and provided reasonable estimates of surface friction from test data. The effect of brake gain errors on the controller and observer are illustrated, and a recursive least squares estimator is derived for the brake gain. The estimator converged within 0.3 s in simulations and vehicle trials.

  6. Elemental composition of current automotive braking materials and derived air emission factors

    NASA Astrophysics Data System (ADS)

    Hulskotte, J. H. J.; Roskam, G. D.; Denier van der Gon, H. A. C.

    2014-12-01

    Wear-related PM emissions are an important constituent of total PM emissions from road transport. Due to ongoing (further) exhaust emission reduction wear emissions may become the dominant PM source from road transport in the near future. The chemical composition of the wear emissions is crucial information to assess the potential health relevance of these PM emissions. Here we provide an elemental composition profile of brake wear emissions as used in the Netherlands in 2012. In total, 65 spent brake pads and 15 brake discs were collected in car maintenance shops from in-use personal cars vehicles and analyzed with XRF for their metal composition (Fe, Cu, Zn, Sn, Al, Si, Zr, Ti, Sb, Cr, Mo, Mn, V, Ni, Bi, W, P, Pb and Co). Since car, engine and safety regulations are not nationally determined but controlled by European legislation the resulting profiles will be representative for the European personal car fleet. The brake pads contained Fe and Cu as the dominant metals but their ratio varied considerably, other relatively important metals were Sn, Zn and Sb. Overall a rather robust picture emerged with Fe, Cu, Zn and Sn together making up about 80-90% of the metals present in brake pads. Because the XRF did not give information on the contents of other material such as carbon, oxygen and sulphur, a representative selection of 9 brake pads was further analyzed by ICP-MS and a carbon and sulphur analyzer. The brake pads contained about 50% of non-metal material (26% C, 3% S and the remainder mostly oxygen and some magnesium). Based on our measurements, the average brake pad profile contained 20% Fe, 10% Cu, 4% Zn and 3% Sn as the dominant metals. The brake discs consisted almost entirely of metal with iron being the dominant metal (>95%) and only traces of other metals (<1% for individual metals). Non-metal components in the discs were 2-3% Silicon and, according to literature, ∼3% carbon. The robust ratio between Fe and Cu as found on kerbsides has been used to

  7. 49 CFR 383.135 - Passing knowledge and skills tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... performs the skills test in a vehicle not equipped with any type of air brake system is issued a CDL, an... applicant who performs the skills test in a vehicle equipped with air over hydraulic brakes is issued a CDL... that the applicant can safely and effectively operate the vehicle's full air brakes, air over...

  8. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... indicators. 393.53 Section 393.53 Transportation Other Regulations Relating to Transportation (Continued... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial... vehicle at the time it was manufactured. (c) Brake adjustment indicator (air brake systems). On...

  9. Mechanically braked elliptical Wingate test: modification considerations, load optimization, and reliability.

    PubMed

    Ozkaya, Ozgur; Colakoglu, Muzaffer; Kuzucu, Erinc O; Yildiztepe, Engin

    2012-05-01

    The 30-second, all-out Wingate test evaluates anaerobic performance using an upper or lower body cycle ergometer (cycle Wingate test). A recent study showed that using a modified electromagnetically braked elliptical trainer for Wingate testing (EWT) leads to greater power outcomes because of larger muscle group recruitment. The main purpose of this study was to modify an elliptical trainer using an easily understandable mechanical brake system instead of an electromagnetically braked modification. Our secondary aim was to determine a proper test load for the EWT to reveal the most efficient anaerobic test outcomes such as peak power (PP), average power (AP), minimum power (MP), power drop (PD), and fatigue index ratio (FI%) and to evaluate the retest reliability of the selected test load. Delta lactate responses (ΔLa) were also analyzed to confirm all the anaerobic performance of the athletes. Thirty healthy and well-trained male university athletes were selected to participate in the study. By analysis of variance, an 18% body mass workload yielded significantly greater test outcomes (PP = 19.5 ± 2.4 W·kg, AP = 13.7 ± 1.7 W·kg, PD = 27.9 ± 5 W·s, FI% = 58.4 ± 3.3%, and ΔLa = 15.4 ± 1.7 mM) than the other (12-24% body mass) tested loads (p < 0.05). Test and retest results for relative PP, AP, MP, PD, FI%, and ΔLa were highly correlated (r = 0.97, 0.98, 0.94, 0.91, 0.81, and 0.95, respectively). In conclusion, it was found that the mechanically braked modification of an elliptical trainer successfully estimated anaerobic power and capacity. A workload of 18% body mass was optimal for measuring maximal and reliable anaerobic power outcomes. Anaerobic testing using an EWT may be more useful to athletes and coaches than traditional cycle ergometers because a greater proportion of muscle groups are worked during exercise on an elliptical trainer.

  10. Brake Fluid Compatibility Studies with Advanced Brake Systems

    DTIC Science & Technology

    2016-01-16

    brake fluid in a hydraulic power brake system revealed deposits only with the silicone brake fluid after 20,000- cycles of testing. These results are...revealed deposits formed only with the silicone brake fluid after 20,000- cycles of testing. The objective was accomplished by conducting static soak...testing to halt when testing MIL-PRF-46176. Deposits were not present in SAE J1703 testing for the same number of test cycles . The objective of this

  11. 76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    ...-brake systems; or that the agency require a driver-controllable switch that would allow the driver to... deactivation switch to allow the driver to disable the ABS. The petition cited data from a recent NHTSA report... in FMVSS No. 121. The agency was not aware of any reason to consider including an ABS on-off...

  12. Wheel brakes and their application to aircraft

    NASA Technical Reports Server (NTRS)

    Dowty, G H

    1928-01-01

    The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls.

  13. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  14. A Test of the Tau-Dot Hypothesis of Braking Control in the Real World

    ERIC Educational Resources Information Center

    Rock, Paul B.; Harris, Mike G.; Yates, Tim

    2006-01-01

    A controlled experiment used instrumented vehicles in a real-world driving task to compare D. N. Lee's (1976) tau-dot hypothesis of braking control with an alternative based on the direct estimation and control of ideal deceleration (T. Yates, M. Harris, & P. Rock, 2004). Drivers braked to stop as closely as possible to a visual target from…

  15. Typical pedestrian accident scenarios for the development of autonomous emergency braking test protocols.

    PubMed

    Lenard, James; Badea-Romero, Alexandro; Danton, Russell

    2014-12-01

    An increasing proportion of new vehicles are being fitted with autonomous emergency braking systems. It is difficult for consumers to judge the effectiveness of these safety systems for individual models unless their performance is evaluated through track testing under controlled conditions. This paper aimed to contribute to the development of relevant test conditions by describing typical circumstances of pedestrian accidents. Cluster analysis was applied to two large British databases and both highlighted an urban scenario in daylight and fine weather where a small pedestrian walks across the road, especially from the near kerb, in clear view of a driver who is travelling straight ahead. For each dataset a main test configuration was defined to represent the conditions of the most common accident scenario along with test variations to reflect the characteristics of less common accident scenarios. Some of the variations pertaining to less common accident circumstances or to a minority of casualties in these scenarios were proposed as optional or supplementary test elements for an outstanding performance rating. Many considerations are incorporated into the final design and implementation of an actual testing regime, such as cost and the state of development of technology; only the representation of accident data lay within the scope of this paper. It would be desirable to ascertain the wider representativeness of the results by analysing accident data from other countries in a similar manner.

  16. Integrated assessment of pedestrian head impact protection in testing secondary safety and autonomous emergency braking.

    PubMed

    Searson, D J; Anderson, R W G; Hutchinson, T P

    2014-02-01

    Pedestrian impact testing is used to provide information to the public about the relative level of protection provided by different vehicles to a struck pedestrian. Autonomous Emergency Braking (AEB) is a relatively new technology that aims to reduce the impact speed of such crashes. It is expected that vehicles with AEB will pose less harm to pedestrians, and that the benefit will come about through reductions in the number of collisions and a change in the severity of impacts that will still occur. In this paper, an integration of the assessment of AEB performance and impact performance is proposed based on average injury risk. Average injury risk is calculated using the result of an impact test and a previously published distribution of real world crash speeds. A second published speed distribution is used that accounts for the effects of AEB, and reduced average risks are implied. This principle allows the effects of AEB systems and secondary safety performance to be integrated into a single measure of safety. The results are used to examine the effect of AEB on Euro NCAP and ANCAP assessments using previously published results on the likely effect of AEB. The results show that, given certain assumptions about AEB performance, the addition of AEB is approximately the equivalent of increasing Euro NCAP test performance by one band, which corresponds to an increase in the score of 25% of the maximum.

  17. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inspected for leaks in the brake system. (n) Securement of unattended equipment. A train's air brake shall... brakes. (f) Each car in a train shall have its air brakes in effective operating condition unless the car is being moved for repairs in accordance with §§ 232.15 and 232.609. The air brakes on a car are...

  18. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... inspected for leaks in the brake system. (n) Securement of unattended equipment. A train's air brake shall... brakes. (f) Each car in a train shall have its air brakes in effective operating condition unless the car is being moved for repairs in accordance with §§ 232.15 and 232.609. The air brakes on a car are...

  19. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... inspected for leaks in the brake system. (n) Securement of unattended equipment. A train's air brake shall... brakes. (f) Each car in a train shall have its air brakes in effective operating condition unless the car is being moved for repairs in accordance with §§ 232.15 and 232.609. The air brakes on a car are...

  20. A test-based method for the assessment of pre-crash warning and braking systems.

    PubMed

    Bálint, András; Fagerlind, Helen; Kullgren, Anders

    2013-10-01

    In this paper, a test-based assessment method for pre-crash warning and braking systems is presented where the effectiveness of a system is measured by its ability to reduce the number of injuries of a given type or severity in car-to-car rear-end collisions. Injuries with whiplash symptoms lasting longer than 1 month and MAIS2+ injuries in both vehicles involved in the crash are considered in the assessment. The injury reduction resulting from the impact speed reduction due to a pre-crash system is estimated using a method which has its roots in the dose-response model. Human-machine interaction is also taken into account in the assessment. The results reflect the self-protection as well as the partner-protection performance of a pre-crash system in the striking vehicle in rear-end collisions and enable a comparison between two or more systems. It is also shown how the method may be used to assess the importance of warning as part of a pre-crash system.

  1. Gravity brake

    DOEpatents

    Lujan, Richard E.

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  2. Advanced air revitalization system testing

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Hallick, T. M.; Schubert, F. H.

    1983-01-01

    A previously developed experimental air revitalization system was tested cyclically and parametrically. One-button startup without manual interventions; extension by 1350 hours of tests with the system; capability for varying process air carbon dioxide partial pressure and humidity and coolant source for simulation of realistic space vehicle interfaces; dynamic system performance response on the interaction of the electrochemical depolarized carbon dioxide concentrator, the Sabatier carbon dioxide reduction subsystem, and the static feed water electrolysis oxygen generation subsystem, the carbon dioxide concentrator module with unitized core technology for the liquid cooled cell; and a preliminary design for a regenerative air revitalization system for the space station are discussed.

  3. Better Brakes

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

  4. Eddy current braking experiment using brake disc from aluminium series of A16061 and A17075

    NASA Astrophysics Data System (ADS)

    Baharom, M. Z.; Nuawi, M. Z.; Priyandoko, G.; Harris, S. M.

    2012-09-01

    The electromagnetic braking using eddy current was studied, focused on two series of aluminium as the brake disc which are A16061 and A17075. This paper presents the comparison for both series in a few varied parameters related to eddy current braking such as air-gap, number of turns and brake disc thickness. Optical tachometer has been used along with PULSE analyzer to capture the speed (rpm) and time (s). The findings shows that the smaller the air-gap, the larger of electromagnet turns and the thicker disc thickness is, will generate higher braking torque to stop the rotational motion of disc brake and give great performance for eddy current braking. Thos parameters that been evaluated also addressed a potential on expanding this knowledge to develop an electromagnetic braking system to replace the conventional braking system.

  5. Braking system

    DOEpatents

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  6. Determining the frequency of asbestos use in automotive brakes from a fleet of on-road California vehicles.

    PubMed

    De Vita, Joseph; Wall, Stephen; Wagner, Jeff; Wang, Zhong-Min; Rao, Leela E

    2012-02-07

    Asbestos is a known human carcinogen, and recent regulation in California limits asbestiform fibers in brakes to trace levels beginning in 2014, although there is no corresponding federal requirement. In order to gauge the current prevalence of asbestos use in automotive brake applications, the California Air Resources Board tested brake linings from 137 light- and medium-duty vehicles and 54 heavy-duty vehicles. Only about 3% of the light- and medium-duty vehicle brake linings contained chrysotile asbestos. All of those brake linings were drum-type shoes, which are generally being phased out. No asbestos was found in low mileage vehicles presumed to have their original stock linings from the vehicle manufacturer. Additionally, no asbestos was found in the heavy-duty vehicle brake shoe linings sampled. Given the small percentage of vehicle brake linings with asbestos observed, it appears that the prior federal ban that was subsequently overturned, in combination with a threat of litigation, has reduced asbestos use in brake linings. However, our study was limited in scope and without a national ban, the current and future prevalence of asbestos in brakes is uncertain, suggesting the need for continued monitoring of materials released as toxic air contaminants in normal braking operations.

  7. Magnetostrictive Brake

    NASA Technical Reports Server (NTRS)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

    A magnetostrictive brake has been designed as a more energy-efficient alternative to a magnetic fail-safe brake in a robot. (In the specific application, failsafe signifies that the brake is normally engaged; that is, power must be supplied to allow free rotation.) The magnetic failsafe brake must be supplied with about 8 W of electric power to initiate and maintain disengagement. In contrast, the magnetostrictive brake, which would have about the same dimensions and the same torque rating as those of the magnetic fail-safe brake, would demand only about 2 W of power for disengagement. The brake (see figure) would include a stationary base plate and a hub mounted on the base plate. Two solenoid assemblies would be mounted in diametrically opposed recesses in the hub. The cores of the solenoids would be made of the magnetostrictive alloy Terfenol-D or equivalent. The rotating part of the brake would be a ring-and spring- disk subassembly. By means of leaf springs not shown in the figure, this subassembly would be coupled with the shaft that the brake is meant to restrain. With no power supplied to the solenoids, a permanent magnet would pull axially on a stepped disk and on a shelf in the hub, causing the ring to be squeezed axially between the stepped disk and the hub. The friction associated with this axial squeeze would effect the braking action. Supplying electric power to the solenoids would cause the magnetostrictive cylinders to push radially inward against a set of wedges that would be in axial contact with the stepped disk. The wedges would convert the radial magnetostrictive strain to a multiplied axial displacement of the stepped disk. This axial displacement would be just large enough to lift the stepped disk, against the permanent magnetic force, out of contact with the ring. The ring would then be free to turn because it would no longer be squeezed axially between the stepped disk and the hub.

  8. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and transfer of goods by, or between various modes of transport, such as highway, rail, sea and air... maximum drive-through speed, whichever is less, on a 500-foot radius curved roadway with a wet level... failure in a common diaphragm may instead be met with the level of leakage-type failure determined in...

  9. Airborne asbestos concentration from brake changing does not exceed permissible exposure limit.

    PubMed

    Blake, Charles L; Van Orden, Drew R; Banasik, Marek; Harbison, Raymond D

    2003-08-01

    The use in the past, and to a lesser extent today, of chrysotile asbestos in automobile brake systems causes health concerns among professional mechanics. Therefore, we conducted four separate tests in order to evaluate an auto mechanic's exposure to airborne asbestos fibers while performing routine brake maintenance. Four nearly identical automobiles from 1960s having four wheel drum brakes were used. Each automobile was fitted with new replacement asbestos-containing brake shoes and then driven over a predetermined public road course for about 2253 km. Then, each car was separately brought into a repair facility; the brakes removed and replaced with new asbestos-containing shoes. The test conditions, methods, and tools were as commonly used during the 1960s. The mechanic was experienced in brake maintenance, having worked in the automobile repair profession beginning in the 1960s. Effects of three independent variables, e.g., filing, sanding, and arc grinding of the replacement brake shoe elements, were tested. Personal and area air samples were collected and analyzed for the presence of fibers, asbestos fibers, total dust, and respirable dust. The results indicated a presence in the air of only chrysotile asbestos and an absence of other types of asbestos. Airborne chrysotile fiber exposures for each test remained below currently applicable limit of 0.1 fiber/ml (eight-hour time-weighted average).

  10. Performance and aerodynamic braking of a horizontal-axis wind turbine from small-scale wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Cao, H. V.; Wentz, W. H., Jr.

    1987-01-01

    Wind tunnel tests of three 20" diameter, zero twist, zero pitch wind turbine rotor models were conducted in a 7' x 10' wind tunnel to determine the performance of such rotors with NACA 23024 and NACA 64 sub 3-621 airfoil sections. Aerodynamic braking characteristics of a 38% span, 30% chord, vented aileron configuration were measured on the NACA 23024 rotor. Surface flow patterns were observed using fluorescent mini-tufts attached to the suction side of the rotor blades. Experimental results with and without ailerons are compared to predictions using airfoil section data and a momentum performance code. Results of the performance studies show that the 64 sub 3-621 rotor produces higher peak power than the 23024 rotor for a given rotor speed. Analytical studies, however, indicate that the 23024 should produce higher power. Transition strip experiments show that the 23024 rotor is much more sensitive to roughness than the 64 sub 3-621 rotor. These trends agree with analytical predictions. Results of the aileron test show that this aileron, when deflected, produces a braking torque at all tip speed ratios. In free wheeling coastdowns the rotor blade stopped, then rotated backward at a tip speed ratio of -0.6.

  11. Seal-rotordynamic-coefficient Test Results for a Model SSME ATD-HPFTP Turbine Interstage Seal with and Without a Swirl Brake

    NASA Technical Reports Server (NTRS)

    Childs, Dara W.; Ramsey, Christopher

    1991-01-01

    The predictions of Scharrer's (1988) theory for rotordynamic coefficients of labyrinth gas seals were compared with measurements for a model SSME Alternate Turbopump Development High Pressure Fuel Turbopump with and without swirl brakes. Using the test apparatus described by Childs et al., tests were conducted with supply pressures up to 18.3 bars and speeds up to 16,000 rpm. Seal back pressure was controlled to provide four pressure ratios at all supply pressures. No measurable differences in leakage was detected for the seal with and without the swirl brakes. Comparisons of the measurement results for the seal without a swirl brake with the Scharrer theory showed that the theory can be used only to provide design guidelines; systematic differences were observed between theory and experiment due to changes in running speed, supply pressure, and pressure ratio.

  12. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... with other than an AB, ABD, ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment of each cab car shall be cleaned, repaired, and tested at intervals in accordance with the following schedule: (1) Every 1,476 days for that portion of the cab car brake system using brake valves that...

  13. 10. "TEST STAND 15, AIR FORCE FLIGHT TEST CENTER." ca. ...

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

    10. "TEST STAND 1-5, AIR FORCE FLIGHT TEST CENTER." ca. 1958. Test Area 1-115. Original is a color print, showing Test Stand 1-5 from below, also showing the superstructure of TS1-4 at left. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Leuhman Ridge near Highways 58 & 395, Boron, Kern County, CA

  14. BRAKE DEVICE

    DOEpatents

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  15. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... passenger equipment containing a power brake defect at the time a Class I or IA brake test is performed... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its consist passenger equipment containing a power brake defect at the time that a Class I or IA brake...

  16. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  17. Flight testing air-to-air missiles for flutter

    NASA Technical Reports Server (NTRS)

    Kutschinski, C. R.

    1975-01-01

    The philosophy of the design of air-to-air missiles and hence of flight testing them for flutter differs from that of manned aircraft. Primary emphasis is put on analytical and laboratory evaluation of missile susceptibility to aeroelastic and aero-servo-elastic instabilities and uses flight testing for confirmation of the absence of such instabilities. Flight testing for flutter is accomplished by using specially instrumented programmed missiles, air or ground launched with a booster to reach the extreme flight conditions of tactical use, or by using guided missiles with telemetered performance data. The instrumentation and testing techniques are discussed along with the success of recent flight tests.

  18. Preliminary test results of the joint FAA-USAF-NASA runway research program. Part 1: Traction measurements of several runways under wet and dry conditions with a Boeing 727, a diagonal-braked vehicle, and a mu-meter

    NASA Technical Reports Server (NTRS)

    Horne, W. B.; Yager, T. J.; Sleeper, R. K.; Merritt, L. R.

    1977-01-01

    The stopping distance, brake application velocity, and time of brake application were measured for two modern jet transports, along with the NASA diagonal-braked vehicle and the British Mu-Meter on several runways, which when wetted, cover the range of slipperiness likely to be encountered in the United States. Tests were designed to determine if correlation between the aircraft and friction measuring vehicles exists. The test procedure, data reduction techniques, and preliminary test results obtained with the Boeing 727, the Douglas DC-9, and the ground vehicles are given. Time histories of the aircraft test run parameters are included.

  19. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  20. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  1. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  2. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  3. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  4. Modelling and validation of magnetorheological brake responses using parametric approach

    NASA Astrophysics Data System (ADS)

    Z, Zainordin A.; A, Abdullah M.; K, Hudha

    2013-12-01

    Magnetorheological brake (MR Brake) is one x-by-wire systems which performs better than conventional brake systems. MR brake consists of a rotating disc that is immersed with Magnetorheological Fluid (MR Fluid) in an enclosure of an electromagnetic coil. The applied magnetic field will increase the yield strength of the MR fluid where this fluid was used to decrease the speed of the rotating shaft. The purpose of this paper is to develop a mathematical model to represent MR brake with a test rig. The MR brake model is developed based on actual torque characteristic which is coupled with motion of a test rig. Next, the experimental are performed using MR brake test rig and obtained three output responses known as angular velocity response, torque response and load displacement response. Furthermore, the MR brake was subjected to various current. Finally, the simulation results of MR brake model are then verified with experimental results.

  5. Recent studies of tire braking performance. [for aircraft

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.; Leland, T. J. W.

    1973-01-01

    The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

  6. Testing of chemically treated adsorbent air purifiers

    SciTech Connect

    Kelly, T.J. . Dept. of Atmospheric Science and Applied Technology); Kinkead, D.A. )

    1993-07-01

    New highly sensitive continuous monitors permit testing of air filters at parts-per-billion contaminant concentrations. This article describes testing of air purification filters intended for use in the National Archives 2 building in College Park, Maryland, using a test procedure that simulates the actual conditions of use. This test demonstrates both the effectiveness of the adsorbers at low contaminant levels, and the capability of existing instruments for conducting such tests. ASHRAE TC 2.3 (Gaseous Air Contaminants and Gas Contaminant Removal Equipment) is currently sponsoring research projects (follow-on studies to ASHRAE Project RP-674) aimed at developing a standard that will test and rate the performance of different types of gas phase air purification equipment at low concentrations. The work detailed in this article represents a first of this type of testing and a technical benchmark that may aid in the further development of ASHRAE gas phase performance standards.

  7. PREDICTING RANGES FOR PULSARS' BRAKING INDICES

    SciTech Connect

    Magalhaes, Nadja S.; Miranda, Thaysa A.; Frajuca, Carlos

    2012-08-10

    The theoretical determination of braking indices of pulsars is still an open problem. In this paper we report results of a study concerning such determination based on a modification of the canonical model, which admits that pulsars are rotating magnetic dipoles, and on data from the seven pulsars with known braking indices. In order to test the modified model, we predict ranges for the braking indices of other pulsars.

  8. Experiments with airplane brakes

    NASA Technical Reports Server (NTRS)

    Michael, Franz

    1931-01-01

    This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading. From the load distribution we merely defined the position of the normal force resultant, while for the rest, the effect of the distribution was disregarded in the comparison of the different shoe dispositions.

  9. Accelerometer-controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1973-01-01

    Braking system, which employs angular accelerometer to control wheel braking and results in low level of tire slip, has been developed and tested. Tests indicate that system is feasible for operations on surfaces of different slipperinesses. System restricts tire slip and is capable of adapting to rapidly-changing surface conditions.

  10. Effect of surface texture and working gap on the braking performance of the magnetorheological fluid brake

    NASA Astrophysics Data System (ADS)

    Wang, Na; Li, Dong Heng; Li Song, Wan; Chao Xiu, Shi; Zhi Meng, Xiang

    2016-10-01

    In this paper, the effect of the surface textures of braking disc on the braking performance is experimentally investigated under the conditions of different working gaps and applied currents. For this purpose, a new configuration of magnetorheological fluid brake (MRB) with adjustable working gap is developed to improve the manufacturing accuracy and cost, and to reduce the problem of replacing the braking disc. In addition, the braking discs with three types of surface texture are designed and machined. Based on the test bed developed for the proposed MRB, a series of experiments are carried out on the manufactured prototype and the results are presented to obtain the relationship among the surface texture of the braking disc, applied current, working gap and the braking performance. The results show that the braking torque is significantly influenced by the working gap and surface texture of the braking disc, and the maximum braking torque is obtained on the conditions of 0.25 mm working gap and the braking disc with square surface texture.

  11. United States Air Force Wipe Solvent Testing

    NASA Technical Reports Server (NTRS)

    Hornung, Steven D.; Beeson, Harold D.

    2000-01-01

    The Wright-Patterson Air Force Base (WPAFB), as part of the Air Force Material Command, requested that NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) conduct testing and analyses in support of the United States Air Force Wipe Solvent Development Project. The purpose of the wipe solvent project is to develop an alternative to be used by Air Force flight line and maintenance personnel for the wipe cleaning of oxygen equipment. This report provides material compatibility, liquid oxygen (LOX) mechanical impact, autogenous ignition temperature (AIT), and gauge cleaning test data for some of the currently available solvents that may be used to replace CFC-113 and methyl chloroform. It provides data from previous WSTF test programs sponsored by the Naval Sea Systems Command, the Kennedy Space Center, and other NASA programs for the purpose of assisting WP AFB in identifying the best alternative solvents for validation testing.

  12. Optimal design of a novel configuration of MR brake with coils placed on the side housings

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc Hung; Nguyen, Ngoc Diep; Choi, Seung-Bok

    2014-03-01

    It is well known that in design of traditional magneto-rheological brake (MRB), coils are placed on the cylindrical housing of the brake. In this study, a new configuration of MR brake with coils placed on the side housings of the brake is proposed and analyzed. After briefly explaining the operating principle of the proposed configuration, the braking torque of the MR brake is analyze based on Bingham-plastic rheological model of MR fluid. The optimization of the proposed and conventional MR brakes is then performed considering maximum braking torque and mass of the brake. Based on the optimal results, a comparison between the proposed MR brakes and the conventional ones is undertaken. In addition, experimental test of the MR brakes is conducted and the results are presented in order to validate the performance characteristics of the proposed MR brake.

  13. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not to exceed 92 days. The AFM indicator calibration test orifices shall be calibrated at temperatures... feet per minute (CFM). (2) The inspector(s) shall take a position on each side of each car sometime... shall not constitute an inspection of that side of the train for purposes of this requirement; (3)...

  14. Mechanically versus electro-magnetically braked cycle ergometer: performance and energy cost of the Wingate Anaerobic Test.

    PubMed

    Micklewright, D; Alkhatib, A; Beneke, R

    2006-04-01

    Performance and metabolic profiles of the Wingate Anaerobic Test (WAnT) were compared between a mechanically resisted (ME) and an electro-magnetically braked (EE) cycle ergometer. Fifteen healthy subjects (24.0+/-3.5 years, 180.5+/-6.1 cm, 75.4+/-11.9 kg) performed a WAnT on ME, and EE 3 days apart. Performance was measured as peak power (PP), minimum power (MP), mean power (AP), time to PP (TTPP), fatigue rate (FR), and maximum cadence (RPM(MAX)). Lactic (W (LAC)) and alactic (W (PCR)) anaerobic energy were calculated from net lactate appearance and the fast component of post-exercise oxygen uptake. Aerobic metabolism (W (AER)) was calculated from oxygen uptake during the WAnT. Total energy cost (W (TOT)) was calculated as the sum of W (LAC), W (PCR), and W (AER). There was no difference between ME and EE in PP (873+/-159 vs. 931+/-193 W) or AP (633+/-89 vs. 630+/-89 W). In the EE condition TTPP (2.3+/-0.7 vs. 4.3+/-0.7 s) was longer (P<0.001), MP (464+/-78 vs. 388+/-57 W) was lower (P<0.001), FR (15.2+/-5.2 vs. 20.5+/-6.8%) was higher (P<0.005), and RPM(MAX) (168+/-18 vs. 128+/-15 rpm) was slower (P<0.001). There was no difference in W (TOT) (1,331+/-182 vs. 1,373+/-120 J kg(-1)), W (AER) (292+/-76 vs. 309+/-72 J kg(-1)), W (PCR) (495+/-153 vs. 515+/-111 J kg(-1)) or W (LAC) (545+/-132 vs. 549+/-141 J kg(-1)) between ME and EE devices. The EE produces distinctly different performance measures but valid metabolic WAnT results that may be used to evaluate anaerobic fitness.

  15. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  16. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  17. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  18. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  19. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  20. 76 FR 9717 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ..., however, specify performance requirements for the emergency brakes, after the service braking system has... antilock braking systems (ABS) on the lead unit. Some of the combinations tested exceeded 75 feet in length... & Associates, Inc., Vehicle Systems Consultants (August 1996). ``Braking and Offtracking Tests on...

  1. Antiskid braking system

    NASA Technical Reports Server (NTRS)

    Pazdera, J. S.

    1974-01-01

    Published report describes analytical development and simulation of braking system. System prevents wheels from skidding when brakes are applied, significantly reducing stopping distance. Report also presents computer simulation study on system as applied to aircraft.

  2. 49 CFR 383.135 - Passing knowledge and skills tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., a full air brake restriction must be indicated on the license as required in § 383.95(b). (5) If a... that the applicant can safely and effectively operate the vehicle's full air brakes, air over hydraulic brakes, and/or manual transmission. In addition, to remove the air brake or full air brake...

  3. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system....

  4. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system....

  5. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system....

  6. Performance of an aircraft tire under cyclic braking and of a currently operational antiskid braking system

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1972-01-01

    An experimental investigation was conducted to study the performance of an aircraft tire under cyclic braking conditions and to study the performance of a currently operational aircraft antiskid braking system. Dry, damp, and flooded runway surface conditions were used in the investigation. The results indicated that under cyclic braking conditions the braking and cornering-force friction coefficients may be influenced by fluctuations in the vertical load, flexibility in the wheel support, and the spring coupling between the wheel and the tire-pavement interface. The cornering capability was shown to be negligible at wheel slip ratios well below a locked-wheel skid under all test surface conditions. The maximum available brake-force friction coefficient was shown to be dependent upon the runway surface condition, upon velocity, and, for wet runways, upon tire differences. Moderate reductions in vertical load and brake system pressure did not significantly affect the overall wet-runway performance of the tire.

  7. ASTM Validates Air Pollution Test Methods

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1973

    1973-01-01

    The American Society for Testing and Materials (ASTM) has validated six basic methods for measuring pollutants in ambient air as the first part of its Project Threshold. Aim of the project is to establish nationwide consistency in measuring pollutants; determining precision, accuracy and reproducibility of 35 standard measuring methods. (BL)

  8. Experimental investigation of an accelerometer controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1972-01-01

    An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

  9. Brake Fundamentals. Automotive Articulation Project.

    ERIC Educational Resources Information Center

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  10. Landing and Braking of Airplanes

    NASA Technical Reports Server (NTRS)

    Breguet, Louis

    1929-01-01

    In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.

  11. Review of NASA antiskid braking research

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1982-01-01

    NASA antiskid braking system research programs are reviewed. These programs include experimental studies of four antiskid systems on the Langley Landing Loads Track, flights tests with a DC-9 airplane, and computer simulation studies. Results from these research efforts include identification of factors contributing to degraded antiskid performance under adverse weather conditions, tire tread temperature measurements during antiskid braking on dry runway surfaces, and an assessment of the accuracy of various brake pressure-torque computer models. This information should lead to the development of better antiskid systems in the future.

  12. Reel safety brake

    NASA Technical Reports Server (NTRS)

    Carle, C. E. (Inventor)

    1976-01-01

    A braking apparatus is described for a tape transport device having two stacked coaxial reels and feelers mounted in proximity to the reels for sensing the tape being wound on each reel. A device is mounted in proximity to adjacent central hubs of the reels to a simultaneously, frictionally engage both hubs and brake both reels. A mechanical actuator is coupled to both feelers and to the brake device. The brake means comprises a pair of rubber shoulders that extend in opposite directions relative to a common axis, and turns about the axis in response to either of the feelers.

  13. VERIFICATION TESTING OF TECHNOLOGIES TO CLEAN OR FILTER VENTILATION AIR

    EPA Science Inventory

    Because of the importance of indoor air quality, Research Triangle Institute's Air Pollution Control Technology is adding indoor air products as a new technology category available for testing. This paper discusses RTI's participation in previous Environmental Technology Verifica...

  14. An antilock molecular braking system.

    PubMed

    Sun, Wei-Ting; Huang, Shou-Ling; Yao, Hsuan-Hsiao; Chen, I-Chia; Lin, Ying-Chih; Yang, Jye-Shane

    2012-08-17

    A light-driven molecular brake displaying an antilock function is constructed by introducing a nonradiative photoinduced electron transfer (PET) decay channel to compete with the trans (brake-off) → cis (brake-on) photoisomerization. A fast release of the brake can be achieved by deactivating the PET process through addition of protons. The cycle of irradiation-protonation-irradiation-deprotonation conducts the brake function and mimics the antilock braking system (ABS) of vehicles.

  15. Air-breathing Rocket Engine Test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This Quick Time movie depicts the Rocketdyne static test of an air-breathing rocket. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's advanced Transportation Program at the Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  16. Optical Air Flow Measurements for Flight Tests and Flight Testing Optical Air Flow Meters

    NASA Technical Reports Server (NTRS)

    Jentink, Henk W.; Bogue, Rodney K.

    2005-01-01

    Optical air flow measurements can support the testing of aircraft and can be instrumental to in-flight investigations of the atmosphere or atmospheric phenomena. Furthermore, optical air flow meters potentially contribute as avionics systems to flight safety and as air data systems. The qualification of these instruments for the flight environment is where we encounter the systems in flight testing. An overview is presented of different optical air flow measurement techniques applied in flight and what can be achieved with the techniques for flight test purposes is reviewed. All in-flight optical airflow velocity measurements use light scattering. Light is scattered on both air molecules and aerosols entrained in the air. Basic principles of making optical measurements in flight, some basic optical concepts, electronic concepts, optoelectronic interfaces, and some atmospheric processes associated with natural aerosols are reviewed. Safety aspects in applying the technique are shortly addressed. The different applications of the technique are listed and some typical examples are presented. Recently NASA acquired new data on mountain rotors, mountain induced turbulence, with the ACLAIM system. Rotor position was identified using the lidar system and the potentially hazardous air flow profile was monitored by the ACLAIM system.

  17. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake...

  18. Status of recent aircraft braking and cornering research

    NASA Technical Reports Server (NTRS)

    Stubbs, S. M.; Tanner, J. A.

    1976-01-01

    The sources of degraded performance which sometimes occurs under adverse runway conditions, are investigated to obtain data necessary to the development of more advanced systems, in an effort to insure safe ground handling operations under all-weather conditions. Tire-to-ground friction characteristics are determined under braking conditions which closely resemble those of airplanes under heavy braking. Braking data from single-wheel landing loads track tests are related with those available from full-scale flight tests.

  19. Aerodynamic braking of high speed ground transportation vehicles.

    NASA Technical Reports Server (NTRS)

    Marte, J. E.; Marko, W. J.

    1973-01-01

    The drag effectiveness of aerodynamic brakes arranged in series on a train-like vehicle was investigated. Fixed- and moving-model testing techniques were used in order to determine the importance of proper vehicle-ground interference simulation. Fixed-model tests were carried out on a sting-mounted model: alone; with a fixed ground plane; and in proximity to an image model. Moving-model tests were conducted in a vertical slide-wire facility with and without a ground plane. Results from investigations of one brake configuration are presented which show the effect of the number of brakes in the set and of spacing between brakes.

  20. A New Dynamometer Brake

    NASA Technical Reports Server (NTRS)

    Segre, Marco

    1921-01-01

    The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.

  1. Space shuttle wheels and brakes

    NASA Technical Reports Server (NTRS)

    Carsley, R. B.

    1985-01-01

    The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

  2. WIND BRAKING OF MAGNETARS

    SciTech Connect

    Tong, H.; Xu, R. X.; Qiao, G. J.; Song, L. M.

    2013-05-10

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L{sub x}<- E-dot{sub rot} may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  3. Air-Breathing Rocket Engine Test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This photograph depicts an air-breathing rocket engine that completed an hour or 3,600 seconds of testing at the General Applied Sciences Laboratory in Ronkonkoma, New York. Referred to as ARGO by its design team, the engine is named after the mythological Greek ship that bore Jason and the Argonauts on their epic voyage of discovery. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's Advanced SpaceTransportation Program at Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  4. Improved Electromagnetic Brake

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may

  5. Wind-Tunnel Investigations of Diving Brakes

    NASA Technical Reports Server (NTRS)

    Fucha, D.

    1942-01-01

    Unduly high diving speeds can be effectively controlled by diving brakes but their employment involves at the same time a number of disagreeable features: namely, rotation of zero lift direction, variation of diviving moment, and, the creation of a potent dead air region.

  6. Braking System for Wind Turbines

    NASA Technical Reports Server (NTRS)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  7. Evaluation of materials and design modifications for aircraft brakes

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  8. Consideration of Materials for Aircraft Brakes

    NASA Technical Reports Server (NTRS)

    Peterson, M. B.; Ho, T.

    1972-01-01

    An exploratory investigation was conducted concerning materials and their properties for use in aircraft brakes. Primary consideration was given to the heat dissipation and the frictional behavior of materials. Used brake pads and rotors were analyzed as part of the investigation. A simple analysis was conducted in order to determine the most significant factors which affect surface temperatures. It was found that where size and weight restrictions are necessary, the specific heat of the material, and maintaining uniform contact area are the most important factors. A criterion was suggested for optimum sizing of the brake disks. Bench friction tests were run with brake materials. It was found that there is considerable friction variation due to the formation and removal of surface oxide films. Other causes of friction variations are surface softening and melting. The friction behavior at high temperature was found to be more characteristic of the steel surface rather than the copper brake material. It is concluded that improved brake materials are feasible.

  9. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its... Class I or IA brake test. Passenger equipment hauled or used in service in a commuter or passenger train... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which...

  10. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its... Class I or IA brake test. Passenger equipment hauled or used in service in a commuter or passenger train... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which...

  11. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its... Class I or IA brake test. Passenger equipment hauled or used in service in a commuter or passenger train... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which...

  12. A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

    NASA Technical Reports Server (NTRS)

    Barthlome, D. E.

    1975-01-01

    Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

  13. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    NASA Astrophysics Data System (ADS)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  14. Test plan for air monitoring during the Cryogenic Retrieval Demonstration

    SciTech Connect

    Yokuda, E.

    1992-06-01

    This report presents a test plan for air monitoring during the Cryogenic Retrieval Demonstration (CRD). Air monitors will be used to sample for the tracer elements neodymium, terbium, and ytterbium, and dysprosium. The results from this air monitoring will be used to determine if the CRD is successful in controlling dust and minimizing contamination. Procedures and equipment specifications for the test are included.

  15. TEST PAGE Air Data From Richmond, VA

    EPA Pesticide Factsheets

    This page presents graphs showing radiation air monitoring data for Riverside, CA from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  16. Airborne asbestos exposure during light aircraft brake replacement.

    PubMed

    Blake, Charles L; Johnson, Giffe T; Harbison, Raymond D

    2009-08-01

    Asbestos containing materials are a component of many vehicle brake systems, including those found in some light aircraft. To characterize the asbestos exposure that results from the installation and maintenance of these components, an aircraft fitted with asbestos containing brake pads had brake changes performed while both area and personal air samples were taken. The brake changing process took place in a closed, unventilated aircraft hanger and all operations were performed according to the manufacturer's recommended procedure. Personal air samples did not detect any measurable amount of asbestos fibers during the brake changing or subsequent cleanup procedures. Analysis of personal samples (n=9) using phase contrast microscopy indicated airborne fiber concentrations at or below 0.003f/ml as 8-h time weighted averages (TWAs) and less than 0.069f/ml averaged over 28-30min sampling periods. Airborne chrysotile fibers were detected by two area air samples with fiber concentrations remaining at or below 0.0013f/ml over an 8-h TWA. These results indicate that normal brake changing work practices on aircraft with asbestos containing brake pads does not produce a harmful level of asbestos exposure for aircraft mechanics.

  17. Copper leaching from brake wear debris in standard extraction solutions.

    PubMed

    Hur, Jin; Yim, Soobin; Schlautman, Mark A

    2003-10-01

    Quantification of the copper content of and copper leaching from a disc brake wear debris sample was performed using microwave-assisted acid digestion, the Federal Toxicity Characteristic Leaching Procedure (TCLP), and the State of California Waste Extraction Test (WET). The brake wear debris tested was a composite sample obtained from a brake dynamometer test of one brake pad source material. Comparative digestion studies demonstrated that a modified aqua regia matrix (HNO3:HCl:H2O2 = 1:3:0.5) optimized the digestion effectiveness for determining the total copper content in the brake wear debris. No significant sample heterogeneity within the brake wear debris was observed, based on statistically indistinguishable total copper content results for subsamples with a wide range of sample masses. Upon pooling all subsample results, an overall total copper content for the composite brake wear debris sample was determined to be 10.8% (g/g), with a 95% confidence limit of +/- 0.5% (g/g). Copper leaching increased with decreasing solid-to-liquid ratios in TCLP tests, but was unaffected by the solid-to-liquid ratio in the WET. For a 1:10(4) (g/g) solid-to-liquid ratio, 85% and 99% of the total mass of copper present in the composite brake wear debris sample was leached into solution during the TCLP and WET, respectively. Rate studies also demonstrated that the WET resulted in a faster rate and higher extent of copper leaching relative to the TCLP. Compared to reference copper-containing materials, the composite brake wear debris sample exhibited relatively higher TCLP and WET copper leaching characteristics. The higher copper leaching exhibited by the brake wear debris sample may have resulted from its higher specific surface area and/or from changes in the chemical form of copper that occurred during the braking process.

  18. Acceptance Test Report for 241-U compressed air system

    SciTech Connect

    Freeman, R.D.

    1994-10-20

    This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027.

  19. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) The piston travel limits indicated on the stencil, sticker, or badge plate for the brake cylinder with... diameters) brake cylinders, all cars shall have a legible decal, stencil, or sticker affixed to the car or..., if different from Class I brake test limits. The decal, stencil, sticker, or badge plate shall...

  20. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) The piston travel limits indicated on the stencil, sticker, or badge plate for the brake cylinder with... diameters) brake cylinders, all cars shall have a legible decal, stencil, or sticker affixed to the car or..., if different from Class I brake test limits. The decal, stencil, sticker, or badge plate shall...

  1. Nondestructive testing using air-borne ultrasound.

    PubMed

    Hsu, David K

    2006-12-22

    Over the last two decades, more efficient transducers were developed for the generation and reception of air-borne ultrasound, thus enabling the non-contact, non-contaminating inspection of composite laminates and honeycomb structures widely used in the aerospace industry. This paper presents the fundamentals of making air-borne ultrasonic measurement, and point out special considerations unique to propagating ultrasound in air and through solids. Transducer beam profile characterization, thickness dependence and resonance effects in the transmission of air-coupled ultrasound through plates, and the detection and imaging of defects and damage in solid laminates and honeycomb sandwich will be discussed and illustrated with examples. Finally, a manual scan system developed for implementing air-borne ultrasonic imaging in the field and on aircraft will be introduced.

  2. Safety brake for tape reels

    NASA Technical Reports Server (NTRS)

    Carle, C. E.

    1977-01-01

    All-mechanical device senses end of tape and stops reel, even in event of electronic system failure. Assembly includes stop to prevent brake from overriding tape. Recentering mechanism returns brake to neutral position after torque is removed from reels.

  3. Brake-By-Wire Program

    DTIC Science & Technology

    2006-05-31

    SUPPLEMENTARY NOTES Report contains color. 14. ABSTRACT Two design iterations for electric calipers and two systems (full brake by wire and hybrid brakes ...were developed for use on a ground vehicle. The program demonstrated a fully integrated electric caliper and full brake -by-wire system on a sports...release. Project Context The development of an electric brake caliper and associated systems for automotive application represented a significant

  4. Brake Fluid Compatibility with Hardware

    DTIC Science & Technology

    2014-05-19

    had two servo valves for each wheel. One of the wheel servo valves controlled pressurized fluid to the brake calipers , while the second servo valve...was responsible for anti-lock or brake release action by relieving caliper circuit pressure back to the reservoir. Brake circuit action was initiated...

  5. Air Pollution Tests Using the "DEMA"

    ERIC Educational Resources Information Center

    Wilt, L. M.

    1970-01-01

    Describes the making and calibrating of a DEMA (DEvice for Measuring Air) from readily available, inexpensive materials. Procedures for measuring atmospheric particulates, acids, and carbon monoxide are described. (PR)

  6. Air Velocity Mapping of Environmental Test Chambers

    DTIC Science & Technology

    1989-07-01

    variable that must be measured for the evaluations of the air diffusion performance index (ADPI), or the thermal comfort indices such as predicted mean...altered. The impact of asymmetrical airflow patterns undoubtedly affect human thermal comfort votes. The standardized 6 technique described in this...report could be easily employed prior to or along with specific studies requiring precise air velocity data, and coupled with human thermal comfort surveys

  7. Development and testing of a hot-air solar collector

    NASA Technical Reports Server (NTRS)

    Caudle, J. M.

    1979-01-01

    Summarized report on development and testing of hot-air flat-plate solar collector includes structural details, coating selection, and spacing between coating and glass plate. Report gives complete performance specifications and extensive certifications test report.

  8. Design of haptic master featuring small-sized MR brakes

    NASA Astrophysics Data System (ADS)

    Gang, Han Gyeol; Choi, Seung-Bok; Sohn, Jung Woo

    2016-04-01

    In this work, a new type of haptic master featuring small-sized MR brake is proposed and its performances are evaluated. The proposed haptic master consists of base frame, stick grip and small-sized four MR brakes for 3-DOF rotational motion and 1-DOF gripper motion. To obtain large braking torque under limited small size of MR brake, dual tapered shape inner magnetic core is proposed and its performance is evaluated via both numerical estimation and experimental test. After design and implementation of control algorithm, it has been demonstrated through experiment that the proposed actuator has good performances on tracking control of desired torques. Then, a new haptic master device is designed and constructed by adopting the proposed MR brakes and light weight frame structures. It is verified that the proposed haptic master device is effective for the real application in the field.

  9. Heat distribution in disc brake

    NASA Astrophysics Data System (ADS)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

    This article is deals by the thermal analysis of the disc brake with floating caliper. The issue is solved by numerically. The half 2D model is used for solution in program ADINA 8.8. Two brake discs without the ventilation are solved. One disc is made from cast iron and the second is made from stainless steel. Both materials are an isotropic. By acting the pressure force on the brake pads will be pressing the pads to the brake disc. Speed will be reduced (slowing down). On the contact surface generates the heat, which the disc and pads heats. In the next part of article is comparison the maximum temperature at the time of braking. The temperatures of both materials for brake disc (gray cast iron, stainless steel) are compares. The heat flux during braking for the both materials is shown.

  10. Dental air turbine handpiece performance testing.

    PubMed

    Dyson, J E; Darvell, B W

    1995-10-01

    Air turbine handpieces are expected to continue to be widely used as the main means of carrying out dental cutting work and scope exists for further design improvements. An understanding of the theoretical principles governing the performance of these devices seems essential for the systematic development of better handpiece designs and methods of specification. Furthermore, for experimental work on cutting behaviour with air turbine equipment, this knowledge is required for appropriate characterization of the performance of the particular handpiece used with respect to actual rates of energy disposition. The literature relating to air turbine handpiece performance is critically reviewed to assess currently available methods of measuring important variables such as speed, torque, and power. In this, consideration is given to the current state of knowledge of the influence on these variables of air pressure, flow and turbine design features. It is apparent that, although various measurement methods have been described and data for individual handpieces published, no attempt has yet been made to explore the functional relationships that exist between the variables. It is concluded that there is a need to identify the factors influencing turbine performance, to develop measurement systems which would provide adequate accuracy and precision and then to investigate the functional relationships between these relevant variables.

  11. PERFORMANCE TESTING OF AIR CLEANING PRODUCTS

    EPA Science Inventory

    The paper discuses the application of the Environmental Technology Verification (ETV) Program for products that clean ventilation air to the problem of protecting buildings from chemical and biological attack. This program is funded by the U.S. Environmental Protection Agency und...

  12. An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part V - Wing-Alone Tests and Effect of Modifications to the Vertical Fins, Speed Brakes, and Fuselage TED No. NACA DE308. Part V; Wing-Alone Tests and Effect of Modifications to the Vertical Fins, Speed Brakes, and Fuselage, TED No. NACA DE308

    NASA Technical Reports Server (NTRS)

    Kuhri, Richard E.; Myers, Boyd C., II

    1947-01-01

    Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The wing-alone tests and the effect of the various vertical-fin modifications, speed-brake modifications, and fuselage modifications on the aerodynamic characteristics in pitch and yaw are presented in the present paper with a limited analysis of the results. Also included are tuft studies of the flow for some of the modifications tested.

  13. Radiant heat test of Perforated Metal Air Transportable Package (PMATP).

    SciTech Connect

    Gronewald, Patrick James; Oneto, Robert; Mould, John; Pierce, Jim Dwight

    2003-08-01

    A conceptual design for a plutonium air transport package capable of surviving a 'worst case' airplane crash has been developed by Sandia National Laboratories (SNL) for the Japan Nuclear Cycle Development Institute (JNC). A full-scale prototype, designated as the Perforated Metal Air Transport Package (PMATP) was thermally tested in the SNL Radiant Heat Test Facility. This testing, conducted on an undamaged package, simulated a regulation one-hour aviation fuel pool fire test. Finite element thermal predictions compared well with the test results. The package performed as designed, with peak containment package temperatures less than 80 C after exposure to a one-hour test in a 1000 C environment.

  14. Air Force Reading Abilities Test: Utilization Assessment.

    DTIC Science & Technology

    1984-03-01

    COMPLETING FORM 1. REPORT NUMBER 2 . GOVTAC NO Y3C NT. CATALOG NUMBER AFHRL-SR-83-23 Ik6. 4. TITLE (awd Su,$9k) S. TYPE OF REPORT & PERIOD COVERED AIR FORCE...the R&DI AFHRL. TR-78.82, Predichon of Reading Grade Li.s of Seim. AApdwo from Armed Serice. Vocaionaj Ap ude Batery (ASVAB); AFHRL.TR-80-11, Reading

  15. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    Rudd, A.; Bergey, D.

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  16. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    Rudd, Armin; Bergey, Daniel

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  17. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  18. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  19. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... the braking surface. (iii) Braking is to be performed using only those braking systems, including... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  20. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  1. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  2. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  3. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... the braking surface. (iii) Braking is to be performed using only those braking systems, including... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  4. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  5. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  6. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  7. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  8. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  9. Characterization of vehicular brake service personnel exposure to airborne asbestos and particulate.

    PubMed

    Weir, F W; Tolar, G; Meraz, L B

    2001-12-01

    Evaluation of fibers and total particulate generated during the servicing of drum brakes on motor vehicles as well as during the resurfacing (arcing) of brake shoes was conducted. Conditions for the studies were based on review of contemporary (approximately 1950-1980) working practices in the industry. This work was conducted in two parts. Phase 1 estimated the release of asbestos fibers and total particulate during brake inspection and replacement of light-duty vehicle rear drum brakes at an auto/truck repair facility. Two distinct work practices were evaluated: One rear wheel from each vehicle was serviced using compressed air to remove dust while the second rear wheel was serviced without compressed air. Area and personal monitoring of fiber levels demonstrated counts (without compressed air) that ranged from 0.05 to 0.2 f/cc. Fiber counts when using compressed air averaged from 0.05 to 0.9 f/cc. Results from real-time aerosol monitoring indicated elevated dust levels for about 15 minutes after blow out. With shop doors open, dust levels increased to 5.0 mg/m3 at blow out and returned to 0.08 mg/m3 within two minutes. When the shop doors were closed, the dust levels reached 13.5 mg/m3 at blow out and decreased to 1.68 mg/m3 within one minute and to background within 14 minutes. The Phase 2 series evaluated the release of fibers and other particulate from are grinding. For operations conducted under conditions simulating a workplace, a mean of 0.19 f/cc +/- 0.16 was determined. Dust levels averaged 0.25 mg/m3 +/- 0.05. Brake service monitoring in these tests demonstrates that asbestos fiber concentrations, considered on a time weighted average basis, should not exceed currently acceptable workplace standards whether or not the worker uses compressed air, nor during the arc grinding process when arcing is conducted in accord with the design of the equipment.

  10. Evaluation of unsaturated zone air permeability through pneumatic tests

    USGS Publications Warehouse

    Baehr, Arthur L.; Hult, Marc F.

    1991-01-01

    Predicting the steady state distribution of air pressure in the unsaturated zone resulting from a pneumatic test provides a method for determining air-phase permeability. This technique is analogous to the inverse problem of well hydraulics; however, air flow is more complicated than ground water flow because of air compressibility, the Klinkenberg effect, variations in air density and viscosity that result from temperature fluctuations in the unsaturated zone and the possibility of inducing water movement during the pneumatic test. An analysis of these complicating factors reveals that, when induced water movement can be neglected, a linear version of the airflow equation can provide an appropriate approximation for the purpose of determining air-phase permeability. Two analytical solutions for steady state, two-dimensional, axisymmetric airflow to a single well partially screened in the unsaturated zone are developed. One solution applies where there is a stratum of relatively low air permeability, separating the stratum in which the well is completed, from the atmosphere. The other solution applies where there is no separating stratum between the domain and atmosphere. In both situations the water table forms the lower horizontal boundary. Applications of both solutions to determine air permeability from data collected during pneumatic tests are presented.

  11. MHD air preheaters: Results of thermomechanical tests

    SciTech Connect

    Valente, T. )

    1994-12-01

    The thermomechanical tests conducted on four different high-purity periclase magnesia-fired brick were used to select suitable refractory material for the design of a regenerative heat exchanger (Cowper type) for an open-cycle indirect preheating, MHD pilot plant. Tests were conducted under the most severe temperature condition allowable in standard test equipment. The choice among the refractories were made supposing that the ranking established with these tests does not change for higher temperatures (up to 1,900 C). Refractory material M1 exhibited the best behavior. The reported values can be used for the preliminary design of the heat exchanger, using the appropriate safety coefficient. The effective behavior of the materials can be completely understood only with experimental data obtained by the effective operation condition, because size and shape of the material strongly affect the service behavior. The best test is a pilot plant, using scaled-down criteria. This will overcome the difficulty of the standard test at 1,900 C, caused by test equipment limitations.

  12. DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS

    SciTech Connect

    Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

    2012-09-20

    Soil vapor extraction (SVE) and air injection well testing was performed at the Dynamic Underground Stripping (DUS) site located near the M-Area Settling Basin (referred to as DUS II in this report). The objective of this testing was to determine the effectiveness of continued operation of these systems. Steam injection ended on September 19, 2009 and since this time the extraction operations have utilized residual heat that is present in the subsurface. The well testing campaign began on June 5, 2012 and was completed on June 25, 2012. Thirty-two (32) SVE wells were purged for 24 hours or longer using the active soil vapor extraction (ASVE) system at the DUS II site. During each test five or more soil gas samples were collected from each well and analyzed for target volatile organic compounds (VOCs). The DUS II site is divided into four parcels (see Figure 1) and soil gas sample results show the majority of residual VOC contamination remains in Parcel 1 with lesser amounts in the other three parcels. Several VOCs, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were detected. PCE was the major VOC with lesser amounts of TCE. Most soil gas concentrations of PCE ranged from 0 to 60 ppmv with one well (VEW-22A) as high as 200 ppmv. Air sparging (AS) generally involves the injection of air into the aquifer through either vertical or horizontal wells. AS is coupled with SVE systems when contaminant recovery is necessary. While traditional air sparging (AS) is not a primary component of the DUS process, following the cessation of steam injection, eight (8) of the sixty-three (63) steam injection wells were used to inject air. These wells were previously used for hydrous pyrolysis oxidation (HPO) as part of the DUS process. Air sparging is different from the HPO operations in that the air was injected at a higher rate (20 to 50 scfm) versus HPO (1 to 2 scfm). . At the DUS II site the air injection wells were tested to determine if air sparging affected

  13. Brake lock mechanism for the two axis pointing system

    NASA Technical Reports Server (NTRS)

    Posey, Alan; Clark, Mike; Mignosa, Larry

    1991-01-01

    Six months prior to shipment of the Broadband X-ray Telescope to the Kennedy Space Center for flight aboard the Space Shuttle Columbia, a major system failure occurred. During modal survey testing of the telescope's gimbal pointing system, the roll axis brake unexpectedly released. Low level vibration and static preloads present during the modal survey were within the expected flight environment. Brake release during shuttle liftoff or ascent was an unacceptable risk to mission success; thus, a Brake Lock Mechanism (BLM) was developed.

  14. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system. [70 FR 48050, Aug. 15, 2005]...

  15. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system. [70 FR 48050, Aug. 15, 2005]...

  16. Air-Breathing Engine Test Facilities Register,

    DTIC Science & Technology

    1981-07-01

    Ontario Pratt & Whitney Aircraft 4 8 + (1) 2-4 of Canada Ltd. St. Hubert and Longueuil , Quebec (1) Rolls Royce (Canada) Ltd. 2 2 2-5 Lachine and Montreal...ORGANISATION NAME Pratt & Whitney Aircraft of Canada Ltd. ADDRESS Longueuil , Quebec, Canada CONTACT Manager, Test Support Engineering Phone 677-9411...CELLS IDENTIFICATION ORGANISATION LOCATION TEST CELL DESIGNATION Pratt & Whitney Longueuil 1 - 11 A Aircraft of Canada Ltd. Quebec Longueuil , Quebec

  17. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  18. Combined hydraulic and regenerative braking system

    SciTech Connect

    Venkataperumal, Rama R.; Mericle, Gerald E.

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  19. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  20. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  1. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  2. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  3. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  4. The History of Static Test and Air Force Structures Testing

    DTIC Science & Technology

    1979-06-01

    incremental loads were being appllied according to the spanwise and chordwise requirements. Once that load increent was in place, the structure was then loaded...Programming of this equipment was accomplished with a language called FOCAL, then BASIC and finally FORTRAN with aisembly language handlers. it took...programs. Software was custort tailored and written in Control Data Corporation 1604 computer assembly language . Air Force efforts to improve the

  5. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-11-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel-Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0-2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

  6. Laboratory Performance Testing of Residential Window Air Conditioners

    SciTech Connect

    Winkler, J.; Booten, C.; Christensen, D.; Tomerlin, J.

    2013-03-01

    Window air conditioners are the dominant cooling product for residences, in terms of annual unit sales. They are inexpensive, portable and can be installed by the owner. For this reason, they are an attractive solution for supplemental cooling, for retrofitting air conditioning into a home which lacks ductwork, and for renters. Window air conditioners for sale in the United States are required to meet very modest minimum efficiency standards. Four window air conditioners' performance were tested in the Advanced HVAC Systems Laboratory on NREL's campus in Golden, CO. In order to separate and study the refrigerant system's performance, the unit's internal leakage pathways, the unit's fanforced ventilation, and the leakage around the unit resulting from installation in a window, a series of tests were devised that focused on each aspect of the unit's performance. These tests were designed to develop a detailed performance map to determine whole-house performance in different climates. Even though the test regimen deviated thoroughly from the industry-standard ratings test, the results permit simple calculation of an estimated rating for both capacity and efficiency that would result from a standard ratings test. Using this calculation method, it was found that the three new air conditioners' measured performance was consistent with their ratings. This method also permits calculation of equivalent SEER for the test articles. Performance datasets were developed across a broad range of indoor and outdoor operating conditions, and used them to generate performance maps.

  7. IMPROVED TEST METHODS FOR ELECTRONIC AIR CLEANERS

    EPA Science Inventory

    The objective of this project was to develop a fractional filtration efficiency test protocol for residential electrostatic precipitators (ESPs) that avoids the limitations of the ASHRAE 52.2 method. Specifically, the objectives were to a) determine the change in efficiency that ...

  8. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    NASA Astrophysics Data System (ADS)

    Minh, Vu Trieu; Oamen, Godwin; Vassiljeva, Kristina; Teder, Leo

    2016-11-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. This paper provides educational theories and practices on the design of control for system dynamics.

  9. Estimation of personal exposure to asbestos of brake repair workers.

    PubMed

    Cely-García, María Fernanda; Curriero, Frank C; Sánchez-Silva, Mauricio; Breysse, Patrick N; Giraldo, Margarita; Méndez, Lorena; Torres-Duque, Carlos; Durán, Mauricio; González-García, Mauricio; Parada, Patricia; Ramos-Bonilla, Juan Pablo

    2016-12-14

    Exposure assessments are key tools to conduct epidemiological studies. Since 2010, 28 riveters from 18 brake repair shops with different characteristics and workloads were sampled for asbestos exposure in Bogotá, Colombia. Short-term personal samples collected during manipulation activities of brake products, and personal samples collected during non-manipulation activities were used to calculate 103 8-h TWA PCM-equivalent personal asbestos concentrations. The aims of this study are to identify exposure determinant variables associated with the 8-h TWA personal asbestos concentrations among brake mechanics, and propose different models to estimate potential asbestos exposure of brake mechanics in an 8-h work-shift. Longitudinal-based multivariate linear regression models were used to determine the association between personal asbestos concentrations in a work-shift with different variables related to work tasks and workload of the mechanics, and some characteristics of the shops. Monte Carlo simulations were used to estimate the 8-h TWA PCM-Eq personal asbestos concentration in work-shifts that had manipulations of brake products or cleaning activities of the manipulation area, using the results of the sampling campaigns. The simulations proposed could be applied for both current and retrospective studies to determine personal asbestos exposures of brake mechanics, without the need of sampling campaigns or historical data of air asbestos concentrations.Journal of Exposure Science and Environmental Epidemiology advance online publication, 14 December 2016; doi:10.1038/jes.2016.76.

  10. Air Force Officer Qualifying Test (AFOQT) Form P: Test Manual

    DTIC Science & Technology

    1990-04-01

    Training Corps (AFROTC) and the Officer Training School (OTS). (The third program, which is offered at the Air Force Academy in Colorado Springs...Ine first is a pair ot words I’,md by the phrasu "is to" to express a relationship between them, followed i)v a third word, the stimulus. Ihe...cells increase from left to right and from top to bottom. A cell number may be identical to the cell number in the cell above or to the left of it or

  11. Fabrication of VB2/Air Cells for Electrochemical Testing

    PubMed Central

    Stuart, Jessica; Lopez, Ruben; Lau, Jason; Li, Xuguang; Waje, Mahesh; Mullings, Matthew; Rhodes, Christopher; Licht, Stuart

    2013-01-01

    A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode. PMID:23962835

  12. Fabrication of VB2/air cells for electrochemical testing.

    PubMed

    Stuart, Jessica; Lopez, Ruben; Lau, Jason; Li, Xuguang; Waje, Mahesh; Mullings, Matthew; Rhodes, Christopher; Licht, Stuart

    2013-08-05

    A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

  13. HESTIA Phase I Test Results: The Air Revitalization System

    NASA Technical Reports Server (NTRS)

    Wright, Sarah E.; Hansen, Scott W.

    2016-01-01

    In any human spaceflight mission, a number of Environmental Control & Life Support System (ECLSS) technologies work together to provide the conditions astronauts need to live healthily, productively, and comfortably in space. In a long-duration mission, many of these ECLSS technologies may use materials supplied by In-Situ Resource Utilization (ISRU), introducing more interactions between systems. The Human Exploration Spacecraft Test-bed for Integration & Advancement (HESTIA) Project aims to create a test-bed to evaluate ECLSS and ISRU technologies and how they interact in a high-fidelity, closed-loop, human-rated analog habitat. Air purity and conditioning are essential components within any ECLSS and for HESTIA's first test they were achieved with the Air Revitalization System (ARS) described below. The ARS provided four essential functions to the test-bed chamber: cooling the air, removing humidity from the air, removing trace contaminants, and scrubbing carbon dioxide (CO2) from the air. In this case, the oxygen supply function was provided by ISRU. In the current configuration, the ARS is a collection of different subsystems. A fan circulates the air, while a condensing heat exchanger (CHX) pulls humidity out of the air. A Trace Contaminant Removal System (TCRS) filters the air of potentially harmful contaminants. Lastly, a Reactive Plastic Lithium Hydroxide (RP-LiOH) unit removes CO2 from the breathing air. During the HESTIA Phase I test in September 2015, the ARS and its individual components each functioned as expected, although further analysis is underway. During the Phase I testing and in prior bench-top tests, the energy balance of heat removed by the CHX was not equal to the cooling it received. This indicated possible instrument error and therefore recalibration of the instruments and follow-up testing is planned in 2016 to address the issue. The ARS was tested in conjunction with two other systems: the Human Metabolic Simulator (HMS) and the

  14. Comparison of weighted jump squat training with and without eccentric braking.

    PubMed

    Hori, Naruhiro; Newton, Robert U; Kawamori, Naoki; McGuigan, Michael R; Andrews, Warren A; Chapman, Dale W; Nosaka, Kazunori

    2008-01-01

    The purpose of this study was to investigate the effect of weighted jump squat training with and without eccentric braking. Twenty male subjects were divided into two groups (n = 10 per group), Non-Braking Group and Braking Group. The subjects were physically active, but not highly trained. The program for Non-Braking Group consisted of 6 sets of 6 repetitions of weighted jump squats without reduction of eccentric load for 8 weeks. The training program for the Braking Group consisted of the same sets and repetitions, but eccentric load was reduced by using an electromagnetic braking mechanism. Jump and reach, countermovement jump, static jump, drop jump, one repetition maximum half squat, weighted jump squat, and isometric/isokinetic knee extension/flexion at several different positions/angular velocities were tested pre- and posttraining intervention. The Non-Braking Group exhibited greater improvement in peak torque during isokinetic concentric knee flexion at 300 degrees/s [Non-Braking Group: (mean +/- SD) 124.0 +/- 22.6 Nm at pre- and 134.1 +/- 18.4 Nm at posttraining, and Braking Group: 118.5 +/- 32.7 Nm at pre- and 113.2 +/- 26.7 Nm at posttraining]. Braking Group exhibited superior adaptations in peak power relative to body mass during weighted jump squat [Non-Braking Group: (mean +/- SD) 49.1 +/- 8.6 W/kg at pre- and 50.9 +/- 6.2 W/kg at posttraining, and Braking Group: 47.9 +/- 6.9 W/kg at pre- and 53.7 +/- 7.3 W/kg at posttraining]. It appears that power output in relatively slow movement (weighted jump squat) was improved more in the Braking Group, however strength in high velocity movements (isokinetic knee flexion at 300 degrees/s) was improved more in Non-Braking Group. This study supports load and velocity specific effects of weighted jump squat training.

  15. Airline Transport Pilot-Airplane (Air Carrier) Written Test Guide.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    Presented is information useful to applicants who are preparing for the Airline Transport Pilot-Airplane (Air Carrier) Written Test. The guide describes the basic aeronautical knowledge and associated requirements for certification, as well as information on source material, instructions for taking the official test, and questions that are…

  16. Air Force Officer Qualifying Test Form O: Development and Standardization.

    ERIC Educational Resources Information Center

    Rogers, Deborah L.; And Others

    This report presents the rationale, development, and standardization of the Air Force Officer Qualifying Test (AFOQT) Form O. The test is used to select individuals for officer commissioning programs, and candidates for pilot and navigator training. Form O contains 380 items organized in 16 subtests. All items are administered in a single test…

  17. Emergency Brake for Tracked Vehicles

    NASA Technical Reports Server (NTRS)

    Green, G. L.; Hooper, S. L.

    1986-01-01

    Caliper brake automatically stops tracked vehicle as vehicle nears end of travel. Bar on vehicle, traveling to right, dislodges block between brake pads. Pads then press against bar, slowing vehicle by friction. Emergencybraking system suitable for elevators, amusement rides and machine tools.

  18. Turbine Air-Flow Test Rig CFD Results for Test Matrix

    NASA Technical Reports Server (NTRS)

    Wilson, Josh

    2003-01-01

    This paper presents the Turbine Air-Flow Test (TAFT) rig computational fluid dynamics (CFD) results for test matrix. The topics include: 1) TAFT Background; 2) Design Point CFD; 3) TAFT Test Plan and Test Matrix; and 4) CFD of Test Points. This paper is in viewgraph form.

  19. Report of the Building 9207 air bag test

    SciTech Connect

    Huff, T.E.; Fricke, K.E.; Jones, W.D.

    1992-12-01

    As part of a major testing program now underway at the Department of Energy`s (DOE) Oak Ridge Y-12 Plant, managed by Martin Marietta Energy Systems, Inc. (MMES), a full-scale air bag test was conducted in Building 9207. The test program, supported and managed by the Center for Natural Phenomena Engineering (CNPE), is intended to determine the stiffness and strength of unreinforced hollow clay tile walls (HCTVS) in order to more accurately analyze and predict the response of buildings containing these type of walls, especially when subjected to seismic and high wind loadings. The air bag test was a very large undertaking that started more than a year before the test was actually performed. Preparation for the test included the following activities: (1) preparation of the wall and the adjacent building areas; (2) design and field fabrication of test supporting structures; (3) procurement of equipment and instrumentation; (4) development of supporting test procedures and checklists; (5) installation of over seventy linear variable differential transformers (LVDTs) and strain gages; (6) development of computer programs for use in the data acquisition systems; (7) extensive review into the existing engineering literature; (8) discussions with researchers with prior experience performing air bag tests; (9) coordination with the building operators; (10) plant safety reviews; and (11) dry runs of the test itself.

  20. Experimental investigations for uncertainty quantification in brake squeal analysis

    NASA Astrophysics Data System (ADS)

    Renault, A.; Massa, F.; Lallemand, B.; Tison, T.

    2016-04-01

    The aim of this paper is to improve the correlation between the experimental and the numerical prediction of unstable frequencies for automotive brake systems considering uncertainty. First, an experimental quantification of uncertainty and a discussion analysing the contributions of uncertainty to a numerical squeal simulation are proposed. Frequency and transient simulations are performed considering nominal values of model parameters, determined experimentally. The obtained results are compared with those derived from experimental tests to highlight the limitation of deterministic simulations. The effects of the different kinds of uncertainty detected in working conditions of brake system, the pad boundary condition, the brake system material properties and the pad surface topography are discussed by defining different unstable mode classes. Finally, a correlation between experimental and numerical results considering uncertainty is successfully proposed for an industrial brake system. Results from the different comparisons reveal also a major influence of the pad topography and consequently the contact distribution.

  1. NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

    NASA Technical Reports Server (NTRS)

    Horne, W. B.

    1977-01-01

    Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

  2. Automatic transmission brake assembly including an overrunning roller brake and a friction brake

    SciTech Connect

    Premiski, V.; Hohnel, R.; Premiski, C.

    1988-10-11

    This patent describes an overrunning roller brake assembly for a planetary gear unit in an automatic transmission for automobiles, the gear unit having a ring gear, a carrier and a sun gear, the carrier having planet pinions thereon engaging the sun and ring gears; a brake for anchoring a reaction member of the gear unit, at least one other member of the gear unit being adapted to receive driving torque; the brake comprising an annular inner brake race surrounding a fixed part of the transmission, an annular outer brake race connected to the reaction member and surrounding the inner race, the outer race comprising an extrusion with an outer brake drum surface adapted to be engaged by a reaction friction brake band; overrunning brake rollers between the races, a pair of support rings between the races on either side of the rollers; the support rings having a C-shaped cross section whereby the inner and outer surfaces thereof provide a bearing support for the races; retainer rings enclosed within the support rings, the retainer rings having a radial thickness approximately equal to the radial inside dimension of the C-shaped cross section of the support rings whereby radial loads are transmitted between the races through the retainer rings and support rings.

  3. Real-Time Dynamic Brake Assessment Proof of Concept Final Report

    SciTech Connect

    Lascurain, Mary Beth; Franzese, Oscar; Capps, Gary J

    2011-11-01

    This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes are not applied due the nature of the mechanical system. This value, which may vary somewhat from one wheel end to another, is approximately 10 psi. Therefore, only pressures 15 psi and above were used in the analysis. The Department of Energy s Medium Truck Duty Cycle research has indicated that under the real-world circumstances of the test vehicle brake pressures of up to approximately 30 psi can be expected. Several different types of data were collected during the testing task of this project. Constant-pressure stopping tests were conducted at several combinations of brake application pressure (15, 20, 25, and 30 psi), load conditions (moderately and fully laden), and speeds (20 and

  4. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake system, shall meet the automatic brake adjustment system requirements of Federal Motor Vehicle Safety...

  5. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... equipped with an electrical circuit that is capable of transmitting a malfunction signal from the antilock... malfunction circuits and signals for air braked vehicles. (1) Each truck tractor manufactured on or after... to the requirements of paragraph (c) of this section, shall be equipped with an electrical...

  6. 22. INTERIOR OF BRIDGE TENDER'S HOUSE SHOWING CLUTCH AND BRAKE ...

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

    22. INTERIOR OF BRIDGE TENDER'S HOUSE SHOWING CLUTCH AND BRAKE HANDLES, AIR VALVE FOR RAIL LOCKS, AND MOTOR CONTROLLER FOR TURNING MACHINERY, LOOKING N. PHOTOGRAPHER: SARAH J. DENNETT & ROBERT A. RYAN - Keokuk & Hamilton Bridge, Spanning Mississippi River, Keokuk, Lee County, IA

  7. Study on the dynamic characteristics of a high frequency brake based on giant magnetostrictive material

    NASA Astrophysics Data System (ADS)

    Xu, Ai Qun

    2016-06-01

    In order to meet the requirements of rapid and smooth braking, high-frequency braking using a giant magnetostrictive actuator is proposed, which can solve the problems in hydraulic braking, such as, it leaks easily, catches fire easily, is difficult to find failures, high cost on maintenance and repairing, etc. The main factors affecting the force of a high-frequency braking actuator are emphatically analyzed, the brakes dynamic model is established and a performance testing device for high frequency braking is constructed based on LabVIEW. The output force of the actuator increases with the excitation current of the driving coil increasing, and the increased multiple of the output force is greater than that of the excitation current; the range of the actuator force amplitude is 121.63 N ∼ 158.14 N, which changes little, while excitation frequency changes between 200 Hz ∼ 1000 Hz. In a minor range of pre-stress, the output force decreases with an increase in the axial pre-stress of the giant magnetostrictive rod, but is not obvious. It is known by finite element simulation analysis that high-frequency braking shortens the braking displacement and time effectively, which proves the feasibility and effectiveness of high frequency braking. Theoretical analysis and experimental results indicate that the output force of the actuator changes at the same frequency with excitation current; it is controllable and its mechanical properties meet the requirements of high frequency braking.

  8. Diagnostics monitor of the braking efficiency in the on board diagnostics system for the motor vehicles

    NASA Astrophysics Data System (ADS)

    Gajek, Andrzej

    2016-09-01

    The article presents diagnostics monitor for control of the efficiency of brakes in various road conditions in cars equipped with pressure sensor in brake (ESP) system. Now the brake efficiency of the vehicles is estimated periodically in the stand conditions on the base of brake forces measurement or in the road conditions on the base of the brake deceleration. The presented method allows to complete the stand - periodical tests of the brakes by current on board diagnostics system OBD for brakes. First part of the article presents theoretical dependences between deceleration of the vehicle and brake pressure. The influence of the vehicle mass, initial speed of braking, temperature of brakes, aerodynamic drag, rolling resistance, engine resistance, state of the road surface, angle of the road sloping on the deceleration have been analysed. The manner of the appointed of these parameters has been analysed. The results of the initial investigation have been presented. At the end of the article the strategy of the estimation and signalization of the irregular value of the deceleration are presented.

  9. Brakes Specialist. Teacher Edition. Automotive Service Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for a course on becoming an automotive brakes specialist, based on the National Institute of Automotive Service Excellence task lists. The course consists of three instructional units: service brake hydraulic system and wheel bearings, service drum brakes, and service disc brakes. Depending on the…

  10. Theoretical and numerical analysis of the corneal air puff test

    NASA Astrophysics Data System (ADS)

    Simonini, Irene; Angelillo, Maurizio; Pandolfi, Anna

    2016-08-01

    Ocular analyzers are used in the current clinical practice to estimate, by means of a rapid air jet, the intraocular pressure and other eye's parameters. In this study, we model the biomechanical response of the human cornea to the dynamic test with two approaches. In the first approach, the corneal system undergoing the air puff test is regarded as a harmonic oscillator. In the second approach, we use patient-specific geometries and the finite element method to simulate the dynamic test on surgically treated corneas. In spite of the different levels of approximation, the qualitative response of the two models is very similar, and the most meaningful results of both models are not significantly affected by the inclusion of viscosity of the corneal material in the dynamic analysis. Finite element calculations reproduce the observed snap-through of the corneal shell, including two applanate configurations, and compare well with in vivo images provided by ocular analyzers, suggesting that the mechanical response of the cornea to the air puff test is actually driven only by the elasticity of the stromal tissue. These observations agree with the dynamic characteristics of the test, since the frequency of the air puff impulse is several orders of magnitude larger than the reciprocal of any reasonable relaxation time for the material, downplaying the role of viscosity during the fast snap-through phase.

  11. Testing Theoretical Models of Magnetic Damping Using an Air Track

    ERIC Educational Resources Information Center

    Vidaurre, Ana; Riera, Jaime; Monsoriu, Juan A.; Gimenez, Marcos H.

    2008-01-01

    Magnetic braking is a long-established application of Lenz's law. A rigorous analysis of the laws governing this problem involves solving Maxwell's equations in a time-dependent situation. Approximate models have been developed to describe different experimental results related to this phenomenon. In this paper we present a new method for the…

  12. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  13. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  14. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  15. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  16. 40 CFR 92.123 - Test procedure; general requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... 92.123 Section 92.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92... measurements of brake specific emissions and smoke opacity at each throttle position and of measurements...

  17. Effects of air ventilation during stationary exercise testing.

    PubMed

    Van Schuylenbergh, R; Vanden Eynde, B; Hespel, P

    2004-07-01

    The impact of air ventilation on performance and physiological responses during stationary exercise in the laboratory was studied. Fourteen well-trained cyclists performed three exercise tests on a cycle ergometer, each separated by a 1-week interval. The first test was a graded test to determine the power output corresponding with the 4-mmol l(-1) lactate level. Tests 2 and 3 were 30-min constant-load tests at a power output corresponding with this 4-mmol l(-1) lactate threshold. One constant-load test was performed in the absence (NAV), whilst the other was performed in the presence (AV) of air ventilation (3 m s(-1)). During the constant-load tests, heart rate, tympanic temperature, blood lactate concentration and oxygen uptake (VO2) were measured at 10-min intervals and at the end of the test. Differences between the two test conditions were evaluated using paired t-tests. During NAV, 12 subjects interrupted the test due to premature exhaustion (exercise duration <30 min), versus only seven in AV ( P<0.05). At the end of the test tympanic temperature was 35.9 (0.2) degrees C in AV and was higher in NAV [36.7 (0.2) degrees C, P<0.05]. Exercise heart rate increased at a faster rate during NAV [+2.2 (0.3) beats min(-1)] than during AV [+1.5 (0.2) beats min(-1), P<0.05]. Blood lactate concentration and VO2 were similar between conditions. Air ventilation is essential to prevent an upward shift in the lactate:heart rate as well as the power output:heart rate relationship during laboratory exercise testing and indoor exercise training.

  18. Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

    NASA Astrophysics Data System (ADS)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Liu, Yahui; Song, Jian; Ran, Xu

    2016-02-01

    Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

  19. CALS Test Network Sacramento Air Logistics Center. CALS/EDI Transfer Test Number 2, Quick Short Test Report.

    DTIC Science & Technology

    2007-11-02

    McClellan AFB , CA. The test required CALS data (MIL-R-28002A Raster) to be sent in an EDI (Electronic Data Interchange) envelope over a commercial VAN...Livermore National Laboratory EC/EDI (Electronic Commerce Through Electronic Data Interchange) Project, and the Sacramento Air Logistics Center (SM-ALC...Value Added Network). CALS Test Network Sacramento Air Logistics Center CALS/EDI Data Transfer Test Number 2 Quick Short Test Report.

  20. Planes, Politics and Oral Proficiency: Testing International Air Traffic Controllers

    ERIC Educational Resources Information Center

    Moder, Carol Lynn; Halleck, Gene B.

    2009-01-01

    This study investigates the variation in oral proficiency demonstrated by 14 Air Traffic Controllers across two types of testing tasks: work-related radio telephony-based tasks and non-specific English tasks on aviation topics. Their performance was compared statistically in terms of level ratings on the International Civil Aviation Organization…

  1. Mechanical Mixer for Rudder/Braking Wedge

    NASA Technical Reports Server (NTRS)

    Grimm, D.

    1985-01-01

    Right and left rudder panels moved separately. Mechanical mixer enables panels of two-panel rudder to rotate in same direction for steering or in opposite directions for dynamic braking. Steering and braking inputs separate so any combination of steering and braking motions executed simultaneously. Developed for aerodynamic braking of Space Shuttle orbiter, steering/braking drive train and rudder arrangement used for similar purposes on aircraft, thereby reducing sizes of thrust reversers.

  2. Brake Stops Both Rotation And Translation

    NASA Technical Reports Server (NTRS)

    Allred, Johnny W.; Fleck, Vincent J., Jr.

    1995-01-01

    Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

  3. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  4. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  5. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  6. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  7. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  8. Brake control system modification, augmentor Wing Jet STOL Research Airplane (AWJSRA)

    NASA Technical Reports Server (NTRS)

    Amberg, R. L.; Arline, J. A.; Jenny, R. W.

    1974-01-01

    The braking system for a short takeoff aircraft is discussed and the deficiencies are described. The installation of a Boeing 727 aircraft brake system was made to correct the deficiencies. Tests of the modified system were conducted using an analog computer/hardware simulator. Actual performance tests were conducted and the characteristics of the system were satisfactory.

  9. The 1979 Clear Air Turbulence Flight Test Program

    NASA Technical Reports Server (NTRS)

    Weaver, E. A.; Ehernberger, L. J.; Gary, B. L.; Kurkowski, R. L.; Kuhn, P. M.; Stearns, L. P.

    1981-01-01

    The flight experiments for clear air turbulence (CAT) detection and measurement concepts are described. The test were conducted over the western part of the United States during the winter season of 1979 aboard NASA's Galileo 2 flying laboratory. A carbon dioxide pulsed Doppler lidar and an infrared radiometer were tested for the remote detection and measurement of CAT. Two microwave radiometers were evaluated for their ability to provide encounter warning and altitude avoidance information.

  10. Air injection test on a Kaplan turbine: prototype - model comparison

    NASA Astrophysics Data System (ADS)

    Angulo, M.; Rivetti, A.; Díaz, L.; Liscia, S.

    2016-11-01

    Air injection is a very well-known resource to reduce pressure pulsation magnitude in turbines, especially on Francis type. In the case of large Kaplan designs, even when not so usual, it could be a solution to mitigate vibrations arising when tip vortex cavitation phenomenon becomes erosive and induces structural vibrations. In order to study this alternative, aeration tests were performed on a Kaplan turbine at model and prototype scales. The research was focused on efficiency of different air flow rates injected in reducing vibrations, especially at the draft tube and the discharge ring and also in the efficiency drop magnitude. It was found that results on both scales presents the same trend in particular for vibration levels at the discharge ring. The efficiency drop was overestimated on model tests while on prototype were less than 0.2 % for all power output. On prototype, air has a beneficial effect in reducing pressure fluctuations up to 0.2 ‰ of air flow rate. On model high speed image computing helped to quantify the volume of tip vortex cavitation that is strongly correlated with the vibration level. The hydrophone measurements did not capture the cavitation intensity when air is injected, however on prototype, it was detected by a sonometer installed at the draft tube access gallery.

  11. Regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1982-01-12

    Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

  12. Evaluation of the Flush/Fill and High-Pressure Air Purge Procedures for Converting Army Vehicles to Silicone Brake Fluid.

    DTIC Science & Technology

    1982-02-01

    dispersed spray/ fog . 4 100 Acetylene 50 The initial spray was ignited by the torch Torch and burned until the fluid/air ratio be- came too low to support... burning . 5 150 None 40 A spray ot large droplets followed by a very finely dispersed spray/ fog . 6 150 Acetylene 40 The initial spray was ignited by...Results ! 50 None 60 Initially a spray of large droplets followed by a very fine mist/ fog . 2 50 Acetylene 60 The initial mist was ignited by the torch

  13. Test Report for Perforated Metal Air Transportable Package (PMATO) Prototype.

    SciTech Connect

    Bobbe, Jeffery G.; Pierce, Jim Dwight

    2003-06-01

    A prototype design for a plutonium air transport package capable of carrying 7.6 kg of plutonium oxide and surviving a ''worst-case'' plane crash has been developed by Sandia National Laboratories (SNL) for the Japan Nuclear Cycle Development Institute (JNC). A series of impact tests were conducted on half-scale models of this design for side, end, and comer orientations at speeds close to 282 m/s onto a target designed to simulate weathered sandstone. These tests were designed to evaluate the performance of the overpack concept and impact-limiting materials in critical impact orientations. The impact tests of the Perforated Metal Air Transportable Package (PMATP) prototypes were performed at SNL's 10,000-ft rocket sled track. This report describes test facilities calibration and environmental testing methods of the PMATP under specific test conditions. The tests were conducted according to the test plan and procedures that were written by the authors and approved by SNL management and quality assurance personnel. The result of these tests was that the half-scale PMATP survived the ''worst-case'' airplane crash conditions, and indicated that a full-scale PMATP, utilizing this overpack concept and these impact-limiting materials, would also survive these crash conditions.

  14. Testing of a refuelable zinc/air bus battery

    SciTech Connect

    Cooper, J.F.; Fleming, D.; Koopman, R.; Hargrove, D.; Maimoni, A.; Peterman, K.

    1995-02-22

    We report tests of a refuelable zinc/air battery of modular, bipolar-cell design, intended for fleet electric busses and vans. The stack consists of twelve 250-cm{sup 2} cells built of two units: (1) a copper-clad glass-reinforced epoxy board supporting anode and cathode current collectors, and (2) polymer frame providing for air- and electrolyte distribution and zinc fuel storage. The stack was refueled in 4 min. by a hydraulic transfer of zinc particles entrained in solution flow.

  15. Test results of flight guidance for fuel conservative descents in a time-based metered air traffic environment. [terminal configured vehicle

    NASA Technical Reports Server (NTRS)

    Knox, C. E.; Person, L. H., Jr.

    1981-01-01

    The NASA developed, implemented, and flight tested a flight management algorithm designed to improve the accuracy of delivering an airplane in a fuel-conservative manner to a metering fix at a time designated by air traffic control. This algorithm provides a 3D path with time control (4D) for the TCV B-737 airplane to make an idle-thrust, clean configured (landing gear up, flaps zero, and speed brakes retracted) descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms are described and flight test results are presented.

  16. Thermal Modeling of Disc Brake Rotor in Frictional Contact

    NASA Astrophysics Data System (ADS)

    Ali, Belhocine; Ghazaly, Nouby Mahdi

    2013-01-01

    Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyze the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor. The analysis also gives us, the heat flux distribution for the two discs.

  17. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  18. Effects of cryogenic treatment on the wear properties of brake discs

    NASA Astrophysics Data System (ADS)

    Nadig, D. S.; Shivakumar, P.; Anoop, S.; Chinmay, Kulkarni; Divine, P. V.; Harsha, H. P.

    2017-02-01

    Disc brakes are invariably used in all the automobiles either to reduce the rotational speed of the wheel or to hold the vehicle stationary. During the braking action, the kinetic energy is converted into heat which can result in high temperatures resulting in fading of brake effects. Brake discs produced out of martensite stainless steel (SS410) are expected to exhibit high wear resistance properties with low value of coefficient of friction. These factors increase the useful life of the brake discs with minimal possibilities of brake fade. To study the effects of cryogenic treatment on the wear behaviour, two types of brake discs were cryotreated at 98K for 8 and 24 hours in a specially developed cryotreatment system using liquid nitrogen. Wear properties of the untreated and cryotreated test specimens were experimentally determined using the pin on disc type tribometer (ASTM G99-95). Similarly, the Rockwell hardness (HRC) of the specimens were tested in a hardness tester in accordance with ASTM E18. In this paper, the effects of cryotreatment on the wear and hardness properties of untreated and cryotreated brake discs are presented. Results indicate enhancement of wear properties and hardness after cryogenic treatment compared with the normal brakes discs.

  19. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    PubMed

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level.

  20. Site 5 air sparging pilot test, Naval Air Station Cecil Field, Jacksonville, Florida.

    PubMed

    Murray, W A; Lunardini, R C; Ullo, F J; Davidson, M E

    2000-02-25

    A 72-h air sparging pilot test was conducted at Site 5 (Operable Unit 2), Naval Air Station Cecil Field, Jacksonville, FL, to determine performance parameters necessary for full-scale design. The sparge well was completed to a depth of 29 ft, several feet below the groundwater plume contaminated with volatile organic compounds (VOCs), primarily benzene, toluene, ethylbenzene, and xylenes (BTEX). Air flow rates supplied to the sparge well were 3 cubic feet/min (cfm) during the first day, 2 cfm during the second day, and 1 cfm during the third day. Water levels in monitoring wells initially rose approximately 2 ft during the first 4-5 h of the test, then receded back to pre-test equilibrium levels over the next 15 h, for a total duration of water mounding of about 20 h. A small (approximately 0.5 ft) water table drop, with subsequent recovery to equilibrium level, occurred each time the air sparging rate was decreased. Although there is considerable variation depending on direction from the sparge well, the average radius of influence varied from approximately 30 ft at 1 cfm to 50 ft at 3 cfm. The air sparge system was capable of increasing the dissolved oxygen from 0 to 6 or 7 mg/l within 12-15 h of air channels reaching a given location. A lag time of approximately 13 h was observed before air channels reached a radius of 30 ft and dissolved oxygen levels began to increase at that radius. CO(2) (stripped out of the groundwater by the sparging) decreased from a pre-test concentration of 150 to 20 mg/l at r=5 ft, and from 150 to 50 mg/l at r=30 ft, within a period of about 24 h. The rate of VOC mass removal during the pilot test was 0.06 lb/day at a sparge rate of 3 cfm, and it appears that air sparging will effect a rapid cleanup of the VOCs in the Site 5 groundwater plume.

  1. Longitudinal wheel slip during ABS braking

    NASA Astrophysics Data System (ADS)

    Hartikainen, Lassi; Petry, Frank; Westermann, Stephan

    2015-02-01

    Anti-lock braking system (ABS) braking tests with two subcompact passenger cars were performed on dry and wet asphalt, as well as on snow and ice surfaces. The operating conditions of the tyres in terms of wheel slip were evaluated using histograms of the wheel slip data. The results showed different average slip levels for different road surfaces. It was also found that changes in the tyre tread stiffness affected the slip operating range through a modification of the slip value at which the maximum longitudinal force is achieved. Variation of the tyre footprint length through modifications in the inflation pressure affected the slip operating range as well. Differences in the slip distribution between vehicles with different brake controllers were also observed. The changes in slip operating range in turn modified the relative local sliding speeds between the tyre and the road. The results highlight the importance of the ABS controller's ability to adapt to changing slip-force characteristics of tyres and provide estimates of the magnitude of the effects of different tyre and road operating conditions.

  2. Open-Air Biowarfare Testing and the Evolution of Values

    PubMed Central

    2016-01-01

    The United States and the United Kingdom ended outdoor biological warfare testing in populated areas nearly half a century ago. Yet, the conduct, health effects, and propriety of those tests remain controversial. The varied views reflect the limits of currently available test information and evolving societal values on research involving human subjects. Western political culture has changed since the early days of the American and British testing programs. People have become less reluctant to question authority, and institutional review boards must now pre-approve research involving human subjects. Further, the heightened stringency of laboratory containment has accentuated the safety gap between a confined test space and one without physical boundaries. All this makes it less likely that masses of people would again be unwittingly subjected to secret open-air biological warfare tests. PMID:27564984

  3. [Studies on the performance of the dental air turbine handpieces. (Part 6) Investigation on the power of several air turbine handpieces (N = No-CvEv gamma) (author's transl)].

    PubMed

    Miyairi, H; Nagai, M; Fukuda, H; Muramatsu, A

    1982-01-01

    We have examined the basic studies on the rotational performance of the air turbine handpieces by using the brake method. Once, we used the constant feed speed testing method in which the test bur was pressed to the brake block at a constant feed speed. In the case of this method, the load increases in inverse proportion to the rotational speed as the loading time increases. In this paper for analyzing on the problem of the brake block materials used to this testing method, we did the performance test of the usually used air turbine handpieces by using the glass and the supper alloy which were superior to the frictional resistance as the brake materials. Consequently, by the difference of these brake materials, the characteristics of handpieces are not influences. But, in the long loading times, the dynamic friction coefficient between the glass block and the test bur became the great values. Therefore, in the constant feed speed testing method, the measured values of normal loads on the test bur, are influenced with the dynamic friction coefficients in the high load levels. On the rapidly dropped phenomenon of the rotational speed of air turbine handpieces, we measured the moment values at the support of test bur. And then we discussed the relation between the rotational performance and the length of burs or points using for cutting instruments. On the basis of the theoretical and experimental investigations of air turbine's rotational performance, we measured and examined the maximum works of the various kinds of the handpieces used in clinical field. The characteristics of the four-type handpieces, such the standard, torque and miniature types and air bearing type, used in this studies, were influenced with the materials of the brake block as far as the bounds of the loads were high in the rotational performance tests.

  4. Why Do the Braking Indices of Pulsars Span a Range of More Than 100 Millions?

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang-Nan; Xie, Yi

    2012-12-01

    Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. range from about -108 to about +108 and are significantly correlated with their characteristic ages. Using the model of magnetic field evolution we developed previously based on the same data, we derive an analytical expression for the braking index which agrees with all the observed statistical properties of the braking indices of the pulsars in the sample of Hobbs et al. Our model is, however, incompatible with the previous interpretation that magnetic field growth is responsible for the small values of braking indices (<3) observed for "baby" pulsars with characteristic ages of less than 2 × 103 yr. We find that the "instantaneous" braking index of a pulsar may be different from the "averaged" braking index obtained from fitting the data over a certain time span. The close match between our model-predicted "instantaneous" braking indices and the observed "averaged" braking indices suggests that the time spans used previously are usually smaller than or comparable to their magnetic field oscillation periods. Our model can be tested with the existing data by calculating the braking index as a function of the time span for each pulsar. In doing so, one can obtain for each pulsar all the parameters in our magnetic field evolution model, and may be able to improve the sensitivity of using pulsars to detect gravitational waves.

  5. Design of a squeeze film magnetorheological brake considering compression enhanced shear yield stress of magnetorheological fluid

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-02-01

    A magnetorheological brake, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnet, is proposed to replace the conventional heavy weight low response hydraulic disk brake. The frictional characteristics of the proposed brake can be controlled by regulating the yield stress of the MR fluid as function of magnetic field and normal compressive force. The controllable yield stress retards the surfaces of rotating disks, thus MR fluid can be used as a brake lining material. The present research work attempts designing a squeeze film MR brake by accounting compression enhanced shear yield stress of magnetorheological fluid. Theoretical calculations indicate that the estimated braking torque of the six plate squeeze film MR brake, under compression, is in the order of 600Nm. To validate the theoretical design and its findings, a prototype of single-plate squeeze film MR disk brake has been developed. Experimental test setup helps to illustrate braking torque under different control currents (0.0 to 1.25 A).

  6. WHY DO THE BRAKING INDICES OF PULSARS SPAN A RANGE OF MORE THAN 100 MILLIONS?

    SciTech Connect

    Zhang Shuangnan; Xie Yi

    2012-12-20

    Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. range from about -10{sup 8} to about +10{sup 8} and are significantly correlated with their characteristic ages. Using the model of magnetic field evolution we developed previously based on the same data, we derive an analytical expression for the braking index which agrees with all the observed statistical properties of the braking indices of the pulsars in the sample of Hobbs et al. Our model is, however, incompatible with the previous interpretation that magnetic field growth is responsible for the small values of braking indices (<3) observed for ''baby'' pulsars with characteristic ages of less than 2 Multiplication-Sign 10{sup 3} yr. We find that the ''instantaneous'' braking index of a pulsar may be different from the ''averaged'' braking index obtained from fitting the data over a certain time span. The close match between our model-predicted ''instantaneous'' braking indices and the observed ''averaged'' braking indices suggests that the time spans used previously are usually smaller than or comparable to their magnetic field oscillation periods. Our model can be tested with the existing data by calculating the braking index as a function of the time span for each pulsar. In doing so, one can obtain for each pulsar all the parameters in our magnetic field evolution model, and may be able to improve the sensitivity of using pulsars to detect gravitational waves.

  7. Evaluation of a sudden brake warning system: effect on the response time of the following driver.

    PubMed

    Isler, Robert B; Starkey, Nicola J

    2010-07-01

    This study used a video-based braking simulation dual task to carry out a preliminary evaluation of the effect of a sudden brake warning system (SBWS) in a leading passenger vehicle on the response time of the following driver. The primary task required the participants (N=25, 16 females, full NZ license holders) to respond to sudden braking manoeuvres of a lead vehicle during day and night driving, wet and dry conditions and in rural and urban traffic, while concurrently performing a secondary tracking task using a computer mouse. The SBWS in the lead vehicle consisted of g-force controlled activation of the rear hazard lights (the rear indicators flashed), in addition to the standard brake lights. Overall, the results revealed that responses to the braking manoeuvres of the leading vehicles when the hazard lights were activated by the warning system were 0.34 s (19%) faster compared to the standard brake lights. The SBWS was particularly effective when the simulated braking scenario of the leading vehicle did not require an immediate and abrupt braking response. Given this, the SBWS may also be beneficial for allowing smoother deceleration, thus reducing fuel consumption. These preliminary findings justify a larger, more ecologically valid laboratory evaluation which may lead to a naturalistic study in order to test this new technology in 'real world' braking situations.

  8. Control room envelope unfiltered air inleakage test protocols

    SciTech Connect

    Lagus, P.L.; Grot, R.A.

    1997-08-01

    In 1983, the Advisory Committee on Reactor Safeguards (ACRS) recommended that the US NRC develop a control room HVAC performance testing protocol. To date no such protocol has been forthcoming. Beginning in mid-1994, an effort was funded by NRC under a Small Business Innovation Research (SBIR) grant to develop several simplified test protocols based on the principles of tracer gas testing in order to measure the total unfiltered inleakage entering a CRE during emergency mode operation of the control room ventilation system. These would allow accurate assessment of unfiltered air inleakage as required in SRP 6.4. The continuing lack of a standard protocol is unfortunate since one of the significant parameters required to calculate operator dose is the amount of unfiltered air inleakage into the control room. Often it is assumed that, if the Control Room Envelope (CRE) is maintained at +1/8 in. w.g. differential pressure relative to the surroundings, no significant unfiltered inleakage can occur it is further assumed that inleakage due to door openings is the only source of unfiltered air. 23 refs., 13 figs., 2 tabs.

  9. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... forces at the wheel(s) to limit the degree of wheel slip. Baseline test means a stop or a series of stops... forces opposing the movement of the motorcycle are developed. Brake system means the combination of parts... the braking force is supplied by the physical effort of the rider assisted by one or more...

  10. Development of a Test Facility for Air Revitalization Technology Evaluation

    NASA Technical Reports Server (NTRS)

    Lu, Sao-Dung; Lin, Amy; Campbell, Melissa; Smith, Frederick; Curley, Su

    2007-01-01

    Development of new air revitalization system (ARS) technology can initially be performed in a subscale laboratory environment, but in order to advance the maturity level, the technology must be tested in an end-to-end integrated environment. The Air Revitalization Technology Evaluation Facility (ARTEF) at the NASA Johnson Space Center serves as a ground test bed for evaluating emerging ARS technologies in an environment representative of spacecraft atmospheres. At the center of the ARTEF is a hypobaric chamber which serves as a sealed atmospheric chamber for closed loop testing. A Human Metabolic Simulator (HMS) was custom-built to simulate the consumption of oxygen, and production of carbon dioxide, moisture and heat of up to eight persons. A multitude of gas analyzers and dew point sensors are used to monitor the chamber atmosphere upstream and downstream of a test article. A robust vacuum system is needed to simulate the vacuum of space. A reliable data acquisition and control system is required to connect all the subsystems together. This paper presents the capabilities of the integrated test facility and some of the issues encountered during the integration.

  11. Performance testing and analysis of vertical ambient air vaporizers

    NASA Astrophysics Data System (ADS)

    Pandey, A. S.; Singh, V. N.; Shah, M. I.; Acharya, D. V.

    2017-02-01

    Ambient air vaporizers are used to regasify cryogenic liquids at extremely low temperature (below -153°C). Frost formation occurs on it due to large temperature difference between ambient air and cryogenic fluid. Frosting induces additional load on equipment and reduces its heat transfer effectiveness. Hence, mechanical and thermal design of vaporizers account for frosting. An experimental set-up has been designed and effects of flow rate and ground clearance on the performance of ambient air vaporizers are evaluated. The flow rate is increased from the rated capacity of 500 Nm3/h to 640 Nm3/h and ground clearance is reduced from 500 mm to 175 mm. The above variations reduce the time duration for which gaseous nitrogen is delivered at temperature higher than 10.1°C (desired). Hence duty cycle reduces from eight hours to five hours. The other factors affecting performance such as fin configuration, fluid type, fluid pressure, intermittent flow nature and climatic conditions are assumed to be constant over the test duration. The decrement in outlet gas temperature (from 38 °C to 10.1°C) with corresponding increment in frost thickness leads to deterioration of performance of ambient air vaporizers.

  12. STANDARDS CONTROLLING AIR EMISSIONS FOR THE SOIL DESICCATION PILOT TEST

    SciTech Connect

    BENECKE MW

    2010-09-08

    This air emissions document supports implementation of the Treatability Test Plan for Soil Desiccation as outlined in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau (DOE/RL-2007-56). Treatability testing supports evaluation of remedial technologies for technetium-99 (Tc-99) contamination in the vadose zone at sites such as the BC Cribs and Trenches. Soil desiccation has been selected as the first technology for testing because it has been recommended as a promising technology in previous Hanford Site technology evaluations and because testing of soil desiccation will provide useful information to enhance evaluation of other technologies, in particular gas-phase remediation technologies. A soil desiccation pilot test (SDPT) will evaluate the desiccation process (e.g., how the targeted interval is dried) and the long-term performance for mitigation of contaminant transport. The SDPT will dry out a moist zone contaminated by Tc-99 and nitrate that has been detected at Well 299-E13-62 (Borehole C5923). This air emissions document applies to the activities to be completed to conduct the SDPT in the 200-BC-1 operable unit located in the 200 East Area of the Hanford Site. Well 299-E13-62 is planned to be used as an injection well. This well is located between and approximately equidistant from cribs 216-B-16, 216-B-17, 216-B-18. and 216-B-19. Nitrogen gas will be pumped at approximately 300 ft{sup 3}/min into the 299-EI3-62 injection well, located approximately 12 m (39 ft) away from extraction well 299-EI3-65. The soil gas extraction rate will be approximately 150 ft{sup 3}/min. The SDPT will be conducted continuously over a period of approximately six months. The purpose of the test is to evaluate soil desiccation as a potential remedy for protecting groundwater. A conceptual depiction is provided in Figure 1. The soil desiccation process will physically dry, or evaporate, some of the water from the moist zone of interest. As such, it is

  13. Core testing of zinc/air refuelable battery modules

    SciTech Connect

    Cooper, J. F., LLNL

    1998-08-20

    We are developing a refuelable zinc/air battery (6-cells) for evaluation under the five USABC `core` test protocols. In the first half of the two year project ($1OOK, FY1997), an advanced refuelable design was developed, fabricated and tested at power levels up to 415 W. Performance matched or exceeded that of earlier multicell systems. A computer program was developed for automated data acquisition and drive cycle simulation. Small mockup cells (80 cm 2) were constructed for rapid testing of components. In the follow-on effort (FY1998, $1OOK) we will make minor advances in system design and fabrication efficiency, and seek to improve cathode performance and life, before delivery of two final units for test at DOE laboratory.

  14. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment of each cab car shall be..., KB-HS1, or Fastbrake brake systems. (2) Every 1,476 days for that portion of the cab car brake system... that portion of the cab car brake system using brake valves that are identical to the locomotive...

  15. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment of each cab car shall be..., KB-HS1, or Fastbrake brake systems. (2) Every 1,476 days for that portion of the cab car brake system... that portion of the cab car brake system using brake valves that are identical to the locomotive...

  16. Analytical model and finite element computation of braking torque in electromagnetic retarder

    NASA Astrophysics Data System (ADS)

    Ye, Lezhi; Yang, Guangzhao; Li, Desheng

    2014-12-01

    An analytical model has been developed for analyzing the braking torque in electromagnetic retarder by flux tube and armature reaction method. The magnetic field distribution in air gap, the eddy current induced in the rotor and the braking torque are calculated by the developed model. Two-dimensional and three-dimensional finite element models for retarder have also been developed. Results from the analytical model are compared with those from finite element models. The validity of these three models is checked by the comparison of the theoretical predictions and the measurements from an experimental prototype. The influencing factors of braking torque have been studied.

  17. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating..., within the test cell, during all phases of the air conditioning test sequence to 95 ±2 °F on average and... of 30 second intervals. Records of cell air temperatures and values of average test temperatures...

  18. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating..., within the test cell, during all phases of the air conditioning test sequence to 95 ±2 °F on average and... of 30 second intervals. Records of cell air temperatures and values of average test temperatures...

  19. 40 CFR 92.103 - Test procedures; overview.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.103 Test... locomotive engines. The procedures specified here are intended to measure brake-specific mass emissions of... organics (i.e., hydrocarbons, alcohols, and aldehydes); diesel-fueled and biodiesel-fueled...

  20. 40 CFR 92.103 - Test procedures; overview.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.103 Test... locomotive engines. The procedures specified here are intended to measure brake-specific mass emissions of... organics (i.e., hydrocarbons, alcohols, and aldehydes); diesel-fueled and biodiesel-fueled...

  1. A Demonstration of Car Braking Instabilities.

    ERIC Educational Resources Information Center

    Irwin, Jack; Swinson, Derek

    1990-01-01

    Detailed are the construction of a demonstration car, apparatus and procedures used in the demonstration, and the analysis of the effects of car braking. The cases of rear-wheel and front-wheel braking are considered. (CW)

  2. Four-wheel dual braking for automobiles

    NASA Technical Reports Server (NTRS)

    Edwards, H. B.

    1981-01-01

    Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

  3. Hazardous air pollutant testing at the LGTI coal gasification plant

    SciTech Connect

    Wetherold, R.G.; Williams, W.A.; Maxwell, D.P.; Mann, R.M.

    1995-06-01

    A comprehensive hazardous air pollutant test program was conducted in November 1994 at the Louisiana Gasification Technology, Inc. (LGTI), plant in Plaquemine, Louisiana. This program was sponsored by DOE/PETC, the Electric Power Research Institute (EPRI), and Destec Energy. In May of 1995, additional testing of the hot syngas stream was conducted at the LGTI facility under this same program. DOE/METC provided additional technical support for the hot gas testing effort. In this paper, the sampling and analytical methods used during the November and May test program are summarized. The hot gas testing is described in greater detail. In particular, the hot gas sampling probe and probe insertion/withdrawal system are discussed. The sampling probe was designed to collect particulate and extract gas samples at process temperature and pressure. The design of the probe system is described, and the operating procedures are summarized. The operation of the probe during the testing is discussed, and photographs of the testing are provided. In addition to the summaries and descriptions of the test methodologies, selected preliminary emissions results of the November sampling are included in the paper.

  4. Frictional behavior of automotive brake materials under wet and dry conditions

    SciTech Connect

    Blau, P.J.; Martin, R.L.; Weintraub, M.H.; Jang, Ho; Donlon, W.

    1996-12-15

    The purpose of this effort was to develop an improved understanding of the relationship between the structure and frictional behavior of materials in the disc brake/rotor interface with a view toward improving the performance of automotive disc brakes. The three tasks involved in this Cooperative Research and Development Agreement (CRADA) were as follows: Task 1. Investigation of Brake Pads and Rotors. Characterize surface features of worn brake pads and rotors, with special attention to the transfer film which forms on them during operation. Ford to supply specimens for examination and other supporting information. Task 2. Effects of Atmosphere and Repeated Applications on Brake Material Friction. Conduct pin-on-disk friction tests at ORNL under controlled moisture levels to determine effects of relative humidity on frictional behavior of brake pad and rotor materials. Conduct limited tests on the characteristics of friction under application of repeated contacts. Task 3. Comparison of Dynamometer Tests with Laboratory Friction Tests. Compare ORNL friction data with Ford dynamometer test data to establish the degree to which the simple bench tests can be useful in helping to understand frictional behavior in full-scale brake component tests. This final report summarizes work performed under this CRADA.

  5. Computer-Aided Environmental Impact Analysis for Industrial, Procurement, and Research, Development, Test, and Evaluation Activities: User Manual.

    DTIC Science & Technology

    1978-06-01

    Inhibitors Trifluorine Chlork)e Phosphate Ester Brake System Preservative Cosmolene 70 Drying - 71 Evaporation Air Compressed Air Ovens Infrared Lamps 72...measure acceleration tests microwave adhesion tests ligh t aging tests lasers bearing tests Infrared certification Ionizing radiation tests compression...175 through 183 and 190 throug h 21 8) . electromagnetic waves (radio , light , lasers , infrare d , etc.). 187 Endurance tests. Tests of a person’s or

  6. Prosthetic leg powered by MR brake and SMA wires

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  7. Testing of heat exchangers in membrane oxygenators using air pressure.

    PubMed

    Hamilton, Carole; Stein, Jutta; Seidler, Rainer; Kind, Robert; Beck, Karin; Tosok, Jürgen; Upterfofel, Jörg

    2006-03-01

    All heat exchangers (HE) in membrane oxygenators are tested by the manufacturer for water leaks during the production phase. However, for safety reasons, it is highly recommended that HEs be tested again before clinical use. The most common method is to attach the heater-cooler to the HE and allow the water to recirculate for at least 10 min, during which time a water leak should be evident. To improve the detection of water leaks, a test was devised using a pressure manometer with an integrated bulb used to pressurize the HE with air. The cardiopulmonary bypass system is set up as per protocol. A pressure manometer adapted to a 1/2" tubing is connected to the water inlet side of the oxygenator. The water outlet side is blocked with a short piece of 1/2" deadend tubing. The HE is pressurized with 250 mmHg for at least 30 sec and observed for any drop. Over the last 2 years, only one oxygenator has been detected with a water leak in which the air-method leaktest was performed. This unit was sent back to the manufacturer who confirmed the failure. Even though the incidence of water leaks is very low, it does occur and it is, therefore, important that all HEs are tested before they are used clinically. This method of using a pressure manometer offers many advantages, as the HE can be tested outside of the operating room (OR), allowing earlier testing of the oxygenator, no water contact is necessary, and it is simple, easy and quick to perform.

  8. Compact, Lightweight Servo-Controllable Brakes

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  9. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  10. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  11. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  12. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  13. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  14. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... wheel braking system must not exceed the pressure specified by the brake manufacturer. (d) If antiskid devices are installed, the devices and associated systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of...

  15. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  16. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  17. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  18. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  19. 77 FR 15813 - Preoperational Testing of Instrument and Control Air Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-16

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Preoperational Testing of Instrument and Control Air Systems AGENCY: Nuclear Regulatory Commission... testing of the instrument and control air systems (ICAS) in a commercial nuclear power plant....

  20. 76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ....'' This guide applies to the design, inspection, and testing of air filtration and iodine adsorption units... the design, inspection, and testing of air filtration and iodine adsorption units of...

  1. Spring- And Air-Suspension Mechanism For Testing Structures

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.

    1994-01-01

    Spring-and air-suspension mechanism supports weight of one end of test structure, yet allows that end to move almost completely unhindered as though it were weightless and not attached to suspension. Mechanisms of this type called "zero-spring-rate mechanisms" (ZSRM's) because they support structure in manner of spring suspension exhibiting approximately zero stiffness (zero spring rate) within some range of motion about nominal equilibrium or central support position. This suspension mechanism does not include overhead cables, which necessitate large amounts of overhead clearance and overhead support structures: suspension mechanism more compact (much smaller than structure) and supports structure from below.

  2. The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site

    SciTech Connect

    Ray, J.M.; Newsom, J.C.

    1994-12-01

    The Prototype Air-Coring Test was conducted at the Nevada Test Site (NTS) G-Tunnel facility to evaluate standard coring techniques, modified slightly for air circulation, for use in testing at a prospective nuclear waste repository at Yucca Mountain, Nevada. Air-coring technology allows sampling of subsurface lithology with minimal perturbation to ambient characteristic such as that required for exploratory holes near aquifers, environmental applications, and site characterization work. Two horizontal holes were cored, one 50 ft long and the other 150 ft long, in densely welded fractured tuff to simulate the difficult drilling conditions anticipated at Yucca Mountain. Drilling data from seven holes on three other prototype tests in nonwelded tuff were also collected for comparison. The test was used to establish preliminary standards of performance for drilling and dust collection equipment and to assess procedural efficiencies. The Longyear-38 drill achieved 97% recovery for HQ-size core (-2.5 in.), and the Atlas Copco dust collector (DCT-90) captured 1500 lb of fugitive dust in a mine environment with only minor modifications. Average hole production rates were 6-8 ft per 6-h shift in welded tuff and almost 20 ft per shift on deeper holes in nonwelded tuff. Lexan liners were successfully used to encapsulate core samples during the coring process and protect core properties effectively. The Prototype Air-Coring Test demonstrated that horizontal air coring in fractured welded tuff (to at least 150 ft) can be safely accomplished by proper selection, integration, and minor modification of standard drilling equipment, using appropriate procedures and engineering controls. The test also indicated that rig logistics, equipment, and methods need improvement before attempting a large-scale dry drilling program at Yucca Mountain.

  3. VAPOR SPACE AND LIQUID/AIR INTERFACECORROSION TESTS

    SciTech Connect

    Zapp, P.; Hoffman, E.

    2009-11-09

    The phenomena of vapor space corrosion and liquid/air interface corrosion of carbon steel in simulated liquid waste environments have been investigated. Initial experiments have explored the hypothesis that vapor space corrosion may be accelerated by the formation of a corrosive electrolyte on the tank wall by a process of evaporation of relatively warmer waste and condensation of the vapor on the relatively cooler tank wall. Results from initial testing do not support the hypothesis of electrolyte transport by evaporation and condensation. The analysis of the condensate collected by a steel specimen suspended over a 40 C simulated waste solution showed no measurable concentrations of the constituents of the simulated solution and a decrease in pH from 14 in the simulant to 5.3 in the condensate. Liquid/air interface corrosion was studied as a galvanic corrosion system, where steel at the interface undergoes accelerated corrosion while steel in contact with bulk waste is protected. The zero-resistance-ammeter technique was used to measure the current flow between steel specimens immersed in solutions simulating (1) the high-pH bulk liquid waste and (2) the expected low-pH meniscus liquid at the liquid/air interface. Open-circuit potential measurements of the steel specimens were not significantly different in the two solutions, with the result that (1) no consistent galvanic current flow occurred and (2) both the meniscus specimen and bulk specimen were subject to pitting corrosion.

  4. LIQUID AIR INTERFACE CORROSION TESTING FOR FY2010

    SciTech Connect

    Zapp, P.

    2010-12-16

    An experimental study was undertaken to investigate the corrosivity to carbon steel of the liquid-air interface of dilute simulated radioactive waste solutions. Open-circuit potentials were measured on ASTM A537 carbon steel specimens located slightly above, at, and below the liquid-air interface of simulated waste solutions. The 0.12-inch-diameter specimens used in the study were sized to respond to the assumed distinctive chemical environment of the liquid-air interface, where localized corrosion in poorly inhibited solutions may frequently be observed. The practical inhibition of such localized corrosion in liquid radioactive waste storage tanks is based on empirical testing and a model of a liquid-air interface environment that is made more corrosive than the underlying bulk liquid due to chemical changes brought about by absorbed atmospheric carbon dioxide. The chemical changes were assumed to create a more corrosive open-circuit potential in carbon in contact with the liquid-air interface. Arrays of 4 small specimens spaced about 0.3 in. apart were partially immersed so that one specimen contacted the top of the meniscus of the test solution. Two specimens contacted the bulk liquid below the meniscus and one specimen was positioned in the vapor space above the meniscus. Measurements were carried out for up to 16 hours to ensure steady-state had been obtained. The results showed that there was no significant difference in open-circuit potentials between the meniscus-contact specimens and the bulk-liquid-contact specimens. With the measurement technique employed, no difference was detected between the electrochemical conditions of the meniscus versus the bulk liquid. Stable open-circuit potentials were measured on the specimen located in the vapor space above the meniscus, showing that there existed an electrochemical connection through a thin film of solution extending up from the meniscus. This observation supports the Hobbs-Wallace model of the development

  5. Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

    NASA Astrophysics Data System (ADS)

    Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

    2015-11-01

    This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced

  6. Acceptance Test Procedure: SY101 air pallet system

    SciTech Connect

    Koons, B.M.

    1995-05-30

    The purpose of this test procedure is to verify that the system(s) procured to load the SY-101 Mitigation Test Pump package fulfills its functional requirements. It will also help determine the man dose expected due to handling of the package during the actual event. The scope of this procedure focuses on the ability of the air pallets and container saddles to carry the container package from the new 100 foot concrete pad into 2403-WD where it will be stored awaiting final disposition. This test attempts to simulate the actual event of depositing the SY-101 hydrogen mitigation test pump into the 2403-WD building. However, at the time of testing road modifications required to drive the 100 ton trailer into CWC were not performed. Therefore a flatbed trailer will be use to transport the container to CWC. The time required to off load the container from the 100 ton trailer will be recorded for man dose evaluation on location. The cranes used for this test will also be different than the actual event. This is not considered to be an issue due to minimal effects on man dose.

  7. Thermal measurement of brake pad lining surfaces during the braking process

    NASA Astrophysics Data System (ADS)

    Piątkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Małachowski, Jerzy; Mazurkiewicz, Łukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  8. Aluminum runway surface as possible aid to aircraft braking

    NASA Technical Reports Server (NTRS)

    Miller, C. D.; Pinkel, I. I.

    1973-01-01

    Several concepts are described for use singly or in combination to improve aircraft braking. All involve a thin layer of aluminum covering all or part of the runway. Advantage would derive from faster heat conduction from the tire-runway interface. Heating of tread surface with consequent softening and loss of friction coefficient should be reduced. Equations are developed indicating that at least 99 percent of friction heat should flow into the aluminum. Preliminary test results indicate a coefficient of sliding friction of 1.4, with predictably slight heating of tread. Elimination of conventional brakes is at least a remote possibility.

  9. 77 FR 38857 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... COMMISSION Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal..., Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems..., entitled, ``Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of...

  10. 30 CFR 75.152 - Tests of air flow; qualified person.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of air flow; qualified person. 75.152....152 Tests of air flow; qualified person. A person is a qualified person within the meaning of the provisions of Subpart D—Ventilation of this part requiring that tests of air flow be made by a...

  11. Relationships Among an Individual Intelligence Test and Two Air Force Screening and Selection Tests.

    ERIC Educational Resources Information Center

    McGrevy, David F.; And Others

    With the implementation of the all volunteer force concept, the Air Force must ensure that the objectively measurable range of ability in its manpower pool is being utilized. This is especially true for minority groups who have been categorized and channeled into military career areas based on their performance on two selection tests: the Armed…

  12. 78 FR 17185 - U.S. Air Force Space Command Notice of Test

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... Department of the Air Force U.S. Air Force Space Command Notice of Test AGENCY: U.S. Air Force Space Command... inform users of an upcoming event related to the GPS satellite constellation. U.S. Air Force Space... process L2C or L5 CNAV. U.S. Air Force Space Command ] expects to conduct one to two CNAV tests per...

  13. Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

    NASA Technical Reports Server (NTRS)

    Byrdsong, T. A.

    1973-01-01

    An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

  14. Design of permanent magnet eddy current brake for a small scaled electromagnetic launch model

    NASA Astrophysics Data System (ADS)

    Zhou, Shigui; Yu, Haitao; Hu, Minqiang; Huang, Lei

    2012-04-01

    A variable pole-pitch double-sided permanent magnet (PM) linear eddy current brake (LECB) is proposed for a small scaled electromagnetic launch model. A two-dimensional (2D) analytical steady state model is presented for the double-sided PM-LECB, and the expression for the braking force is derived. Based on the analytical model, the material and eddy current skin effect of the conducting plate are analyzed. Moreover, a variable pole-pitch double-sided PM-LECB is proposed for the effective braking of the moving plate. In addition, the braking force is predicted by finite element (FE) analysis, and the simulated results are in good agreement with the analytical model. Finally, a prototype is presented to test the braking profile for validation of the proposed design.

  15. Bidirectional drive and brake mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A. (Inventor)

    1991-01-01

    A space transport vehicle is disclosed as including a body which is arranged to be movably mounted on an elongated guide member disposed in outer space and driven therealong. A drive wheel is mounted on a drive shaft and arranged to be positioned in rolling engagement with the elongated guide carrying the vehicle. A brake member is arranged on the drive shaft for movement into and out of engagement with an adjacent surface of the drive wheel. An actuator is mounted on the body to be manually moved back and forth between spaced positions in an arc of movement. A ratchet-and-pawl mechanism is arranged to operate upon movements of the actuator in one direction between first and second positions for coupling the actuator to the drive wheel to incrementally rotate the wheel in one rotational direction and to operate upon movements of the actuator in the opposite direction for uncoupling the actuator from the wheel. The brake member is threadedly coupled to the drive shaft in order that the brake member will be operated only when the actuator is moved on beyond its first and second positions for shifting the brake member along the drive shaft and into frictional engagement with the adjacent surface on the drive wheel.

  16. Preliminary survey report: control technology for brake lining at Northwest Local School District, Cincinnati, Ohio

    SciTech Connect

    Cooper, T.C.; McGlothlin, J.D.; Godbey, F.W.; Sheehy, J.W.; O'Brien, D.M.

    1986-05-01

    A walk-through survey of control technology for reducing asbestos exposure during maintenance and repair of vehicular brakes was conducted at Northwest Local School District, Cincinnati, Ohio in January, 1986. The primary method for controlling and collecting dust during brake servicing was a wet-washing technique and good work practices, ensuring that exposure to hazardous physical or chemical agents was reduced or eliminated. Also available was an enclosed-type brake assembly cleaner designed to be connected to the shop air and a vacuum system. The brake assembly cleaner did not have a viewing port to examine the area being cleaned. The operator had to remove the unit to inspect the cleaned area potentially exposing himself to any dust remaining on the brake shoes or hub. The unit itself was a potential dust source as it was designed to fit 16-inch wheels and did not form a tight seal on the smaller 15-inch wheels of the newer buses. The authors conclude that the wet wash technique is an excellent method for controlling asbestos emissions during brake maintenance. The vacuum brake-assembly cleaner is inadequate and potentially hazardous. An in-depth survey of the wet technique is recommended.

  17. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements of this section. The petition shall be filed as provided in § 238.21. (b) MU locomotives. The brake equipment of each MU locomotive shall be cleaned, repaired, and tested at intervals in accordance with the following schedule: (1) Every 736 days if the MU locomotive is part of a fleet that is not...

  18. Investigation on hardness and impact resistance of automotive brake pad composed with rice husk dust

    NASA Astrophysics Data System (ADS)

    Bahari, Shahril Anuar; Isa, Khairul Hafizee; Kassim, Masitah Abu; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    In this study, hardness and impact resistance properties of automotive brake pad composed with rice husk dust (RHD) were documented. RHD was mixed with other metallic and synthetic ingredients of automotive brake pad. To obtain RHD, rice husk was ground and dried to 1 - 3% moisture content. The RHD was screened to obtain different dust sizes (80 and 100-mesh) before it was mixed with other materials at different percentages of composition (10 and 30%). The mixture was then pressed to produce brake pad. Rockwell hardness testing machine was used in hardness determination, while Izod impact testing machine was used in impact resistance determination. Hardness resistance of automotive brake pad mixed with 10% composition and 80-mesh size of RHD was significantly higher than 100-mesh. Hardness resistance of automotive brake pad mixed with 30% composition and 100-mesh size of RHD was slightly higher than 80 mesh. However, based on analysis, the difference was not significant. According to the result, hardness resistance of automotive brake pad mixed with 30% composition of RHD was higher than 10%. RHD has filled up the space and enhanced the micro structural behaviour of automotive brake pad. Impact resistance of automotive brake pad mixed with 10% composition and 80-mesh size of RHD was insignificantly higher than 100-mesh. Impact resistance of automotive brake pad mixed with 30% composition and 80-mesh size of RHD was significantly higher than 100 mesh. Large RHD size has increased the capability to resist high-rated impact loading. The impact energy was distributed over wider area for larger particle size. This factor has increased the impact resistance of automotive brake pad from large dust size. Impact resistance of automotive brake pad mixed with 80-mesh size and 30% composition of RHD was higher than 10%. In contrast, impact resistance of automotive brake pad mixed with 100-mesh size and 10% composition of RHD was higher than 30%. However, the difference was not

  19. Brake blending strategy for a hybrid vehicle

    SciTech Connect

    Boberg, Evan S.

    2000-12-05

    A hybrid electric powertrain system is provided including a transmission for driving a pair of wheels of a vehicle and a heat engine and an electric motor/generator coupled to the transmission. A friction brake system is provided for applying a braking torque to said vehicle. A controller unit generates control signals to the electric motor/generator and the friction brake system for controllably braking the vehicle in response to a drivers brake command. The controller unit determines and amount of regenerative torque available and compares this value to a determined amount of brake torque requested for determining the control signals to the electric motor/generator and the friction brake system.

  20. Experiments on composites meant for making brake pads for the rolling stock

    NASA Astrophysics Data System (ADS)

    Socalici, A.; Pascu, L.; Ardelean, E.; Putan, V.

    2017-01-01

    For noise rail decrease and observance of the limits in UE rolling stock must be equipped with silent brake blocks of composite material to replace the conventional cast-iron blocks. For testing composite materials test pieces have been produced according to the characteristics of the experimental installation. The paper presents the laboratory experimentation phase on obtaining composite materials for brake blocks and wear behavior of the experimental test pieces.

  1. Air Conditioning Stall Phenomenon Testing, Model Development, and Simulation

    SciTech Connect

    Irminger, Philip; Rizy, D Tom; Li, Huijuan; Smith, Travis; Rice, C Keith; Li, Fangxing; Adhikari, Sarina

    2012-01-01

    Electric distribution systems are experiencing power quality issues of extended reduced voltage due to fault-induced delayed voltage recovery (FIDVR). FIDVR occurs in part because modern air conditioner (A/C) and heat pump compressor motors are much more susceptible to stalling during a voltage sag or dip such as a sub-transmission fault. They are more susceptible than older A/C compressor motors due to the low inertia of these newer and more energy efficient motors. There is a concern that these local reduced voltage events on the distribution system will become more frequent and prevalent and will combine over larger areas and challenge transmission system voltage and ultimately power grid reliability. The Distributed Energy Communications and Controls (DECC) Laboratory at Oak Ridge National Laboratory (ORNL) has been employed to (1) test, (2) characterize and (3) model the A/C stall phenomenon.

  2. Generation of Nanoparticles from Friction between Railway Brake Disks and Pads.

    PubMed

    Namgung, Hyeong-Gyu; Kim, Jong-Bum; Woo, Sang-Hee; Park, Sechan; Kim, Minhae; Kim, Min-Soo; Bae, Gwi-Nam; Park, Duckshin; Kwon, Soon-Bark

    2016-04-05

    In this study, we measured the size distribution of particles ranging in size from 5.6 to 560 nm that were emitted between brake disks and pads under various braking conditions to observe and analyze changes to the resulting particle size distribution over braking time. A peak of 178-275 nm (200 nm peak) was observed in all braking conditions. However, the generation of spherical particles of a 10 nm range was observed only when the disk speed and brake force were above certain levels and intensified only when speed and brake force further increased. The total number concentration of ultrafine particles (no larger than 0.1 μm; PM0.1) generated was found to correlate with disk speed and brake force. Thus, the generation of nanoparticles resulting from disk speed and brake force was attributable primarily to increases in the contact surface temperature. The critical temperature for the generation of nanoparticles of a 10 nm range was found to be about 70 °C, which is the average temperature between the surface and the inside of the disk. If the speed or brake force was higher, that is, the temperature of the contact surface reached a certain level, evaporation and condensation took place. Vapor then left the friction surface, met with the air, and quickly cooled to form nanoparticles through nucleation. When the newly generated particles became highly concentrated, they grew through coagulation to form agglomerates or the vapor condensed directly onto the surface of existing particles of about 200 nm (formed by mechanical friction).

  3. 7 CFR 28.603 - Procedures for air flow tests of micronaire reading.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Procedures for air flow tests of micronaire reading... of the United States for Fiber Fineness and Maturity § 28.603 Procedures for air flow tests of...) Air flow instrument complete with accessories to measure the fineness and maturity, in combination,...

  4. Characterization of the high-frequency squeal on a laboratory brake setup

    NASA Astrophysics Data System (ADS)

    Giannini, Oliviero; Massi, Francesco

    2008-02-01

    This paper presents an experimental investigation on high-frequency brake squeal noise conducted on an appropriately designed experimental rig, called laboratory brake. Brake squeal is one of the major issues in the design process of an automotive brake and the development of a robust procedure for a "squeal-free" design is still under investigation. The high-frequency squeal is the most frequent noise generated by automotive brakes and is characterized by a wavelength of the "squealing mode" comparable to the length of the brake pad. The proposed "laboratory brake" is a good compromise between simple test rigs, such as the beam-on-disc, and the experimental setups that use real brakes. The beam-on-disc setup is a useful tool to understand the mechanism leading to the instability, but it does not simulate appropriately a real brake. On the other hand, real brakes are too complex for fundamental investigation and for efficient modeling. The experimental analysis shows a strong correlation between the length of the pad, the dynamic behavior of the system, and the squealing deformed shape. Moreover, depending on the length of the pad compared with the wavelength of the disc mode, three different kind of squeal instability may occur during experiments: the sine mode squeal, the cosine mode squeal and the rotating squeal. The latter is characterized by nodal diameters rotating during a squeal cycle. A linear reduced model, able to reproduce the dynamic behavior of the experimental setup, is used to predict the squeal occurrence. However, such linear model is not able to predict the rotating squeal characteristic that seems to be caused by nonlinear interactions due to the contact between the disc and the caliper.

  5. Analysis of the stability of PTW riders in autonomous braking scenarios.

    PubMed

    Symeonidis, Ioannis; Kavadarli, Gueven; Erich, Schuller; Graw, Matthias; Peldschus, Steffen

    2012-11-01

    While fatalities of car occupants in the EU decreased remarkably over the last decade, Powered Two Wheelers (PTWs) fatalities still increase following the increase of PTW ownership. Autonomous braking systems have been implemented in several types of vehicles and are presently addressed by research in the field of PTWs. A major concern in this context is the rider stability. Experiments with volunteers were performed in order to find out whether autonomous braking for PTWs will produce a greater instability of the rider in comparison to manual braking. The PTW's braking conditions were simulated in a laboratory with a motorcycle mock-up mounted on a sled, which was accelerated with an average of 0.35 g. The motion of the rider was captured in autonomous braking scenarios with and without pre-warning as well as in manual braking scenarios. No significant differences between the scenarios were found with respect to maximum forward displacement of the volunteer's torso and head (p<0.05). By performing clustering analysis on two kinematic parameters, two different strategies of the volunteers were identified. They were not related to the braking scenarios. A relation of the clusters with the initial posture represented by the elbow angle was revealed (p<0.05). It is concluded that autonomous braking at low deceleration will not cause significant instabilities of the rider in comparison to manual braking in idealized laboratory conditions. Based on this, further research into the development and implementation of autonomous braking systems for PTWs, e.g. by extensive riding tests, seems valuable.

  6. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  7. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  8. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  9. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  10. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  11. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  12. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  13. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  14. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles... 49 Transportation 5 2011-10-01 2011-10-01 false Parking brake system. 393.41 Section 393.41...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  15. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  16. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles... 49 Transportation 5 2010-10-01 2010-10-01 false Parking brake system. 393.41 Section 393.41...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  17. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  18. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  19. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  20. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  1. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  2. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  3. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle

    PubMed Central

    Lee, Nam-Jin; Kang, Chul-Goo

    2015-01-01

    A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component’s purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system. PMID:26267883

  4. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle.

    PubMed

    Lee, Nam-Jin; Kang, Chul-Goo

    2015-01-01

    A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component's purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system.

  5. Prototypes of Cognitive Measures for Air Force Officers: Test Development and Item Banking

    DTIC Science & Technology

    1990-05-01

    AFHRL-TP-89-737 3, COPY AIR FORCE PROTOTYPES OF COGNITIVE MEASURES FOR AIR FORCE OFFICERS: TEST DEVELOPMENT AND ITEM BANKING DTIC f1 ELECTF H Frances...Jacobina Skinner MANPOWER AND PERSONNEL DIVISION R Brooks Air Force Base, Texas 78235-5601 E S O May 1990U Final Technical Paper for Period September 1987...November 1989 R C Approved for public release; distribution is unlimited. E S LABORATORY AIR FORCE SYSTEMS COMMAND BROOKS AIR FORCE BASE, TEXAS

  6. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  7. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  8. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  9. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  10. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  11. 7 CFR 28.603 - Procedures for air flow tests of micronaire reading.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Department of Agriculture, or its equivalent. (2) A suitable supply of compressed air filtered to remove... specimen. The weight of the test specimen shall be that weight prescribed for the air flow instrument...

  12. Field Test of Room-to-Room Uniformity of Ventilation Air Distribution in Two New Houses

    SciTech Connect

    Hendron, Robert; Anderson, Ren; Barley, Dennis; Rudd, Armin; Townsend, Aaron; Hancock, Ed

    2006-12-01

    This report describes a field test to characterize the uniformity of room-to-room ventilation air distribution under various operating conditions by examining multi-zone tracer gas decay curves and calculating local age-of-air.

  13. Frictional and heat resistance characteristics of coconut husk particle filled automotive brake pad

    NASA Astrophysics Data System (ADS)

    Bahari, Shahril Anuar; Chik, Mohd Syahrizul; Kassim, Masitah Abu; Som Said, Che Mohamad; Misnon, Mohd Iqbal; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    The objective of this study was to determine the friction and heat resistance characteristics of automotive brake pad composed with different sizes and percentages of coconut husk particle. The materials used were phenolic resin (phenol formaldehyde) as binder, copper, graphite and brass as friction producer/modifiers, magnesium oxide as abrasive material, steel and barium sulfate as reinforcement while coconut husk particle as filler. To obtain particle, the coconut husk was ground and dried to 3% moisture content. Then the coconut husk particle was screened using 80 mesh (to obtain coarse dust) and 100 mesh (to obtain fine dust). Different percentages of particle, such as 10 and 30% were used in the mixture of brake pad materials. Then the mixture was hot-pressed to produce brake pad. Chase machine was used to determine the friction coefficient in friction resistance testing, while thermogravimetric analyzer (TGA) machine was used to determine the heat decomposition values in heat resistance testing. Results showed that brake pad with 100 mesh and 10% composition of coconut husk particle showed the highest friction coefficient. For heat resistance, brake pad with 100 mesh and 30% composition of coconut husk dust showed the highest decomposition temperature, due to the high percentage of coconut husk particle in the composition, thus increased the thermal stability. As a comparison, brake pad composed with coconut husk particle showed better heat resistance results than commercial brake pad.

  14. Evaluation the course of the vehicle braking process in case of hydraulic circuit malfunction

    NASA Astrophysics Data System (ADS)

    Szczypiński-Sala, W.; Lubas, J.

    2016-09-01

    In the paper, the results of the research were discussed, the aim of which was the evaluation of the vehicle braking performance efficiency and the course of this process with regard to the dysfunction which may occur in braking hydraulic circuit. As part of the research, on-road tests were conducted. During the research, the delay of the vehicle when braking was measured with the use of the set of sensors placed in the parallel and the perpendicular axis of the vehicle. All the tests were conducted on the same flat section of asphalt road with wet surface. Conditions of diminished tire-to-road adhesion were chosen in order to force the activity of anti-lock braking system. The research was conducted comparatively for the vehicle with acting anti-lock braking system and subsequently for the vehicle without the system. In both cases, there was a subsequent evaluation of the course of braking with efficient braking system and with the dysfunction of hydraulic circuit.

  15. Electromagnetic braking for Mars spacecraft

    NASA Technical Reports Server (NTRS)

    Holt, A. C.

    1986-01-01

    Aerobraking concepts are being studied to improve performance and cost effectiveness of propulsion systems for Mars landers and Mars interplanetary spacecraft. Access to megawatt power levels (nuclear power coupled to high-storage inductive or capacitive devices) on a manned Mars interplanetary spacecraft may make feasible electromagnetic braking and lift modulation techniques which were previously impractical. Using pulsed microwave and magnetic field technology, potential plasmadynamic braking and hydromagnetic lift modulation techniques have been identified. Entry corridor modulation to reduce loads and heating, to reduce vertical descent rates, and to expand horizontal and lateral landing ranges are possible benefits. In-depth studies are needed to identify specific design concepts for feasibility assessments. Standing wave/plasma sheath interaction techniques appear to be promising. The techniques may require some tailoring of spacecraft external structures and materials. In addition, rapid response guidance and control systems may require the use of structurally embedded sensors coupled to expert systems or to artificial intelligence systems.

  16. 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 ...

  17. Design and Analysis of a Novel Centrifugal Braking Device for a Mechanical Antilock Braking System.

    PubMed

    Yang, Cheng-Ping; Yang, Ming-Shien; Liu, Tyng

    2015-06-01

    A new concept for a mechanical antilock braking system (ABS) with a centrifugal braking device (CBD), termed a centrifugal ABS (C-ABS), is presented and developed in this paper. This new CBD functions as a brake in which the output braking torque adjusts itself depending on the speed of the output rotation. First, the structure and mechanical models of the entire braking system are introduced and established. Second, a numerical computer program for simulating the operation of the system is developed. The characteristics of the system can be easily identified and can be designed with better performance by using this program to studying the effects of different design parameters. Finally, the difference in the braking performance between the C-ABS and the braking system with or without a traditional ABS is discussed. The simulation results indicate that the C-ABS can prevent the wheel from locking even if excessive operating force is provided while still maintaining acceptable braking performance.

  18. 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.

  19. Gravity Slides With Magnetic Braking

    NASA Technical Reports Server (NTRS)

    Goodrick, Thomas F.

    1995-01-01

    Slides with magnetic braking enable safe emergency descent from tall buildings, fire-truck ladders, towers, and like. According to concept, slide includes sled that moves along stationary aluminum track tilted against top of building. Sled holds set of permanent magnets at preset small distance from surface of track. Passenger stands on, sits on, or strapped to platform on sled. Release device at top of slide holds sled in place until passenger prepared for descent.

  20. What brakes the Crab pulsar?

    NASA Astrophysics Data System (ADS)

    Čadež, A.; Zampieri, L.; Barbieri, C.; Calvani, M.; Naletto, G.; Barbieri, M.; Ponikvar, D.

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

  1. Operational test report for 241-AW tank inlet air control stations

    SciTech Connect

    Minteer, D.J., Westinghouse Hanford

    1996-07-03

    This document reports the results of operational testing on tank inlet air control stations in 241-AW tank farm. An air control station was installed on each of the six AW tanks. Operational testing consisted of a simple functional test of each station`s air flow controller, aerosol testing of each station`s HEPA filter, and final ventilation system balancing (i.e., tank airflows and vacuum level) using the air control stations. The test was successful and the units were subsequently placed into operation.

  2. NAC Aftermarket Brake Components Project (Secondary Items)

    DTIC Science & Technology

    2006-09-25

    NAC Aftermarket Brake Components Project (Secondary Items) SAE Paper #2006-01-3192 25 September 2006, Grapevine Version R4 (Final) Report...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE NAC Aftermarket Brake Components Project (Secondary Items) 5a. CONTRACT NUMBER 5b...PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 NAC Aftermarket Brake Components Project By: Leo Miller, USA

  3. Braking indices of pulsars obtained in the presence of an effective force

    NASA Astrophysics Data System (ADS)

    Magalhaes, N. S.; Okada, A. S.; Frajuca, C.

    2016-10-01

    Braking indices of pulsars present a scientific challenge as their theoretical calculation is still an open problem. In this paper, we report results of a study regarding such calculation which adapts the canonical model (which admits that pulsars are rotating magnetic dipoles) basically by introducing a compensating component in the energy conservation equation of the system. This component would correspond to an effective force that varies with the first power of the tangential velocity of the pulsar's crust. We test the proposed model using data available and predict braking indices values for different stars. We comment on the high braking index recently measured of the pulsar J1640-4631.

  4. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    ERIC Educational Resources Information Center

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  5. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  6. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  7. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  8. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  9. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  10. Bidirectional Drive-And-Brake Mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A.

    1991-01-01

    Vehicle that crawls along monorail combines features of both bicycle and railroad handcar. Bidirectional drive-and-brake mechanism includes selectable-pawl-and-ratchet overrunning clutch (drive mechanism) and mating stationary and rotating conical surfaces pressing against each other (brake mechanism). Operates similarly to bicycle drive-and-brake mechanism except limits rotation of sprocket in both directions and brakes at both limits. Conceived for use by astronaut traveling along structure in outer space, concept also applied on Earth to make very small railraod handcars or crawling vehicles for use on large structures, in pipelines under construction, or underwater.

  11. Influences on nonlinear judder vibrations of railway brakes

    NASA Astrophysics Data System (ADS)

    Heckmann, Andreas; Kurzeck, Bernhard; Carrarini, Antonio; Günther, Frank; Schroeder-Bodenstein, Kaspar

    2010-06-01

    The paper reports on a joined research project of Knorr-Bremse, Siemens Mobility and the Institute of Robotics and Mechatronics. The goal of the project was to analyse the dynamical behaviour of friction brakes for high-speed trains. It was intended to gain insight into possible vibration mechanisms and to assess the potential for lay-out and operation improvements for future light-weight designs. In particular, the frequency range up to 250 Hz has been addressed, since the corresponding excitation is unavoidable at least to some extent and has to be considered when the brake system is designed. The study includes a comprehensive multibody simulation study and its comparison to experimental results at the test rig of Knorr-Bremse in Munich. The simulation model is adapted step by step in order to clearly identify and separate the influences on the dynamical properties of the complete brake system including its mounting. Additionally a minimal model is introduced that demonstrates some characteristics of the brake system. It turned out that the underlying knowledge is essential for the mechanical lay-out, which could be demonstrated by solving a particular vibration problem in an actual high-speed project.

  12. Wear and related characteristics of an aircraft tire during braking

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.

    1972-01-01

    Wear and related characteristics of friction and temperature developed during braking of size 22 x 5.5, type aircraft tires are studied. The testing technique involved gearing the tire to a driving wheel of a ground vehicle to provide operations at constant slip ratios on asphalt, concrete, and slurry-seal surfaces. Data were obtained over the range of slip ratios generally attributed to an aircraft braking system during dry runway operations. The results show that the cumulative tire wear varies linearly with distance traveled and the wear rate increases with increasing slip ratio and is influenced by the runway-surface character. Differences in the wear rates associated with the various surfaces suggest that runways can be rated on the basis of tire wear. The results also show that the friction coefficients developed during fixed-slip-ratio operations are in good agreement with those obtained by other investigators during cyclic braking, in that the dry friction is insensitive to the tire tread temperature is shown to increase with increasing slip ratio and, at the higher ratios, to be greater during braking on asphalt and slurry seal than on concrete.

  13. Air Force Dynamic Mechanical Analysis Testing of NATO Round Robin Propellant Testing for Development of AOP-4717

    DTIC Science & Technology

    2015-08-01

    NATO Round Robin Propellant Testing for Development of AOP-4717 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...provided by Naval Air Warfare Center Weapons Division (NAWCWD). The purpose of the tests was to participate in an international round robin that would...Analysis Testing of NATO Round Robin Propellant Testing for Development of AOP-4717 Timothy C. Miller, Air Force Research Laboratory Patrick N

  14. Design and evaluation of a novel magnetorheological brake with coils placed on the side housings

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc Hung; Diep Nguyen, Ngoc; Bok Choi, Seung

    2015-04-01

    In the design of a traditional magnetorheological brake (MRB), coils are often placed on the cylindrical housing of the brake. This results in many disadvantages such as a ‘bottle-neck’ problem of magnetic flux. Moreover, in this design a nonmagnetic bobbin is required, and difficulties in manufacturing and maintenance exist. In order to resolve this problem, in this study a new configuration of MRB with coils placed on the side housings of the brake is proposed, optimally designed and experimentally evaluated. After describing an introduction of the proposed configuration, braking torque of the MRB is analyzed based on the Bingham-plastic rheological model of magnetorheological fluid (MRF). The optimization of the proposed and conventional MRBs is then performed considering maximum braking torque and mass of the brakes. In the optimization, both rectangular and polygonal shapes of the brake housing are considered. Based on the optimal results, a comparison of the performance characteristics of the proposed MRB and the conventional one is undertaken. In addition, an experimental test of the MRBs is conducted, and the results are presented in order to validate the performance characteristics of the proposed MRB.

  15. A method to model anticipatory postural control in driver braking events.

    PubMed

    Östh, Jonas; Eliasson, Erik; Happee, Riender; Brolin, Karin

    2014-09-01

    Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated braking differ greatly from autonomous braking. In the present study, an anticipatory postural response was hypothesized, modelled in a whole-body HBM with feedback controlled muscles, and validated using existing volunteer data. The anticipatory response was modelled as a time dependent change in the reference value for the feedback controllers, which generates correcting moments to counteract the braking deceleration. The results showed that, in 11 m/s(2) driver braking simulations, including the anticipatory postural response reduced the peak forward displacement of the head by 100mm, of the shoulder by 30 mm, while the peak head flexion rotation was reduced by 18°. The HBM kinematic response was within a one standard deviation corridor of corresponding test data from volunteers performing maximum braking. It was concluded that the hypothesized anticipatory responses can be modelled by changing the reference positions of the individual joint feedback controllers that regulate muscle activation levels. The addition of anticipatory postural control muscle activations appears to explain the difference in occupant kinematics between driver and autonomous braking. This method of modelling postural reactions can be applied to the simulation of other driver voluntary actions, such as emergency avoidance by steering.

  16. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    A. Rudd and D. Bergey

    2015-08-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs.

  17. Test/QA Plan (TQAP) for Verification of Semi-Continuous Ambient Air Monitoring Systems

    EPA Science Inventory

    The purpose of the semi-continuous ambient air monitoring technology (or MARGA) test and quality assurance plan is to specify procedures for a verification test applicable to commercial semi-continuous ambient air monitoring technologies. The purpose of the verification test is ...

  18. Applications of magnetorheological brakes in manual control of lifting devices and manipulators

    NASA Astrophysics Data System (ADS)

    Chciuk, M.; Milecki, A.; Myszkowski, A.

    2009-02-01

    The article is aimed to design and testing of joystick with force feedback used in direct, human control of lifting device. The paper starts with the basic description of designed and tested by us MR rotary brake. Some initial laboratory investigations results of such brakes are presented. The usage of MR brakes in 2 axis joystick is proposed. Such, built by as joystick, is described. It was used as Human-Machine Interface in active control of lifting device. The designed and built 2 axis manipulator with electrohydraulic drive is described. In the paper, the based on PC with input/output card, control system of mentioned above joystick with MR brake and manipulator is described. Finally the control algorithm is proposed.

  19. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    NASA Astrophysics Data System (ADS)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

  20. Energy use test facility: CAC-DOE solar air heater test report

    NASA Astrophysics Data System (ADS)

    1981-11-01

    The solar air heater testing demonstrated an attractive application for residential space heating, especially appealing to the do-it-yourself market. Simple improvements in construction, such as caulking of the glazing, could increase collector performance at little cost. The operating cost of the fan was insignificant, being less than $0.05/week. Tested in its as-shipped configuration at 96.1 cfm (3 cfm/ft (2)), the useful energy delivered averaged 20,000 Btu/day for six days in December. The electrical consumption of the fan was approximately 1 kWh. Doubling the flowrate did not increase collector performance appreciably. A TRNSYS computer simulation model for this solar air heater design was validated by comparing the measured test data on Jaunary 4, 1981 with calculated values. TRNSYS predicted that measured collector outlet temperatures within +- 1.20F and the energy delivered within +- 3%. The excellent agreement was obtained by adjusting the collector loss coefficient to an unrealistically low value; therefore, a parametric study is recommended to determine the model sensitivity to varying different parameters. A first-order collector efficiency curve was derived from the TRNSYS simulations which compared well with the curve defined by the clear-day measured data.

  1. Position control optimization of aerodynamic brake device for high-speed trains

    NASA Astrophysics Data System (ADS)

    Zuo, Jianyong; Luo, Zhuojun; Chen, Zhongkai

    2014-03-01

    The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions—constant, linear, and quadratic—are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25.71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

  2. Effect of Carbon Nanotubes on Tribo-Performance of Brake Friction Materials

    NASA Astrophysics Data System (ADS)

    Singh, Tej; Patnaik, Amar; Satapathy, Bhabani K.

    2011-12-01

    Brake friction composites filled with multiwalled carbon nanotubes have been fabricated and evaluated for their tribo-performance. The tribological behavior of the frictional composites has been evaluated on a krauss testing machine as per the ECE regulations. The friction performance (μP), frictions fade (μF) and friction recovery (μR) gets enhanced with the addition of carbon nanotubes. The wear performance and brake pad thickness loss of the composites decreased with the increase in carbon nanotubes.

  3. Wear, friction, and temperature characteristics of an aircraft tire undergoing braking and cornering

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.; Yager, T. J.; Riccitiello, S. R.

    1979-01-01

    An investigation to evaluate the wear, friction, and temperature characteristics of aircraft tire treads fabricated from different elastomers is presented. The braking and cornering tests performed on aircraft tires retreaded with currently employed and experimental elastomers are described. The tread wear rate is discussed in relation to the slip ratio during braking and yaw angle during cornering. The extent of wear in either operational mode is examined in relation to the runway surface.

  4. Braking index of isolated pulsars

    NASA Astrophysics Data System (ADS)

    Hamil, O.; Stone, J. R.; Urbanec, M.; Urbancová, G.

    2015-03-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities Ω , and their time derivatives that show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of detailed debate, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of Ω . This relation leads to the power law Ω ˙ =-K Ωn where n is called the braking index. The MDR model predicts n exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of n , individually accurate to a few percent or better, in the range 1 braking index within the MDR model. Four microscopic equations of state are employed as input to two different computational codes that solve Einstein's equations numerically, either exactly or using the perturbative Hartle-Thorne method, to calculate the

  5. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  6. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  7. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  8. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  9. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  10. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  11. Constraining the braking indices of magnetars

    NASA Astrophysics Data System (ADS)

    Gao, Z. F.; Li, X.-D.; Wang, N.; Yuan, J. P.; Wang, P.; Peng, Q. H.; Du, Y. J.

    2016-02-01

    Because of the lack of long-term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index n of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of the mean braking indices of eight magnetars with SNRs, and find that they cluster in the range of 1-42. Five magnetars have smaller mean braking indices of 1 < n < 3, and we interpret them within a combination of magneto-dipole radiation and wind-aided braking. The larger mean braking indices of n > 3 for the other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with 1 < n < 3, and the dipolar magnetic field decay rates for the magnetars with n > 3, within the updated magneto-thermal evolution models. Although the constrained range of the magnetars' braking indices is tentative, as a result of the uncertainties in the SNR ages due to distance uncertainties and the unknown conditions of the expanding shells, our method provides an effective way to constrain the magnetars' braking indices if the measurements of the SNR ages are reliable, which can be improved by future observations.

  12. Orbital-Transfer Vehicle With Aerodynamic Braking

    NASA Technical Reports Server (NTRS)

    Scott, C. D.; Nagy, K.; Roberts, B. B.; Ried, R. C.; Kroll, K.; Gamble, J.

    1986-01-01

    Vehicle includes airbrake for deceleration into lower orbit. Report describes vehicle for carrying payloads between low and high orbits around Earth. Vehicle uses thin, upper atmosphere for braking when returning to low orbit. Since less propellant needed than required for full retrorocket braking, vehicle carries larger payload and therefore reduces cost of space transportation.

  13. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  14. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  15. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  16. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  17. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) In addition, for commuter...

  18. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) For airplanes required to meet §...

  19. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) In addition, for commuter...

  20. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) For airplanes required to meet §...

  1. Method and apparatus for electromagnetically braking a motor

    NASA Technical Reports Server (NTRS)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  2. Design of MR brake featuring tapered inner magnetic core

    NASA Astrophysics Data System (ADS)

    Sohn, Jung Woo; Oh, Jong-Soek; Choi, Seung-Bok

    2015-04-01

    In this work, a new type of MR brake featuring tapered inner magnetic core is proposed and its braking performance is numerically evaluated. In order to achieve high braking torque with restricted size and weight of MR brake system, tapered inner magnetic core is designed and expands the area that the magnetic flux is passing by MR fluid-filled gap. The mathematical braking torque model of the proposed MR brake is derived based on the field-dependent Bingham rheological model of MR fluid. Finite element analysis is carried out to identify electromagnetic characteristics of the conventional and the proposed MR brake configuration. To demonstrate the superiority of the proposed MR brake, the braking torque of the proposed MR brake is numerically evaluated and compared with that of conventional MR brake model.

  3. a Study on the Squeal of a Drum Brake which has Shoes of Non-Uniform Cross-Section

    NASA Astrophysics Data System (ADS)

    LEE, J. M.; YOO, S. W.; KIM, J. H.; AHN, C. G.

    2001-03-01

    A stability analysis of a drum brake, which has shoes of non-uniform cross-section, is performed to find a simple and effective method of reducing the squeal of the drum brake by partially changing the shapes of the shoes. The squeal is considered as a noise induced by the self-excited vibration of the drum brake which makes the brake unstable. Shoes of non-uniform cross-section are often used for the drum brake of current passenger cars to reduce the squeal. However, the influence of this non-uniformity upon the squeal has not been analyzed theoretically. In this study, the drum and the shoes are assumed as a uniform ring and non-uniform arches, respectively, for modelling the brake. For a reasonable method of modelling, the vibration characteristics of the brake and their relations to the squeal are discussed based on the results of modal tests. The influences of brake design parameters upon the squeal are investigated, and a minor change of the cross-section is proposed to reduce the squeal. The effect of the minor change is verified through noise dynamometer tests. In addition, the effect of asymmetry of the drum, which can be built by mass addition, is presented.

  4. VERIFICATION TESTING OF AIR POLLUTION CONTROL TECHNOLOGY QUALITY MANAGEMENT PLAN

    EPA Science Inventory

    This document is the basis for quality assurance for the Air Pollution Control Technology Verification Center (APCT Center) operated under the U.S. Environmental Protection Agency (EPA). It describes the policies, organizational structure, responsibilities, procedures, and qualit...

  5. Some wear studies on aircraft brake systems

    NASA Technical Reports Server (NTRS)

    Ho, T. L.

    1975-01-01

    An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

  6. Driving and braking control of PM synchronous motor based on low-resolution hall sensor for battery electric vehicle

    NASA Astrophysics Data System (ADS)

    Gu, Jing; Ouyang, Minggao; Li, Jianqiu; Lu, Dongbin; Fang, Chuan; Ma, Yan

    2013-01-01

    Resolvers are normally employed for rotor positioning in motors for electric vehicles, but resolvers are expensive and vulnerable to vibrations. Hall sensors have the advantages of low cost and high reliability, but the positioning accuracy is low. Motors with Hall sensors are typically controlled by six-step commutation algorithm, which brings high torque ripple. This paper studies the high-performance driving and braking control of the in-wheel permanent magnetic synchronous motor (PMSM) based on low-resolution Hall sensors. Field oriented control (FOC) based on Hall-effect sensors is developed to reduce the torque ripple. The positioning accuracy of the Hall sensors is improved by interpolation between two consecutive Hall signals using the estimated motor speed. The position error from the misalignment of the Hall sensors is compensated by the precise calibration of Hall transition timing. The braking control algorithms based on six-step commutation and FOC are studied. Two variants of the six-step commutation braking control, namely, half-bridge commutation and full-bridge commutation, are discussed and compared, which shows that the full-bridge commutation could better explore the potential of the back electro-motive forces (EMF), thus can deliver higher efficiency and smaller current ripple. The FOC braking is analyzed with the phasor diagrams. At a given motor speed, the motor turns from the regenerative braking mode into the plug braking mode if the braking torque exceeds a certain limit, which is proportional to the motor speed. Tests in the dynamometer show that a smooth control could be realized by FOC driving control and the highest efficiency and the smallest current ripple could be achieved by FOC braking control, compared to six-step commutation braking control. Therefore, FOC braking is selected as the braking control algorithm for electric vehicles. The proposed research ensures a good motor control performance while maintaining low cost and high

  7. Evaluation of asbestos exposure during brake repair and replacement.

    PubMed

    Kakooei, Hossein; Hormozy, Maryam; Marioryad, Hossein

    2011-01-01

    Occupational exposure to asbestos fiber of brake repair job (auto mechanics) has seldom been evaluated in Iran. Accordingly, we evaluated asbestos fiber concentrations in the breathing zone of auto mechanics between July 2008 and December 2008. The asbestos fiber concentrations of 60 personal air samples collected from 30 cars and trucks brake replacement and they were analyzed by phase-contrast optical microscopy (PCM) and scanning electron microscopy (SEM) by energy-dispersive X-ray analysis. The geometric means of the personal monitoring fiber concentrations were 0.92 PCM f/ml and 0.46 PCM f/ml respectively in car and passenger heavy truck auto shops. There was a significant differences in the asbestos fiber concentrations between the car and truck auto shops (p=0.006). Based on these findings, auto mechanics who worked with asbestos containing brake may have been exposed to asbestos concentrations approximately 7 times higher than the current occupational safety and health agency (OSHA) permissible exposure limit (PEL) of 0.1 f/ml. Fiber morphology and energy dispersive X-ray analysis by SEM revealed that amphibole fibers such as tremolite and actinolite existed in the brakes dust and that the vast majority (>30%) of the airborne chrysotile fibers were greater than 1 μm in diameter. It can be concluded that the imported chrysotile asbestos contains trace amounts of tremolite and actinolite fibers and they are responsible for the high airborne asbestos levels and occupational exposure to amphibole asbestos in auto mechanics job in Iran. Thus, it is to be expected that the auto mechanics will suffer negative health effects due to exposure to the serpentine and amphibole asbestos fibers.

  8. Sliding simulation of automotive brake primary contact with variable amounts of copper and graphite nanoparticles

    NASA Astrophysics Data System (ADS)

    Dmitriev, A. I.; Österle, W.

    2016-11-01

    Copper is one of the most important components in brake pads and its amount can reach up to 14%. In spite of a number of positive features copper usage in brake pad formulations has recently become the subject of considerable discussions, primarily due to concerns about potential risks related to environmental impacts of copper particles. So, for developing new pad formulations with possible replacements of copper content, it is very important to understand the functionality of copper additions to brake friction materials. In the paper theoretical investigation of the role of copper as a pad ingredient was carried out on the basis of modelling by the method of movable cellular automata (MCA). In the study the concentration of copper particles in a Fe3O4-matrix was varied. The sliding simulations were performed while assuming material properties at 500°C in order to assess the beneficial role of copper during severe braking conditions corresponding to fading cycles during dynamometer testing.

  9. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such as the tailpipe emissions, air conditioning compressor load, and fuel economy. (2) For any...

  10. Building America Top Innovations 2014 Profile: HVAC Cabinet Air Leakage Test Method

    SciTech Connect

    none,

    2014-11-01

    This 2014 Top Innovation profile describes Building America-funded research by teams and national laboratories that resulted in the development of an ASHRAE standard and a standardized testing method for testing the air leakage of HVAC air handlers and furnace cabinets and has spurred equipment manufacturers to tighten the cabinets they use for residential HVAC systems.

  11. 76 FR 50164 - Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... of the Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing... AGENCY 40 CFR Parts 72 and 75 RIN 2060-AQ06 Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing; Corrections AGENCY: Environmental Protection Agency (EPA)....

  12. Analysis of natural frequency variability of a brake component

    NASA Astrophysics Data System (ADS)

    Gallina, A.; Lisowski, W.; Pichler, L.; Stachowski, A.; Uhl, T.

    2012-10-01

    The manufacture of automotive disc brake calipers is subjected to many inherent variabilities resulting in product variability. In particular, the dispersion of natural frequency values is a primary issue in the context of vehicle comfort. This paper aims to quantify natural frequency variability and search for its causes. Extensive experimental tests and numerical simulations, described in the paper, point out the fundamental role of mold wear and assembling process in this variability.

  13. Environmental Technology Verification: Supplement to Test/QA Plan for Biological and Aerosol Testing of General Ventilation Air Cleaners; Bioaerosol Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners

    EPA Science Inventory

    The Air Pollution Control Technology Verification Center has selected general ventilation air cleaners as a technology area. The Generic Verification Protocol for Biological and Aerosol Testing of General Ventilation Air Cleaners is on the Environmental Technology Verification we...

  14. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the governor cuts in. Increased engine speed to fast idle and charge the system to its governed... engine speed to fast idle and charge the system to its governed pressure. Stop the engine and record...

  15. Design Considerations and Experimental Verification of a Rail Brake Armature Based on Linear Induction Motor Technology

    NASA Astrophysics Data System (ADS)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    This paper describes the design considerations and experimental verification of an LIM rail brake armature. In order to generate power and maximize the braking force density despite the limited area between the armature and the rail and the limited space available for installation, we studied a design method that is suitable for designing an LIM rail brake armature; we considered adoption of a ring winding structure. To examine the validity of the proposed design method, we developed a prototype ring winding armature for the rail brakes and examined its electromagnetic characteristics in a dynamic test system with roller rigs. By repeating various tests, we confirmed that unnecessary magnetic field components, which were expected to be present under high speed running condition or when a ring winding armature was used, were not present. Further, the necessary magnetic field component and braking force attained the desired values. These studies have helped us to develop a basic design method that is suitable for designing the LIM rail brake armatures.

  16. Functional performance testing of the universal super absorbing air filters FSU 70 „Air by Corneliu”

    NASA Astrophysics Data System (ADS)

    Raţiu, S.; Birtok-Băneasă, C.; Alexa, V.; Kiss, I.

    2015-06-01

    This paper presents the experimental methodology to carry out functional performance tests for an air filter with a particular design of its housing, generically named Universal super absorbing FSU 70 „Air by Corneliu”. The tests were carried out in the Internal Combustion Engines Laboratory, within the specialization "Road automotives" belonging to the Faculty of Engineering Hunedoara, component of “Politehnica” University of Timisoara. We present some comparative values of various operating parameters of the engine fitted, in the first measuring session, with the original filter, and then with the studied filter.

  17. Further experimental studies in wet-brake friction

    SciTech Connect

    Staph, H.E.; Marbach, H.W. Jr.

    1986-01-01

    This paper describes further experimental efforts to determine friction characteristics that define the chatter potential in wet-brake systems as used in tractors and other off-road applications. Changes and improvements to a bench facility described at the 1985 Off-Highway Conference are described. Of particular interest is the decision to examine the very low sliding velocity regime, particularly below 0.34 m/s sliding velocity. Interesting and informative data have been obtained by feeding the input of an accelerometer attached in effect to the caliper brake pads to a frequency analyzer. A spectrum of the energy developed by the vibrating pads over the frequency range of 0 to 250 Hz while the sliding velocity is increased from 0 to 0.85 m/s is obtained. Specifically, the area under the composite frequency curve from 70 to 125 Hz shows good correlation to the chatter propensity of the oil. The results of tests on several oils are described. The ultimate purpose of the research is to provide a relatively rapid screening test for evaluating brake oils for the John Deere-type qualification tests. The overall results emphasize the importance of a low ratio between the breakaway friction and the friction at moderate sliding velocities for low or no chatter.

  18. Recycled brake linings as partial aggregate substitute in asphalt paving. Construction and final report. Report for July 1992-August 1996

    SciTech Connect

    Miller, P.A.; Sukley, R.

    1996-09-01

    The purpose of this project was to evaluate the performance of asphalt containing various percentages of brake lining as an aggregate, and compare its performance to that of normal asphalt containing natural aggregate. This project is an effort to explore alternate ways to use waste product. Four test section of FB-2 Modified mix containing brake lining materials were placed in July 1992 along with one control section on SR 3022 in Mercer county. To date all sections are performing satisfactory, and Brake linings should be recommended as a viable partial replacement of aggregate in bituminous materials. This study only considered the performance of only off-spec brake linings, therefore, any performance data or enviromental effects of placement of used brake material should be addressed.

  19. Relationship between Air Force Officer Qualifying Test Scores and Success in Air Weapons Controller Training. Interim Report for the Period November 1982-February 1984.

    ERIC Educational Resources Information Center

    Finegold, Lawrence S.; Rogers, Deborah

    This project investigated the relationship between Air Force Officer Qualifying Test (AFOQT) composite scores and student performance in Air Force air weapons controller training. The purpose of this study was to examine the feasibility of using AFOQT scores as one selection criteria for entry to the air weapons controller field. An analysis of…

  20. A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes

    NASA Astrophysics Data System (ADS)

    Sinou, J.-J.; Loyer, A.; Chiello, O.; Mogenier, G.; Lorang, X.; Cocheteux, F.; Bellaj, S.

    2013-09-01

    This paper presents an overview of recent experimental and numerical investigations on industrial railway brakes. The goal of the present study is to discuss the relevance of the mechanical modeling strategy for squeal prediction. Specific experimental set-ups based on transient and controlled braking tests are designed for this purpose. Measurements are performed on it to investigate the dynamic behavior of TGV squeal noise and its squeal characterization through experiments. It will be demonstrated that it is possible to build consistent and efficient finite element models to simulate squeal events in TGV brake systems. The numerical strategy will be presented, including not only the modeling of the TGV brake system and the stability analysis, but also the transient nonlinear dynamic and computational process based on efficient reduced basis. This complete numerical strategy allows us to perform relevance squeal prediction on industrial railway brakes. This study comes within the scope of a research program AcouFren that is supported by ADEME (Agence De l'Environnement et de la Maîtrise de l'Energie) concerning the reduction of the squeal noise generated by high power railway disc brakes. experiments with an evolution of the rotational speed of the disc: these tests are called "transient braking tests" and correspond to real braking tests, experiments with a controlled steady rotational speed (i.e. dynamic fluctuations in rotational speed are not significant): these tests are called "controlled braking tests". In the present study, the Continuous Wavelet Transform (CWT) [20] is used to study the time-history responses of the TGV brake system. So, a brief basic theory of the wavelet analysis that transforms a signal into wavelets that are well localized both in frequency and time is presented in this part of the paper. Considering a function f(t), the associated Continuous Wavelet Transform (CWT) corresponds to a wavelet transform given by W(a,b

  1. Brakes. Auto Mechanics Curriculum Guide. Module 6. Instructor's Guide.

    ERIC Educational Resources Information Center

    Allain, Robert

    This module is the sixth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Eight units cover: introduction to automotive brake systems; disc and drum brake system components and how they operate; properties of brake fluid and procedures for bleeding the brake system; diagnosing and determining needed repairs on…

  2. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2011-10-01 2011-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  3. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2010-10-01 2010-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  4. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2012-10-01 2012-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  5. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2014-10-01 2014-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  6. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2013-10-01 2013-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  7. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    ERIC Educational Resources Information Center

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

  8. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  9. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  10. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  11. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  12. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  13. Air Sensor Kit Performance Testing and Pollutant Mapping Supports Community Air Monitoring Project

    EPA Pesticide Factsheets

    EPA is collaborating on a research project with the South Coast Air Quality Management District in Diamond Bar, Calif. to gain an enhanced understanding of fine particulate matter (PM2.5) and ozone concentrations across the study area.

  14. Immobilisation of the knee and ankle and its impact on drivers' braking times: a driving simulator study.

    PubMed

    Waton, A; Kakwani, R; Cooke, N J; Litchfield, D; Kok, D; Middleton, H; Irwin, L

    2011-07-01

    The purpose of this study was to investigate the effects of right leg restriction at the knee, ankle or both, on a driver's braking times. Previous studies have not investigated the effects of knee restriction on braking performance. A total of 23 healthy drivers performed a series of emergency braking tests in a driving simulator in either an above-knee plaster cast, a below-knee cast, or in a knee brace with an increasing range of restriction. The study showed that total braking reaction time was significantly longer when wearing an above-knee plaster cast, a below-knee plaster cast or a knee brace fixed at 0°, compared with braking normally (p < 0.001). Increases in the time taken to move the foot from the accelerator to the brake accounted for some of the increase in the total braking reaction time. Unexpectedly, thinking time also increased with the level of restriction (p < 0.001). The increase in braking time with an above-knee plaster cast in this study would increase the stopping distance at 30 miles per hour by almost 3 m. These results suggest that all patients wearing any lower-limb plaster cast or knee brace are significantly impaired in their ability to perform an emergency stop. We suggest changes to the legislation to prevent patients from driving with lower-limb plaster casts or knee braces.

  15. Electromechanical imitator of antilock braking modes of wheels with pneumatic tire and its application for the runways friction coefficient measurement

    NASA Astrophysics Data System (ADS)

    Putov, A. V.; Kopichev, M. M.; Ignatiev, K. V.; Putov, V. V.; Stotckaia, A. D.

    2017-01-01

    In this paper it is considered a discussion of the technique that realizes a brand new method of runway friction coefficient measurement based upon the proposed principle of measuring wheel braking control for the imitation of antilock braking modes that are close to the real braking modes of the aircraft chassis while landing that are realized by the aircraft anti-skid systems. Also here is the description of the model of towed measuring device that realizes a new technique of runway friction coefficient measuring, based upon the measuring wheel braking control principle. For increasing the repeatability accuracy of electromechanical braking imitation system the sideslip (brake) adaptive control system is proposed. Based upon the Burkhard model and additive random processes several mathematical models were created that describes the friction coefficient arrangement along the airstrip with different qualitative adjectives. Computer models of friction coefficient measuring were designed and first in the world the research of correlation between the friction coefficient measuring results and shape variations, intensity and cycle frequency of the measuring wheel antilock braking modes. The sketch engineering documentation was designed and prototype of the latest generation measuring device is ready to use. The measuring device was tested on the autonomous electromechanical examination laboratory treadmill bench. The experiments approved effectiveness of method of imitation the antilock braking modes for solving the problem of correlation of the runway friction coefficient measuring.

  16. Modeling regenerative braking and storage for vehicles

    SciTech Connect

    Wicks, F.; Donnelly, K.

    1997-12-31

    The fuel savings benefits of regenerative braking and storage for vehicles are often described but not quantified. For example, the federal government and automobile manufacturers are sponsoring a Program for a New Generation of Vehicles (PGNV) with a goal of obtaining a performance of 80 mpg in a family size car. It is typically suggested that such a vehicle will be a hybrid engine and electric drive with regenerative braking. The authors note that while regenerative braking has the potential of saving fuel, it may also do more harm than good as a result of additional weight, less than ideal charge/discharge efficiency on the batteries or storage flywheels and the limited portion of the entire driving cycle when regenerative braking can be utilized. The authors also noted that if regenerative braking can have a net benefit, it would be on a heavy vehicle such as a municipal bus because of the frequent stop and go requirements for both traffic light and passengers. Thus the authors initiated a study of regenerative braking on such a vehicle. The resulting analysis presented in this paper includes data following municipal buses to define the driving cycle, modeling the bus power requirements from weight, aerodynamics and rolling resistance, and then calculating the fuel saving that could result from an ideal regenerative braking system.

  17. Flapping Wing Micro Air Vehicle Wing Manufacture and Force Testing

    DTIC Science & Technology

    2011-03-03

    Thankfully, nature has already optimized micro air vehicles with the evolution of birds and insects, which become the instinctual inspirational candidates...properties to those wings found in nature. More specifically, with size comparable to a hummingbird , elastic modulus comparable to a cicada, and

  18. Laboratory Testing of Aerosol for Enclosure Air Sealing

    SciTech Connect

    Harrington, Curtis; Modera, Mark

    2012-05-01

    This report presents a process for improving the air tightness of a building envelope by sealing shell leaks with an aerosol sealing technology. Both retrofit and new construction applications are possible through applying this process either in attics and crawlspaces or during rough-in stage.

  19. Indoor tests of a hot-air solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Data taken relating indoor testing using solar simulator at Marshall Space Center has been compared with data taken during outdoor tests in previous studies. Data includes tests on thermal performance, time constance, and incidence-angle modifier tests in table/graph form.

  20. Structure Topology Optimization of Brake Pad in Large- megawatt Wind Turbine Brake Considering Thermal- structural Coupling

    NASA Astrophysics Data System (ADS)

    Zhang, S. F.; Yin, J.; Liu, Y.; Sha, Z. H.; Ma, F. J.

    2016-11-01

    There always exists severe non-uniform wear of brake pad in large-megawatt wind turbine brake during the braking process, which has the brake pad worn out in advance and even threats the safety production of wind turbine. The root cause of this phenomenon is the non-uniform deformation caused by thermal-structural coupling effect between brake pad and disc while braking under the conditions of both high speed and heavy load. For this problem, mathematical model of thermal-structural coupling analysis is built. Based on the topology optimization method of Solid Isotropic Microstructures with Penalization, SIMP, structure topology optimization of brake pad is developed considering the deformation caused by thermal-structural coupling effect. The objective function is the minimum flexibility, and the structure topology optimization model of brake pad is established after indirect thermal- structural coupling analysis. Compared with the optimization result considering non-thermal- structural coupling, the conspicuous influence of thermal effect on brake pad wear and deformation is proven as well as the rationality of taking thermal-structural coupling effect as optimization condition. Reconstructed model is built according to the result, meanwhile analysis for verification is carried out with the same working condition. This study provides theoretical foundation for the design of high-speed and heavy-load brake pad. The new structure may provide design reference for improving the stress condition between brake pad and disc, enhancing the use ratio of friction material and increasing the working performance of large-megawatt wind turbine brake.

  1. Toxic effects of brake wear particles on epithelial lung cells in vitro

    PubMed Central

    2009-01-01

    Background Fine particulate matter originating from traffic correlates with increased morbidity and mortality. An important source of traffic particles is brake wear of cars which contributes up to 20% of the total traffic emissions. The aim of this study was to evaluate potential toxicological effects of human epithelial lung cells exposed to freshly generated brake wear particles. Results An exposure box was mounted around a car's braking system. Lung cells cultured at the air-liquid interface were then exposed to particles emitted from two typical braking behaviours („full stop“ and „normal deceleration“). The particle size distribution as well as the brake emission components like metals and carbons was measured on-line, and the particles deposited on grids for transmission electron microscopy were counted. The tight junction arrangement was observed by laser scanning microscopy. Cellular responses were assessed by measurement of lactate dehydrogenase (cytotoxicity), by investigating the production of reactive oxidative species and the release of the pro-inflammatory mediator interleukin-8. The tight junction protein occludin density decreased significantly (p < 0.05) with increasing concentrations of metals on the particles (iron, copper and manganese, which were all strongly correlated with each other). Occludin was also negatively correlated with the intensity of reactive oxidative species. The concentrations of interleukin-8 were significantly correlated with increasing organic carbon concentrations. No correlation was observed between occludin and interleukin-8, nor between reactive oxidative species and interleukin-8. Conclusion These findings suggest that the metals on brake wear particles damage tight junctions with a mechanism involving oxidative stress. Brake wear particles also increase pro-inflammatory responses. However, this might be due to another mechanism than via oxidative stress. PMID:19930544

  2. Screw-released roller brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  3. Building America Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts, Tyler, Texas

    SciTech Connect

    2015-08-01

    ?Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy.

  4. Laboratory Testing of Aerosol for Enclosure Air Sealing

    SciTech Connect

    Harrington, C.; Modera, M.

    2012-05-01

    Space conditioning energy use can be significantly reduced by addressing uncontrolled infiltration and exfiltration through the envelope of a building. A process for improving the air tightness of a building envelope by sealing shell leaks with an aerosol sealing technology is presented. Both retrofit and new construction applications are possible through applying this process either in attics and crawlspaces or during rough-in stage.

  5. Optimal design and selection of magneto-rheological brake types based on braking torque and mass

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Lang, V. T.; Choi, S. B.

    2015-06-01

    In developing magnetorheological brakes (MRBs), it is well known that the braking torque and the mass of the MRBs are important factors that should be considered in the product’s design. This research focuses on the optimal design of different types of MRBs, from which we identify an optimal selection of MRB types, considering braking torque and mass. In the optimization, common types of MRBs such as disc-type, drum-type, hybrid-type, and T-shape types are considered. The optimization problem is to find an optimal MRB structure that can produce the required braking torque while minimizing its mass. After a brief description of the configuration of the MRBs, the MRBs’ braking torque is derived based on the Herschel-Bulkley rheological model of the magnetorheological fluid. Then, the optimal designs of the MRBs are analyzed. The optimization objective is to minimize the mass of the brake while the braking torque is constrained to be greater than a required value. In addition, the power consumption of the MRBs is also considered as a reference parameter in the optimization. A finite element analysis integrated with an optimization tool is used to obtain optimal solutions for the MRBs. Optimal solutions of MRBs with different required braking torque values are obtained based on the proposed optimization procedure. From the results, we discuss the optimal selection of MRB types, considering braking torque and mass.

  6. Compressed-air energy storage: Pittsfield aquifer field test

    SciTech Connect

    Bui, H.V.; Herzog, R.A.; Jacewicz, D.M.; Lange, G.R.; Scarpace, E.R.; Thomas, H.H. )

    1990-02-01

    This report documents the results of a comprehensive investigation into the practical feasibility for Compressed Air Energy Storage (CAES) in Porous Media. Natural gas porous media storage technology developed from seventy years of experience by the natural gas storage industry is applied to the investigation of CAES in porous media. A major objective of this investigation is the geologic characterization, deliverability prediction, and operations analysis of the Pittsfield CAES aquifer experiment, conducted in Pike County, Illinois during 1981--85 under EPRI/DOE sponsorship. Emphasis has been placed on applying accepted petroleum engineering concepts to the study of deliverability and on the characterization and quantification of oxygen losses which reportedly occurred at Pittsfield. Other objectives are to apply the natural gas underground storage technology and approach to a general study of CAES feasibility in porous media reservoirs, with emphasis on the practical risks and constraints of air storage in aquifer and depleted natural gas reservoirs, the effects of water on CAES operation, corrosion effects, and a review of air dehydration options.

  7. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  8. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  9. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  10. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  11. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  12. The Effect of Residual Stress on the Distortion of Gray Iron Brake Disks

    NASA Astrophysics Data System (ADS)

    Shin, M. W.; Jang, G. H.; Kim, J. K.; Kim, H. Y.; Jang, Ho

    2013-04-01

    Thermal distortion of gray iron brake disks due to residual stress and its effect on brake vibrations were studied. The residual stress of heat- and non-heat-treated gray iron disks was measured using neutron scattering. Dynamometer tests were performed to measure the friction force oscillation caused by the disk runout during brake applications. High-temperature tensile tests were carried out to find out possible plastic deformation due to residual stress during brake applications. The results showed that the average residual stress of the heat-treated disk (47.6 MPa) was lower than that of the non-heat-treated disk (99.6 MPa). Dynamometer tests at high temperatures (up to 600 °C) indicated that the residual stress pronounced the runout: the increase in disk runout after the tests for the non-heat-treated sample was more than twice that for the heat-treated sample. This difference correlated well with the neutron scattering results and the dimensional changes after a separate vacuum heat treatment. The high-temperature tensile tests showed severe reductions in yield strength at 600 °C, suggesting that disks produced with no stress relaxation could be deformed during severe braking.

  13. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  14. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  15. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  16. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  17. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  18. 14 CFR 29.921 - Rotor brake.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  19. 14 CFR 27.921 - Rotor brake.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  20. CitySpace Air Sensor Network Project Conducted to Test New Monitoring Capabilities

    EPA Pesticide Factsheets

    The CitySpace project is a new research effort by EPA to field test new, lower-cost air pollution sensors in a mid-sized city to understand how this emerging technology can add valuable information on air pollution patterns in neighboorhoods.

  1. The Air Force Officer Qualifying Test: Validity, Fairness, and Bias. Technical Report

    ERIC Educational Resources Information Center

    Hardison, Chaitra M.; Sims, Carra S.; Wong, Eunice C.

    2010-01-01

    The Air Force has long recognized the importance of selecting the most qualified officers possible. For more than 60 years, it has relied on the Air Force Officer Qualifying Test (AFOQT) as one measure of those qualifications. A variety of concerns have been raised about whether the AFOQT is biased, too expensive, or even valid for predicting…

  2. The Effect of Maturation and Educational Experience on Air Force Officer Qualifying Test Scores.

    ERIC Educational Resources Information Center

    Gregg, George

    Maturation and education improve Air Force Officer Qualifying Test (AFOQT) scores. Since the AFOQT is given at different educational levels for the several commissioning programs, differences, largely spurious, exist between the programs. To assess differences produced by maturation and education, the AFOQT was given to 415 Air Force Reserve…

  3. Criterion-Referenced Test (CRT) Items for Air Conditioning, Heating and Refrigeration.

    ERIC Educational Resources Information Center

    Davis, Diane, Ed.

    These criterion-referenced test (CRT) items for air conditioning, heating, and refrigeration are keyed to the Missouri Air Conditioning, Heating, and Refrigeration Competency Profile. The items are designed to work with both the Vocational Instructional Management System and Vocational Administrative Management System. For word processing and…

  4. Power-Factor Controller With Regenerative Braking

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1982-01-01

    Modified power-factor motor-control circuit operates motor as a phase-controlled generator when load attempts to turn at higher than synchronous speed. An induction motor is required to act at times as a brake. Circuit modification allows power-factor controller to save energy in motoring mode and convert automatically to an induction-generator controller in generating, or braking, mode.

  5. Oscillatory flow braking: inner magnetosphere observations

    NASA Astrophysics Data System (ADS)

    Panov, E. V.; Nakamura, R.; Baumjohann, W.; Angelopoulos, V.

    2013-12-01

    We search for damped oscillatory flow braking events observed by THEMIS/ARTEMIS in the near-Earth plasma sheet when their counterpart in the inner magnetosphere was observed. By comparing the particle and magnetic field data in the two locations we analyze the feedback of the inner magnetosphere to plasma sheet oscillatory flow braking. We discuss the possible role of the oscillatory flow events for plasma injection into the inner magnetosphere.

  6. Method and apparatus for wind turbine braking

    DOEpatents

    Barbu, Corneliu; Teichmann, Ralph; Avagliano, Aaron; Kammer, Leonardo Cesar; Pierce, Kirk Gee; Pesetsky, David Samuel; Gauchel, Peter

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  7. NAC Aftermarket Brake Components Project (Secondary Items)

    DTIC Science & Technology

    2007-02-06

    Supporting the Objective Force – NAC Aftermarket Brake Components Project Version: 06 February 2007 Final UNCLAS: Dist A. Approved for public...release NAC Aftermarket Brake Components Project (Secondary Items) Version: 06 February 2007 Final UNCLAS: Dist A. Approved for public release Leo Miller...Technology Insertion Project Officer (TIPO) US Army National Automotive Center ( NAC ) Warren, MI Report Documentation Page Form ApprovedOMB No. 0704

  8. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... 16 17 18 19 20 Service Brake Maximum Stopping Distance—Feet 0-36,000 34 38 43 48 53 59 64 70 76 83 89... 140,000-250,000 56 62 69 77 84 92 100 108 116 125 133 250,000-400,000 59 66 74 81 89 97 105 114...

  9. Optimal design of a new multipole bilayer magnetorheological brake

    NASA Astrophysics Data System (ADS)

    Shiao, Yaojung; Ngoc, Nguyen Anh; Lai, Chien-Hung

    2016-11-01

    This article presents a new high-torque multipole bilayer magneto-rheological brake (MRB). This MRB has a unique structural design with multiple electromagnetic poles and multiple media layers of magnetorheological fluid (MRF). The MRB has two rotors located on the outer and inner sides of a six-pole stator, and therefore, it can provide higher torque and a larger torque-to-volume ratio (TVR) than conventional single- or multipole single-layer MRBs can. Moreover, the problem of potential MRF leakage is solved by using cylindrical separator rings around the stator. In this study, first, the structure of the proposed MRB is introduced. An analog magnetic circuit was built for the MRB to investigate the effects of the MRB parameters on the magnetic field intensity of the MRF layers. In addition, a 3D electromagnetic model of the MRB was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. An approximate optimization method was then applied to obtain the optimal geometric dimensions for the major dimensional parameters of the MRB. The MRB was manufactured and tested to validate its torque and dynamic characteristics. The results showed that the proposed MRB exhibited great enhancement of the braking torque and TVR.

  10. Predictive model of squeal noise occurring on a laboratory brake

    NASA Astrophysics Data System (ADS)

    Giannini, Oliviero; Sestieri, Aldo

    2006-09-01

    This paper on brake squeal instability presents a reduced order model of a laboratory brake considered in a previous paper, and presents a description of the squeal mechanism occurring during experiments. The model uses the modal parameters of the laboratory brake components, the disc and the caliper, when they are not in contact between them. Successively, the caliper and the disc are put in contact through the pad that is modeled as a one degree of freedom system while the Coulomb law models the friction interaction between them. No stick slip motion of the pad is considered, because it was not observed in the experimental tests. As a result the model is linear and particularly suited for a parametric analysis. The stability of the model is studied by a complex eigenvalue analysis and the obtained results show a good agreement with the experimental data, provided that the key parameters of the model are consistent with the experimental set-up. The key role of the disc and the pad dynamics are discussed.

  11. Energy Efficiency in Heavy Vehicle Tires, Drivetrains, and Braking Systems

    SciTech Connect

    Peter J. Blau

    2000-04-26

    This document was prepared to support the primary goals of the Department of Energy, Office of Heavy Vehicle Technologies. These were recently stated as follows: ''Develop by 2004 the enabling technologies for a class 7-8 truck with a fuel efficiency of 10 mpg (at 65 mph) which will meet prevailing emission standards. For Class 3-6 trucks operating on an urban driving cycle, develop by 2004 commercially viable vehicles that achieve at least double the fuel economy of comparable current vehicles (1999), and as a research goal, reduce criteria pollutants to 30% below EPA standards. Develop by 2004 the diesel engine enabling technologies to support large-scale industry dieselization of Class 1 and 2 trucks, achieving a 35 % fuel efficiency improvement over comparable gasoline-fueled trucks, while meeting applicable emissions standards.'' The enabling technologies for improving the fuel efficiency of trucks, include not only engine technologies but also technologies involved with lowering the rolling resistance of tires, reducing vehicle aerodynamic drag, improving thermal management, and reducing parasitic frictional losses in drive train components. Opportunities also exist for making better use of the energy that might ordinarily be dissipated during vehicle braking. Braking systems must be included in this evaluation since safety in truck operations is vital, and braking requirements are greater for vehicles having lowered resistance to rolling. The Office of Heavy Vehicle Technologies has initiated a program to improve the aerodynamics of heavy vehicles through wind tunnel testing, computational modeling, and on-road evaluations. That activity is described in a separate multi-year plan; therefore, emphasis in this document will be on tires, drive trains, and braking systems. Recent, dramatic fluctuations in diesel fuel prices have emphasized the importance of effecting savings in truck fuel economy by implementing new component designs and materials.

  12. 77 FR 60481 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Post-Accident...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... design, inspection, and testing of air filtration and iodine adsorption units of engineered-safety..., inspection, and testing of air filtration and iodine adsorption units of ESF atmosphere cleanup systems...

  13. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... wheel cylinder cup into a test jar, immersed in water-wet brake fluid, capped and placed in an oven at..., the strips, SBR wheel cylinder cup and fluid are examined and tested. The performance results are... cylinder cups tested in each jar. One jar is heated to 70 degrees Celsius (158 degrees Fahrenheit) and...

  14. Brake for counter rotating bladed members

    SciTech Connect

    Cedoz, R.W.

    1987-02-10

    This patent describes a propulsion system including a gas turbine engine having an output shaft and a gear drive having a planetary gear set with a first element connected to the engine output shaft and a second element connected to a first bladed member and a third element connected to a second bladed member whereby the first and second bladed members are rotated in opposite directions by the output shaft. A brake is described comprising, a first transfer shaft supported on a stationary housing for rotation about an axis of the latter, a second transfer shaft supported on the stationary housing for rotation about the axis, gear means between one of the counter rotating bladed members and the first transfer shaft and gear means between the other of the counter rotating bladed members and the second transfer shaft. The brake also includes a selectively operable brake actuator on the housing movable between an extended position and a retracted position, and friction means between the brake actuator and each of first and second transfer shafts operative in the extended position of the brake actuator to simultaneously frictionally retard rotation of each of the first and the second transfer shafts whereby each of the counter rotating bladed members is simultaneously braked.

  15. Automated visual inspection of brake shoe wear

    NASA Astrophysics Data System (ADS)

    Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

    2015-10-01

    With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

  16. 75 FR 31223 - Energy Conservation Program for Consumer Products: Test Procedure for Residential Central Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... tested with installed components to include the most restrictive filter(s), supplementary heating coils... unit without an indoor air filter but requires a compensatory increase of 0.08 in wc for the...

  17. TESTING INDOOR AIR PRODUCTS: ONE APPROACH TO DEVELOPING WIDELY ACCEPTED PROTOCOLS

    EPA Science Inventory

    The paper describes an approach to developing widely acce ted products for testing indoor air products. [NOTE: Research Triangle Institute (RTI) is a partner in the U.S. Environmental Protection Agency's (EPA's) Environmental Technology Verification (ETV) Program with responsibil...

  18. Effect of air-entry angle on performance of a 2-stroke-cycle compression-ignition engine

    NASA Technical Reports Server (NTRS)

    Earle, Sherod L; Dutee, Francis J

    1937-01-01

    An investigation was made to determine the effect of variations in the horizontal and vertical air-entry angles on the performance characteristics of a single-cylinder 2-stroke-cycle compression-ignition test engine. Performance data were obtained over a wide range of engine speed, scavenging pressure, fuel quantity, and injection advance angle with the optimum guide vanes. Friction and blower-power curves are included for calculating the indicated and net performances. The optimum horizontal air-entry angle was found to be 60 degrees from the radial and the optimum vertical angle to be zero, under which conditions a maximum power output of 77 gross brake horsepower for a specific fuel consumption of 0.52 pound per brake horsepower-hour was obtained at 1,800 r.p.m. and 16-1/2 inches of Hg scavenging pressure. The corresponding specific output was 0.65 gross brake horsepower per cubic inch of piston displacement. Tests revealed that the optimum scavenging pressure increased linearly with engine speed. The brake mean effective pressure increased uniformly with air quantity per cycle for any given vane angle and was independent of engine speed and scavenging pressure.

  19. Validating Future Force Performance Measures (Army Class): Reclassification Test and Criterion Development

    DTIC Science & Technology

    2009-09-01

    rear brake pads, calipers , and rotors. 4 Correct malfunction of drag link assembly. 4 Replace air compressor and belts; inspect air brake ...tire inflation system (CTIS). (SL1/2) 6 Replace front and rear brake pads, calipers , and rotors. (SL1/2) 6 Troubleshoot steering system. (SL1/2) 6...steering lines and fittings. (SL1/2) 9 Replace front and rear brake pads, calipers , and rotors. (SL1/2) 9 Replace master cylinder and hydro-boost

  20. The Air Force Officer Qualifying Test: Validity, Fairness, and Bias

    DTIC Science & Technology

    2010-01-01

    useful in the prediction of behavior at work. Integrity tests and drug and alcohol scales fall under the rubric of specific-focus personality tests...J. A. Johnson, H. W. Eber, R. Hogan, M. C. Ashton, C. R. Cloninger , and H. C. Gough, “The International Personality Item Pool and the Future of