Science.gov

Sample records for air pressurizing hose

  1. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  2. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  3. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  4. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  5. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  6. Apparatus for Leak Testing Pressurized Hoses

    NASA Technical Reports Server (NTRS)

    Underwood, Steve D. (Inventor); Garrison, Steve G. (Inventor); Gant, Bobby D. (Inventor); Palmer, John R. (Inventor)

    2015-01-01

    A hose-attaching apparatus for leak-testing a pressurized hose may include a hose-attaching member. A bore may extend through the hose-attaching member. An internal annular cavity may extend coaxially around the bore. At least one of a detector probe hole and a detector probe may be connected to the internal annular cavity. At least a portion of the bore may have a diameter which is at least one of substantially equal to and less than a diameter of a hose to be leak-tested.

  7. 46 CFR 154.556 - Cargo hose: Maximum working pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo hose: Maximum working pressure. 154.556 Section... Equipment Cargo Hose § 154.556 Cargo hose: Maximum working pressure. A cargo hose must have a maximum working pressure not less than the maximum pressure to which it may be subjected and at least 1034...

  8. 46 CFR 154.554 - Cargo hose: Bursting pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo hose: Bursting pressure. 154.554 Section 154.554... Hose § 154.554 Cargo hose: Bursting pressure. Cargo hose that may be exposed to the pressure in the cargo tank, the cargo pump discharge, or the vapor compressor discharge must have a bursting pressure...

  9. 46 CFR 154.556 - Cargo hose: Maximum working pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo hose: Maximum working pressure. 154.556 Section... Equipment Cargo Hose § 154.556 Cargo hose: Maximum working pressure. A cargo hose must have a maximum working pressure not less than the maximum pressure to which it may be subjected and at least 1034...

  10. 46 CFR 154.554 - Cargo hose: Bursting pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo hose: Bursting pressure. 154.554 Section 154.554... Hose § 154.554 Cargo hose: Bursting pressure. Cargo hose that may be exposed to the pressure in the cargo tank, the cargo pump discharge, or the vapor compressor discharge must have a bursting pressure...

  11. 46 CFR 154.554 - Cargo hose: Bursting pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo hose: Bursting pressure. 154.554 Section 154.554... Hose § 154.554 Cargo hose: Bursting pressure. Cargo hose that may be exposed to the pressure in the cargo tank, the cargo pump discharge, or the vapor compressor discharge must have a bursting pressure...

  12. 46 CFR 154.554 - Cargo hose: Bursting pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Cargo hose: Bursting pressure. 154.554 Section 154.554... Hose § 154.554 Cargo hose: Bursting pressure. Cargo hose that may be exposed to the pressure in the cargo tank, the cargo pump discharge, or the vapor compressor discharge must have a bursting pressure...

  13. 49 CFR 178.337-9 - Pressure relief devices, piping, valves, hoses, and fittings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., valves, hose, and fittings. (1) The burst pressure of all piping, pipe fittings, hose and other pressure... of the cargo tank. Additionally, the burst pressure may not be less than 4 times any higher pressure... must be tested for leakage at not less than 225 psig using dry air or inert gas. (c) Marking inlets...

  14. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  15. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  16. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  17. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  18. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  19. The study on leakage reappearance test of high pressure hose for power steering system

    NASA Astrophysics Data System (ADS)

    Lee, Gi-Chun; Kim, Hyoung-Eui; Park, Jong-Won; Jeong, Won-Wook; Lee, Jong-Hwang; Lim, Young-Han; Hwang, Kwon-Tae; Lee, Young-Shin; Kim, Jae-Hoon

    2009-07-01

    Generally, a leakage in a high pressure hose assembly can be determined if hydraulic fluid falls down through fitting which is swaged with a rubber hose. This study tried to visualize leakage, which is considered a failure occurring often in the hydraulic system. In the case of methods which verify leakage paths in the power steering hydraulic system equipped with a high pressure hose assembly, three types of leakage paths, which could be seen by cutting the swaging part, were generally found. However, it was difficult to find out leakage paths by using power steering oil. In this study, four methods, including the thermal burn image method, the hole drilling method of fitting metal, the white paint infiltration method, and the fluorescent infiltration method, were tried to introduce. The thermal burn image method failed to find out the leakage path between the fitting part and the rubber part. The hole drilling method is the way to check a leakage path on the fitting part, which doesn't need to cut a hose assembly. This method succeeds to visualize the leakage path partially but it could not check a sequential path of leakage, either, because it needs to drill more closely. The white paint infiltration method also could find the leakage path partially by using white paint mixed with thinner, which was pressurized by hand pump, instead of power steering oil. This method could check the leakage path by cutting the swaging part. The fluorescent infiltration method could verify the leakage path with naked eyes simply by holding the cutting swaging part closely to the ray of light. Reappearance test methods in the high pressure hose assembly, which include a hole drilling, a white paint infiltration, and a fluorescent infiltration method, can be applied to find the failure mode and to approve the test before the mass production of the high pressure hose.

  20. 49 CFR 178.337-9 - Pressure relief devices, piping, valves, hoses, and fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... chlorine service, see paragraph (b)(7) of this section. (2) Pipe joints must be threaded, welded, or... subchapter. (iii) Mark each hose assembly with the month and year of its original pressure test. (8) Chlorine cargo tanks. Angle valves on cargo tanks intended for chlorine service must conform to the standards...

  1. 49 CFR 178.337-9 - Pressure relief devices, piping, valves, hoses, and fittings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... chlorine service, see paragraph (b)(7) of this section. (2) Pipe joints must be threaded, welded, or... subchapter. (iii) Mark each hose assembly with the month and year of its original pressure test. (8) Chlorine cargo tanks. Angle valves on cargo tanks intended for chlorine service must conform to the standards...

  2. 49 CFR 178.337-9 - Pressure relief devices, piping, valves, hoses, and fittings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... chlorine service, see paragraph (b)(7) of this section. (2) Pipe joints must be threaded, welded, or... subchapter. (iii) Mark each hose assembly with the month and year of its original pressure test. (8) Chlorine cargo tanks. Angle valves on cargo tanks intended for chlorine service must conform to the standards...

  3. 46 CFR 153.972 - Connecting a cargo hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the hose's last pressure test is within one year of the date on which the hose is used to transfer cargo; (d) The recommended working pressure marked on a hose used for discharge meets or exceeds the working pressure marked on the cargo piping at the hose connection; and (e) The cargo's temperature...

  4. 46 CFR 153.972 - Connecting a cargo hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the hose's last pressure test is within one year of the date on which the hose is used to transfer cargo; (d) The recommended working pressure marked on a hose used for discharge meets or exceeds the working pressure marked on the cargo piping at the hose connection; and (e) The cargo's temperature...

  5. 46 CFR 153.972 - Connecting a cargo hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the hose's last pressure test is within one year of the date on which the hose is used to transfer cargo; (d) The recommended working pressure marked on a hose used for discharge meets or exceeds the working pressure marked on the cargo piping at the hose connection; and (e) The cargo's temperature...

  6. 46 CFR 153.972 - Connecting a cargo hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the hose's last pressure test is within one year of the date on which the hose is used to transfer cargo; (d) The recommended working pressure marked on a hose used for discharge meets or exceeds the working pressure marked on the cargo piping at the hose connection; and (e) The cargo's temperature...

  7. 46 CFR 153.972 - Connecting a cargo hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the hose's last pressure test is within one year of the date on which the hose is used to transfer cargo; (d) The recommended working pressure marked on a hose used for discharge meets or exceeds the working pressure marked on the cargo piping at the hose connection; and (e) The cargo's temperature...

  8. 46 CFR 154.562 - Cargo hose: Hydrostatic test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Hose § 154.562 Cargo hose: Hydrostatic test. Each cargo hose must pass a hydrostatic pressure test at ambient temperature of at least one and a half times its specified maximum working pressure but not more... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo hose: Hydrostatic test. 154.562 Section...

  9. 46 CFR 154.562 - Cargo hose: Hydrostatic test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Hose § 154.562 Cargo hose: Hydrostatic test. Each cargo hose must pass a hydrostatic pressure test at ambient temperature of at least one and a half times its specified maximum working pressure but not more... 46 Shipping 5 2014-10-01 2014-10-01 false Cargo hose: Hydrostatic test. 154.562 Section...

  10. 46 CFR 154.562 - Cargo hose: Hydrostatic test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Hose § 154.562 Cargo hose: Hydrostatic test. Each cargo hose must pass a hydrostatic pressure test at ambient temperature of at least one and a half times its specified maximum working pressure but not more... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo hose: Hydrostatic test. 154.562 Section...

  11. 46 CFR 154.562 - Cargo hose: Hydrostatic test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Hose § 154.562 Cargo hose: Hydrostatic test. Each cargo hose must pass a hydrostatic pressure test at ambient temperature of at least one and a half times its specified maximum working pressure but not more... 46 Shipping 5 2013-10-01 2013-10-01 false Cargo hose: Hydrostatic test. 154.562 Section...

  12. 46 CFR 154.562 - Cargo hose: Hydrostatic test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Hose § 154.562 Cargo hose: Hydrostatic test. Each cargo hose must pass a hydrostatic pressure test at ambient temperature of at least one and a half times its specified maximum working pressure but not more... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo hose: Hydrostatic test. 154.562 Section...

  13. 46 CFR 107.257 - Testing of fire hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Testing of fire hose. 107.257 Section 107.257 Shipping... CERTIFICATION Inspection and Certification § 107.257 Testing of fire hose. Each fire hose must be subjected to a..., each fire hose must be subjected to a pressure of at least 100 p.s.i....

  14. 33 CFR 154.500 - Hose assemblies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.500 Hose... requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum of the pressure of the relief valve setting (or four times the maximum pump pressure when no...

  15. 33 CFR 154.500 - Hose assemblies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.500 Hose... requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum of the pressure of the relief valve setting (or four times the maximum pump pressure when no...

  16. 49 CFR 193.2621 - Testing transfer hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2621 Testing transfer hoses. Hoses used in LNG or flammable... months, to the maximum pump pressure or relief valve setting; and (b) Visually inspected for damage...

  17. 49 CFR 193.2621 - Testing transfer hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2621 Testing transfer hoses. Hoses used in LNG or flammable... months, to the maximum pump pressure or relief valve setting; and (b) Visually inspected for damage...

  18. 49 CFR 193.2621 - Testing transfer hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2621 Testing transfer hoses. Hoses used in LNG or flammable... months, to the maximum pump pressure or relief valve setting; and (b) Visually inspected for damage...

  19. 49 CFR 193.2621 - Testing transfer hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2621 Testing transfer hoses. Hoses used in LNG or flammable... months, to the maximum pump pressure or relief valve setting; and (b) Visually inspected for damage...

  20. Flexible collapse-resistant and length-stable vaccum hose

    DOEpatents

    Kashy, David H.

    2003-08-19

    A hose for containing a vacuum, which hose has an impermeable flexible tube capable of holding a vacuum and a braided or interwoven flexible interior wall, said wall providing support to said interior wall of said impermeable flexible tube. Optionally, an exterior braided or woven wall may be provided to the hose for protection or to allow the hose to be used as a pressure hose. The hose may delimit a vacuum space through which may travel a thermal transfer line containing, for example, cryogenic fluid.

  1. 49 CFR 178.337-9 - Pressure relief devices, piping, valves, hoses, and fittings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in service. For chlorine service, see paragraph (b)(7) of this section. (2) Pipe joints must be... original pressure test. (8) Chlorine cargo tanks. Angle valves on cargo tanks intended for chlorine service must conform to the standards of the Chlorine Institute, Inc., Dwg. 104-8 or “Section 3, Pamphlet...

  2. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being...

  3. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being...

  4. 46 CFR 197.312 - Breathing supply hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Breathing supply hoses. 197.312 Section 197.312 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must— (1) Have a maximum working pressure that is equal to or exceeds— (i) The...

  5. 46 CFR 197.312 - Breathing supply hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing supply hoses. 197.312 Section 197.312 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must— (1) Have a maximum working pressure that is equal to or exceeds— (i) The...

  6. 46 CFR 197.312 - Breathing supply hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Breathing supply hoses. 197.312 Section 197.312 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must— (1) Have a maximum working pressure that is equal to or exceeds— (i) The...

  7. 46 CFR 197.312 - Breathing supply hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Breathing supply hoses. 197.312 Section 197.312 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must— (1) Have a maximum working pressure that is equal to or exceeds— (i) The...

  8. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being...

  9. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being...

  10. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being...

  11. 46 CFR 197.312 - Breathing supply hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Breathing supply hoses. 197.312 Section 197.312 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must— (1) Have a maximum working pressure that is equal to or exceeds— (i) The...

  12. 30 CFR 56.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Oxygen hose lines. 56.7802 Section 56.7802... Piercing Rotary Jet Piercing § 56.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen hose lines of 1-inch...

  13. 30 CFR 56.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Oxygen hose lines. 56.7802 Section 56.7802... Piercing Rotary Jet Piercing § 56.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen hose lines of 1-inch...

  14. 30 CFR 56.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Oxygen hose lines. 56.7802 Section 56.7802... Piercing Rotary Jet Piercing § 56.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen hose lines of 1-inch...

  15. 30 CFR 56.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Oxygen hose lines. 56.7802 Section 56.7802... Piercing Rotary Jet Piercing § 56.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen hose lines of 1-inch...

  16. 30 CFR 56.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Oxygen hose lines. 56.7802 Section 56.7802... Piercing Rotary Jet Piercing § 56.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen hose lines of 1-inch...

  17. Fluid Flow through Pipes--Another Look at Fire Hoses and Garden Hoses.

    ERIC Educational Resources Information Center

    Brouwer, W.; Paranjape, B. V.

    1991-01-01

    The forward force of water on a hose is calculated using only the pressure gradient, the radius and length of the hose. The misconception about recoil on the nozzle is discussed. Dissipation energy and the consequent heat generation in a fluid flow are also described. (KR)

  18. Safety Modification of Cam-and-Groove Hose Coupling

    NASA Technical Reports Server (NTRS)

    Schwindt, Paul; Littlefield, Alan

    2008-01-01

    A modification has been made in the mating halves of a cam-and-groove hose coupling to prevent rapid separation of the halves in the event that the cam levers are released while the fluid in the hose is pressurized. The need for this modification arises because commercial off-the-shelf cam-and-groove hose-coupling halves do not incorporate safety features to prevent separation in the pressurized state. Especially when the pressurized fluid is compressible (e.g., steam or compressed air), the separated halves can be propelled with considerable energy, causing personal injury and/or property damage. Therefore, one purpose served by the modification is to provide for venting to release compressive energy in a contained and safe manner while preventing personal injury and/or property damage. Another purpose served by the modification, during the process of connecting the coupling halves, is to ensure that the coupling halves are properly aligned before the cam levers can be locked into position.

  19. 30 CFR 77.412 - Compressed air systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... used at connections to machines of high-pressure hose lines of 1-inch inside diameter or larger,...

  20. 30 CFR 77.412 - Compressed air systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... used at connections to machines of high-pressure hose lines of 1-inch inside diameter or larger,...

  1. 30 CFR 57.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Oxygen hose lines. 57.7802 Section 57.7802... Jet Piercing Rotary Jet Piercing-Surface Only § 57.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen...

  2. 30 CFR 57.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Oxygen hose lines. 57.7802 Section 57.7802... Jet Piercing Rotary Jet Piercing-Surface Only § 57.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen...

  3. 30 CFR 57.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Oxygen hose lines. 57.7802 Section 57.7802... Jet Piercing Rotary Jet Piercing-Surface Only § 57.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen...

  4. 30 CFR 57.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Oxygen hose lines. 57.7802 Section 57.7802... Jet Piercing Rotary Jet Piercing-Surface Only § 57.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen...

  5. 30 CFR 57.7802 - Oxygen hose lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Oxygen hose lines. 57.7802 Section 57.7802... Jet Piercing Rotary Jet Piercing-Surface Only § 57.7802 Oxygen hose lines. Safety chains or other suitable locking devices shall be provided across connections to and between high pressure oxygen...

  6. Air separation with temperature and pressure swing

    DOEpatents

    Cassano, Anthony A.

    1986-01-01

    A chemical absorbent air separation process is set forth which uses a temperature swing absorption-desorption cycle in combination with a pressure swing wherein the pressure is elevated in the desorption stage of the process.

  7. Laser plasma at low air pressure

    NASA Astrophysics Data System (ADS)

    Vas'kovskii, Iu. M.; Moiseev, V. N.; Rovinskii, R. E.; Tsenina, I. S.

    1993-01-01

    The ambient-pressure dependences of the dynamic and optical characteristics of a laser plasma generated by CO2-laser irradiation of an obstacle are investigated experimentally. The change of the sample's surface roughness after irradiation is investigated as a function of air pressure. It is concluded that the transition from the air plasma to the erosion plasma takes place at an air pressure of about 1 mm Hg. The results confirm the existing theory of plasma formation near the surface of an obstacle under the CO2-laser pulse effect in air.

  8. Monitoring Air Circulation Under Reduced Pressures

    NASA Astrophysics Data System (ADS)

    Rygalov, Vadim

    Adequate air circulation is required for controlled environments to maintain uniform temperature and humidity control, and hence the ability to measure air flow accurately is important. Human and associated life support habitats (e.g.,. plant production systems) for future space missions will likely be operated at pressures less than 100 kPa to minimize gas leakage and structural mass. Under such reduced pressures, the outputs from conventional anemometers for monitoring air flow can change and require re-calibration. These effects of atmospheric pressure on different types of air flow measurements are not completely understood; hence we compared the performance of several air flow sensors across a range of hypobaric pressures. Sensors included a propeller type anemometer, a hot-wire anemometer, and a Pitot-tube based device. Theoretical schematics (including mathematical models) underlying these measurements were developed. Results demonstrated that changes in sensor outputs were predictable based on their operating principles, and that corrections could be developed for sensors calibrated under normal Earth atmosphere pressure ( 100 kPa) and then used at different pressures. The potential effects of hypobaric atmospheres and their altered air flows on plant physiology are also discussed.

  9. Microfluidic pressure sensing using trapped air compression.

    PubMed

    Srivastava, Nimisha; Burns, Mark A

    2007-05-01

    We have developed a microfluidic method for measuring the fluid pressure head experienced at any location inside a microchannel. The principal component is a microfabricated sealed chamber with a single inlet and no exit; the entrance to the single inlet is positioned at the location where pressure is to be measured. The pressure measurement is then based on monitoring the movement of a liquid-air interface as it compresses air trapped inside the microfabricated sealed chamber and calculating the pressure using the ideal gas law. The method has been used to measure the pressure of the air stream and continuous liquid flow inside microfluidic channels (d approximately 50 microm). Further, a pressure drop has also been measured using multiple microfabricated sealed chambers. For air pressure, a resolution of 700 Pa within a full-scale range of 700-100 kPa was obtained. For liquids, pressure drops as low as 70 Pa were obtained in an operating range from 70 Pa to 10 kPa. Since the method primarily uses a microfluidic sealed chamber, it does not require additional fabrication steps and may easily be incorporated in several lab-on-a-chip fluidic applications for laminar as well as turbulent flow conditions.

  10. Pressure Drop in Radiator Air Tubes

    NASA Technical Reports Server (NTRS)

    Parsons, S R

    1921-01-01

    This report describes a method for measuring the drop in static pressure of air flowing through a radiator and shows (1) a reason for the discrepancy noted by various observers between head resistance and drop in pressure; (2) a difference in degree of contraction of the jet in entering a circular cell and a square cell; (3) the ratio of internal frictional resistance to total head resistance for two representative types; (4) the effect of smoothness of surface on pressure gradient; and (5) the effects of supplying heat to the radiator on pressure gradient. The fact that the pressure gradients are found to be approximately proportional to the square of the rate of flow of air appears to indicate turbulent flow, even in the short tubes of the radiator. It was found that the drop in the static pressure in the air stream through a cellular radiator and the pressure gradient in the air tubes are practically proportional to the square of the air flow in a given air density; that the difference between the head resistance per unit area and the fall of static pressure through the air tubes in radiators is apparent rather than real; and that radiators of different types differ widely in the amount of contraction of the jet at entrance. The frictional resistance was found to vary considerably, and in one case to be two-thirds of the head resistance in the type using circular cells and one-half of the head resistance of the radiator type using square cells of approximately the same dimensions.

  11. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... not show cracks visible under 7-power magnification after exposure to ozone for 70 hours at 104 °F....2Exposure to ozone. (a) Condition the hose on the cylinder in air at room temperature for 24 hours. (b... mixed with ozone in the proportion of 100 parts of ozone per 100 million parts of air by volume....

  12. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... not show cracks visible under 7-power magnification after exposure to ozone for 70 hours at 104 °F....2Exposure to ozone. (a) Condition the hose on the cylinder in air at room temperature for 24 hours. (b... mixed with ozone in the proportion of 100 parts of ozone per 100 million parts of air by volume....

  13. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... not show cracks visible under 7-power magnification after exposure to ozone for 70 hours at 104 °F....2Exposure to ozone. (a) Condition the hose on the cylinder in air at room temperature for 24 hours. (b... mixed with ozone in the proportion of 100 parts of ozone per 100 million parts of air by volume....

  14. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... withstand water pressure of 4,000 psi for 2 minutes without rupture, and then shall not rupture at less than....3.5Water absorption and burst strength. A hydraulic brake hose assembly, after immersion in water for 70 hours (S6.5), shall withstand water pressure of 4,000 psi for 2 minutes, and then shall...

  15. Building pressurization control with rooftop air conditioners

    SciTech Connect

    Winter, S.

    1982-10-01

    The modulated exhaust fan appears to be the most cost effective positive means to maintain close building pressure control with rooftop air conditioning, but because building construction and applications vary, every building's pressure control needs must be analyzed. Requirements will vary from no relief to barometric dampers to return fans to modulated exhaust fans. As heating and cooling costs continue to rise and tighter building codes prevail, proper selection of building pressure control is one area that must be monitored more carefully by the HVAC system designer.

  16. Model to Design Drip Hose Lateral Line

    NASA Astrophysics Data System (ADS)

    Ludwig, Rafael; Cury Saad, João Carlos

    2014-05-01

    Introduction The design criterion for non-pressure compensating drip hose is normally to have 10% of flow variation (Δq) in the lateral line, corresponding to 20% of head pressure variation (ΔH). Longer lateral lines in drip irrigation systems using conventional drippers provide cost reduction, but it is necessary to obtain to the uniformity of irrigation [1]. The use of Δq higher levels can provide longer lateral lines. [4] proposes the use of a 30% Δq and he found that this value resulted in distribution uniformity over 80%. [1] considered it is possible to extend the lateral line length using two emitters spacing in different section. He assumed that the spacing changing point would be at 40% of the total length, because this is approximately the location of the average flow according with [2]. [3] found that, for practical purposes, the average pressure is located at 40% of the length of the lateral line and that until this point it has already consumed 75% of total pressure head loss (hf ). In this case, the challenge for designers is getting longer lateral lines with high values of uniformity. Objective The objective of this study was to develop a model to design longer lateral lines using non-pressure compensating drip hose. Using the developed model, the hypotheses to be evaluated were: a) the use of two different spacing between emitters in the same lateral line allows longer length; b) it is possible to get longer lateral lines using high values of pressure variation in the lateral lines since the distribution uniformity stays below allowable limits. Methodology A computer program was developed in Delphi® based on the model developed and it is able to design lateral lines in level using non-pressure compensating drip hose. The input data are: desired distribution uniformity (DU); initial and final pressure in the lateral line; coefficients of relationship between emitter discharge and pressure head; hose internal diameter; pipe cross-sectional area

  17. Evaluation of Hose in Hose transfer line service life

    SciTech Connect

    EAGLE, O.H.

    2003-05-30

    This document presents a determination for the amount of expected service life from Hose-in-Hose Transfer Lines based on vendor information and past HIHTL experience. Based on the information presented in this report and referenced documentation, we conclude the service life of the inner hose establishes the limits of service life for the finished assemblies. Since the process and environmental conditions to which the transfer line is subjected will not adversely affect the hose, the effective service life is that stated by the vendor--three years from the date of initial transfer. Transfer line assemblies have a shelf life of seven years from the date of hose manufacture, if stored in accordance with Section 2.1. This evaluation provides documentation showing that a three year service life has been justified. In the event that transfer lines are to be operated after three years from the date of initial transfer and within the shelf life of seven years, they must be reevaluated for their ability to perform intended functions.

  18. 49 CFR 178.338-8 - Pressure relief devices, piping, valves, and fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Piping, valves, and fittings. (1) The burst pressure of all piping, pipe fittings, hoses and other... pressure of the tank. Additionally, the burst pressure may not be less than 4 times any higher pressure to..., and fittings have been tested after installation with gas or air and proved leak tight at not...

  19. 49 CFR 178.338-8 - Pressure relief devices, piping, valves, and fittings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Piping, valves, and fittings. (1) The burst pressure of all piping, pipe fittings, hoses and other... pressure of the tank. Additionally, the burst pressure may not be less than 4 times any higher pressure to..., and fittings have been tested after installation with gas or air and proved leak tight at not...

  20. 49 CFR 178.338-8 - Pressure relief devices, piping, valves, and fittings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Piping, valves, and fittings. (1) The burst pressure of all piping, pipe fittings, hoses and other... pressure of the tank. Additionally, the burst pressure may not be less than 4 times any higher pressure to..., and fittings have been tested after installation with gas or air and proved leak tight at not...

  1. Chlorine transfer hose failure.

    PubMed

    Joseph, Giby

    2004-11-11

    On the morning of 14 August 2002, a 1 in. transfer hose used in a rail tank car unloading operation at DPC Enterprises, near Festus, Missouri, catastrophically ruptured and initiated a sequence of events that led to the release of 48,000 pounds of chlorine--a toxic gas--into neighboring areas. The facility repackages bulk dry liquid chlorine into 1 ton containers and 150 pound cylinders for commercial, industrial, and municipal use in the St. Louis metropolitan area. Fortunately, the wind direction on the day of the release limited the effects of the chlorine plume on the surrounding community. However, 63 people sought hospital treatment due to exposure, and hundreds of others were affected by the release (the community was advised to shelter-in-place for 4 h, and traffic was halted on Interstate 55 for 1.5 h). The US Chemical Safety and Hazard Investigation Board (CSB) investigated this incident for the following reasons: This paper presents the lesson-learned from this incident to help prevent similar occurrences. This paper is based on US Chemical Safety and Hazard Investigation Board Report Number 2002-04-I-MO, which was approved by the Board on 1 May 2003. This paper has not been independently approved by the Board and is published for general informational purposes only. Every effort has been made to accurately present the contents of the Board-approved report in this paper. Any material in the paper that did not originate in the Board-approved report is solely the responsibility of the author and does not represent an official finding, conclusion, or position of the Board. A complete copy of the Board investigation report upon which this paper is based is available on the CSB website at "Completed Investigations."

  2. Air Mobile Utility Distribution Systems.

    DTIC Science & Technology

    WATER PIPES, AIR TRANSPORTABLE EQUIPMENT, POLYVINYL CHLORIDE, GLASS REINFORCED PLASTICS , FUEL HOSES, HOSES....PIPES, *PIPING SYSTEMS, INSULATION, FABRICATION, CORROSION INHIBITION, FEASIBILITY STUDIES, AIR FORCE FACILITIES, POLYURETHANE RESINS, PLASTICS

  3. 46 CFR 148.410 - Fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Fire hoses. 148.410 Section 148.410 Shipping COAST GUARD... SPECIAL HANDLING Additional Special Requirements § 148.410 Fire hoses. When Table 148.10 of this part associates a material with a reference to this section, a fire hose must be available at each hatch...

  4. 46 CFR 148.410 - Fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Fire hoses. 148.410 Section 148.410 Shipping COAST GUARD... SPECIAL HANDLING Additional Special Requirements § 148.410 Fire hoses. When Table 148.10 of this part associates a material with a reference to this section, a fire hose must be available at each hatch...

  5. 46 CFR 148.410 - Fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Fire hoses. 148.410 Section 148.410 Shipping COAST GUARD... SPECIAL HANDLING Additional Special Requirements § 148.410 Fire hoses. When Table 148.10 of this part associates a material with a reference to this section, a fire hose must be available at each hatch...

  6. 46 CFR 148.410 - Fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Fire hoses. 148.410 Section 148.410 Shipping COAST GUARD... SPECIAL HANDLING Additional Special Requirements § 148.410 Fire hoses. When Table 148.10 of this part associates a material with a reference to this section, a fire hose must be available at each hatch...

  7. 46 CFR 64.97 - Cargo hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Cargo hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose assembly, consisting of couplings and a...

  8. 46 CFR 64.97 - Cargo hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Cargo hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose assembly, consisting of couplings and a...

  9. 46 CFR 64.97 - Cargo hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Cargo hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose assembly, consisting of couplings and a...

  10. 46 CFR 64.97 - Cargo hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Cargo hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose assembly, consisting of couplings and a...

  11. 46 CFR 64.97 - Cargo hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Cargo hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose assembly, consisting of couplings and a...

  12. Basic Studies on High Pressure Air Plasmas

    DTIC Science & Technology

    2006-08-30

    33, 2268 (2000). [3] Non- Equilibrium Air Plasmas at Atmospheric Pressure, K.H. Becker, U. Kogelschatz, K.H. Schoenbach, and R.J. Barker, eds., IOP...10). Note that LIFBASE assumes local thermodynamic equilibrium . 120 100 oExperimentalm Siuation 80 60 20- 0 -J ~ LkXi 3060 3070 3080 3090 3100...Dual laser interferometer for plasma density measurements on large tokamaks >>, Rev. Sci. Instrum. 49 p.919 (1978) [5] C.W. Gowers, C. Lamb, « A

  13. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  14. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  15. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  16. 29 CFR 1910.158 - Standpipe and hose systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... facilitate prompt use of the hose valves, the hose, and other equipment at the time of a fire or other... outlet used to meet this standard is equipped with hose connected and ready for use. In extremely cold... installed after January 1, 1981, for use by employees, shall be equipped with lined hose. Unlined hose...

  17. FireHose Streaming Benchmarks

    SciTech Connect

    Karl Anderson, Steve Plimpton

    2015-01-27

    The FireHose Streaming Benchmarks are a suite of stream-processing benchmarks defined to enable comparison of streaming software and hardware, both quantitatively vis-a-vis the rate at which they can process data, and qualitatively by judging the effort involved to implement and run the benchmarks. Each benchmark has two parts. The first is a generator which produces and outputs datums at a high rate in a specific format. The second is an analytic which reads the stream of datums and is required to perform a well-defined calculation on the collection of datums, typically to find anomalous datums that have been created in the stream by the generator. The FireHose suite provides code for the generators, sample code for the analytics (which users are free to re-implement in their own custom frameworks), and a precise definition of each benchmark calculation.

  18. Assessment of Refueling Hose Visibility

    DTIC Science & Technology

    2012-10-01

    Consulting** 2466 W. Golden Hill Rd. Tucson AZ 85745-1879 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S...the parts of the hose that have a lower temperature. The LWIR pictures were taken with a 600 watt incandescent flood lamp (42 inches away) and two...both the 60 Watt Lamps and the 600 Watt Flood Lamp Activated 32 Distribution A: Approved for public release; distribution unlimited. 88ABW Cleared

  19. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a)...

  20. Automated Facility For Cleaning Large Flex Hoses

    NASA Technical Reports Server (NTRS)

    Landry, Louis E.

    1995-01-01

    Technicians no longer exposed to hazardous cleaning materials. Proposed computer-controlled facility cleans bellow-type expansion joints and large flex hoses. Major portions of automated cleaning facility contained in clean room. One piece of equipment in clean room tower in which hose or expansion joint to be cleaned hoisted by hydraulic machinery and hung vertically. Once hose or expansion joint hung in required position, technician initiates programmed cleaning procedure from console on computer monitoring system. Procedure includes degreasing, cleaning with detergents, rinsing, pickling, and passivating operations. After cleaning completed, technician removes hose or expansion joint from tower and wraps open ends to prevent recontamination of interior.

  1. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... magnification after exposure to ozone for 70 hours at 104 °F. (S6.8). S5.3.12High temperature impulse test. A... that as much of its length as possible is in contact. S6.8.2Exposure to ozone. (a) Condition the hose... degrees Fahrenheit (40 degrees Celsius) during the test and containing air mixed with ozone in...

  2. 33 CFR 183.558 - Hoses and connections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.558 Hoses and connections. (a) Each hose used between the fuel pump and the carburetor must be “USCG Type A1” hose. (b)...

  3. 33 CFR 183.558 - Hoses and connections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.558 Hoses and connections. (a) Each hose used between the fuel pump and the carburetor must be “USCG Type A1” hose. (b)...

  4. 33 CFR 183.558 - Hoses and connections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.558 Hoses and connections. (a) Each hose used between the fuel pump and the carburetor must be “USCG Type A1” hose. (b)...

  5. 33 CFR 183.558 - Hoses and connections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.558 Hoses and connections. (a) Each hose used between the fuel pump and the carburetor must be “USCG Type A1” hose. (b)...

  6. 46 CFR 153.940 - Standards for marking of cargo hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... manufacture; (2) Working pressure discribed in paragraph (d) of this section; (3) Date of the last test made... working pressure. (4) Not exceed the test pressure used in the latest test under paragraph (e)(3) of this... both ends of the hose open, no internal deterioration; and (3) Does not burst, bulge, leak,...

  7. Noncontact Monitoring of Respiration by Dynamic Air-Pressure Sensor.

    PubMed

    Takarada, Tohru; Asada, Tetsunosuke; Sumi, Yoshihisa; Higuchi, Yoshinori

    2015-01-01

    We have previously reported that a dynamic air-pressure sensor system allows respiratory status to be visually monitored for patients in minimally clothed condition. The dynamic air-pressure sensor measures vital information using changes in air pressure. To utilize this device in the field, we must clarify the influence of clothing conditions on measurement. The present study evaluated use of the dynamic air-pressure sensor system as a respiratory monitor that can reliably detect change in breathing patterns irrespective of clothing. Twelve healthy volunteers reclined on a dental chair positioned horizontally with the sensor pad for measuring air-pressure signals corresponding to respiration placed on the seat back of the dental chair in the central lumbar region. Respiratory measurements were taken under 2 conditions: (a) thinly clothed (subject lying directly on the sensor pad); and (b) thickly clothed (subject lying on the sensor pad covered with a pressure-reducing sheet). Air-pressure signals were recorded and time integration values for air pressure during each expiration were calculated. This information was compared with expiratory tidal volume measured simultaneously by a respirometer connected to the subject via face mask. The dynamic air-pressure sensor was able to receive the signal corresponding to respiration regardless of clothing conditions. A strong correlation was identified between expiratory tidal volume and time integration values for air pressure during each expiration for all subjects under both clothing conditions (0.840-0.988 for the thinly clothed condition and 0.867-0.992 for the thickly clothed condition). These results show that the dynamic air-pressure sensor is useful for monitoring respiratory physiology irrespective of clothing.

  8. Pressurized solid oxide fuel cell integral air accumular containment

    DOEpatents

    Gillett, James E.; Zafred, Paolo R.; Basel, Richard A.

    2004-02-10

    A fuel cell generator apparatus contains at least one fuel cell subassembly module in a module housing, where the housing is surrounded by a pressure vessel such that there is an air accumulator space, where the apparatus is associated with an air compressor of a turbine/generator/air compressor system, where pressurized air from the compressor passes into the space and occupies the space and then flows to the fuel cells in the subassembly module, where the air accumulation space provides an accumulator to control any unreacted fuel gas that might flow from the module.

  9. Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report

    NASA Technical Reports Server (NTRS)

    Wieland, P. O.; Hawk, H. D.

    2001-01-01

    During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

  10. 46 CFR 193.10-10 - Fire hydrants and hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shaft alleys containing no assigned space for the stowage of combustibles. Fire hydrants must be... be provided with a single length of hose with nozzle attached and a spanner. A suitable hose rack or other device shall be provided for the proper stowage of the hose. If the hose is not stowed in the...

  11. 46 CFR 105.35-15 - Fire hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hose or equivalent of not over 11/2-inch diameter or garden hose of not less than 5/8-inch nominal... accordance with § 162.027-6 of this chapter. (d) If garden hose is used, it shall be of a good commercial... cover or of equivalent material, and shall be fitted with a commercial garden hose nozzle of good...

  12. 46 CFR 105.35-15 - Fire hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... hose or equivalent of not over 11/2-inch diameter or garden hose of not less than 5/8-inch nominal... accordance with § 162.027-6 of this chapter. (d) If garden hose is used, it shall be of a good commercial... cover or of equivalent material, and shall be fitted with a commercial garden hose nozzle of good...

  13. 46 CFR 105.35-15 - Fire hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... hose or equivalent of not over 11/2-inch diameter or garden hose of not less than 5/8-inch nominal... accordance with § 162.027-6 of this chapter. (d) If garden hose is used, it shall be of a good commercial... cover or of equivalent material, and shall be fitted with a commercial garden hose nozzle of good...

  14. 46 CFR 105.35-15 - Fire hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... hose or equivalent of not over 11/2-inch diameter or garden hose of not less than 5/8-inch nominal... accordance with § 162.027-6 of this chapter. (d) If garden hose is used, it shall be of a good commercial... cover or of equivalent material, and shall be fitted with a commercial garden hose nozzle of good...

  15. 46 CFR 105.35-15 - Fire hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fire hose. 105.35-15 Section 105.35-15 Shipping COAST... VESSELS DISPENSING PETROLEUM PRODUCTS Fire Extinguishing Equipment § 105.35-15 Fire hose. (a) One length of fire hose shall be provided for each fire hydrant required. (b) Fire hose may be commercial...

  16. 46 CFR 154.1155 - Hand hose line: Coverage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Hand hose line: Coverage. 154.1155 Section 154.1155... Firefighting System: Dry Chemical § 154.1155 Hand hose line: Coverage. The coverage for the area for a hand hose line under § 154.1150 must not exceed the length of the hand hose line except the coverage for...

  17. 46 CFR 154.1155 - Hand hose line: Coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Hand hose line: Coverage. 154.1155 Section 154.1155... Firefighting System: Dry Chemical § 154.1155 Hand hose line: Coverage. The coverage for the area for a hand hose line under § 154.1150 must not exceed the length of the hand hose line except the coverage for...

  18. 46 CFR 154.1155 - Hand hose line: Coverage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Hand hose line: Coverage. 154.1155 Section 154.1155... Firefighting System: Dry Chemical § 154.1155 Hand hose line: Coverage. The coverage for the area for a hand hose line under § 154.1150 must not exceed the length of the hand hose line except the coverage for...

  19. 46 CFR 154.1155 - Hand hose line: Coverage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Hand hose line: Coverage. 154.1155 Section 154.1155... Firefighting System: Dry Chemical § 154.1155 Hand hose line: Coverage. The coverage for the area for a hand hose line under § 154.1150 must not exceed the length of the hand hose line except the coverage for...

  20. 46 CFR 154.1155 - Hand hose line: Coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Hand hose line: Coverage. 154.1155 Section 154.1155... Firefighting System: Dry Chemical § 154.1155 Hand hose line: Coverage. The coverage for the area for a hand hose line under § 154.1150 must not exceed the length of the hand hose line except the coverage for...

  1. Laboratory performance of alternating pressure air mattresses component and sequelae.

    PubMed

    Bain, Duncan

    The performance of three different alternating pressure air mattresses with different geometries of air cell were compared (Nimbus 3, Heritage, Tamora Plus), using simple performance indices based on pressure mapping. The aim of this study was to examine the effect on performance of elevating the backrest and thigh section of the bed into sitting position. Ten healthy volunteers of various sizes were pressure-mapped over the full pressure cycle on three alternating pressure air mattresseses with differing cell geometries. This was then repeated with the beds profiled to a sitting position. Performance of the alternating pressure air mattresses in terms of their ability to redistribute pressure dynamically was assessed in the different positions. The different alternating pressure air mattresses performed similarly with the bed in the lying flat position, but smaller cells appeared to be more effective in the sitting position. A conclusion was made that cell geometry may have an effect on the ability of the mattress to achieve alternating behaviour in the sitting position.

  2. 58. AIR PRESSURIZATION TANK BEING LIFTED INTO PLACE ON THE ...

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

    58. AIR PRESSURIZATION TANK BEING LIFTED INTO PLACE ON THE VAL BRIDGE STRUCTURE AT ISLIP CANYON, April 9, 1948. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  3. 27. EXTENSION OF SURGE CHAMBER AND AIR PIPES TO PRESSURE ...

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

    27. EXTENSION OF SURGE CHAMBER AND AIR PIPES TO PRESSURE LINE, HIGHLINE PUMPING PLANT. December 11, 1920 - Highline Canal & Pumping Station, South side of Salt River between Tempe, Phoenix & Mesa, Tempe, Maricopa County, AZ

  4. Explosion pressures of hydrocarbon-air mixtures in closed vessels.

    PubMed

    Razus, Domnina; Movileanu, Codina; Brinzea, Venera; Oancea, D

    2006-07-31

    An experimental study on pressure evolution during closed vessel explosions of several gaseous fuel-air mixtures was performed, at various initial pressures within 0.3-1.2 bar and ambient initial temperature. Explosion pressures and explosion times are reported for methane-, n-pentane-, n-hexane-, propene-, butene-, butadiene-, cyclohexane- and benzene-air mixtures. The explosion pressures measured in a spherical vessel (Phi=10 cm) and in three cylindrical vessels with different diameter/height ratios are examined in comparison with the adiabatic explosion pressures, computed by assuming chemical equilibrium within the flame front. The influence of initial pressure, fuel concentration and heat losses during propagation (determined by the size and shape of the explosion vessel and by the position of the ignition source) on explosion pressures and explosion times are discussed for some of the examined systems.

  5. Hose- and Tube-Cleaning Module

    NASA Technical Reports Server (NTRS)

    Rollins, F. P.; Glass, J. S.

    1986-01-01

    Self-contained, single-use module enables hose or tube to be cleaned thoroughly in field, in one operation, using water of unknown or questionable quality. Previously, chemicals for flow cleaning had to be mixed, diluted and pumped through tubes and hoses in many successive steps; deionizers, water-treatment facilities, and chemical storage required. With proposed device cleaning performed safely, without special training. Ready to use, device packaged as cleaning kit with tube to be cleaned.

  6. Method and Apparatus for Measuring Surface Air Pressure

    NASA Technical Reports Server (NTRS)

    Lin, Bing (Inventor); Hu, Yongxiang (Inventor)

    2014-01-01

    The present invention is directed to an apparatus and method for remotely measuring surface air pressure. In one embodiment, the method of the present invention utilizes the steps of transmitting a signal having multiple frequencies into the atmosphere, measuring the transmitted/reflected signal to determine the relative received power level of each frequency and then determining the surface air pressure based upon the attenuation of the transmitted frequencies.

  7. Underground storage systems for high-pressure air and gases

    NASA Technical Reports Server (NTRS)

    Beam, B. H.; Giovannetti, A.

    1975-01-01

    This paper is a discussion of the safety and cost of underground high-pressure air and gas storage systems based on recent experience with a high-pressure air system installed at Moffett Field, California. The system described used threaded and coupled oil well casings installed vertically to a depth of 1200 ft. Maximum pressure was 3000 psi and capacity was 500,000 lb of air. A failure mode analysis is presented, and it is shown that underground storage offers advantages in avoiding catastrophic consequences from pressure vessel failure. Certain problems such as corrosion, fatigue, and electrolysis are discussed in terms of the economic life of such vessels. A cost analysis shows that where favorable drilling conditions exist, the cost of underground high-pressure storage is approximately one-quarter that of equivalent aboveground storage.

  8. Pressure of air on coming to rest from various speeds

    NASA Technical Reports Server (NTRS)

    Zahm, A F

    1927-01-01

    The text gives theoretical formulas from which is computed a table for the pressure of air on coming to rest from various speeds, such as those of aircraft and propeller blades. Pressure graphs are given for speeds from 1 cm. Sec. up to those of swift projectiles.

  9. Teaching Science: Air Pressure "Eggs-periments."

    ERIC Educational Resources Information Center

    Leyden, Michael B.

    1994-01-01

    Discusses how teachers can introduce students to various scientific concept concerning motion, air composition, and heat by conducting an experiment: A peeled, hard-boiled egg is sucked into a bottle neck slightly smaller than the egg, after the bottle has been filled and emptied of hot water. Also discusses how students' understanding of the…

  10. 46 CFR 76.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... requirement need not apply to shaft alleys containing no assigned space for the stowage of combustibles. Fire... fire hose, a spanner, and a hose rack or other device for stowing the hose. (h) Fire hose shall...

  11. Generation of high pressure homogeneous dielectric barrier discharge in air

    NASA Astrophysics Data System (ADS)

    Osawa, Naoki; Takashi, Ami; Yoshioka, Yoshio; Hanaoka, Ryoichi

    2013-02-01

    We succeeded in generating an atmospheric pressure Townsend discharge (APTD) in air by using a simple DBD device that consists of alumina barriers and plane electrodes. So far, we applied the APTD to an ozonizer and found that the ozone generation efficiency was higher by the APTD mode than by the conventional DBD mode in larger specific input energy region. It is well known that an operation under an optimized high gas pressure is advantageous for efficient ozone generation from air. In this paper, we investigated whether the Townsend discharge (TD) in dry air in high pressure up to 0.17 MPa can be generated or not. From the observation results of current waveforms and discharge photographs, we found that (1) the discharge currents flow continuously and have only one peak in every half cycle in all gas pressure and (2) filamentary discharges are not recognized between barriers in all gas pressure. These features completely agree with the features of the APTD we reported. Therefore, we concluded that our TD can be generated even in dry air in the pressure range of 0.1 and 0.17 MPa. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

  12. DETAIL OF FIRE HOSE ON 16’8” LEVEL OF INTERNAL PLATFORMS, ...

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

    DETAIL OF FIRE HOSE ON 16’-8” LEVEL OF INTERNAL PLATFORMS, ALTITUDE CHAMBER L, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  13. Temperature and pressure influence on explosion pressures of closed vessel propane-air deflagrations.

    PubMed

    Razus, Domnina; Brinzea, Venera; Mitu, Maria; Oancea, Dumitru

    2010-02-15

    An experimental study on pressure evolution during closed vessel explosions of propane-air mixtures was performed, for systems with various initial concentrations and pressures ([C(3)H(8)]=2.50-6.20 vol.%, p(0)=0.3-1.2 bar). The explosion pressures and explosion times were measured in a spherical vessel (Phi=10 cm), at various initial temperatures (T(0)=298-423 K) and in a cylindrical vessel (Phi=10 cm; h=15 cm), at ambient initial temperature. The experimental values of explosion pressures are examined against literature values and compared to adiabatic explosion pressures, computed by assuming chemical equilibrium within the flame front. The influence of initial pressure, initial temperature and fuel concentration on explosion pressures and explosion times are discussed. At constant temperature and fuel/oxygen ratio, the explosion pressures are linear functions of total initial pressure, as reported for other fuel-air mixtures. At constant initial pressure and composition, both the measured and calculated (adiabatic) explosion pressures are linear functions of reciprocal value of initial temperature. Such correlations are extremely useful for predicting the explosion pressures of flammable mixtures at elevated temperatures and/or pressures, when direct measurements are not available.

  14. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for Vessels Which Have Their Keel Laid or Are... siamese fitting, at a pitot tube pressure of at least 50 psi (0.345 Newtons per square millimeter) and a... material capable of providing a solid stream and a spray pattern. (4) A fire hose on a vessel 79 feet...

  15. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2011-10-01 2011-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  16. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2014-10-01 2014-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  17. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2012-10-01 2012-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  18. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2013-10-01 2013-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  19. Fuel Cells Utilizing Oxygen From Air at Low Pressures

    NASA Technical Reports Server (NTRS)

    Cisar, Alan; Boyer, Chris; Greenwald, Charles

    2006-01-01

    A fuel cell stack has been developed to supply power for a high-altitude aircraft with a minimum of air handling. The fuel cell is capable of utilizing oxygen from ambient air at low pressure with no need for compression. For such an application, it is advantageous to take oxygen from the air (in contradistinction to carrying a supply of oxygen onboard), but it is a challenging problem to design a fuel-cell stack of reasonable weight that can generate sufficient power while operating at reduced pressures. The present fuel-cell design is a response to this challenge. The design features a novel bipolar plate structure in combination with a gas-diffusion structure based on a conductive metal core and a carbon gas-diffusion matrix. This combination makes it possible for the flow fields in the stack to have a large open fraction (ratio between open volume and total volume) to permit large volumes of air to flow through with exceptionally low backpressure. Operations at reduced pressure require a corresponding increase in the volume of air that must be handled to deliver the same number of moles of oxygen to the anodes. Moreover, the increase in the open fraction, relative to that of a comparable prior fuel-cell design, reduces the mass of the stack. The fuel cell has been demonstrated to operate at a power density as high as 105 W/cm2 at an air pressure as low as 2 psia (absolute pressure 14 kPa), which is the atmospheric pressure at an altitude of about 50,000 ft ( 15.2 km). The improvements in the design of this fuel cell could be incorporated into designs of other fuel cells to make them lighter in weight and effective at altitudes higher than those of prior designs. Potential commercial applications for these improvements include most applications now under consideration for fuel cells.

  20. Inverse association between air pressure and rheumatoid arthritis synovitis.

    PubMed

    Terao, Chikashi; Hashimoto, Motomu; Furu, Moritoshi; Nakabo, Shuichiro; Ohmura, Koichiro; Nakashima, Ran; Imura, Yoshitaka; Yukawa, Naoichiro; Yoshifuji, Hajime; Matsuda, Fumihiko; Ito, Hiromu; Fujii, Takao; Mimori, Tsuneyo

    2014-01-01

    Rheumatoid arthritis (RA) is a bone destructive autoimmune disease. Many patients with RA recognize fluctuations of their joint synovitis according to changes of air pressure, but the correlations between them have never been addressed in large-scale association studies. To address this point we recruited large-scale assessments of RA activity in a Japanese population, and performed an association analysis. Here, a total of 23,064 assessments of RA activity from 2,131 patients were obtained from the KURAMA (Kyoto University Rheumatoid Arthritis Management Alliance) database. Detailed correlations between air pressure and joint swelling or tenderness were analyzed separately for each of the 326 patients with more than 20 assessments to regulate intra-patient correlations. Association studies were also performed for seven consecutive days to identify the strongest correlations. Standardized multiple linear regression analysis was performed to evaluate independent influences from other meteorological factors. As a result, components of composite measures for RA disease activity revealed suggestive negative associations with air pressure. The 326 patients displayed significant negative mean correlations between air pressure and swellings or the sum of swellings and tenderness (p = 0.00068 and 0.00011, respectively). Among the seven consecutive days, the most significant mean negative correlations were observed for air pressure three days before evaluations of RA synovitis (p = 1.7 × 10(-7), 0.00027, and 8.3 × 10(-8), for swellings, tenderness and the sum of them, respectively). Standardized multiple linear regression analysis revealed these associations were independent from humidity and temperature. Our findings suggest that air pressure is inversely associated with synovitis in patients with RA.

  1. Inverse Association between Air Pressure and Rheumatoid Arthritis Synovitis

    PubMed Central

    Furu, Moritoshi; Nakabo, Shuichiro; Ohmura, Koichiro; Nakashima, Ran; Imura, Yoshitaka; Yukawa, Naoichiro; Yoshifuji, Hajime; Matsuda, Fumihiko; Ito, Hiromu; Fujii, Takao; Mimori, Tsuneyo

    2014-01-01

    Rheumatoid arthritis (RA) is a bone destructive autoimmune disease. Many patients with RA recognize fluctuations of their joint synovitis according to changes of air pressure, but the correlations between them have never been addressed in large-scale association studies. To address this point we recruited large-scale assessments of RA activity in a Japanese population, and performed an association analysis. Here, a total of 23,064 assessments of RA activity from 2,131 patients were obtained from the KURAMA (Kyoto University Rheumatoid Arthritis Management Alliance) database. Detailed correlations between air pressure and joint swelling or tenderness were analyzed separately for each of the 326 patients with more than 20 assessments to regulate intra-patient correlations. Association studies were also performed for seven consecutive days to identify the strongest correlations. Standardized multiple linear regression analysis was performed to evaluate independent influences from other meteorological factors. As a result, components of composite measures for RA disease activity revealed suggestive negative associations with air pressure. The 326 patients displayed significant negative mean correlations between air pressure and swellings or the sum of swellings and tenderness (p = 0.00068 and 0.00011, respectively). Among the seven consecutive days, the most significant mean negative correlations were observed for air pressure three days before evaluations of RA synovitis (p = 1.7×10−7, 0.00027, and 8.3×10−8, for swellings, tenderness and the sum of them, respectively). Standardized multiple linear regression analysis revealed these associations were independent from humidity and temperature. Our findings suggest that air pressure is inversely associated with synovitis in patients with RA. PMID:24454853

  2. Tongue-Palate Contact Pressure, Oral Air Pressure, and Acoustics of Clear Speech

    ERIC Educational Resources Information Center

    Searl, Jeff; Evitts, Paul M.

    2013-01-01

    Purpose: The authors compared articulatory contact pressure (ACP), oral air pressure (Po), and speech acoustics for conversational versus clear speech. They also assessed the relationship of these measures to listener perception. Method: Twelve adults with normal speech produced monosyllables in a phrase using conversational and clear speech.…

  3. 33 CFR 127.1102 - Transfer hoses and loading arms.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Transfer hoses and loading arms... Transfer hoses and loading arms. (a) Each hose within the marine transfer area for LHG used for the... arm used for the transfer of LHG or its vapor must— (1) Be made of materials resistant to each...

  4. 33 CFR 127.1102 - Transfer hoses and loading arms.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Transfer hoses and loading arms... Transfer hoses and loading arms. (a) Each hose within the marine transfer area for LHG used for the... arm used for the transfer of LHG or its vapor must— (1) Be made of materials resistant to each...

  5. 33 CFR 127.1102 - Transfer hoses and loading arms.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Transfer hoses and loading arms... Transfer hoses and loading arms. (a) Each hose within the marine transfer area for LHG used for the... arm used for the transfer of LHG or its vapor must— (1) Be made of materials resistant to each...

  6. 33 CFR 127.1102 - Transfer hoses and loading arms.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Transfer hoses and loading arms... Transfer hoses and loading arms. (a) Each hose within the marine transfer area for LHG used for the... arm used for the transfer of LHG or its vapor must— (1) Be made of materials resistant to each...

  7. 46 CFR 193.10-10 - Fire hydrants and hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cases the hose shall be 75 feet in length, and only one hose will be required at each fire station; however, if all such stations can be satisfactorily served with 50-foot lengths, 50-foot hose may be used... shore fire lines. Vessels of 500 gross tons and over on an international voyage, must be provided...

  8. 46 CFR 193.10-10 - Fire hydrants and hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cases the hose shall be 75 feet in length, and only one hose will be required at each fire station; however, if all such stations can be satisfactorily served with 50-foot lengths, 50-foot hose may be used... shore fire lines. Vessels of 500 gross tons and over on an international voyage, must be provided...

  9. 46 CFR 95.10-10 - Fire hydrants and hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hose shall be 75 feet in length, and only one hose will be required at each fire station; however, if all such stations can be satisfactorily served with 50-foot lengths, 50-foot hose may be used. (c) On... international voyage, must be provided with at least one international shore connection complying with ASTM...

  10. 46 CFR 95.10-10 - Fire hydrants and hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... hose shall be 75 feet in length, and only one hose will be required at each fire station; however, if all such stations can be satisfactorily served with 50-foot lengths, 50-foot hose may be used. (c) On... international voyage, must be provided with at least one international shore connection complying with ASTM...

  11. 46 CFR 107.257 - Testing of fire hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Testing of fire hose. 107.257 Section 107.257 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.257 Testing of fire hose. Each fire hose must be subjected to...

  12. 46 CFR 107.257 - Testing of fire hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Testing of fire hose. 107.257 Section 107.257 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.257 Testing of fire hose. Each fire hose must be subjected to...

  13. 46 CFR 107.257 - Testing of fire hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Testing of fire hose. 107.257 Section 107.257 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.257 Testing of fire hose. Each fire hose must be subjected to...

  14. 46 CFR 107.257 - Testing of fire hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Testing of fire hose. 107.257 Section 107.257 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.257 Testing of fire hose. Each fire hose must be subjected to...

  15. 46 CFR 154.1170 - Hand hose line: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Hand hose line: General. 154.1170 Section 154.1170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must:...

  16. 46 CFR 154.1170 - Hand hose line: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Hand hose line: General. 154.1170 Section 154.1170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must:...

  17. 46 CFR 154.1170 - Hand hose line: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Hand hose line: General. 154.1170 Section 154.1170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must:...

  18. 46 CFR 154.1170 - Hand hose line: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Hand hose line: General. 154.1170 Section 154.1170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must:...

  19. 46 CFR 154.1170 - Hand hose line: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Hand hose line: General. 154.1170 Section 154.1170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must:...

  20. 46 CFR 167.45-10 - Couplings on fire hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Couplings on fire hose. 167.45-10 Section 167.45-10... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be...

  1. 46 CFR 167.45-10 - Couplings on fire hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Couplings on fire hose. 167.45-10 Section 167.45-10... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be...

  2. 46 CFR 167.45-10 - Couplings on fire hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Couplings on fire hose. 167.45-10 Section 167.45-10... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be...

  3. 46 CFR 167.45-10 - Couplings on fire hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Couplings on fire hose. 167.45-10 Section 167.45-10... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be...

  4. 46 CFR 167.45-10 - Couplings on fire hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Couplings on fire hose. 167.45-10 Section 167.45-10... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be...

  5. 33 CFR 183.532 - Clips, straps, and hose clamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Clips, straps, and hose clamps... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a...

  6. 33 CFR 183.532 - Clips, straps, and hose clamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Clips, straps, and hose clamps... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a...

  7. The Jar Magic--Instructional Activities for Teaching Air Pressure

    ERIC Educational Resources Information Center

    Ku, Bing-Hong; Chen, Chyong-Sun

    2013-01-01

    There are a variety of impressive activities designed for teaching the concept of air pressure to junior high school students. Water, glasses, balloons, plastic bottles, and suction cups are some of the items commonly used in these experiments. For example, if we take a glass of water, cover it with a piece of cardboard, and invert the glass,…

  8. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Alternating pressure air flotation mattress. 880.5550 Section 880.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

  9. Experimental Air Pressure Tank Systems for Process Control Education

    ERIC Educational Resources Information Center

    Long, Christopher E.; Holland, Charles E.; Gatzke, Edward P.

    2006-01-01

    In process control education, particularly in the field of chemical engineering, there is an inherent need for industrially relevant hands-on apparatuses that enable one to bridge the gap between the theoretical content of coursework and real-world applications. At the University of South Carolina, two experimental air-pressure tank systems have…

  10. Mitigating the hosing instability in relativistic laser-plasma interactions

    NASA Astrophysics Data System (ADS)

    Ceurvorst, L.; Ratan, N.; Levy, M. C.; Kasim, M. F.; Sadler, J.; Scott, R. H. H.; Trines, R. M. G. M.; Huang, T. W.; Skramic, M.; Vranic, M.; Silva, L. O.; Norreys, P. A.

    2016-05-01

    A new physical model of the hosing instability that includes relativistic laser pulses and moderate densities is presented and derives the density dependence of the hosing equation. This is tested against two-dimensional particle-in-cell simulations. These simulations further examine the feasibility of using multiple pulses to mitigate the hosing instability in a Nd:glass-type parameter space. An examination of the effects of planar versus cylindrical exponential density gradients on the hosing instability is also presented. The results show that strongly relativistic pulses and more planar geometries are capable of mitigating the hosing instability which is in line with the predictions of the physical model.

  11. Improved fireman's compressed air breathing system pressure vessel development program

    NASA Technical Reports Server (NTRS)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  12. Investigation of Electrostatic Charge in Hose Lines

    DTIC Science & Technology

    2006-10-01

    storage tanks and, thereby, impose hazardous electrical energy concentrations sufficient to cause incendive arc discharges. This hazard problem... dissipater additives with the objective of quantifying and minimizing electrostatic charging in flexible fuel transport hoses. 0 1 2 3 4 5 6 7 8

  13. High-flexibility, noncollapsing lightweight hose

    DOEpatents

    Williams, David A.

    1993-01-01

    A high-flexibility, noncollapsing, lightweight, large-bore, wire-reinforced hose is inside fiber-reinforced PVC tubing that is flexible, lightweight, and abrasion resistant. It provides a strong, kink- and collapse-free conduit for moving large quantities of dangerous fluids, e.g., removing radioactive waste water or processing chemicals.

  14. High-flexibility, noncollapsing lightweight hose

    DOEpatents

    Williams, D.A.

    1993-04-20

    A high-flexibility, noncollapsing, lightweight, large-bore, wire-reinforced hose is inside fiber-reinforced PVC tubing that is flexible, lightweight, and abrasion resistant. It provides a strong, kink- and collapse-free conduit for moving large quantities of dangerous fluids, e.g., removing radioactive waste water or processing chemicals.

  15. Research on fire hose couplings damages

    NASA Astrophysics Data System (ADS)

    Babut, C.; Ungureanu, N.; Ungureanu, M.

    2017-01-01

    This paper presents a part of a research on the damaging of fire hose coupling. These are important components of the hydraulic systems used by firefighters to deliver one or more suppression agents into the fire. The operating regime parameters, working environment and general functioning conditions during fire suppression operations may lead to malfunctions and/or damaging of the couplings.

  16. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  17. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  18. Evaluation of Hose in Hose Transfer Line Service Life for Hanford's Interim Stabilization Program

    SciTech Connect

    TORRES, T.D.

    2000-08-24

    RPP-6153, Engineering Task Plan for Hose-in-Hose Transfer System for the Interim Stabilization Program, defines the programmatic goals, functional requirements, and technical criteria for the development and subsequent installation of transfer line equipment to support Hanford's Interim Stabilization Program. RPP-6028, Specification for Hose in Hose Transfer Lines for Hanford's Interim Stabilization Program, has been issued to define the specific requirements for the design, manufacture, and verification of transfer line assemblies for specific waste transfer applications. Included in RPP-6028 are tables defining the chemical constituents of concern to which transfer lines will be exposed. Current Interim Stabilization Program planning forecasts that the at-grade transfer lines will be required to convey pumpable waste for as much as three years after commissioning. Prudent engineering dictates that the equipment placed in service have a working life in excess of this forecasted time period, with some margin to allow for future adjustments to the planned schedule. This document evaluates the effective service life of the Hose-in-Hose Transfer Lines, based on information submitted by the manufacturer and published literature. The effective service life of transfer line assemblies is a function of several factors. Foremost among these are process fluid characteristics, ambient environmental conditions, and the manufacturer's stated shelf life. This evaluation examines the manufacturer's certification of shelf life, the manufacturer's certifications of chemical compatibility with waste, and published literature on the effects of exposure to ionizing radiation on the mechanical properties of elastomeric materials to evaluate transfer line service life.

  19. Flame structures in the pressurized methane-air combustor

    SciTech Connect

    Yamamoto, Tsuyoshi; Miyazaki, Tomonaga, Furuhata, Tomohiko; Arai, Norio

    1998-07-01

    This study has been carried out in order to investigate the applicability of a pressurized and fuel-rich burner at a first stage combustor for a newly proposed chemical gas turbine system. The flammability limits, exhaust gas composition and the NO{sub x} emission characteristics under the pressurized conditions of 1.1--4.1 MPa have been investigated in a model combustor. This paper focuses on the influence of pressure and F/A equivalence ratio on flame structures of pressurized combustion with methane and air to obtain detailed data for designing of fuel-rich combustor for gas turbine application. The flame under fuel-rich condition and pressure of 1 MPa showed underventilated structure like other atmospheric fuel-rich flames while the flame under pressure over 1.5 MPa had shapes as fuel-lean flame. The flame becomes longer as the pressure was increased under the fuel-lean conditions, which under fuel-rich condition the influence of pressure on flame length was smaller in comparison with the flame under fuel-lean conditions. These results give an opportunity for developing smaller combustor under fuel-rich and pressurized condition compared to fuel-lean one. Numerical simulation has been done for defining the temperature profile in the model combustor using the k-{var{underscore}epsilon} turbulence model and three-step reaction model. The comparison between theoretical results and experimental data showed fair agreements.

  20. Evaluation of Hose in Hose Transfer Line Service Life for Hanfords Interim Stabilization Program

    SciTech Connect

    TORRES, T.D.

    2001-03-23

    RPP-6153, Engineering Task Plan for Hose-in-Hose Transfer System for the Interim Stabilization Program (Torres, 2000a), defines the programmatic goals, functional requirements, and technical criteria for the development and subsequent installation of waste transfer line equipment to support Hanford's Interim Stabilization Program. RPP-6028, Specification for Hose in Hose Transfer Lines for Hanford's Interim Stabilization Program (Torres, 2000b), has been issued to define the specific requirements for the design, manufacture, and verification of transfer line assemblies for specific waste transfer applications associated with Interim Stabilization. Included in RPP-6028 are tables defining the chemical constituents of concern to which transfer lines will be exposed. Current Interim Stabilization Program planning forecasts that the at-grade transfer lines will be required to convey pumpable waste for as much as three years after commissioning, RPP-6028 Section 3.2.7. Performance Incentive Number ORP-05 requires that all the Single Shell Tanks be Interim Stabilized by September 30, 2003. The Tri-Party Agreement (TPA) milestone M-41-00, enforced by a federal consent decree, requires all the Single Shell Tanks to be Interim stabilized by September 30, 2004. By meeting the Performance Incentive the TPA milestone is met. Prudent engineering dictates that the equipment used to transfer waste have a life in excess of the forecasted operational time period, with some margin to allow for future adjustments to the planned schedule. This document evaluates the effective service life of the Hose-in-Hose Transfer Lines, based on information submitted by the manufacturer, published literature and calculations. The effective service life of transfer line assemblies is a function of several factors. Foremost among these are the hose material's resistance to the harmful effects of process fluid characteristics, ambient environmental conditions, exposure to ionizing radiation and the

  1. Air and gas pockets in sewerage pressure mains.

    PubMed

    Lubbers, C L; Clemens, F

    2005-01-01

    In The Netherlands, wastewater is collected in municipal areas and transported to large centralised WWTPs by means of an extensive system of pressure mains. Over the past decades these pressure mains did not receive much attention in terms of monitoring of performance or maintenance. For that reason, in practice their state of functioning is often not known. Failure of operation is only noticed when the capacity of the system proves to be insufficient to fulfil the minimum design capacity demand. A recent inventory showed that half of the pressure mains show an increased pressure loss for no directly obvious reason. Many causes may account for the reduction of the system's nominal capacity like an increased wall roughness, scaling or occurrence of free gas in the pipeline. The occurrence of free gas may be caused by degassing of dissolved (bio) gas or by air entrained at the pumps' inlet or at air valves. A research study is started that will focus on three main issues: The description of the gas-water phenomena in wastewater pressure mains with respect to transportation and dynamic hydraulic behaviour, A method to diagnose gas problems, and To overcome future problems by either applying remedial measures or improving the design of wastewater pressure systems. For this study, two experimental facilities are constructed, a small circuit for the study of multi-phase flow and a second, larger one for the research into diagnostic methods. This paper describes the preliminary results of the experiments in the multi-phase circuit.

  2. One-Component Pressure-Temperature Phase Diagrams in the Presence of Air

    ERIC Educational Resources Information Center

    Andrade-Gamboa, Julio; Martire, Daniel O.; Donati, Edgardo R.

    2010-01-01

    One-component phase diagrams are good approximations to predict pressure-temperature ("P-T") behavior of a substance in the presence of air, provided air pressure is not much higher than the vapor pressure. However, at any air pressure, and from the conceptual point of view, the use of a traditional "P-T" phase diagram is not strictly correct. In…

  3. Generation of subnanosecond electron beams in air at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Kostyrya, I. D.; Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Lomaev, M. I.; Rybka, D. V.

    2009-11-01

    Optimum conditions for the generation of runaway electron beams with maximum current amplitudes and densities in nanosecond pulsed discharges in air at atmospheric pressure are determined. A supershort avalanche electron beam (SAEB) with a current amplitude of ˜30 A, a current density of ˜20 A/cm2, and a pulse full width at half maximum (FWHM) of ˜100 ps has been observed behind the output foil of an air-filled diode. It is shown that the position of the SAEB current maximum relative to the voltage pulse front exhibits a time shift that varies when the small-size collector is moved over the foil surface.

  4. Impacts of Changes of Indoor Air Pressure and Air Exchange Rate in Vapor Intrusion Scenarios.

    PubMed

    Shen, Rui; Suuberg, Eric M

    2016-02-01

    There has, in recent years, been increasing interest in understanding the transport processes of relevance in vapor intrusion of volatile organic compounds (VOCs) into buildings on contaminated sites. These studies have included fate and transport modeling. Most such models have simplified the prediction of indoor air contaminant vapor concentrations by employing a steady state assumption, which often results in difficulties in reconciling these results with field measurements. This paper focuses on two major factors that may be subject to significant transients in vapor intrusion situations, including the indoor air pressure and the air exchange rate in the subject building. A three-dimensional finite element model was employed with consideration of daily and seasonal variations in these factors. From the results, the variations of indoor air pressure and air exchange rate are seen to contribute to significant variations in indoor air contaminant vapor concentrations. Depending upon the assumptions regarding the variations in these parameters, the results are only sometimes consistent with the reports of several orders of magnitude in indoor air concentration variations from field studies. The results point to the need to examine more carefully the interplay of these factors in order to quantitatively understand the variations in potential indoor air exposures.

  5. Impacts of Changes of Indoor Air Pressure and Air Exchange Rate in Vapor Intrusion Scenarios

    PubMed Central

    Shen, Rui; Suuberg, Eric M.

    2016-01-01

    There has, in recent years, been increasing interest in understanding the transport processes of relevance in vapor intrusion of volatile organic compounds (VOCs) into buildings on contaminated sites. These studies have included fate and transport modeling. Most such models have simplified the prediction of indoor air contaminant vapor concentrations by employing a steady state assumption, which often results in difficulties in reconciling these results with field measurements. This paper focuses on two major factors that may be subject to significant transients in vapor intrusion situations, including the indoor air pressure and the air exchange rate in the subject building. A three-dimensional finite element model was employed with consideration of daily and seasonal variations in these factors. From the results, the variations of indoor air pressure and air exchange rate are seen to contribute to significant variations in indoor air contaminant vapor concentrations. Depending upon the assumptions regarding the variations in these parameters, the results are only sometimes consistent with the reports of several orders of magnitude in indoor air concentration variations from field studies. The results point to the need to examine more carefully the interplay of these factors in order to quantitatively understand the variations in potential indoor air exposures. PMID:28090133

  6. Microcontrolled air-mattress for ulcer by pressure prevention

    NASA Astrophysics Data System (ADS)

    Pasluosta, Cristian F.; Fontana, Juan M.; Beltramone, Diego A.; Taborda, Ricardo A. M.

    2007-11-01

    An ulcer by pressure is produced when a constant pressure is exerted over the skin. This generates the collapse of the blood vessels and, therefore, a lack in the contribution of the necessary nutrients for the affected zone. As a consequence, the skin deteriorates, eventually causing an ulcer. In order to prevent it, a protocol must be applied to the patient, which is reflected on time and cost of treatment. There are some air mattresses available for this purpose, but whose performance does not fulfill all requirements. The prototype designed in our laboratory is based on the principle of the air mattress. Its objective is to improve on existing technologies and, due to an increased automation, reduce time dedication for personnel in charge of the patient. A clinical experience was made in the local Emergencies Hospital and also in an institution dedicated to aged patients care. In both cases, the results obtained and the comments from the personnel involved were favorable.

  7. The Jar Magic -- Instructional Activities for Teaching Air Pressure

    NASA Astrophysics Data System (ADS)

    Ku, Bing-Hong; Chen, Chyong-Sun

    2013-12-01

    There are a variety of impressive activities designed for teaching the concept of air pressure to junior high school students. Water, glasses, balloons, plastic bottles, and suction cups are some of the items commonly used in these experiments. For example, if we take a glass of water, cover it with a piece of cardboard, and invert the glass, amazingly, no water spills out. Further, one may also use balloons and plastic bottles as the components in another experiment. Place a balloon in a plastic bottle and spread the balloon's mouth over the bottle's rim. Inflate the balloon by blowing into it. Students will be astonished at the fact that the balloon remains inflated even though its mouth is open. Making suction cups "stick" to the wall is also an instance of proving how air pressure works.

  8. AIR SEPARATION BY PRESSURE SWING ADSORPTION USING SUPERIOR ADSORBENTS

    SciTech Connect

    Ralph T. Yang

    2001-08-31

    Li-X zeolite (Si/Al = 1.0) is currently the best sorbent for use in the separation of air by adsorption processes. In particular, pressure swing adsorption (PSA) using zeolite sorbents is being increasingly used for air separation. Silver is also known to strongly affect the adsorptive properties of zeolites; and it is known that thermal vacuum dehydration of silver zeolites leads to the formation of silver clusters within the zeolite. In this work we have synthesized type X zeolites containing Ag and also varying mixtures of Li and Ag. In this project, we developed the Ag-containing zeolite as the best sorbent for air separation. We have also studied Co-ligand compounds as oxygen-selective sorbents. Syntheses, structural characterization and adsorption properties have been performed on all sorbents. The results are described in detail in 5 chapters.

  9. Low pressure high speed Stirling air engine. Final technical report

    SciTech Connect

    Ross, M.A.

    1980-06-16

    The purpose of this project was to design, construct and test a simple, appropriate technology low pressure, high speed, wood-fired Stirling air engine of 100 W output. The final design was a concentric piston/displacer engine of 454 in. bore and 1 in. stroke with a rhombic drive mechanism. The project engine was ultimately completed and tested, using a propane burner for all tests as a matter of convenience. The 100 W aim was exceeded, at atmospheric pressure, over a wide range of engine speed with the maximum power being 112 W at 1150 rpm. A pressure can was constructed to permit pressurization; however the grant funds were running out, and the only pressurized power test attempted was unsuccessful due to seal difficulties. This was a disappointment because numerous tests on the 4 cubic inch engine suggested power would be more than doubled with pressurization at 25 psig. A manifold was designed and constructed to permit operation of the engine over a standard No. 40 pot bellied stove. The engine was run successfully, but at reduced speed and power, over this stove. The project engine started out being rather noisy in operation, but modifications ultimately resulted in a very quiet engine. Various other difficulties and their solutions also are discussed. (LCL)

  10. 78 FR 1735 - Airworthiness Directives; Honeywell International Inc. Air Data Pressure Transducers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... International Inc. Air Data Pressure Transducers AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... certain Honeywell International Inc. air data pressure transducers as installed on various aircraft. This AD requires various tests or checks of equipment having certain air data pressure transducers,...

  11. Breakdown of air pockets in downwardly inclined sewerage pressure mains.

    PubMed

    Lubbers, C L; Clemens, F H L R

    2006-01-01

    In the Netherlands, wastewater is collected in municipal areas and transported to centralised WWTPs by an extensive system of pressure mains. Over the last decades these pressure mains did not receive much attention in terms of monitoring of performance or maintenance. A recent inventory showed that half of the pressure mains show an increased pressure loss for no directly obvious reason. One of the many causes that account for the reduction of the flow capacity is the occurrence of free gas in the pipeline. During dry weather periods with low flow velocities, gas may accumulate at high points in the system. Once the velocity increases during storm weather flow, the air pockets may be broken down and transported to the end of the system. A research study is started focussing on the description of the gas-water phenomena in wastewater pressure mains with respect to transportation of gas. An experimental facility is constructed for the study of multi-phase flow. This paper describes the preliminary results of experiments on breakdown rates of gas pockets as a function of inclination angle and water flow rate. The results show an increasing breakdown rate with increasing inclination angle.

  12. Air Flow and Pressure Drop Measurements Across Porous Oxides

    NASA Technical Reports Server (NTRS)

    Fox, Dennis S.; Cuy, Michael D.; Werner, Roger A.

    2008-01-01

    This report summarizes the results of air flow tests across eight porous, open cell ceramic oxide samples. During ceramic specimen processing, the porosity was formed using the sacrificial template technique, with two different sizes of polystyrene beads used for the template. The samples were initially supplied with thicknesses ranging from 0.14 to 0.20 in. (0.35 to 0.50 cm) and nonuniform backside morphology (some areas dense, some porous). Samples were therefore ground to a thickness of 0.12 to 0.14 in. (0.30 to 0.35 cm) using dry 120 grit SiC paper. Pressure drop versus air flow is reported. Comparisons of samples with thickness variations are made, as are pressure drop estimates. As the density of the ceramic material increases the maximum corrected flow decreases rapidly. Future sample sets should be supplied with samples of similar thickness and having uniform surface morphology. This would allow a more consistent determination of air flow versus processing parameters and the resulting porosity size and distribution.

  13. 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.

  14. Experimental investigation of air pressure affecting filtration performance of fibrous filter sheet.

    PubMed

    Xu, Bin; Yu, Xiao; Wu, Ya; Lin, Zhongping

    2017-03-01

    Understanding the effect of air pressure on their filtration performance is important for assessing the effectiveness of fibrous filters under different practical circumstances. The effectiveness of three classes of air filter sheets were investigated in laboratory-based measurements at a wide range of air pressures (60-130 KPa). The filtration efficiency was found most sensitive to the air pressure change at smaller particle sizes. As the air pressure increased from 60 to 130 KPa, significant decrease in filtration efficiency (up to 15%) and increase in pressure drop (up to 90 Pa) were observed. The filtration efficiency of the filter sheet with largest fiber diameter and smallest solid volume fraction was affected most, while the pressure drop of the filter sheet with smallest fiber diameter and largest solid volume fraction was affected most. The effect of air pressure on the filtration efficiency was slightly larger at greater filter face air velocity. However, the effect of air pressure on the pressure drop was negligible. The filtration efficiency and pressure drop were explicitly expressed as functions of the air pressure. Two coefficients were empirically derived and successfully accounted for the effects of air pressure on filtration efficiency and pressure drop.

  15. Vandenberg Air Force Base Pressure Gradient Wind Study

    NASA Technical Reports Server (NTRS)

    Shafer, Jaclyn A.

    2013-01-01

    Warning category winds can adversely impact day-to-day space lift operations at Vandenberg Air Force Base (VAFB) in California. NASA's Launch Services Program and other programs at VAFB use wind forecasts issued by the 30 Operational Support Squadron Weather Flight (30 OSSWF) to determine if they need to limit activities or protect property such as a launch vehicle. The 30 OSSWF tasked the AMU to develop an automated Excel graphical user interface that includes pressure gradient thresholds between specific observing stations under different synoptic regimes to aid forecasters when issuing wind warnings. This required the AMU to determine if relationships between the variables existed.

  16. Heart-rate monitoring by air pressure and causal analysis

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Naoki; Nakajima, Hiroshi; Hata, Yutaka

    2011-06-01

    Among lots of vital signals, heart-rate (HR) is an important index for diagnose human's health condition. For instance, HR provides an early stage of cardiac disease, autonomic nerve behavior, and so forth. However, currently, HR is measured only in medical checkups and clinical diagnosis during the rested state by using electrocardiograph (ECG). Thus, some serious cardiac events in daily life could be lost. Therefore, a continuous HR monitoring during 24 hours is desired. Considering the use in daily life, the monitoring should be noninvasive and low intrusive. Thus, in this paper, an HR monitoring in sleep by using air pressure sensors is proposed. The HR monitoring is realized by employing the causal analysis among air pressure and HR. The causality is described by employing fuzzy logic. According to the experiment on 7 males at age 22-25 (23 on average), the correlation coefficient against ECG is 0.73-0.97 (0.85 on average). In addition, the cause-effect structure for HR monitoring is arranged by employing causal decomposition, and the arranged causality is applied to HR monitoring in a setting posture. According to the additional experiment on 6 males, the correlation coefficient is 0.66-0.86 (0.76 on average). Therefore, the proposed method is suggested to have enough accuracy and robustness for some daily use cases.

  17. Thermal separation of soil particles from thermal conductivity measurement under various air pressures

    NASA Astrophysics Data System (ADS)

    Lu, Sen; Ren, Tusheng; Lu, Yili; Meng, Ping; Zhang, Jinsong

    2017-01-01

    The thermal conductivity of dry soils is related closely to air pressure and the contact areas between solid particles. In this study, the thermal conductivity of two-phase soil systems was determined under reduced and increased air pressures. The thermal separation of soil particles, i.e., the characteristic dimension of the pore space (d), was then estimated based on the relationship between soil thermal conductivity and air pressure. Results showed that under both reduced and increased air pressures, d estimations were significantly larger than the geometrical mean separation of solid particles (D), which suggested that conductive heat transfer through solid particles dominated heat transfer in dry soils. The increased air pressure approach gave d values lower than that of the reduced air pressure method. With increasing air pressure, more collisions between gas molecules and solid surface occurred in micro-pores and intra-aggregate pores due to the reduction of mean free path of air molecules. Compared to the reduced air pressure approach, the increased air pressure approach expressed more micro-pore structure attributes in heat transfer. We concluded that measuring thermal conductivity under increased air pressure procedures gave better-quality d values, and improved soil micro-pore structure estimation.

  18. Thermal separation of soil particles from thermal conductivity measurement under various air pressures.

    PubMed

    Lu, Sen; Ren, Tusheng; Lu, Yili; Meng, Ping; Zhang, Jinsong

    2017-01-05

    The thermal conductivity of dry soils is related closely to air pressure and the contact areas between solid particles. In this study, the thermal conductivity of two-phase soil systems was determined under reduced and increased air pressures. The thermal separation of soil particles, i.e., the characteristic dimension of the pore space (d), was then estimated based on the relationship between soil thermal conductivity and air pressure. Results showed that under both reduced and increased air pressures, d estimations were significantly larger than the geometrical mean separation of solid particles (D), which suggested that conductive heat transfer through solid particles dominated heat transfer in dry soils. The increased air pressure approach gave d values lower than that of the reduced air pressure method. With increasing air pressure, more collisions between gas molecules and solid surface occurred in micro-pores and intra-aggregate pores due to the reduction of mean free path of air molecules. Compared to the reduced air pressure approach, the increased air pressure approach expressed more micro-pore structure attributes in heat transfer. We concluded that measuring thermal conductivity under increased air pressure procedures gave better-quality d values, and improved soil micro-pore structure estimation.

  19. Thermal separation of soil particles from thermal conductivity measurement under various air pressures

    PubMed Central

    Lu, Sen; Ren, Tusheng; Lu, Yili; Meng, Ping; Zhang, Jinsong

    2017-01-01

    The thermal conductivity of dry soils is related closely to air pressure and the contact areas between solid particles. In this study, the thermal conductivity of two-phase soil systems was determined under reduced and increased air pressures. The thermal separation of soil particles, i.e., the characteristic dimension of the pore space (d), was then estimated based on the relationship between soil thermal conductivity and air pressure. Results showed that under both reduced and increased air pressures, d estimations were significantly larger than the geometrical mean separation of solid particles (D), which suggested that conductive heat transfer through solid particles dominated heat transfer in dry soils. The increased air pressure approach gave d values lower than that of the reduced air pressure method. With increasing air pressure, more collisions between gas molecules and solid surface occurred in micro-pores and intra-aggregate pores due to the reduction of mean free path of air molecules. Compared to the reduced air pressure approach, the increased air pressure approach expressed more micro-pore structure attributes in heat transfer. We concluded that measuring thermal conductivity under increased air pressure procedures gave better-quality d values, and improved soil micro-pore structure estimation. PMID:28054663

  20. 46 CFR 78.47-20 - Fire hose stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Fire hose stations. 78.47-20 Section 78.47-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-20 Fire hose stations. (a) Each fire hydrant shall be...

  1. 46 CFR 169.735 - Fire hose stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Fire hose stations. 169.735 Section 169.735 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.735 Fire hose stations. Each fire hydrant must be identified in red letters and figures at least two inches high “FIRE STATION NO. 1,” “2,”...

  2. 30 CFR 18.65 - Flame test of hose.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Flame test of hose. 18.65 Section 18.65 Mineral... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... wide by thickness of the hose. (b) Flame-test apparatus. The principal parts of the apparatus...

  3. 30 CFR 18.65 - Flame test of hose.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Flame test of hose. 18.65 Section 18.65 Mineral... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... wide by thickness of the hose. (b) Flame-test apparatus. The principal parts of the apparatus...

  4. 33 CFR 183.540 - Hoses: Standards and markings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours. SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square meter.... (g) Each character must be block capital letters and numerals that are at least one eighth-inch...

  5. Air pressure waves from Mount St. Helens eruptions

    SciTech Connect

    Reed, J.W.

    1987-10-20

    Weather station barograph records as well as infrasonic recordings of the pressure wave from the Mount St. Helens eruption of May 18, 1980, have been used to estimate an equivalent explosion airblast yield for this event. Pressure amplitude versus distance patterns in various directions compared with patterns from other large explosions, such as atmospheric nuclear tests, the Krakatoa eruption, and the Tunguska comet impact, indicate that the wave came from an explosion equivalent of a few megatons of TNT. The extent of tree blowdown is considerably greater than could be expected from such an explosion, and the observed forest damage is attributed to outflow of volcanic material. The pressure-time signature obtained at Toledo, Washington, showed a long, 13-min duration negative phase as well as a second, hour-long compression phase, both probably caused by ejacta dynamics rather than standard explosion wave phenomenology. The peculiar audibility pattern, with the blast being heard only at ranges beyond about 100 km, is explicable by finite amplitude propagation effects. Near the source, compression was slow, taking more than a second but probably less than 5 s, so that it went unnoticed by human ears and susceptible buildings were not damaged. There was no damage as Toledo (54 km), where the recorded amplitude would have broken windows with a fast compression. An explanation is that wave emissions at high elevation angles traveled to the upper stratosphere, where low ambient air pressures caused this energetic pressure oscillation to form a shock wave with rapid, nearly instantaneous compression. Atmospheric refraction then returned part of this wave to ground level at long ranges, where the fast compressions were clearly audible. copyright American Geophysical Union 1987

  6. Pressurized air cathodes for enhanced stability and power generation by microbial fuel cells

    NASA Astrophysics Data System (ADS)

    He, Weihua; Yang, Wulin; Tian, Yushi; Zhu, Xiuping; Liu, Jia; Feng, Yujie; Logan, Bruce E.

    2016-11-01

    Large differences between the water and air pressure in microbial fuel cells (MFCs) can deform and damage cathodes. To avoid deformation, the cathode air pressure was controlled to balance pressure differences between the air and water. Raising the air pressures from 0 to 10 kPa at a set cathode potential of -0.3 V (versus Ag/AgCl) enhanced cathode performance by 17%, but pressures ≥25 kPa decreased current and resulted in air leakage into the solution. Matching the air pressure with the water pressure avoided cathode deformation and improved performance. The maximum power density increased by 15%, from 1070 ± 20 to 1230 ± 70 mW m-2, with balanced air and water pressures of 10-25 kPa. Oxygen partial pressures ≥12.5 kPa in the cathode compartment maintained the oxygen reduction rate to be within 92 ± 1% of that in ambient air. The use of pressurized air flow through the cathode compartments can enable closer spacing of the cathodes compared to passive gas transfer systems, which could make the reactor design more compact. The energy cost of pressurizing the cathodes was estimated to be smaller than the increase in power that resulted from the use of pressurized cathodes.

  7. Effects of pressure on syngas/air turbulent nonpremixed flames

    NASA Astrophysics Data System (ADS)

    Lee, Bok Jik; Im, Hong G.; Ciottoli, Pietro Paolo; Valorani, Mauro

    2016-11-01

    Large eddy simulations (LES) of turbulent non-premixed jet flames were conducted to investigate the effects of pressure on the syngas/air flame behavior. The software to solve the reactive Navier-Stokes equations was developed based on the OpenFOAM framework, using the YSLFM library for the flamelet-based chemical closure. The flamelet tabulation is obtained by means of an in-house code designed to solve unsteady flamelets of both ideal and real fluid mixtures. The validation of the numerical setup is attained by comparison of the numerical results with the Sandia/ETH-Zurich experimental database of the CO/H2/N2 non-premixed, unconfined, turbulent jet flame, referred to as "Flame A". Two additional simulations, at pressure conditions of 2 and 5 atm, are compared and analyzed to unravel computational and scientific challenges in characterizing turbulent flames at high pressures. A set of flamelet solutions, representative of the jet flames under review, are analyzed following a CSP approach. In particular, the Tangential Stretching Rate (TSR), representing the reciprocal of the most energetic time scale associated with the chemical source term, and its extension to reaction-diffusion systems (extended TSR), are adopted.

  8. Investigation of Radiation and Chemical Resistance of Flexible HLW Transfer Hose

    SciTech Connect

    E. Skidmore; Billings, K.; Hubbard, M.

    2010-03-24

    A chemical transfer hose constructed of an EPDM (ethylene-propylene diene monomer) outer covering with a modified cross-linked polyethylene (XLPE) lining was evaluated for use in high level radioactive waste transfer applications. Laboratory analysis involved characterization of the hose liner after irradiation to doses of 50 to 300 Mrad and subsequent exposure to 25% NaOH solution at 93 C for 30 days, simulating 6 months intermittent service. The XLPE liner mechanical and structural properties were characterized at varying dose levels. Burst testing of irradiated hose assemblies was also performed. Literature review and test results suggest that radiation effects below doses of 100 kGy are minimal, with acceptable property changes to 500 kGy. Higher doses may be feasible. At a bounding dose of 2.5 MGy, the burst pressure is reduced to the working pressure (1.38 MPa) at room temperature. Radiation exposure slightly reduces liner tensile strength, with more significant decrease in liner elongation. Subsequent exposure to caustic solutions at elevated temperature slightly increases elongation, suggesting an immersion/hydrolytic effect or possible thermal annealing of radiation damage. This paper summarizes the laboratory results and recommendations for field deployment.

  9. Inflation pressure effect on performance of air-filled wheelchair cushions.

    PubMed

    Krouskop, T A; Williams, R; Noble, P; Brown, J

    1986-02-01

    Air-filled wheelchair cushions are frequently used in the prevention of pressure sores. Their effectiveness in reducing interface pressures and in redistributing body weight (BW) appears dependent on their internal inflation pressure. This pilot study examines and defines this relationship. Interface pressures were measured with the TIPE (Texas Interface Pressure Evaluator) system for 14 subjects while sitting on each of three commercially available air-filled wheelchair cushions. This relationship between interface pressure and internal pressure was then determined for each of the three body-build categories. In each category the interface pressure displayed a higher degree of sensitivity to underinflation than to overinflation. A high correlation found between BW and internal air pressure (IAP), may be useful in the design of a customized pressure indicator system. The study documents the influence of IAP on seating pressure and supports the need for further research in the development of an indicator system that alerts users to under- or overinflation of the cushion.

  10. 33 CFR 183.530 - Spud, pipe, and hose fitting configuration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Spud, pipe, and hose fitting....530 Spud, pipe, and hose fitting configuration. Except when used for a tank fill line, each spud, pipe, or hose fitting used with hose clamps must have: (a) A bead; (b) A flare; or (c) A series of...

  11. EFFECT OF LASER LIGHT ON LASER PLASMAS: Laser plasma at low air pressure

    NASA Astrophysics Data System (ADS)

    Vas'kovskiĭ, Yu M.; Moiseev, V. N.; Rovinskiĭ, R. E.; Tsenina, I. S.

    1993-01-01

    The dynamic and optical characteristics of the laser plasma produced during the application of a CO2 laser pulse to a target have been studied as a function of the ambient air pressure. The changes in the surface roughness of the sample after bombardment were studied as a function of the air pressure. It is concluded from the results that a transition from an air plasma to an erosion plasma occurs at a residual air pressure on the order of 1 torr. The experiment data support the existing picture of the process by which a plasma is produced near the surface of a target in air by laser pulses.

  12. Assessment of Refueling Hose Visibility: Post-Cleaning Evaluation

    DTIC Science & Technology

    2013-10-01

    Consulting** 2466 W. Golden Hill Rd. Tucson AZ 85745-1879 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S...positioned in a reflection geometry and two measurements will be made for each hose location measured. The light source (e.g., photo flood light) will be...made for each hose location measured: one of the hose and one of the BaSO4 reference. The light source (e.g., photo flood light) will be positioned to

  13. [Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air].

    PubMed

    Xu, Wei-Hua; Shen, Hua-Hao

    2010-02-25

    When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.

  14. Response of entrained air-void systems in cement paste to pressure

    NASA Astrophysics Data System (ADS)

    Frazier, Robert

    2011-12-01

    Scope and Method of Study: Determine the response of entrained air-void systems in fresh cement paste to applied pressures by utilizing micro-computed tomography. Compare results to those suggested by the ASTM C231 Type B pressure meter calibration equations. Findings and Conclusions: The results of this research suggest that although the Type B pressure meter assumptions are valid for the compression of individual voids, the volume of air-voids which dissolve under pressure is significant enough to register noticeable errors when using a synthetic air-entraining admixture with the Type B pressure meter test. Results currently suggest that air-void systems with a significant percentage of small voids present will have higher deviation from the Boyle's Law model used by the Type B pressure meter due to the dissolution of these air-voids.

  15. DDT in fuel air mixtures at elevated temperatures and pressures

    NASA Astrophysics Data System (ADS)

    Card, J.; Rival, D.; Ciccarelli, G.

    2005-11-01

    An experimental study was carried out to investigate flame acceleration and deflagration-to-detonation transition (DDT) in fuel air mixtures at initial temperatures up to 573 K and pressures up to 2 atm. The fuels investigated include hydrogen, ethylene, acetylene and JP-10 aviation fuel. The experiments were performed in a 3.1-m long, 10-cm inner-diameter heated detonation tube equipped with equally spaced orifice plates. Ionization probes were used to measure the flame time-of-arrival from which the average flame velocity versus propagation distance could be obtained. The DDT composition limits and the distance required for the flame to transition to detonation were obtained from this flame velocity data. The correlation developed by Veser et al. (run-up distance to supersonic flames in obstacle-laden tubes. In the proceedings of the 4th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions, France (2002)) for the flame choking distance proved to work very well for correlating the detonation run-up distance measured in the present study. The only exception was for the hydrogen air data at elevated initial temperatures which tended to fall outside the scatter of the hydrocarbon mixture data. The DDT limits obtained at room temperature were found to follow the classical d/λ = 1 correlation, where d is the orifice plate diameter and λ is the detonation cell size. Deviations found for the high-temperature data could be attributed to the one-dimensional ZND detonation structure model used to predict the detonation cell size for the DDT limit mixtures. This simple model was used in place of actual experimental data not currently available.

  16. Study of short atmospheric pressure dc glow microdischarge in air

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, Anatoly; Bogdanov, Eugene; Chirtsov, Alexander; Emelin, Sergey

    2011-10-01

    The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen and oxygen atoms; ozone molecule; and different nitrogen and oxygen ions with different plasmochemical reactions between them. Simulations predicted the main regions of the dc glow discharges including cathode and anode sheath and plasma of negative glow, Faraday dark space and transition region. Gas heating plays an important role in shaping the discharge profiles. The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen

  17. Compression-ignition Engine Performance at Altitudes and at Various Air Pressures and Temperatures

    NASA Technical Reports Server (NTRS)

    Moore, Charles S; Collins, John H

    1937-01-01

    Engine test results are presented for simulated altitude conditions. A displaced-piston combustion chamber on a 5- by 7-inch single cylinder compression-ignition engine operating at 2,000 r.p.m. was used. Inlet air temperature equivalent to standard altitudes up to 14,000 feet were obtained. Comparison between performance at altitude of the unsupercharged compression-ignition engine compared favorably with the carburetor engine. Analysis of the results for which the inlet air temperature, inlet air pressure, and inlet and exhaust pressure were varied indicates that engine performance cannot be reliably corrected on the basis of inlet air density or weight of air charge. Engine power increases with inlet air pressure and decreases with inlet air temperatures very nearly as straight line relations over a wide range of air-fuel ratios. Correction factors are given.

  18. 46 CFR 95.10-10 - Fire hydrants and hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... need not apply to shaft alleys containing no assigned space for the stowage of combustibles. Fire... hydrant must have at least one length of firehose, a spanner, and a hose rack or other device for...

  19. 46 CFR 181.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cargo decks, where no protection is provided, hoses may be temporarily removed during heavy weather or... being changed between a solid stream and a spray pattern. A nozzle on a vessel of not more than...

  20. 46 CFR 181.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cargo decks, where no protection is provided, hoses may be temporarily removed during heavy weather or... being changed between a solid stream and a spray pattern. A nozzle on a vessel of not more than...

  1. 46 CFR 181.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... cargo decks, where no protection is provided, hoses may be temporarily removed during heavy weather or... being changed between a solid stream and a spray pattern. A nozzle on a vessel of not more than...

  2. 46 CFR 181.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cargo decks, where no protection is provided, hoses may be temporarily removed during heavy weather or... being changed between a solid stream and a spray pattern. A nozzle on a vessel of not more than...

  3. 33 CFR 183.560 - Hose clamps: Installation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.560... the engine, a hose between the fuel pump and the carburetor, or a vent line must: (a) Be used...

  4. 33 CFR 183.560 - Hose clamps: Installation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.560... the engine, a hose between the fuel pump and the carburetor, or a vent line must: (a) Be used...

  5. 33 CFR 183.560 - Hose clamps: Installation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.560... the engine, a hose between the fuel pump and the carburetor, or a vent line must: (a) Be used...

  6. 33 CFR 183.560 - Hose clamps: Installation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.560... the engine, a hose between the fuel pump and the carburetor, or a vent line must: (a) Be used...

  7. 46 CFR 108.425 - Fire hoses and associated equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Fire station hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch (38 millimeter) and...

  8. 46 CFR 108.425 - Fire hoses and associated equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Fire station hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch (38 millimeter) and...

  9. 46 CFR 108.425 - Fire hoses and associated equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Fire station hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch (38 millimeter) and...

  10. 46 CFR 108.425 - Fire hoses and associated equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Fire station hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch (38 millimeter) and...

  11. 46 CFR 108.425 - Fire hoses and associated equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Fire station hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch (38 millimeter) and...

  12. 33 CFR 183.540 - Hoses: Standards and markings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) SAE Standard J1527DEC85, Class 1 and the fire test in § 183.590; or (2) Underwriters' Laboratories... SAE Standard J1527DEC85, Class 2 and the fire test in § 183.590; (c) “USCG Type B1” hose means hose that meets the performance requirements of SAE Standard J1527DEC85, Class 1. (d) “USCG Type B2”...

  13. 33 CFR 183.540 - Hoses: Standards and markings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) SAE Standard J1527DEC85, Class 1 and the fire test in § 183.590; or (2) Underwriters' Laboratories... SAE Standard J1527DEC85, Class 2 and the fire test in § 183.590; (c) “USCG Type B1” hose means hose that meets the performance requirements of SAE Standard J1527DEC85, Class 1. (d) “USCG Type B2”...

  14. 46 CFR 97.37-15 - Fire hose stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Fire hose stations. 97.37-15 Section 97.37-15 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-15 Fire hose stations. (a) Each fire hydrant shall be identified in red letters and figures at least two inches high “FIRE STATION NO. 1,” “2,” “3,”...

  15. 46 CFR 97.37-15 - Fire hose stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Fire hose stations. 97.37-15 Section 97.37-15 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-15 Fire hose stations. (a) Each fire hydrant shall be identified in red letters and figures at least two inches high “FIRE STATION NO. 1,” “2,” “3,”...

  16. 30 CFR 18.65 - Flame test of hose.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen. (1) (2) Hose—four specimens each 6 inches long by 1/2-inch... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flame test of hose. 18.65 Section 18.65...

  17. 30 CFR 18.65 - Flame test of hose.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen. (1) (2) Hose—four specimens each 6 inches long by 1/2-inch... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Flame test of hose. 18.65 Section 18.65...

  18. Air Pressure Responses to Sudden Vocal Tract Pressure Bleeds during Production of Stop Consonants: New Evidence of Aeromechanical Regulation.

    ERIC Educational Resources Information Center

    Zajac, David J.; Weissler, Mark C.

    2004-01-01

    Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults…

  19. Respiratory and Laryngeal Responses to an Oral Air Pressure Bleed during Speech

    ERIC Educational Resources Information Center

    Huber, Jessica E.; Stathopoulos, Elaine T.

    2003-01-01

    Researchers have hypothesized that the respiratory and laryngeal speech subsystems would respond to an air pressure bleed, but these responses have not been empirically studied. The present study examined the nature of the responses of the respiratory and laryngeal subsystems to an air pressure bleed in order to provide information relevant to the…

  20. LESSONS LEARNED IN OPERATING THE HOSE-IN-HOSE SYSTEM FOR TRANSFSERRING SLUDGE AT HANFORDS K-BASINS

    SciTech Connect

    PERES MW

    2008-01-07

    In May 2007, the Department of Energy and the Fluor Hanford K Basin Closure Project completed transferring sludge from the K East Basin to new containers in the K West Basin using a Hose-in-Hose system. This project presented a number of complex and unique technical, operational, and management challenges that had to be resolved to complete the required transfers and satisfy project milestones. The project team (including DOE; regulators; and Fluor management, operations, maintenance, engineering and all other support organizations) found innovative solutions to each challenge. This paper records lessons learned during the operational phase of the sludge transfer via the Hose-In-Hose system. The subject is limited to the operational phase and does not cover design, development, testing or turnover. A discussion of the situation or problem encountered is provided, along with the lesson learned as applicable to a future program or project.

  1. High pressure flame system for pollution studies with results for methane-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Miller, I. M.; Maahs, H. G.

    1977-01-01

    A high pressure flame system was designed and constructed for studying nitrogen oxide formation in fuel air combustion. Its advantages and limitations were demonstrated by tests with a confined laminar methane air diffusion flame over the pressure range from 1 to 50 atm. The methane issued from a 3.06 mm diameter port concentrically into a stream of air contained within a 20.5 mm diameter chimney. As the combustion pressure is increased, the flame changes in shape from wide and convex to slender and concave, and there is a marked increase in the amount of luminous carbon. The height of the flame changes only moderately with pressure.

  2. A falling-pressure method for measuring air permeability of asphalt in laboratory

    NASA Astrophysics Data System (ADS)

    Li, Hailong; Jiao, Jiu Jimmy; Luk, Mario

    2004-01-01

    This paper presents a simple analytical solution for estimating air permeability using the test data obtained by a falling-pressure method in laboratory. The perimeter of the column-shaped sample is fixed in a steel cylinder with the upper sample surface open to the atmosphere. The lower surface of the sample and the cylinder form an air chamber. A water manometer is connected to the air chamber to measure the air pressure inside after the chamber is pressurized. The data of pressure versus time in the air chamber are recorded and analyzed. An approximate analytical solution is derived to describe the pressure-time relationship in the air chamber. The air permeability can be easily estimated using the approximate analytical solution based on the linear least-squares fitting to the recorded pressure-time test data. This method is used to estimate the falling-pressure test data of 15 asphalt samples. The agreement between the test data and the analytical prediction is satisfactory for all the samples. To investigate the error caused by the approximate analytical solution, the air permeabilities are also estimated based on fully numerical solutions. The permeability values obtained from analytical and numerical solutions are very close. The maximum relative error is less than 6% for samples with more than five pressure-time records. A quantitative condition is given under which the analytical solution applies with negligible estimation error. Compared with the common, steady-state method for measuring air permeability, the falling-pressure method has its advantages such as simplicity and economy. The steady-state method has to measure the air flux through the sample, while the falling-pressure method does not.

  3. Effect of air pressure differential on vapor flow through sample building walls

    SciTech Connect

    Stewart, W.E. Jr.

    1998-12-31

    Laboratory scale experiments were performed on two small sample composite walls of typical building construction to determine the approximate opposing air pressure difference required to stop or significantly reduce the transmission of water vapor due to a water vapor pressure difference. The experiments used wall section samples between two controlled atmosphere chambers. One chamber was held at a temperature and humidity condition approximating that of a typical summer day, while the other chamber was controlled at a condition typical of indoor conditioned space. Vapor transmission data through the wall samples were obtained over a range of vapor pressure differentials and opposing air pressure differentials. The results show that increasing opposing air pressure differences decrease water vapor transmission, as expected, and relatively small opposing air pressure differentials are required for wall materials of small vapor permeability and large air permeability. The opposing air pressure that stopped or significantly reduced the flow of water vapor through the wall sample was determined experimentally and also compared to air pressures as predicted by an analytical model.

  4. Biofilms on Hospital Shower Hoses: Characterization and ...

    EPA Pesticide Factsheets

    Although the source of drinking water used in hospitals is commonly, biofilms on water pipelines are refuge to bacteria that survive different disinfection strategies. Drinking water (DW) biofilms are well known to harbor opportunistic pathogens, however, these biofilm communities remain poorly characterized by culture-independent approaches that circumvent the limitations of conventional monitoring efforts. Hence, the frequency of pathogens in DW biofilms and how biofilm members withstand high doses of disinfectants and/or chlorine residuals in the water supply remain speculative, but directly impact public health. The aim of this study was to characterize the composition of microbial communities growing on five hospital shower hoses using both culture-dependent and culture-independent techniques. Two different sequence-based methods were used to characterize the bacterial fractions: 16S rRNA gene sequencing of bacterial cultures and next generation sequencing of metagenomes. Based on the metagenomic data, we found that Mycobacterium-like species was the abundant bacterial taxa that overlapped among the five samples. We also recovered the draft genome of a novel Mycobacterium species, closely related to opportunistic pathogenic nontuberculous mycobacteria, M. rhodesiae and M. tusciae, in addition to other, less abundant species. In contrast, the cultured fraction was mostly affiliated to Proteobacteria, such as members of the Sphingomonas, Blastomonas and Porph

  5. 29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., 1963. They shall be subjected to a hydrostatic pressure test of one and one-half times the working... quarterly by a competent person. They shall be subjected yearly to a hydrostatic pressure test of one and... 29 Labor 7 2012-07-01 2012-07-01 false Portable air receivers and other unfired pressure...

  6. 29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., 1963. They shall be subjected to a hydrostatic pressure test of one and one-half times the working... quarterly by a competent person. They shall be subjected yearly to a hydrostatic pressure test of one and... 29 Labor 7 2011-07-01 2011-07-01 false Portable air receivers and other unfired pressure...

  7. 29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., 1963. They shall be subjected to a hydrostatic pressure test of one and one-half times the working... quarterly by a competent person. They shall be subjected yearly to a hydrostatic pressure test of one and... 29 Labor 7 2013-07-01 2013-07-01 false Portable air receivers and other unfired pressure...

  8. 29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., 1963. They shall be subjected to a hydrostatic pressure test of one and one-half times the working... quarterly by a competent person. They shall be subjected yearly to a hydrostatic pressure test of one and... 29 Labor 7 2014-07-01 2014-07-01 false Portable air receivers and other unfired pressure...

  9. Insect hygroreceptor responses to continuous changes in humidity and air pressure

    PubMed Central

    Tichy, H.; Kallina, W.

    2011-01-01

    The most favored model of humidity transduction views the cuticular wall of insect hygroreceptive sensilla as a hygromechanical transducer. Hygroscopic swelling or shrinking alters the geometry of the wall, deforming the dendritic membranes of the moist and dry cells. The small size the sensilla and their position surrounded by elevated structures creates technical difficulties to mechanically stimulate them by direct contact. The present study investigated hygroreceptors on the antennae of the cockroach and the stick insect. Accurately controlled, homogeneous mechanical input was delivered by modulating air pressure. Both the moist and dry cells responded not only to changes in air pressure, but also in the opposite direction, as observed during changes in air humidity. The moist-cell’s excitatory response to increasing humidity and increasing air pressure implies that swelling of the hygroscopic cuticle compresses the dendrites, and the dry-cell’s excitatory response to decreasing humidity and decreasing air pressure implies that shrinking of the hygroscopic cuticle expands the dendrites. The moist and dry cells of the stick insect are more sensitive to pressure changes than those of the cockroach, but the responses to air pressure are generally weaker than to humidity. Therefore, the hygroreceptive sensilla differ in their physical properties and constitutions. Furthermore, the mechanical parameters associated with homogeneous changes in air pressure on the sensillum surface can only partially account for the responses of the moist and dry cells of both species to humidity stimulation. PMID:20375249

  10. Air Circulation and Heat Exchange Under Reduced Pressures

    NASA Technical Reports Server (NTRS)

    Rygalov, V.; Wheeler, R.; Dixon, M.; Fowler, P.; Hillhouse, L.

    2010-01-01

    Heat exchange rates decrease non-linearly with reductions in atmospheric pressure. This decrease creates risk of thermal stress (elevated leaf temperatures) for plants under reduced pressures. Forced convection (fans) significantly increases heat exchange rate under almost all pressures except below 10 kPa. Plant cultivation techniques under reduced pressures will require forced convection. The cooling curve technique is a reliable means of assessing the influence of environmental variables like pressure and gravity on gas exchange of plant. These results represent the extremes of gas exchange conditions for simple systems under variable pressures. In reality, dense plant canopies will exhibit responses in between these extremes. More research is needed to understand the dependence of forced convection on atmospheric pressure. The overall thermal balance model should include latent and radiative exchange components.

  11. Air humidity and water pressure effects on the performance of air-cathode microbial fuel cell cathodes

    NASA Astrophysics Data System (ADS)

    Ahn, Yongtae; Zhang, Fang; Logan, Bruce E.

    2014-02-01

    To better understand how air cathode performance is affected by air humidification, microbial fuel cells were operated under different humidity conditions or water pressure conditions. Maximum power density decreased from 1130 ± 30 mW m-2 with dry air to 980 ± 80 mW m-2 with water-saturated air. When the cathode was exposed to higher water pressures by placing the cathode in a horizontal position, with the cathode oriented so it was on the reactor bottom, power was reduced for both with dry (1030 ± 130 mW m-2) and water-saturated (390 ± 190 mW m-2) air. Decreased performance was partly due to water flooding of the catalyst, which would hinder oxygen diffusion to the catalyst. However, drying used cathodes did not improve performance in electrochemical tests. Soaking the cathode in a weak acid solution, but not deionized water, mostly restored performance (960 ± 60 mW m-2), suggesting that there was salt precipitation in the cathode that was enhanced by higher relative humidity or water pressure. These results showed that cathode performance could be adversely affected by both flooding and the subsequent salt precipitation, and therefore control of air humidity and water pressure may need to be considered for long-term MFC operation.

  12. Method and apparatus for monitoring oxygen partial pressure in air masks

    NASA Technical Reports Server (NTRS)

    Kelly, Mark E. (Inventor); Pettit, Donald R. (Inventor)

    2006-01-01

    Method and apparatus are disclosed for monitoring an oxygen partial pressure in an air mask and providing a tactile warning to the user. The oxygen partial pressure in the air mask is detected using an electrochemical sensor, the output signal from which is provided to a comparator. The comparator compares the output signal with a preset reference value or range of values representing acceptable oxygen partial pressures. If the output signal is different than the reference value or outside the range of values, the air mask is vibrated by a vibrating motor to alert the user to a potentially hypoxic condition.

  13. An objective definition of air mass types affecting Athens, Greece; the corresponding atmospheric pressure patterns and air pollution levels.

    PubMed

    Sindosi, O A; Katsoulis, B D; Bartzokas, A

    2003-08-01

    This work aims at defining characteristic air mass types that dominate in the region of Athens, Greece during the cold (November-March) and the warm (May-September) period of the year and also at evaluating the corresponding concentration levels of the main air pollutants. For each air mass type, the mean atmospheric pressure distribution (composite maps) over Europe and the Mediterranean is estimated in order to reveal the association of atmospheric circulation with air pollution levels in Athens. The data basis for this work consists of daily values of thirteen meteorological and six pollutant parameters covering the period 1993-97. The definition of the characteristic air mass types is attempted objectively by using the methods of Factor Analysis and Cluster Analysis. The results show that during the cold period of the year there are six prevailing air mass types (at least 3% of the total number of days) and six infrequent ones. The examination of the corresponding air pollution concentration levels shows that the primary air pollutants appear with increased concentrations when light or southerly winds prevail. This is usually the case when a high pressure system is located over the central Mediterranean or a low pressure system lays over south Italy, respectively. Low levels of the primary pollutants are recorded under northeasterly winds, mainly caused by a high pressure system over Ukraine. During the warm period of the year, the southwestern Asia thermal low and the subtropical anticyclone of the Atlantic Ocean affect Greece. Though these synoptic systems cause almost stagnant conditions, four main air mass types are dominant and ten others, associated with extreme weather, are infrequent. Despite the large amounts of total solar radiation characterizing this period, ozone concentrations remain at low levels in central Athens because of its destruction by nitric oxide.

  14. Velocity and pressure distribution behind bodies in an air current

    NASA Technical Reports Server (NTRS)

    Betz, A

    1924-01-01

    The following experiments on the air flow behind bodies were made for the purpose of assisting in the explanation of the phenomena connected with air resistance. The first two series of experiments dealt with the phenomena behind a cylinder. The third series of experiments was carried out behind a streamlined strut.

  15. Influence of air pressure on the performance of plasma synthetic jet actuator

    NASA Astrophysics Data System (ADS)

    Li, Yang; Jia, Min; Wu, Yun; Li, Ying-hong; Zong, Hao-hua; Song, Hui-min; Liang, Hua

    2016-09-01

    Plasma synthetic jet actuator (PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity. In this paper, the influence of the air pressure on the performance of a two-electrode PSJA is investigated by the schlieren method in a large range from 7 kPa to 100 kPa. The energy consumed by the PSJA is roughly the same for all the pressure levels. Traces of the precursor shock wave velocity and the jet front velocity vary a lot for different pressures. The precursor shock wave velocity first decreases gradually and then remains at 345 m/s as the air pressure increases. The peak jet front velocity always appears at the first appearance of a jet, and it decreases gradually with the increase of the air pressure. A maximum precursor shock wave velocity of 520 m/s and a maximum jet front velocity of 440 m/s are observed at the pressure of 7 kPa. The averaged jet velocity in one period ranges from 44 m/s to 54 m/s for all air pressures, and it drops with the rising of the air pressure. High velocities of the precursor shock wave and the jet front indicate that this type of PSJA can still be used to influence the high-speed flow field at 7 kPa. Project supported by the National Natural Science Foundation of China (Grant Nos. 51407197, 51522606, 51336011, 91541120, and 11472306).

  16. Firefighter's compressed air breathing system pressure vessel development program

    NASA Technical Reports Server (NTRS)

    Beck, E. J.

    1974-01-01

    The research to design, fabricate, test, and deliver a pressure vessel for the main component in an improved high-performance firefighter's breathing system is reported. The principal physical and performance characteristics of the vessel which were required are: (1) maximum weight of 9.0 lb; (2) maximum operating pressure of 4500 psig (charge pressure of 4000 psig); (3) minimum contained volume of 280 in. 3; (4) proof pressure of 6750 psig; (5) minimum burst pressure of 9000 psig following operational and service life; and (6) a minimum service life of 15 years. The vessel developed to fulfill the requirements described was completely sucessful, i.e., every category of performence was satisfied. The average weight of the vessel was found to be about 8.3 lb, well below the 9.0 lb specification requirement.

  17. Apparatus and methods for splicing conduits and hoses subsea

    SciTech Connect

    Slocum, Alexander Henry; Gutierrez, Luis Javier

    2014-03-11

    A hose connection system comprises a body including an internal cavity and a port in fluid communication with a portion of the internal cavity. In addition, the system comprises a hose end fitting positioned in the cavity. The hose end fitting includes an inner tubular member and an outer tubular member concentrically disposed about the inner tubular member. The outer tubular member includes a plurality of circumferentially spaced axial slits. Further, the system comprises a plurality of wedge members arranged circumferentially about the outer tubular member. Still further, the system comprises an annular piston movably disposed within the internal cavity of the body. An end of the piston has an inner frustoconical surface that slidingly engages the plurality of wedge members. The piston is configured to move axially through the body and compress the wedge members and the outer tubular member radially inward.

  18. Status of Plasma Electron Hose Instability Studies in FACET

    SciTech Connect

    Adli, Erik; England, Robert Joel; Frederico, Joel; Hogan, Mark; Li, Selina Zhao; Litos, Michael Dennis; Nosochkov, Yuri; An, Weiming; Mori, Warren; /UCLA

    2011-12-13

    In the FACET plasma-wakefield acceleration experiment a dense 23 GeV electron beam will interact with lithium and cesium plasmas, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons may lead to a fast growing electron hose instability. By using optics dispersion knobs to induce a controlled z-x tilt along the beam entering the plasma, we investigate the transverse behavior of the beam in the plasma as function of the tilt. We seek to quantify limits on the instability in order to further explore potential limitations on future plasma wakefield accelerators due to the electron hose instability. The FACET plasma-wakefield experiment at SLAC will study beam driven plasma wakefield acceleration. A dense 23 GeV electron beam will interact with lithium or cesium plasma, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons drives the electron hose instability, as first studied by Whittum. While Ref. [2] indicates the possibility of a large instability growth rate for typical beam and plasma parameters, other studies including have shown that several physical effects may mitigate the hosing growth rate substantially. So far there has been no quantitative benchmarking of experimentally observed hosing in previous experiments. At FACET we aim to perform such benchmarking by for example inducing a controlled z-x tilt along the beamentering the plasma, and observing the transverse behavior of the beam in the plasma as function. The long-term objective of these studies is to quantify potential limitations on future plasma wakefield accelerators due to the electron hose instability.

  19. The rate of pressure rise of gaseous propylene-air explosions in spherical and cylindrical enclosures.

    PubMed

    Razus, Domnina; Movileanua, Codina; Oancea, Dumitru

    2007-01-02

    The maximum rates of pressure rise of propylene-air explosions at various initial pressures and various fuel/oxygen ratios in three closed vessels (a spherical vessel with central ignition and two cylindrical vessels with central or with top ignition) are reported. It was found that in explosions of quiescent mixtures the maximum rates of pressure rise are linear functions on total initial pressure, at constant initial temperature and fuel/oxygen ratio. The slope and intercept of found correlations are greatly influenced by vessel's volume and shape and by the position of the ignition source--factors which determine the amount of heat losses from the burned gas in a closed vessel explosion. Similar data on propylene-air inert mixtures are discussed in comparison with those referring to propylene-air, revealing the influence of nature and amount of inert additive. The deflagration index KG of centrally ignited explosions was also calculated from maximum rates of pressure rise.

  20. The upper explosion limit of lower alkanes and alkenes in air at elevated pressures and temperatures.

    PubMed

    Van den Schoor, F; Verplaetsen, F

    2006-01-16

    The upper explosion limit (UEL) of ethane-air, propane-air, n-butane-air, ethylene-air and propylene-air mixtures is determined experimentally at initial pressures up to 30 bar and temperatures up to 250 degrees C. The experiments are performed in a closed spherical vessel with an internal diameter of 200 mm. The mixtures are ignited by fusing a coiled tungsten wire, placed at the centre of the vessel, by electric current. Flame propagation is said to have taken place if there is a pressure rise of at least 1% of the initial pressure after ignition of the mixture. In the pressure-temperature range investigated, a linear dependence of UEL on temperature and a bilinear dependence on pressure are found except in the vicinity of the auto-ignition range. A comparison of the UEL data of the lower alkanes shows that the UEL expressed as equivalence ratio (the actual fuel/air ratio divided by the stoichiometric fuel/air ratio) increases with increasing carbon number in the homologous series of alkanes.

  1. 46 CFR 32.50-30 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... REQUIREMENTS Pumps, Piping, and Hose for Cargo Handling § 32.50-30 Cargo hose—TB/ALL. Cargo hose carried on... head of the cargo pump or pump relief valve setting, less static head, but in no case less than 150 pounds per square inch. Note: For additional requirements concerning cargo hose, see 33 CFR 154.500,...

  2. 46 CFR 32.50-30 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... REQUIREMENTS Pumps, Piping, and Hose for Cargo Handling § 32.50-30 Cargo hose—TB/ALL. Cargo hose carried on... head of the cargo pump or pump relief valve setting, less static head, but in no case less than 150 pounds per square inch. Note: For additional requirements concerning cargo hose, see 33 CFR 154.500,...

  3. 46 CFR 167.45-15 - Capacity of pipes and hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-15 Capacity of pipes and hose. The capacity of the pipes and hose leading from the pumps shall in no case be less than that of the discharge opening of the pump: Provided, however, That the pipe and hose shall in no instance be less than...

  4. 46 CFR 32.50-30 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS Pumps, Piping, and Hose for Cargo Handling § 32.50-30 Cargo hose—TB/ALL. Cargo hose carried on... head of the cargo pump or pump relief valve setting, less static head, but in no case less than 150 pounds per square inch. Note: For additional requirements concerning cargo hose, see 33 CFR 154.500,...

  5. 46 CFR 32.50-30 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... REQUIREMENTS Pumps, Piping, and Hose for Cargo Handling § 32.50-30 Cargo hose—TB/ALL. Cargo hose carried on... head of the cargo pump or pump relief valve setting, less static head, but in no case less than 150 pounds per square inch. Note: For additional requirements concerning cargo hose, see 33 CFR 154.500,...

  6. 46 CFR 32.50-30 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... REQUIREMENTS Pumps, Piping, and Hose for Cargo Handling § 32.50-30 Cargo hose—TB/ALL. Cargo hose carried on... head of the cargo pump or pump relief valve setting, less static head, but in no case less than 150 pounds per square inch. Note: For additional requirements concerning cargo hose, see 33 CFR 154.500,...

  7. 33 CFR 150.532 - What are the requirements for connection and stowage of fire hoses?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... connection and stowage of fire hoses? 150.532 Section 150.532 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Miscellaneous Operations § 150.532 What are the requirements for connection and stowage... stowed on a hose rack. (c) The hydrant nearest the edge of a deck must have enough fire hose...

  8. 46 CFR 167.45-15 - Capacity of pipes and hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Capacity of pipes and hose. 167.45-15 Section 167.45-15... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-15 Capacity of pipes and hose. The capacity of the pipes and hose leading from the pumps shall in no case be less than that of the...

  9. 46 CFR 167.45-15 - Capacity of pipes and hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Capacity of pipes and hose. 167.45-15 Section 167.45-15... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-15 Capacity of pipes and hose. The capacity of the pipes and hose leading from the pumps shall in no case be less than that of the...

  10. 46 CFR 167.45-15 - Capacity of pipes and hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Capacity of pipes and hose. 167.45-15 Section 167.45-15... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-15 Capacity of pipes and hose. The capacity of the pipes and hose leading from the pumps shall in no case be less than that of the...

  11. 46 CFR 167.45-15 - Capacity of pipes and hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Capacity of pipes and hose. 167.45-15 Section 167.45-15... SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-15 Capacity of pipes and hose. The capacity of the pipes and hose leading from the pumps shall in no case be less than that of the...

  12. Alloys For Flexible Hoses In A Corrosive Environment

    NASA Technical Reports Server (NTRS)

    Macdowell, Louis G., III; Ontiveros, Cordelia

    1992-01-01

    High-nickel alloy resists pitting corrosion. Report evaluates metal alloys for flexible hoses in corrosive environment. Tested to find alternatives to 304L stainless steel. Nineteen alloys selected for testing on basis of reputation for resistance to corrosion. Top five, in order of decreasing resistance to corrosion: Hastelloy(R) C-22, Inconel(R) 625, Hastelloy(R) C-276, Hastelloy(R) C-4, and Inco(R) alloy G-3. Of these, Hastelloy(R) C-22 found best for flexible-hose application.

  13. Response of pulmonary veins to increased intracranial pressure and pulmonary air embolization

    SciTech Connect

    Peterson, B.T.; Grauer, S.E.; Hyde, R.W.; Ortiz, C.; Moosavi, H.; Utell, M.J.

    1980-01-01

    To see whether air emboli to the lungs rather than brain compression caused these findings, anesthetized dogs received intravenous air infusions, subdural air infusions, or brain compression from balloons inflated in the subdural space. Subdural air and intravenous air resulted in similar vascular responses. Pulmonary artery pressure (Ppa) increased 160% (P < 0.01) and pulmonary venous pressure transiently rose 13 +- 5 Torr (P < 0.05) without an increase in left atrial pressure or cardiac output (Q). The end-tidal PCP/sub 2/ fell 55% (P < 0.01) and the postmortem weight of the lungs increased 55% (P < 0.05). Brain compression with a subdural balloon instead of air only caused a 20% rise in Ppa and Q without pulmonary edema. Thus, pulmonary air emboli rather than brain compression accounts for the edema and pulmonary hypertension caused by subdural air. Catheters in pulmonary veins and the left atrium showed that air emboli cause transient pulmonary venous hypertension as well as a reproducible form of noncardiogenic pulmonary edema.

  14. Further experiments on the stability of laminar and turbulent hydrogen-air flames at reduced pressures

    NASA Technical Reports Server (NTRS)

    Fine, Burton

    1957-01-01

    Stability limits for laminar and turbulent hydrogen-air burner flames were measured as a function of pressure, burner diameter, and composition. On the basis of a simple flame model, turbulent flashback involved a smaller effective penetration distance than laminar flashback. No current theoretical treatment predicts the observed pressure and diameter dependence of laminar and turbulent blowoff.

  15. Variation of the pressure limits of flame propagation with tube diameter for propane-air mixtures

    NASA Technical Reports Server (NTRS)

    Belles, Frank E; Simon, Dorothy M

    1951-01-01

    An investigation was made of the variation of the pressure limits of flame propagation with tube diameter for quiescent propane with tube diameter for quiescent propane-air mixtures. Pressure limits were measured in glass tubes of six different inside diameters, with a precise apparatus. Critical diameters for flame propagation were calculated and the effect of pressure was determined. The critical diameters depended on the pressure to the -0.97 power for stoichiometric mixtures. The pressure dependence decreased with decreasing propane concentration. Critical diameters were related to quenching distance, flame speeds, and minimum ignition energy.

  16. Operation JANGLE. Project 1(9)a. Ground Acceleration, Ground and Air Pressures for Underground Test

    DTIC Science & Technology

    1952-04-01

    Salmon 0, April .1952 -0o So 0 * per telecon w/Betty Fox ( DNA Tech Libr, Chief), the classified references contained herein may remain. 6-Z I- 7...73 693 Earth Pr.essure . 77 6.4 Damage Criteria - Surface Stracture .... 78 6.5 D-miage Criteria - Underground Targets ... 8...ground pressures, and air pressures produced by a buried shallow) nuclear explosive. AU2 of these physical quantities are functions of at least two

  17. An experimental study of geyser-like flows induced by a pressurized air pocket

    NASA Astrophysics Data System (ADS)

    Elayeb, I. S.; Leon, A.; Choi, Y.; Alnahit, A. O.

    2015-12-01

    Previous studies argues that the entrapment of pressurized air pockets within combined sewer systems can produce geyser flows, which is an oscillating jetting of a mixture of gas-liquid flows. To verify that pressurized air pockets can effectively produce geysers, laboratory experiments were conducted. However, past experiments were conducted in relatively small-scale apparatus (i.e. maximum φ2" vertical shaft). This study conducted a set of experiments in a larger apparatus. The experimental setup consists of an upstream head tank, a downstream head tank, a horizontal pipe (46.5ft long, φ6") and a vertical pipe (10ft long, φ6"). The initial condition for the experiments is constant flow discharge through the horizontal pipe. The experiments are initiated by injecting an air pocket with pre-determined volume and pressure at the upstream end of the horizontal pipe. The air pocket propagates through the horizontal pipe until it arrives to the vertical shaft, where it is released producing a geyser-like flow. Three flow rates in the horizontal pipe and three injected air pressures were tested. The variables measured were pressure at two locations in the horizontal pipe and two locations in the vertical pipe. High resolution videos at two regions in the vertical shaft were also recorded. To gain further insights in the physics of air-water interaction, the laboratory experiments were complemented with numerical simulations conducted using a commercial 3D CFD model, previously validated with experiments.

  18. Plain-jet airblast atomization of alternative liquid petroleum fuels under high ambient air pressure conditions

    NASA Astrophysics Data System (ADS)

    Jasuja, A. K.

    1982-04-01

    The effects that air and fuel properties have upon the spray mean drop size characteristics of a plain-jet airblast atomizer of the type employed in the gas turbine engine are investigated. The tests used kerosene, gas oil and a high-viscosity blend of gas oil in residual fuel oil, and covered a wide range of ambient air pressures. Laser light-scattering technique was employed for drop size measurements. It is concluded that the atomizer's measured mean drop size characteristics are only slightly different from those of the pre-filming type, especially when operating on low-viscosity kerosene under higher ambient air pressure. The beneficial effect of increased levels of ambient air pressure on mean drop size is shown to be much reduced in the case of high-viscosity fuels, thus making the attainment of good atomization performance on such fuels difficult. An expression is derived for correlating the obtained mean drop size data.

  19. Preliminary investigation of cooling-air ejector performance at pressure ratios from 1 to 10

    NASA Technical Reports Server (NTRS)

    Ellis, C W; Hollister, D P; Sargent, A F , Jr

    1951-01-01

    Preliminary investigation was made of conical cooling air ejector at primary pressure ratios from 1 to 10. The cooling-air flow was maintained at zero and the resulting pressure variation in the shroud indicated pumping ability. The cooling-air flow was maintained at zero and the resulting pressure variation in the shroud indicated pumping ability. The gross thrust of the ejector and nozzle were compared. Several ratios of the spacing between the nozzle and shroud exit to the nozzle exit diameter were investigated for several shroud to nozzle exit diameter ratios. Maximum gross thrust loss occurred under conditions of zero cooling-air flow and was as much as 35 percent below nozzle jet thrust. For minimum thrust loss, ejector should be designed with as low diameter and spacing ratio as possible.

  20. Air pressure waves from Mount St. Helens eruptions

    NASA Astrophysics Data System (ADS)

    Reed, Jack W.

    1987-10-01

    Infrasonic recordings of the pressure wave from the Mount St. Helens (MSH) eruption on May 18, 1980, together with the weather station barograph records were used to estimate an equivalent explosion airblast yield for this eruption. Pressure wave amplitudes versus distance patterns were found to be comparable with patterns found for a small-scale nuclear explosion, the Krakatoa eruption, and the Tunguska comet impact, indicating that the MSH wave came from an explosion equivalent of about 5 megatons of TNT. The peculiar audibility pattern reported, with the blast being heard only at ranges beyond about 100 km, is explained by consideration of finite-amplitude shock propagation developments.

  1. Numerical simulation of high pressure release and dispersion of hydrogen into air with real gas model

    NASA Astrophysics Data System (ADS)

    Khaksarfard, R.; Kameshki, M. R.; Paraschivoiu, M.

    2010-06-01

    Hydrogen is a renewable and clean source of energy, and it is a good replacement for the current fossil fuels. Nevertheless, hydrogen should be stored in high-pressure reservoirs to have sufficient energy. An in-house code is developed to numerically simulate the release of hydrogen from a high-pressure tank into ambient air with more accuracy. Real gas models are used to simulate the flow since high-pressure hydrogen deviates from ideal gas law. Beattie-Bridgeman and Abel Noble equations are applied as real gas equation of state. A transport equation is added to the code to calculate the concentration of the hydrogen-air mixture after release. The uniqueness of the code is to simulate hydrogen in air release with the real gas model. Initial tank pressures of up to 70 MPa are simulated.

  2. 60. Same view, showing technicians hosing down the timbers. Shortly ...

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

    60. Same view, showing technicians hosing down the timbers. Shortly after this photograph was made, the timbers were completely submerged in water, held down by heavy concrete castings. - Wabash & Erie Canal, Lock No. 2, 8 miles east of Fort Wayne, adjacent to U.S. Route 24, New Haven, Allen County, IN

  3. 46 CFR 98.25-80 - Cargo hose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Cargo hose. 98.25-80 Section 98.25-80 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  4. 46 CFR 98.25-80 - Cargo hose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Cargo hose. 98.25-80 Section 98.25-80 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  5. 46 CFR 98.25-80 - Cargo hose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Cargo hose. 98.25-80 Section 98.25-80 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  6. 46 CFR 98.25-80 - Cargo hose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Cargo hose. 98.25-80 Section 98.25-80 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  7. 46 CFR 98.25-80 - Cargo hose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Cargo hose. 98.25-80 Section 98.25-80 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  8. Ultra High Pressure Air Properties and CFD Code

    DTIC Science & Technology

    2007-02-28

    than the inconsistencies. To incorporate property consistency in the reconstructed results we use bivariate polynomials of the form 22 23, z(x,.y)= jjq...times faster while the maximum advantage occurs for air where reconstruction is as much as 2500 times faster. The savings achieved by the reconstruction...refined to the deepest level) Table II Column Information in Table I Column Heading Information I Fluid Fluid Type 2 Zone Zone 3 Max Err Maximum error of

  9. Infrasound Sensor and Porous-Hose Filter Characterization Results

    NASA Astrophysics Data System (ADS)

    Hart, D. M.; Harris, J. M.

    2008-12-01

    The Ground-Based Nuclear Explosion Monitoring Research and Development (GNEM R&D) program at Sandia National Laboratories (SNL) is regarded as the primary center for unbiased expertise in testing and evaluation of geophysical sensors and instrumentation for nuclear explosion monitoring. Over the past year much of our work has focused in the area of infrasound sensor characterization through the continuing development of an infrasound sensor characterization test-bed. Our main areas of focus have been in new sensor characterization and understanding the effects of porous-hose filters for reducing acoustic background signals. Three infrasound sensors were evaluated for characteristics of instrument response, linearity and self-noise. The sensors tested were Chaparral Physics model 2.5 low-gain, New Mexico Tech All-Sensor and the Inter-Mountain Labs model SS avalanche sensor. For the infrasound sensors tested, the test results allow us to conclude that two of the three sensors had sufficiently quiet noise floor to be at or below the Acoustic low-noise model from 0.1 to 7 Hz, which make those sensors suitable to explosion monitoring. The other area of focus has been to understand the characteristics of porous-hose filters used at some monitoring sites. For this, an experiment was designed in which two infrasound sensors were co- located. One sensor was connected to a typical porous-hose spatial filter consisting of eight individual hoses covering a 30m aperture and the second sensor was left open to unimpeded acoustic input. Data were collected for several days, power spectrum computed for two-hour windows and the relative gain of the porous-hose filters were estimated by dividing the power spectrum. The porous-hose filter appears to attenuate less than 3 dB (rel 1 Pa**2/Hz) below 0.1 Hz and as much as 25 dB at 1 Hz and between 20 to 10 dB above 10 Hz. Several more experiments will be designed to address the effects of different characteristics of the individual porous-hoses

  10. Air bubble migration rates as a proxy for bubble pressure distribution in ice cores

    NASA Astrophysics Data System (ADS)

    Dadic, Ruzica; Schneebeli, Martin; Bertler, Nancy

    2015-04-01

    Air bubble migration can be used as a proxy to measure the pressure of individual bubbles and can help constrain the gradual close-off of gas bubbles and the resulting age distribution of gases in ice cores. The close-off depth of single bubbles can vary by tens of meters, which leads to a distribution of pressures for bubbles at a given depth. The age distribution of gases (along with gas-age-ice-age differences) decreases the resolution of the gas level reconstructions from ice cores and limits our ability to determine the phase relationship between gas and ice, and thus, the impact of rapid changes of greenhouse gases on surface temperatures. For times of rapid climate change, including the last 150 years, and abrupt climate changes further back in the past, knowledge of the age distribution of the gases trapped in air bubbles will enable us to refine estimates of atmospheric changes. When a temperature gradient is applied to gas bubbles in an ice sample, the bubbles migrate toward warmer ice. This motion is caused by sublimation from the warm wall and subsequent frost deposition on the cold wall. The migration rate depends on ice temperature and bubble pressure and is proportional to the temperature gradient. The spread in migration rates for bubbles in the same samples at given temperatures should therefore reflect the variations in bubble pressures within a sample. Air bubbles with higher pressures would have been closed off higher in the firn column and thus have had time to equilibrate with the surrounding ice pressure, while air bubbles that have been closed off recently would have pressures that are similar to todays atmospheric pressure above the firn column. For ice under pressures up to ~13-16 bar, the pressure distribution of bubbles from a single depth provides a record of the trapping function of air bubbles in the firn column for a certain time in the past. We will present laboratory experiments on air bubble migration, using Antarctic ice core

  11. A novel target-type low pressure drop bidirectional optoelectronic air flow sensor for infant artificial ventilation: Measurement principle and static calibration

    NASA Astrophysics Data System (ADS)

    Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio

    2011-02-01

    An optoelectronic target-type volumetric air flow-rate transducer for bidirectional measurements is presented. The sensor is composed of a T-shaped target and two nominally identical LED-photodiode couples which are operated in differential mode. The sensitive surfaces of the photodiodes are differentially shadowed by the deflection of the target, which in turn depends on the gas flow-rate. The principle of operation is described in mathematical terms and the design parameters have been optimized in order to obtain the highest sensitivity along with minimal pressure drop and reduced dimensions. The sensor is placed in a 20 mm diameter hose and was tested with air flow-rate in the typical temperature range of mechanical ventilation between 20 and 40 °C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min-1. The nonlinear behavior allows sensitivities equal to 0.6 V l-1 min for flow rates ranging from -2.0 to +2.0 l min-1, equal to 2.0 V l-1 min for flow rates ranging from -3.0 to -2.0 l min-1 and from +2.0 to +3.0 l min-1, up to 5.7 V l-1 min at higher flow rates ranging from -7.0 to -3.0 l min-1 and from +3.0 to +7.0 l min-1. The linear range extends from 3.0 to 7.0 l min-1 with constant sensitivity equal to 5.7 V l-1 min. The sensor is able to detect a flow-rate equal to 1.0 l min-1 with a sensitivity of about 400 mV l-1 min. The differential nature of the output minimizes the influence of the LEDs' power supply variations and allows to obtain a repeatability in the order of 3% of full scale output. The small pressure drop produced by the sensor placed in-line the fluid stream, of about 2.4 Pa at 7 l min-1, corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l-1 min.

  12. A novel target-type low pressure drop bidirectional optoelectronic air flow sensor for infant artificial ventilation: Measurement principle and static calibration

    SciTech Connect

    Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio

    2011-02-15

    An optoelectronic target-type volumetric air flow-rate transducer for bidirectional measurements is presented. The sensor is composed of a T-shaped target and two nominally identical LED-photodiode couples which are operated in differential mode. The sensitive surfaces of the photodiodes are differentially shadowed by the deflection of the target, which in turn depends on the gas flow-rate. The principle of operation is described in mathematical terms and the design parameters have been optimized in order to obtain the highest sensitivity along with minimal pressure drop and reduced dimensions. The sensor is placed in a 20 mm diameter hose and was tested with air flow-rate in the typical temperature range of mechanical ventilation between 20 and 40 deg. C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min{sup -1}. The nonlinear behavior allows sensitivities equal to 0.6 V l{sup -1} min for flow rates ranging from -2.0 to +2.0 l min{sup -1}, equal to 2.0 V l{sup -1} min for flow rates ranging from -3.0 to -2.0 l min{sup -1} and from +2.0 to +3.0 l min{sup -1}, up to 5.7 V l{sup -1} min at higher flow rates ranging from -7.0 to -3.0 l min{sup -1} and from +3.0 to +7.0 l min{sup -1}. The linear range extends from 3.0 to 7.0 l min{sup -1} with constant sensitivity equal to 5.7 V l{sup -1} min. The sensor is able to detect a flow-rate equal to 1.0 l min{sup -1} with a sensitivity of about 400 mV l{sup -1} min. The differential nature of the output minimizes the influence of the LEDs' power supply variations and allows to obtain a repeatability in the order of 3% of full scale output. The small pressure drop produced by the sensor placed in-line the fluid stream, of about 2.4 Pa at 7 l min{sup -1}, corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l{sup -1} min.

  13. A novel target-type low pressure drop bidirectional optoelectronic air flow sensor for infant artificial ventilation: measurement principle and static calibration.

    PubMed

    Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio

    2011-02-01

    An optoelectronic target-type volumetric air flow-rate transducer for bidirectional measurements is presented. The sensor is composed of a T-shaped target and two nominally identical LED-photodiode couples which are operated in differential mode. The sensitive surfaces of the photodiodes are differentially shadowed by the deflection of the target, which in turn depends on the gas flow-rate. The principle of operation is described in mathematical terms and the design parameters have been optimized in order to obtain the highest sensitivity along with minimal pressure drop and reduced dimensions. The sensor is placed in a 20 mm diameter hose and was tested with air flow-rate in the typical temperature range of mechanical ventilation between 20 and 40 °C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min(-1). The nonlinear behavior allows sensitivities equal to 0.6 V l(-1) min for flow rates ranging from -2.0 to +2.0 l min(-1), equal to 2.0 V l(-1) min for flow rates ranging from -3.0 to -2.0 l min(-1) and from +2.0 to +3.0 l min(-1), up to 5.7 V l(-1) min at higher flow rates ranging from -7.0 to -3.0 l min(-1) and from +3.0 to +7.0 l min(-1). The linear range extends from 3.0 to 7.0 l min(-1) with constant sensitivity equal to 5.7 V l(-1) min. The sensor is able to detect a flow-rate equal to 1.0 l min(-1) with a sensitivity of about 400 mV l(-1) min. The differential nature of the output minimizes the influence of the LEDs' power supply variations and allows to obtain a repeatability in the order of 3% of full scale output. The small pressure drop produced by the sensor placed in-line the fluid stream, of about 2.4 Pa at 7 l min(-1), corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l(-1) min.

  14. Downhole steam generator using low pressure fuel and air supply

    DOEpatents

    Fox, Ronald L.

    1983-01-01

    An apparatus for generation of steam in a borehole for penetration into an earth formation wherein a spiral, tubular heat exchanger is used in the combustion chamber to isolate the combustion process from the water being superheated for conversion into steam. The isolation allows combustion of a relatively low pressure oxidant and fuel mixture for generating high enthalpy steam. The fuel is preheated by feedback of combustion gases from the top of the combustion chamber through a fuel preheater chamber. The hot exhaust gases of combustion at the bottom of the combustion chamber, after flowing over the heat exchanger enter an exhaust passage and pipe. The exhaust pipe is mounted inside the water supply line heating the water flowing into the heat exchanger. After being superheated in the heat exchanger, the water is ejected through an expansion nozzle and converts into steam prior to penetration into the earth formation. Pressure responsive doors are provided at a steam outlet downstream of the nozzle and close when the steam pressure is lost due to flameout.

  15. Torricelli and the Ocean of Air: The First Measurement of Barometric Pressure

    PubMed Central

    2013-01-01

    The recognition of barometric pressure was a critical step in the development of environmental physiology. In 1644, Evangelista Torricelli described the first mercury barometer in a remarkable letter that contained the phrase, “We live submerged at the bottom of an ocean of the element air, which by unquestioned experiments is known to have weight.” This extraordinary insight seems to have come right out of the blue. Less than 10 years before, the great Galileo had given an erroneous explanation for the related problem of pumping water from a deep well. Previously, Gasparo Berti had filled a very long lead vertical tube with water and showed that a vacuum formed at the top. However, Torricelli was the first to make a mercury barometer and understand that the mercury was supported by the pressure of the air. Aristotle stated that the air has weight, although this was controversial for some time. Galileo described a method of measuring the weight of the air in detail, but for reasons that are not clear his result was in error by a factor of about two. Torricelli surmised that the pressure of the air might be less on mountains, but the first demonstration of this was by Blaise Pascal. The first air pump was built by Otto von Guericke, and this influenced Robert Boyle to carry out his classical experiments of the physiological effects of reduced barometric pressure. These were turning points in the early history of high-altitude physiology. PMID:23455767

  16. Torricelli and the ocean of air: the first measurement of barometric pressure.

    PubMed

    West, John B

    2013-03-01

    The recognition of barometric pressure was a critical step in the development of environmental physiology. In 1644, Evangelista Torricelli described the first mercury barometer in a remarkable letter that contained the phrase, "We live submerged at the bottom of an ocean of the element air, which by unquestioned experiments is known to have weight." This extraordinary insight seems to have come right out of the blue. Less than 10 years before, the great Galileo had given an erroneous explanation for the related problem of pumping water from a deep well. Previously, Gasparo Berti had filled a very long lead vertical tube with water and showed that a vacuum formed at the top. However, Torricelli was the first to make a mercury barometer and understand that the mercury was supported by the pressure of the air. Aristotle stated that the air has weight, although this was controversial for some time. Galileo described a method of measuring the weight of the air in detail, but for reasons that are not clear his result was in error by a factor of about two. Torricelli surmised that the pressure of the air might be less on mountains, but the first demonstration of this was by Blaise Pascal. The first air pump was built by Otto von Guericke, and this influenced Robert Boyle to carry out his classical experiments of the physiological effects of reduced barometric pressure. These were turning points in the early history of high-altitude physiology.

  17. A change for the better? Measuring improvements in upgraded alternating-pressure air mattresses.

    PubMed

    Rithalia, S V; Heath, G H

    2000-10-01

    This study used measurements of interface pressure over time (the pressure relief index) to investigate improvements made to two alternating-pressure air mattresses. Two older models, the Nimbus 2 (Huntleigh Technology) and Pegasus Airwave (Pegasus Egerton), were compared with two new versions, the Nimbus 3 and Cairwave systems, respectively. Pressure relief was improved in seven out of 12 areas in the Nimbus 3 system, and in four out of 12 areas in the Cairwave. Significant differences in pressure relief index measurements at the heel between the Nimbus 3 and Cairwave products may explain the former's better clinical outcomes in this area, but superior pressure relief index performance at the sacrum did not predict better clinical outcomes. Therefore, different levels of pressure relief may be needed at different body sites. Individual practitioners must decide whether these improvements merit list price increases of 11% and 15%, respectively, and whether other features justify a 20% price difference between the two new systems.

  18. Thermodynamic and Transport Properties of Real Air Plasma in Wide Range of Temperature and Pressure

    NASA Astrophysics Data System (ADS)

    Wang, Chunlin; Wu, Yi; Chen, Zhexin; Yang, Fei; Feng, Ying; Rong, Mingzhe; Zhang, Hantian

    2016-07-01

    Air plasma has been widely applied in industrial manufacture. In this paper, both dry and humid air plasmas' thermodynamic and transport properties are calculated in temperature 300-100000 K and pressure 0.1-100 atm. To build a more precise model of real air plasma, over 70 species are considered for composition. Two different methods, the Gibbs free energy minimization method and the mass action law method, are used to determinate the composition of the air plasma in a different temperature range. For the transport coefficients, the simplified Chapman-Enskog method developed by Devoto has been applied using the most recent collision integrals. It is found that the presence of CO2 has almost no effect on the properties of air plasma. The influence of H2O can be ignored except in low pressure air plasma, in which the saturated vapor pressure is relatively high. The results will serve as credible inputs for computational simulation of air plasma. supported by the National Key Basic Research Program of China (973 Program)(No. 2015CB251002), National Natural Science Foundation of China (Nos. 51521065, 51577145), the Science and Technology Project Funds of the Grid State Corporation (SGTYHT/13-JS-177), the Fundamental Research Funds for the Central Universities, and State Grid Corporation Project (GY71-14-004)

  19. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    SciTech Connect

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue Fang, Jing

    2015-10-15

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  20. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    NASA Astrophysics Data System (ADS)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue; Fang, Jing

    2015-10-01

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  1. Measured pressure distributions of large-angle cones in hypersonic flows of tetrafluoromethane, air, and helium

    NASA Technical Reports Server (NTRS)

    Jones, R. A.; Hunt, J. L.

    1973-01-01

    An experimental study of surface pressure distributions on a family of blunt and sharp large angle cones was made in hypersonic flows of helium, air, and tetrafluoromethane. The effective isentropic exponents of these flows were 1.67, 1.40, and 1.12. Thus, the effect of large shock density ratios such as might be encountered during planetary entry because of real-gas effects could be studied by comparing results in tetrafluoromethane with those in air and helium. It was found that shock density ratio had a large effect on both shock shape and pressure distribution. The differences in pressure distribution indicate that for atmospheric flight at high speed where real-gas effects produce large shock density ratios, large-angle cone vehicles can be expected to experience different trim angles of attack, drag coefficient, and lift-drag ratios than those for ground tests in air wind tunnels.

  2. Hydraulic Resistance and Liberation of Air in Aviation Kerosene Flow Through Diaphragms at Low Pressure

    NASA Astrophysics Data System (ADS)

    Kitanin, É. L.; Kitanina, E. É.; Zherebtsov, V. A.; Peganova, M. M.; Stepanov, S. G.; Bondarenko, D. A.; Morisson, D.

    2016-09-01

    This paper presents the results of experimental investigations of the liberation of air in gravity flow of aviation fuel through a pipeline with diaphragms. Experiments were carried out in the pressure range 0.2-1.0 bar and temperature range -20 to +20°C. The TC-1 kerosene was preliminarily saturated with air at atmospheric pressure. The liberation of air after the diaphragms with three ratios of the flow area to the cross-sectional area of the pipeline has been investigated. The results of investigations of the two-phase flow in several experimental pipelines containing one or two diaphragms and other local hydraulic resistances have been generalized. The obtained approximation equations permit calculating the hydraulic resistance of the diaphragm in the two-phase flow and the mass gas content of air after the diaphragm in pipelines of complex geometry.

  3. Atmospheric-pressure air microplasma jets in aqueous media for the inactivation of Pseudomonas fluorescens cells

    SciTech Connect

    Zhang, Xianhui; Yang, Si-ze; Liu, Dongping; Song, Ying; Sun, Yue

    2013-05-15

    The hollow fiber-based cold air microplasma jet array running at atmospheric pressure has been designed to inactivate Pseudomonas fluorescens (P. fluorescens) cells in vitro in aqueous media. The influences of electrode configurations, air flow rate, and applied voltage on the discharge characteristics of the single microplasma jet operating in aqueous media are presented, and the bactericidal efficiency of the hollow fibers-based and large-volume microplasma jet array is reported. Optical emission spectroscopy is utilized to identify excited species during the antibacterial testing of plasma in solutions. These well-aligned and rather stable air microplasma jets containing a variety of short-lived species, such as OH and O radicals and charged particles, are in direct contact with aqueous media and are very effective in killing P. fluorescens cells in aqueous media. This design shows its potential application for atmospheric pressure air plasma inactivation of bacteria cells in aqueous media.

  4. Air pressure waves from Mount St. Helens eruptions

    SciTech Connect

    Reed, J.W.

    1980-01-01

    Barograms from a number of National Weather Service stations were assembled for the May 18, 1980, eruption and compared to airblast wave propagations from large explosions. Wave amplitudes at 50 to 300 km distances were about what might be expected from a nuclear explosion of between 1 megaton and 10 megaton yield. Pressure-time signatures could not be resolved for the first compression phase, because of the slow paper recording speed. The 900 s negative phase duration was much too long for comparison with the negative phase of an explosion. Nevertheless, positive and negative amplitudes were about equal, as often observed at long distances from explosions. Calculations have been made for a simple finite amplitude propagation model. These show rough bounds on the source compression rate, to give the observed inaudible waves at least to 54 km distance, yet cause audibly rapid compression at Seattle, near 150 km, and beyond.

  5. Characterization of the respiratory and heart beat signal from an air pressure-based ballistocardiographic setup.

    PubMed

    Willemen, Tim; Van Deun, Dorien; Verhaert, Vincent; Van Huffel, Sabine; Haex, Bart; Vander Sloten, Jos

    2014-01-01

    Off-body detection of respiratory and cardiac activity presents an enormous opportunity for general health, stress and sleep quality monitoring. The presented setup detects the mechanical activity of both heart and lungs by measuring pressure difference fluctuations between two air volumes underneath the chest area of the subject. The registered signals were characterized over four different sleep postures, three different base air pressures within the air volumes and three different mattress top layer materials. Highest signal strength was detected in prone posture for both the respiratory and heart beat signal. Respiratory signal strength was the lowest in supine posture, while heart beat signal strength was lowest for right lateral. Heart beat cycle variability was highest in prone and lowest in supine posture. Increasing the base air pressure caused a reduction in signal amplitude for both the respiratory and the heart beat signal. A visco-elastic poly-urethane foam top layer had significantly higher respiration amplitude compared to high resilient poly-urethane foam and latex foam. For the heart beat signal, differences between the top layers were small. The authors conclude that, while the influence of the mattress top layer material is small, the base air pressure can be tuned for optimal mechanical transmission from heart and lungs towards the registration setup.

  6. Experimental study of pulsed corona discharge in air at high pressures

    NASA Astrophysics Data System (ADS)

    Lin, Yunghsu; Singleton, Dan; Sanders, Jason; Kuthi, Andras; Gundersen, Martin A.

    2012-10-01

    Understanding of the dynamics of nanosecond scale pulse discharges in air at multiatmospheric pressure is essential for the development of transient plasma enhanced combustion in internal combustion engines. Here we report the result of our experimental investigation of cathode-directed streamer discharges in synthetic air at pressures ranging from 1 to 20 bar. Two pulse generators with maximum pulse amplitudes of 50 kV and 65 kV, pulse width of approximately 12 ns and 85 ns and pulse rise times of 5 ns and 50 ns are used to generate streamers. The electrodes are coaxial with various radial gaps up to 11.75 mm. The discharge chamber is evacuated and backfilled with synthetic dry air at room temperature. Optical data is obtained from PI-MAX 3 ICCD camera with 3 ns gate width. The streamer propagation velocity variation with applied voltage, different pressures and reduced electric field, E/P, will be shown. Preliminary results indicate that the (pd) similarity law is violated at high pressures in agreement with other recent experiments [1].[4pt] [1] ``Nanosecond Scale Discharge Dynamics in High Pressure Air,'' Pierre Tardiveau, Nicolas Moreau, Francois Jorand, Christian Postel, St'ephane Pasquiers, and Pierre Vervisch, IEEE Trans. on Plasma Sci., Vol. 36, No. 4, 2008.

  7. Simplified configuration for the combustor of an oil burner using a low pressure, high flow air-atomizing nozzle

    DOEpatents

    Butcher, Thomas A.; Celebi, Yusuf; Fisher, Leonard

    2000-09-15

    The invention relates to clean burning of fuel oil with air. More specifically, to a fuel burning combustion head using a low-pressure, high air flow atomizing nozzle so that there will be a complete combustion of oil resulting in a minimum emission of pollutants. The improved fuel burner uses a low pressure air atomizing nozzle that does not result in the use of additional compressors or the introduction of pressurized gases downstream, nor does it require a complex design. Inventors:

  8. Pressure-loss and flow coefficients inside a chordwise-finned, impingement, convection, and film air-cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Hippensteele, S. A.

    1974-01-01

    Total-pressure-loss coefficients, flow discharge coefficients, and friction factors were determined experimentally for the various area and geometry changes and flow passages within an air-cooled turbine vane. The results are compared with those of others obtained on similar configurations, both actual and large models, of vane passages. The supply and exit air pressures were controlled and varied. The investigation was conducted with essentially ambient-temperature air and without external flow of air over the vane.

  9. GSOD Based Daily Global Mean Surface Temperature and Mean Sea Level Air Pressure (1982-2011)

    SciTech Connect

    Xuan Shi, Dali Wang

    2014-05-05

    This data product contains all the gridded data set at 1/4 degree resolution in ASCII format. Both mean temperature and mean sea level air pressure data are available. It also contains the GSOD data (1982-2011) from NOAA site, contains station number, location, temperature and pressures (sea level and station level). The data package also contains information related to the data processing methods

  10. Investigation of Ozone Yield of Air Fed Ozonizer by High Pressure Homogeneous Dielectric Barrier Discharge

    DTIC Science & Technology

    2013-07-01

    homogeneous dielectric barrier discharge ( DBD ) in dry air by using a simple DBD device. So far, we have tried to apply the homogeneous DBD to an...specific input energy region. In this work, we investigated the effect of gas pressure (from 0.1 MPa to 0.2 MPa) on the ozone yield by homogeneous DBD . The...homogeneous DBD decreased with increasing the gas pressure. 1. Introduction The dielectric barrier discharge ( DBD ) is composed of many filamentary micro

  11. Effects of hydraulic pressure on the performance of single chamber air-cathode microbial fuel cells.

    PubMed

    Cheng, Shaoan; Liu, Weifeng; Guo, Jian; Sun, Dan; Pan, Bin; Ye, Yaoli; Ding, Weijun; Huang, Haobin; Li, Fujian

    2014-06-15

    Scaling up of microbial fuel cells (MFCs) without losing power density requires a thorough understanding of the effect of hydraulic pressure on MFC performance. In this work, the performance of an activated carbon air-cathode MFC was evaluated under different hydraulic pressures. The MFC under 100 mmH2O hydraulic pressure produced a maximum power density of 1260 ± 24 mW m(-2), while the power density decreased by 24.4% and 44.7% as the hydraulic pressure increased to 500 mmH2O and 2000 mmH2O, respectively. Notably, the performance of both the anode and the cathode had decreased under high hydraulic pressures. Electrochemical impedance spectroscopy tests of the cathode indicated that both charge transfer resistance and diffusion transfer resistance increased with the increase in hydraulic pressure. Denaturing gradient gel electrophoresis of PCR-amplified partial 16S rRNA genes demonstrated that the similarity among anodic biofilm communities under different hydraulic pressures was ≥ 90%, and the communities of all MFCs were dominated by Geobacter sp. These results suggested that the reduction in power output of the single chamber air-cathode MFC under high hydraulic pressures can be attributed to water flooding of the cathode and suppression the metabolism of anodic exoelectrogenic bacteria.

  12. Ambient Air Pollution and Increases in Blood Pressure: Role ...

    EPA Pesticide Factsheets

    Particulate matter (PM) is a complex mixture of extremely small particles and liquid droplets made up of a number of components including elemental carbon, organic chemicals, metals, acids (such as nitrates and sulfates), and soil and dust particles. Epidemiological studies consistently show that exposure to PM in urban areas across the globe is associated with increases in short- and long-term cardiovascular mortality and morbidity, most notably for myocardial infarction, heart failure and ischemic stroke.1 The range in strength of these associations is likely related to variation in PM sources and composition across space and time, and attests to the need to understand the contribution of specific sources to ultimately inform regulatory, public health and clinical strategies to reduce risk. Commentary: In 2014 a systematic review and meta-analysis published in this journal reported a positive association between short-term exposure to PM2.5 and blood pressure.2 The paper discussed potential mechanisms including PM-induced activation of pulmonary nociceptive receptors, pulmonary inflammatory responses and release of endothelin-1, and suggested that activation of pulmonary receptors and vagal afferents could lead to shifts in autonomic balance and vasoconstriction. Other effects including oxidative stress and decreased NO availability, as well as systemic inflammation and endothelial dysfunction have also been widely reported in association with PM compo

  13. Characteristics of short dc glow microdischarges in atmospheric pressure air

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, Anatoly

    2013-09-01

    The main reason that high pressure current-carrying plasmas tend to be unstable is various instability (primarily thermal) of the positive column (PC). So a promising approach is to use short (without PC) discharges that have growing voltage-current characteristic (VAC). These discharges are ignited near the minimum of the Paschen breakdown curve Lmin and it usually have a gap pL <10-20 cm Torr when a distinct PC is absent. In this report the most stable microdischarges were burning with a flat cathode and rounded (or thin rod) anode, which located to a distance less than Lmin when the microdischarge ``choose'' their length itself, so that to match the stable work near Lmin by changing their binding on the anode. For simulations we used 2D hybrid model. Simulations predicted the main regions of the dc glow discharges including cathode and anode sheath and plasma of negative glow, Faraday dark space and transition region, in which the electric field is distributed no uniformly and plasma is nonlocal. Gas heating plays an important role in shaping the discharge profiles. Work supported by FZP and SPbSU.

  14. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... test; Type C supplied-air respirator, pressure-demand class; minimum requirements. (a) The static...) per minute shall not exceed the static pressure in the facepiece by more than 51 mm. (2 inches)...

  15. Effect of pressure on structure and NO sub X formation in CO-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Maahs, H. G.; Miller, I. M.

    1979-01-01

    A study was made of nitric oxide formation in a laminar CO-air diffusion flame over a pressure range from 1 to 50 atm. The carbon monoxide (CO) issued from a 3.06 mm diameter port coaxially into a coflowing stream of air confined within a 20.5 mm diameter chimney. Nitric oxide concentrations from the flame were measured at two carbon monoxide (fuel) flow rates: 73 standard cubic/min and 146 sccm. Comparison of the present data with data in the literature for a methane-air diffusion flame shows that for flames of comparable flame height (8 to 10 mm) and pseudoequivalence ratio (0.162), the molar emission index of a CO-air flame is significantly greater than that of a methane-air flame.

  16. Liquid Rocket Lines, Bellows, Flexible Hoses, and Filters

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Fluid-flow components in a liquid propellant rocket engine and the rocket vehicle which it propels are interconnected by lines, bellows, and flexible hoses. Elements involved in the successful design of these components are identified and current technologies pertaining to these elements are reviewed, assessed, and summarized to provide a technology base for a checklist of rules to be followed by project managers in guiding a design or assessing its adequacy. Recommended procedures for satisfying each of the design criteria are included.

  17. [Effects of sudden air temperature and pressure changes on mortality in the Czech Republic].

    PubMed

    Plavcová, E; Kyselý, J

    2009-04-01

    We have developed an algorithm for identifying sudden changes in air pressure and temperature over the Czech Republic. Such events were retrieved from the data covering in 1986-2005 and were matched with the daily numbers of all-cause deaths and deaths due to cardiovascular diseases from the national database, separately for the whole population and that aged 70 years and over. Excess daily mortality was determined by calculating deviations of the observed number of deaths from the expected number of deaths for each day in the respective groups. The relative deviation of the mortality the mean was calculated as the ratio of the excess mortality to the expected number of deaths. We used 3-hour air pressure data from 10 meteorological stations and hourly air temperature data from 9 stations representative of the Czech Republic. Pressure changes were evaluated on time scales of 3, 6 and 12 hours, separately for summer and winter time. Temperature changes were evaluated on a 24-hour time scale, separately for summer and winter season. Events characterized by pressure or temperature changes above the critical threshold and recorded within 24 hours at more than 50% of meteorological stations were retrieved. The critical thresholds were defined separately for each station using quantiles of distributions of air pressure and temperature changes. Relative mortality deviations for days D-2 (2 days before the change) to D+7 (7 days after the change) were averaged over the retrieved events. Statistical significance of the mean relative deviation was tested using the Monte Carlo method. Increased mortality followed large temperature increases and large pressure drops both in summer and winter months. Decreased mortality was observed after large pressure increases and large temperature drops in summer. Mortality variations are usually more pronounced in the population aged 70 years and over, and cardiovascular diseases account for most deaths after sudden temperature changes.

  18. 49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Warning signals, air pressure and vacuum gauges... and vacuum gauges. (a) General Rule. Every bus, truck and truck tractor, except as provided in.... (d) Vacuum brakes. A commercial motor vehicle (regardless of the date it was manufactured)...

  19. 49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Warning signals, air pressure and vacuum gauges... and vacuum gauges. (a) General Rule. Every bus, truck and truck tractor, except as provided in.... (d) Vacuum brakes. A commercial motor vehicle (regardless of the date it was manufactured)...

  20. The Determination of the Percent of Oxygen in Air Using a Gas Pressure Sensor

    ERIC Educational Resources Information Center

    Gordon, James; Chancey, Katherine

    2005-01-01

    The experiment of determination of the percent of oxygen in air is performed in a general chemistry laboratory in which students compare the results calculated from the pressure measurements obtained with the calculator-based systems to those obtained in a water-measurement method. This experiment allows students to explore a fundamental reaction…

  1. SOIL-AIR PERMEABILITY MEASUREMENT WITH A TRANSIENT PRESSURE BUILDUP METHOD

    EPA Science Inventory

    An analytical solution for transient pressure change in a single venting well was derived from mass conservation of air, Darcy's law of flow in porous media, and the ideal gas law equation of state. Slopes of plots of Pw2 against ln (t+Δt)/Δt similar to Homer's plot were used to ...

  2. Acute Effects of Continuous Positive Air way Pressure on Pulse Pressure in Chronic Heart Failure

    PubMed Central

    Quintão, Mônica; Chermont, Sérgio; Marchese, Luana; Brandão, Lúcia; Bernardez, Sabrina Pereira; Mesquita, Evandro Tinoco; Rocha, Nazareth de Novaes; Nóbrega, Antônio Claudio L.

    2014-01-01

    Background Patients with heart failure (HF) have left ventricular dysfunction and reduced mean arterial pressure (MAP). Increased adrenergic drive causes vasoconstriction and vessel resistance maintaining MAP, while increasing peripheral vascular resistance and conduit vessel stiffness. Increased pulse pressure (PP) reflects a complex interaction of the heart with the arterial and venous systems. Increased PP is an important risk marker in patients with chronic HF (CHF). Non-invasive ventilation (NIV) has been used for acute decompensated HF, to improve congestion and ventilation through both respiratory and hemodynamic effects. However, none of these studies have reported the effect of NIV on PP. Objective The objective of this study was to determine the acute effects of NIV with CPAP on PP in outpatients with CHF. Methods Following a double-blind, randomized, cross-over, and placebo-controlled protocol, twenty three patients with CHF (17 males; 60 ± 11 years; BMI 29 ± 5 kg/cm2, NYHA class II, III) underwent CPAP via nasal mask for 30 min in a recumbent position. Mask pressure was 6 cmH2O, whereas placebo was fixed at 0-1 cmH2O. PP and other non invasive hemodynamics variables were assessed before, during and after placebo and CPAP mode. Results CPAP decreased resting heart rate (Pre: 72 ± 9; vs. Post 5 min: 67 ± 10 bpm; p < 0.01) and MAP (CPAP: 87 ± 11; vs. control 96 ± 11 mmHg; p < 0.05 post 5 min). CPAP decreased PP (CPAP: 47 ± 20 pre to 38 ± 19 mmHg post; vs. control: 42 ± 12 mmHg, pre to 41 ± 18 post p < 0.05 post 5 min). Conclusion NIV with CPAP decreased pulse pressure in patients with stable CHF. Future clinical trials should investigate whether this effect is associated with improved clinical outcome. PMID:24676373

  3. Air Purification Effect of Positively and Negatively Charged Ions Generated by Discharge Plasma at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Nishikawa, Kazuo; Nojima, Hideo

    2001-08-01

    In this paper, the air purification effect of positively and negatively charged ions generated by discharge plasma at atmospheric pressure is reported. We have developed a novel ion generation device which consists of a cylindrical glass tube and attached inner and outer mesh electrodes. With the application of AC voltage between the electrodes, positively charged ions and negatively charged ions have been generated at atmospheric pressure. The ion densities of 3.0× 104--7.0× 104 counts/cm3 have been obtained with the AC voltage of 1.8-2.3 kV (effective value). We have examined the air purification properties of this device. By the operation of this device, the initial oxygen nitride (NO) density of 10 ppm in 1 m3 (in cigarette smoke) was decreased to 1 ppm after 30 min. The number of suspended germs in air has been significantly reduced by the use of this type of ion generation device.

  4. An investigation of air solubility in Jet A fuel at high pressures

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1981-01-01

    Problems concerned with the supercritical injection concept are discussed. Supercritical injection involves dissolving air into a fuel prior to injection. A similar effect is obtained by preheating the fuel so that a portion of the fuel flashes when its pressure is reduced. Flashing improves atomization properties and the presence of air in the primary zone of a spray flame reduces the formation of pollutants. The investigation is divided into three phases: (1) measure the solubility and density properties of fuel/gas mixtures, including Jet A/air, at pressures and correlate these results using theory; (2) investigate the atomization properties of flashing liquids, including fuel/dissolved gas systems. Determine and correlate the effect of inlet properties and injector geometry on mass flow rates, Sauter mean diameter and spray angles; (3) examine the combustion properties of flashing injection in an open burner flame, considering flame shape and soot production.

  5. Layers of air in the water beneath the floating fern Salvinia are exposed to fluctuations in pressure.

    PubMed

    Mayser, Matthias J; Barthlott, Wilhelm

    2014-12-01

    Superhydrophobic, hierarchically structured, technical surfaces (Lotus-effect) are of high scientific and economic interest because of their remarkable properties. Recently, the immense potential of air-retaining superhydrophobic surfaces, for example, for low-friction transport of fluids and drag-reducing coatings of ships has begun to be explored. A major problem of superhydrophobic surfaces mimicking the Lotus-effect is the limited persistence of the air retained, especially under rough conditions of flow. However, there are a variety of floating or diving plant and animal species that possess air-retaining surfaces optimized for durable water-repellency (Salvinia-effect). Especially floating ferns of the genus Salvinia have evolved superhydrophobic surfaces capable of maintaining layers of air for months. Apart from maintaining stability under water, the layer of air has to withstand the stresses of water pressure (up to 2.5 bars). Both of these aspects have an application to create permanent air layers on ships' hulls. We investigated the effect of pressure on air layers in a pressure cell and exposed the air layer to pressures of up to 6 bars. We investigated the suppression of the air layer at increasing pressures as well as its restoration during decreases in pressure. Three of the four examined Salvinia species are capable of maintaining air layers at pressures relevant to the conditions applying to ships' hulls. High volumes of air per surface area are advantageous for retaining at least a partial Cassie-Baxter-state under pressure, which also helps in restoring the air layer after depressurization. Closed-loop structures such as the baskets at the top of the "egg-beater hairs" (see main text) also help return the air layer to its original level at the tip of the hairs by trapping air bubbles.

  6. 46 CFR 35.40-17 - Foam hose/monitor stations-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Foam hose/monitor stations-T/ALL. 35.40-17 Section 35.40... Requirements-TB/ALL. § 35.40-17 Foam hose/monitor stations—T/ALL. (a) At each required foam hose/monitor valve there shall be marked in not less than 2-inch red letters and figures: “FOAM STATION 1,” 2, 3, etc. (b)...

  7. Subsonic tests of an all-flush-pressure-orifice air data system

    NASA Technical Reports Server (NTRS)

    Larson, T. J.; Siemers, P. M., III

    1981-01-01

    The use of an all-flush-pressure-orifice array as a subsonic air data system was evaluated in flight and wind tunnel tests. Two orifice configurations were investigated. Both used orifices arranged in a cruciform pattern on the airplane nose. One configuration also used orifices on the sides of the fuselage for a source of static pressure. The all-nose-orifice configuration was similar to the shuttle entry air data system (SEADS). The flight data were obtained with a KC-135A airplane. The wind tunnel data were acquired with a 0.035-scale model of the KC-135A airplane. With proper calibration, several orifices on the vertical centerline of the vehicle's nose were found to be satisfactory for the determination of total pressure and angle of attack. Angle of sideslip could be accurately determined from pressure measurements made on the horizontal centerline of the aircraft. Orifice pairs were also found that provided pressure ratio relationships suitable for the determination of Mach number. The accuracy that can be expected for the air data determined with SEADS during subsonic orbiter flight is indicated.

  8. On Static Pressure Fluctuation between Sirocco Fan Blades in a Car Air-Conditioning System

    NASA Astrophysics Data System (ADS)

    Sakai, Yasuhiko; Kato, Takaaki; Moriguchi, Yuu; Sakai, Masaharu; Ito, Kouji; Mitsuishi, Yasushi; Nagata, Kouji; Kubo, Takashi

    In this study, special attention is directed to static pressure fluctuation in a sirocco fan for a car air-conditioning system, because it is expected that there is a close connection between the fluid noise and the pressure fluctuation. The final purpose of this study is to clarify the relationship between the static pressure fluctuation between fan blades and the sound noise emitted to the outside of the fan, and to develop an air-conditioning system with highly low noise level. For this purpose, first of all, a new micro probe for the measurement of static pressure fluctuation has been developed. This new micro probe is composed of an L-type static pressure tube (the outer diameter is 0.5 mm and the inner diameter is 0.34 mm) and a very small pressure transducer. This probe exhibits a flat frequency response until approximately 2,000 Hz, and it is set between the blades of the fan rotating at 1,500 rpm. The measurements of the static pressure fluctuation between the blades have been performed, and the intensity of sound source was quantified from the second derivative of the phase-averaged static pressure fluctuation signals on the basis of Ribner's formula (Ribner 1962). The experiments have been made in two different modes, i.e., the cooling mode (FACE MODE) and the heating mode (FOOT MODE). It is shown that the static pressure increases rapidly as the blade approaches to the nose of the casing. It is also found that the sound source for FACE MODE shows the larger value than that for FOOT MODE as a whole. In particular, the largest intensity of sound source is observed when the blade approaches to the nose. From these results, it is confirmed that the present new static pressure probe is useful to specify the distributions of sound source in a sirocco fan.

  9. Acute changes in pulse pressure in relation to constituents of particulate air pollution in elderly persons

    SciTech Connect

    Jacobs, Lotte; Buczynska, Anna; Walgraeve, Christophe; Delcloo, Andy; Potgieter-Vermaak, Sanja; Van Grieken, Rene; Demeestere, Kristof; Dewulf, Jo; Van Langenhove, Herman; De Backer, Hugo; Nemery, Benoit; Nawrot, Tim S.

    2012-08-15

    An increased pulse pressure (difference between systolic and diastolic blood pressure) suggests aortic stiffening. The objective of this study was to examine the acute effects of both particulate matter (PM) mass and composition on blood pressure, among elderly persons. We carried out a panel study in persons living in elderly homes in Antwerp, Belgium. We recruited 88 non-smoking persons, 70% women with a mean age of 83 years (standard deviation: 5.2). Blood pressure was measured and a blood sample was collected on two time points, which were chosen so that there was an exposure contrast in ambient PM exposure. The elemental content of the collected indoor and outdoor PM{sub 2.5} (particulate matter with an aerodynamic diameter <2.5 {mu}m) mass concentration was measured. Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) on outdoor PM{sub 10} (particulate matter with an aerodynamic diameter <10 {mu}m) were measured. Each interquartile range increase of 20.8 {mu}g/m Superscript-Three in 24-h mean outdoor PM{sub 2.5} was associated with an increase in pulse pressure of 4.0 mmHg (95% confidence interval: 1.8-6.2), in persons taking antihypertensive medication (n=57), but not in persons not using antihypertensive medication (n=31) (p for interaction: 0.02). Vanadium, iron and nickel contents of PM{sub 2.5} were significantly associated with systolic blood pressure and pulse pressure, among persons on antihypertensive medication. Similar results were found for indoor concentrations. Of the oxy-PAHs, chrysene-5,6-dione and benzo[a]pyrene-3,6-dione were significantly associated with increases in systolic blood pressure and pulse pressure. In elderly, pulse pressure was positively associated with acute increases in outdoor and indoor air pollution, among persons taking antihypertensive medication. These results might form a mechanistic pathway linking air pollution as a trigger of cardiovascular events.

  10. Effect of Air Pressure and Gutter Angle on Flame Stability and DeZubay Number for Methane-Air Combustion

    NASA Astrophysics Data System (ADS)

    Boopathi, S.; Maran, P.

    2017-04-01

    The combustion at high speed reactants requires a flame holding characteristics to sustain the flame in the afterburner. The flame holding characteristics of the combustor is carried out by the bluff-body stabilizers. The range of conditions of parameters influencing the flame stabilization is to be identified and the effects on the flame sustainability have to be investigated. DeZubay used the concept of DeZubay number and flame stability envelope to determine the stabilization and blowout range. In the present work, the effect of air pressure and the angle of apex of the V-gutter on flame stabilization and blowout mechanism have been experimentally investigated for six different apex angles and four different air pressure conditions. The value of DeZubay number at each condition has been calculated and verified with DeZubay stability chart for flame stabilization. The results show that stable flame is obtained for the entire pressure range when the apex angle of the V gutter is in 60° and 90°.

  11. PTV analysis of the entrained air into the diesel spray at high-pressure injection

    NASA Astrophysics Data System (ADS)

    Toda, Naoki; Yamashita, Hayato; Mashida, Makoto

    2014-08-01

    In order to clarify the effect of high-pressure injection on soot reduction in terms of the air entrainment into spray, the air flow surrounding the spray and set-off length indicating the distance from the nozzle tip to the flame region in diffusion diesel combustion were investigated using 300MPa injection of a multi-hole injector. The measurement of the air entrainment flow was carried out at non-evaporating condition using consecutive PTV (particle tracking velocimetry) method with a high-speed camera and a high-frequency pulse YAG laser. The set-off length was measured at highpressure and high-temperature using the combustion bomb of constant volume and optical system of shadow graph method. And the amount of air entrainment into spray until reaching set-off length in diffusion combustion was studied as a factor of soot formation.

  12. Time evolution of nanosecond runaway discharges in air and helium at atmospheric pressure

    SciTech Connect

    Yatom, S.; Vekselman, V.; Krasik, Ya. E.

    2012-12-15

    Time- and space-resolved fast framing photography was employed to study the discharge initiated by runaway electrons in air and He gas at atmospheric pressure. Whereas in the both cases, the discharge occurs in a nanosecond time scale and its front propagates with a similar velocity along the cathode-anode gap, the later stages of the discharge differ significantly. In air, the main discharge channels develop and remain in the locations with the strongest field enhancement. In He gas, the first, diode 'gap bridging' stage, is similar to that obtained in air; however, the development of the discharge that follows is dictated by an explosive electron emission from micro-protrusions on the edge of the cathode. These results allow us to draw conclusions regarding the different conductivity of the plasma produced in He and air discharges.

  13. A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor

    ERIC Educational Resources Information Center

    Amrani, D.

    2013-01-01

    This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

  14. Calibrating airborne measurements of airspeed, pressure and temperature using a Doppler laser air-motion sensor

    NASA Astrophysics Data System (ADS)

    Cooper, W. A.; Spuler, S. M.; Spowart, M.; Lenschow, D. H.; Friesen, R. B.

    2014-09-01

    A new laser air-motion sensor measures the true airspeed with a standard uncertainty of less than 0.1 m s-1 and so reduces uncertainty in the measured component of the relative wind along the longitudinal axis of the aircraft to about the same level. The calculated pressure expected from that airspeed at the inlet of a pitot tube then provides a basis for calibrating the measurements of dynamic and static pressure, reducing standard uncertainty in those measurements to less than 0.3 hPa and the precision applicable to steady flight conditions to about 0.1 hPa. These improved measurements of pressure, combined with high-resolution measurements of geometric altitude from the global positioning system, then indicate (via integrations of the hydrostatic equation during climbs and descents) that the offset and uncertainty in temperature measurement for one research aircraft are +0.3 ± 0.3 °C. For airspeed, pressure and temperature, these are significant reductions in uncertainty vs. those obtained from calibrations using standard techniques. Finally, it is shown that although the initial calibration of the measured static and dynamic pressures requires a measured temperature, once calibrated these measured pressures and the measurement of airspeed from the new laser air-motion sensor provide a measurement of temperature that does not depend on any other temperature sensor.

  15. Study of flow fields induced by surface dielectric barrier discharge actuator in low-pressure air

    SciTech Connect

    Che, Xueke E-mail: st@mail.iee.ac.cn; Nie, Wansheng; Tian, Xihui; Hou, Zhiyong; He, Haobo; Zhou, Penghui; Zhou, Siyin; Yang, Chao; Shao, Tao E-mail: st@mail.iee.ac.cn

    2014-04-15

    Surface dielectric barrier discharge (SDBD) is a promising method for a flow control. Flow fields induced by a SDBD actuator driven by the ac voltage in static air at low pressures varying from 1.0 to 27.7 kPa are measured by the particle image velocimetry method. The influence of the applied ac voltage frequency and magnitude on the induced flow fields is studied. The results show that three different classes of flow fields (wall jet flow field, complex flow field, and vortex-shape flow field) can be induced by the SDBD actuator in the low-pressure air. Among them, the wall jet flow field is the same as the tangential jet at atmospheric pressure, which is, together with the vertical jet, the complex flow field. The vortex-shape flow field is composed of one vertical jet which points towards the wall and two opposite tangential jets. The complex and the vortex-shape flow fields can be transformed to the wall jet flow field when the applied ac voltage frequency and magnitude are changed. It is found that the discharge power consumption increases initially, decreases, and then increases again at the same applied ac voltage magnitude when the air pressure decreases. The tangential velocity of the wall jet flow field increases when the air pressure decreases. It is however opposite for the complex flow field. The variation of the applied ac voltage frequency influences differently three different flow fields. When the applied ac voltage magnitude increases at the same applied ac voltage frequency, the maximal jet velocity increases, while the power efficiency increases only initially and then decreases again. The discharge power shows either linear or exponential dependences on the applied ac voltage magnitude.

  16. Elevated Plasma Endothelin-1 and Pulmonary Arterial Pressure in Children Exposed to Air Pollution

    PubMed Central

    Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J.; Reed, William

    2007-01-01

    Background Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. Objectives The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O3 that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. Methods We conducted a study of 81 children, 7.9 ± 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O3 levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Results Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 μm in aerodynamic diameter (PM2.5) before endothelin-1 measurement (p = 0.03). Conclusions Chronic exposure of children to PM2.5 is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure. PMID:17687455

  17. Bronchomotor response to cold air or helium-oxygen at normal and high ambient pressures.

    PubMed

    Jammes, Y; Burnet, H; Cosson, P; Lucciano, M

    1988-05-01

    Effects of inhalation of cold air or helium-oxygen mixture on lung resistance (RL) were studied in anesthetized and tracheotomized rabbits under normal ambient pressure and in human volunteers under normo- and hyperbaric conditions. In artificially ventilated rabbits, an increase in RL occurred when the tracheal temperature fell to 10 degrees C. This effect was more than double with helium breathing compared to air, despite a lower respiratory heat loss by convection (Hc) with helium. In 3 normal humans, inhalation of cold air (mouth temperature = 8 degrees C) at sea level had no effect on RL value. However, with a helium-nitrogen-oxygen mixture, a weak but significant increase in RL due to cold gas breathing was measured in 1 subject at 2 ATA and in 2 individuals at 3.5 ATA. The density of inhaled gas mixture (air or He-N2-O2) was near the same in the three circumstances (1, 2, and 3.5 ATA) but Hc value increased with helium. At 8 ATA a 30-55% increase in RL occurred in the 3 divers during inhalation of cold gas (Hc was multiplied by 6 compared to air at sea level) and at 25 ATA the cold-induced bronchospasm ranged between 38 and 95% (Hc multiplied by 27). Thus, in rabbits and humans helium breathing enhanced the cold-induced increase in RL at normal or elevated ambient pressure, and this effect was interpreted as resulting from different mechanisms in the two circumstances.

  18. Heat transfer and pressure drop for air flow through enhanced passages. Final report

    SciTech Connect

    Obot, N.T.; Esen, E.B.

    1992-06-01

    An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

  19. Heat transfer and pressure drop for air flow through enhanced passages

    SciTech Connect

    Obot, N.T.; Esen, E.B.

    1992-06-01

    An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

  20. Long-Term Air Pollution Exposure and Blood Pressure in the Sister Study

    PubMed Central

    Chan, Stephanie H.; Van Hee, Victor C.; Bergen, Silas; Szpiro, Adam A.; DeRoo, Lisa A.; London, Stephanie J.; Marshall, Julian D.; Sandler, Dale P.

    2015-01-01

    Background Exposure to air pollution has been consistently associated with cardiovascular morbidity and mortality, but mechanisms remain uncertain. Associations with blood pressure (BP) may help to explain the cardiovascular effects of air pollution. Objective We examined the cross-sectional relationship between long-term (annual average) residential air pollution exposure and BP in the National Institute of Environmental Health Sciences’ Sister Study, a large U.S. cohort study investigating risk factors for breast cancer and other outcomes. Methods This analysis included 43,629 women 35–76 years of age, enrolled 2003–2009, who had a sister with breast cancer. Geographic information systems contributed to satellite-based nitrogen dioxide (NO2) and fine particulate matter (≤ 2.5 μm; PM2.5) predictions at participant residences at study entry. Generalized additive models were used to examine the relationship between pollutants and measured BP at study entry, adjusting for cardiovascular disease risk factors and including thin plate splines for potential spatial confounding. Results A 10-μg/m3 increase in PM2.5 was associated with 1.4-mmHg higher systolic BP (95% CI: 0.6, 2.3; p < 0.001), 1.0-mmHg higher pulse pressure (95% CI: 0.4, 1.7; p = 0.001), 0.8-mmHg higher mean arterial pressure (95% CI: 0.2, 1.4; p = 0.01), and no significant association with diastolic BP. A 10-ppb increase in NO2 was associated with a 0.4-mmHg (95% CI: 0.2, 0.6; p < 0.001) higher pulse pressure. Conclusions Long-term PM2.5 and NO2 exposures were associated with higher blood pressure. On a population scale, such air pollution–related increases in blood pressure could, in part, account for the increases in cardiovascular disease morbidity and mortality seen in prior studies. Citation Chan SH, Van Hee VC, Bergen S, Szpiro AA, DeRoo LA, London SJ, Marshall JD, Kaufman JD, Sandler DP. 2015. Long-term air pollution exposure and blood pressure in the Sister Study. Environ Health

  1. Effect of Different Levels of Pressure Relieving Air-Mattress Firmness on Cough Strength.

    PubMed

    Kamikawa, Norimichi; Taito, Shunsuke; Takahashi, Makoto; Sekikawa, Kiyokazu; Hamada, Hironobu

    2016-01-01

    Cough is an important host-defense mechanism. The elderly and patients who are severely ill cannot cough effectively when lying in the supine position. Furthermore, pressure relieving air-mattresses are recommended for preventing the development of pressure ulcers. In this study, we clarified whether or not the cough peak flow (CPF), an index of cough strength, is affected by different firmness levels of a pressure relieving air-mattress in healthy volunteers in the supine position. Fifty-two healthy young men participated. All the measurements were carried out on each participant in the supine position on a pressure relieving air-mattress. The participants were assessed at two firmness levels, a "hard" and "soft" mode. The CPF, forced vital capacity (FVC), maximal expiratory pressure (PEmax), and maximal inspiratory pressure (PImax) were determined for each mode. The sinking distance of the body into the mattress was measured without any activity and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax, and PImax were determined for each mode. The sinking distance of the body into the mattress was measured and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax and PImax values of the participants coughing on the mattress were significantly lower when the mattress was in "soft" than in "hard" mode. The differences between the sinking distances of the mattress in "soft" and "hard" modes were larger for the anterior superior iliac spine. A harder mattress may lead to increased CPF in healthy young men lying in the supine position, and increased CPF may be important for host defense.

  2. Influence of air pressure on the detailed characteristics of corona current pulse due to positive corona discharge

    NASA Astrophysics Data System (ADS)

    Li, Xuebao; Cui, Xiang; Lu, Tiebing; Li, Dayong; Chen, Bo; Fu, Yuke

    2016-12-01

    Air pressure is one of the main factors affecting the corona discharge and influence of air pressure should be carefully investigated. In order to obtain the influence of air pressure on the detailed characteristics of corona current pulse, such as pulse amplitude, rise time, pulse width, duration time, and pulse repetition frequency, a systematic investigation is carried out though a coaxial conductor-cylinder electrode structure with a corona point on the conductor. The electrodes are put into a pressure chamber for adjusting the air pressure. The results show that pulse amplitude increases with the increase of air pressure, while rise time, pulse width, duration time, and pulse repetition frequency decrease significantly at the same ratio between applied voltage and onset voltage (U/U0). Empirical formulas for the pulse amplitude, rise time, pulse width, and duration time varying with air pressure are first established. On the basis of the development of positive corona discharge, the influence of air pressure on the typical time intervals and experimental results are qualitatively explained.

  3. Calibrating airborne measurements of airspeed, pressure and temperature using a Doppler laser air-motion sensor

    NASA Astrophysics Data System (ADS)

    Cooper, W. A.; Spuler, S. M.; Spowart, M.; Lenschow, D. H.; Friesen, R. B.

    2014-03-01

    A new laser air-motion sensor measures the true airspeed with an uncertainty of less than 0.1 m s-1 (standard error) and so reduces uncertainty in the measured component of the relative wind along the longitudinal axis of the aircraft to about the same level. The calculated pressure expected from that airspeed at the inlet of a pitot tube then provides a basis for calibrating the measurements of dynamic and static pressure, reducing standard-error uncertainty in those measurements to less than 0.3 hPa and the precision applicable to steady flight conditions to about 0.1 hPa. These improved measurements of pressure, combined with high-resolution measurements of geometric altitude from the Global Positioning System, then indicate (via integrations of the hydrostatic equation during climbs and descents) that the offset and uncertainty in temperature measurement for one research aircraft are +0.3 ± 0.3 °C. For airspeed, pressure and temperature these are significant reductions in uncertainty vs. those obtained from calibrations using standard techniques. Finally, it is shown that the new laser air-motion sensor, combined with parametrized fits to correction factors for the measured dynamic and ambient pressure, provides a measurement of temperature that is independent of any other temperature sensor.

  4. Experimental Study on a Standing Wave Thermoacoustic Prime Mover with Air Working Gas at Various Pressures

    NASA Astrophysics Data System (ADS)

    Setiawan, Ikhsan; Achmadin, Wahyu N.; Murti, Prastowo; Nohtomi, Makoto

    2016-04-01

    Thermoacoustic prime mover is an energy conversion device which converts thermal energy into acoustic work (sound wave). The advantages of this machine are that it can work with air as the working gas and does not produce any exhaust gases, so that it is environmentally friendly. This paper describes an experimental study on a standing wave thermoacoustic prime mover with air as the working gas at various pressures from 0.05 MPa to 0.6 MPa. We found that 0.2 MPa is the optimum pressure which gives the lowest onset temperature difference of 355 °C. This pressure value would be more preferable in harnessing low grade heat sources to power the thermoacoustic prime mover. In addition, we find that the lowest onset temperature difference is obtained when rh /δ k ratio is 2.85, where r h is the hydraulic radius of the stack and δ k is the thermal penetration depth of the gas. Moreover, the pressure amplitude of the sound wave is significantly getting larger from 2.0 kPa to 9.0 kPa as the charged pressure increases from 0.05 MPa up to 0.6 MPa.

  5. Emission measurements for a lean premixed propane/air system at pressures up to 30 atmospheres

    NASA Technical Reports Server (NTRS)

    Roffe, G.; Venkataramani, K. S.

    1978-01-01

    The emissions of a lean premixed system of propane/air were measured in a flametube apparatus. Tests were conducted at inlet temperatures of 600K and 800K and pressures of 10 atm and 30 atm over a range of equivalence ratios. The data obtained were combined with previous data taken in the same apparatus to correlate nitrogen oxide emissions with operating conditions. Sampling probe design was found to have a pronounced effect on measured CO levels but did not influence measurements. The most effective probe tested was one which combined thermal and pressure quenching of the gas sample.

  6. Investigation of air solubility in jet A fuel at high pressures

    NASA Technical Reports Server (NTRS)

    Rupprecht, S. D.; Faeth, G. M.

    1981-01-01

    The solubility and density properties of saturated mixtures of fuels and gases were measured. The fuels consisted of Jet A and dodecane, the gases were air and nitrogen. The test range included pressures of 1.03 to 10.34 MPa and temperatures of 298 to 373 K. The results were correlated successfully, using the Soave equation of state. Over this test range, dissolved gas concentrations were roughly proportional to pressure and increased slightly with increasing temperature. Mixture density was relatively independent of dissolved gas concentration.

  7. Parameters of a supershort avalanche electron beam generated in atmospheric-pressure air

    SciTech Connect

    Tarasenko, V. F.

    2011-05-15

    Conditions under which the number of runaway electrons in atmospheric-pressure air reaches {approx}5 Multiplication-Sign 10{sup 10} are determined. Recommendations for creating runaway electron accelerators are given. Methods for measuring the parameters of a supershort avalanche electron beam and X-ray pulses from gas-filled diodes, as well as the discharge current and gap voltage, are described. A technique for determining the instant of runaway electron generation with respect to the voltage pulse is proposed. It is shown that the reduction in the gap voltage and the decrease in the beam current coincide in time. The mechanism of intense electron beam generation in gas-filled diodes is analyzed. It is confirmed experimentally that, in optimal regimes, the number of electrons generated in atmospheric-pressure air with energies T > eU{sub m}, where U{sub m} is the maximum gap voltage, is relatively small.

  8. Evaluation of analytical methodology for hydrocarbons in high pressure air and nitrogen systems. [evaluation of methodology

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Samples of liquid oxygen, high pressure nitrogen, low pressure nitrogen, and missile grade air were studied to determine the hydrocarbon concentrations. Concentration of the samples was achieved by adsorption on a molecular sieve and activated charcoal. The trapped hydrocarbons were then desorbed and transferred to an analytical column in a gas chromatograph. The sensitivity of the method depends on the volume of gas passed through the adsorbent tubes. The value of the method was verified through recoverability and reproducibility studies. The use of this method enables LOX, GN2, and missile grade air systems to be routinely monitored to determine low level increases in specific hydrocarbon concentration that could lead to potentially hazardous conditions.

  9. Parameters of a supershort avalanche electron beam generated in atmospheric-pressure air

    NASA Astrophysics Data System (ADS)

    Tarasenko, V. F.

    2011-05-01

    Conditions under which the number of runaway electrons in atmospheric-pressure air reaches ˜5 × 1010 are determined. Recommendations for creating runaway electron accelerators are given. Methods for measuring the parameters of a supershort avalanche electron beam and X-ray pulses from gas-filled diodes, as well as the discharge current and gap voltage, are described. A technique for determining the instant of runaway electron generation with respect to the voltage pulse is proposed. It is shown that the reduction in the gap voltage and the decrease in the beam current coincide in time. The mechanism of intense electron beam generation in gas-filled diodes is analyzed. It is confirmed experimentally that, in optimal regimes, the number of electrons generated in atmospheric-pressure air with energies T > eU m , where U m is the maximum gap voltage, is relatively small.

  10. A smart-hose for concrete displacing booms

    NASA Astrophysics Data System (ADS)

    Ripamonti, Francesco; Bucca, Giuseppe; Fava, Victor; Resta, Ferruccio

    2016-04-01

    During the last years, continuum robots have been used in many applications. They are smart structures with continuous curving, similar to a worm or an elephant trunk, characterized by a very high number of sub-actuated degrees of freedom (dof). They need a robust control system, aiming at both positioning the robot and suppressing induced vibrations. The idea is to adopt such a robot on a construction machine for the concrete distribution, substituting the reinforced rubber hose with the robotic smart solution. Particular attention has been paid to a control strategy able to reduce vibrations induced by the pumping procedure.

  11. Ion-Hose Instability in Long Pulse Induction Accelerators

    SciTech Connect

    Caporaso, G J; McCarrick, J F

    2000-08-02

    The ion-hose (or fast-ion) instability sets limits on the allowable vacuum in a long-pulse, high current accelerator. Beam-induced ionization of the background gas leads to the formation of an ion channel which couples to the transverse motion of the beam. The instability is studied analytically and numerically for several ion frequency distributions. The effects of beam envelope oscillations on the growth of the instability will be discussed. The saturated non-linear growth of the instability is derived analytically and numerically for two different ion frequency distributions.

  12. Effect of Mixture Pressure and Equivalence Ratio on Detonation Cell Size for Hydrogen-Air Mixtures

    DTIC Science & Technology

    2015-06-01

    Detonation MAPE Mean Absolute Percent Error PDE Pulsed Detonation Engine RDE Rotating Detonation Engine ZND...1997. DeBarmore, Nick D., Paul King, Fred Schauer, and John Hoke, “Nozzle Guide Vane Integration into Rotating Detonation Engine,” 51st AIAA...initial mixture pressure and equivalence ratio. ^Hydrogen and air, detonation cell size, detonation , cell size, Rotating Detonation Engine, RDE U U U UU 129 Dr. Paul I. King, AFIT/ENY (937) 255-3636 x4628

  13. Travel of the center of pressure of airfoils transversely to the air stream

    NASA Technical Reports Server (NTRS)

    Katzmayr, Richard

    1929-01-01

    The experiments here described were performed for the purpose of obtaining the essential facts concerning the distribution of the air force along the span. We did not follow, however, the time-consuming method of point-to-point measurements of the pressure distribution on the wing surfaces, but determined directly the moment of mean force about an axis passing through the middle of the span parallel to the direction of flight.

  14. Characterization of an atmospheric pressure air plasma source for polymer surface modification

    NASA Astrophysics Data System (ADS)

    Yang, Shujun; Tang, Jiansheng

    2013-10-01

    An atmospheric pressure air plasma source was generated through dielectric barrier discharge (DBD). It was used to modify polyethyleneterephthalate (PET) surfaces with very high throughput. An equivalent circuit model was used to calculate the peak average electron density. The emission spectrum from the plasma was taken and the main peaks in the spectrum were identified. The ozone density in the down plasma region was estimated by Absorption Spectroscopy. NSF and ARC-ODU

  15. Optical refractive index of air: dependence on pressure, temperature and composition.

    PubMed

    Owens, J C

    1967-01-01

    The theoretical background and present status of formulas for the refractive index of air are reviewed. In supplement to Edlén's recently revised formula for relative refractivity, the density dependence of refractive index is reanalyzed. New formulas are presented for both phase and group refractive index which are more useful over a wide range of pressure, temperature, and composition than any presently available. The application of the new formulas to optical distance measuring is briefly discussed.

  16. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length...

  17. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length...

  18. 46 CFR 76.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... weather. Except when closed to prevent freezing, such valves shall be sealed open. (f) The outlet at each... heavy weather, or where the hose may be liable to damage from the handling of cargo the hose may be....027 of this chapter as follows— (1) In accommodation and service areas—two firehoses; and (2) In...

  19. 46 CFR 76.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Fire station hydrants, hose and nozzles-T/ALL. 76.10-10... PROTECTION EQUIPMENT Fire Main System, Details § 76.10-10 Fire station hydrants, hose and nozzles-T/ALL. (a... each fire station; however, if all such stations can be satisfactorily served with 50-foot lengths,...

  20. 46 CFR 76.10-10 - Fire station hydrants, hose and nozzles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Fire station hydrants, hose and nozzles. 76.10-10... PROTECTION EQUIPMENT Fire Main System, Details § 76.10-10 Fire station hydrants, hose and nozzles. (a) The... fire station; however, if all such stations can be satisfactorily served with 50-foot lengths,...

  1. 46 CFR 76.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Fire station hydrants, hose and nozzles-T/ALL. 76.10-10... PROTECTION EQUIPMENT Fire Main System, Details § 76.10-10 Fire station hydrants, hose and nozzles-T/ALL. (a... each fire station; however, if all such stations can be satisfactorily served with 50-foot lengths,...

  2. 46 CFR 58.30-20 - Fluid power hose and fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-20 Fluid power hose and fittings. (a) The requirements of this section are applicable to those hydraulic and pneumatic systems listed in... of flexible hose where required for proper operation of machinery and components in the...

  3. 46 CFR 58.30-20 - Fluid power hose and fittings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-20 Fluid power hose and fittings. (a) The requirements of this section are applicable to those hydraulic and pneumatic systems listed in... of flexible hose where required for proper operation of machinery and components in the...

  4. Fire Hose, Nozzles and Applicances. Fire Service Certification Series. Unit FSCS-FF-8-80.

    ERIC Educational Resources Information Center

    Pribyl, Paul F.

    This training unit on fire hose, nozzles, and appliances is part of a 17-unit course package written to aid instructors in the development, teaching, and evaluation of fire fighters in the Wisconsin Fire Service Certification Series. The purpose stated for the 18-hour unit is to present accepted hose practices that meet federal standards and can…

  5. 33 CFR 149.550 - What are the requirements for lights on a floating hose string?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... feet) above the water; (5) Approximately equally spaced; (6) Not more than 10 meters (32.8 feet) apart...) Two red lights at each end of the hose string, including the ends in a channel where the hose string... (3 feet) apart in a vertical line with the lower light at the same height above the water as...

  6. 33 CFR 149.550 - What are the requirements for lights on a floating hose string?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... feet) above the water; (5) Approximately equally spaced; (6) Not more than 10 meters (32.8 feet) apart...) Two red lights at each end of the hose string, including the ends in a channel where the hose string... (3 feet) apart in a vertical line with the lower light at the same height above the water as...

  7. 33 CFR 149.550 - What are the requirements for lights on a floating hose string?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... feet) above the water; (5) Approximately equally spaced; (6) Not more than 10 meters (32.8 feet) apart...) Two red lights at each end of the hose string, including the ends in a channel where the hose string... (3 feet) apart in a vertical line with the lower light at the same height above the water as...

  8. 33 CFR 149.550 - What are the requirements for lights on a floating hose string?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... feet) above the water; (5) Approximately equally spaced; (6) Not more than 10 meters (32.8 feet) apart...) Two red lights at each end of the hose string, including the ends in a channel where the hose string... (3 feet) apart in a vertical line with the lower light at the same height above the water as...

  9. 46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and weather decks accessible to crew while at sea may be reached with two effective spray patterns of... of such spaces shall be capable of being reached by at least 2 effective spray patterns of water..., Marine Inspection. A suitable hose rack or other device must be provided. Hose racks on weather...

  10. 46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... and weather decks accessible to crew while at sea may be reached with two effective spray patterns of... of such spaces shall be capable of being reached by at least 2 effective spray patterns of water..., Marine Inspection. A suitable hose rack or other device must be provided. Hose racks on weather...

  11. 46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and weather decks accessible to crew while at sea may be reached with two effective spray patterns of... of such spaces shall be capable of being reached by at least 2 effective spray patterns of water..., Marine Inspection. A suitable hose rack or other device must be provided. Hose racks on weather...

  12. 46 CFR 38.15-5 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Cargo hose-TB/ALL. 38.15-5 Section 38.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Special Requirements § 38.15-5 Cargo hose—TB/ALL. (a) When the liquid and vapor line hoses used for loading and...

  13. Temperature and pressure influence on maximum rates of pressure rise during explosions of propane-air mixtures in a spherical vessel.

    PubMed

    Razus, D; Brinzea, V; Mitu, M; Movileanu, C; Oancea, D

    2011-06-15

    The maximum rates of pressure rise during closed vessel explosions of propane-air mixtures are reported, for systems with various initial concentrations, pressures and temperatures ([C(3)H(8)]=2.50-6.20 vol.%, p(0)=0.3-1.3 bar; T(0)=298-423 K). Experiments were performed in a spherical vessel (Φ=10 cm) with central ignition. The deflagration (severity) index K(G), calculated from experimental values of maximum rates of pressure rise is examined against the adiabatic deflagration index, K(G, ad), computed from normal burning velocities and peak explosion pressures. At constant temperature and fuel/oxygen ratio, both the maximum rates of pressure rise and the deflagration indices are linear functions of total initial pressure, as reported for other fuel-air mixtures. At constant initial pressure and composition, the maximum rates of pressure rise and deflagration indices are slightly influenced by the initial temperature; some influence of the initial temperature on maximum rates of pressure rise is observed only for propane-air mixtures far from stoichiometric composition. The differentiated temperature influence on the normal burning velocities and the peak explosion pressures might explain this behaviour.

  14. 46 CFR 154.517 - Piping: Liquid pressure relief.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo... crossover headers, cargo hoses, and cargo loading arms must have means to relieve cargo pressure and...

  15. 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....

  16. 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....

  17. 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....

  18. Development of 72kV High Pressure Air-insulated GIS with Vacuum Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Rokunohe, Toshiaki; Yagihashi, Yoshitaka; Endo, Fumihiro; Aoyagi, Kenji; Saitoh, Hitoshi; Oomori, Takashi

    SF6 gas has excellent dielectric strength and interruption performance. For these reasons, it has been widely used for gas insulated switchgear (GIS). However, use of SF6 gas has become regulated under agreements set at the 1997 COP3. So investigation and development for GIS with a lower amount of SF6 gas are being carried out worldwide. Presently, SF6 gas-free GIS has been commercialized for the 24kV class. Air or N2 gas is used as insulation gas for this GIS. On the other hand, SF6 gas-free GIS has not been commercialized for 72kV class GIS. Dielectric strengths of air and N2 gas are approximately 1/3 that of SF6 gas. So to enhance insulation performance of air and N2, we have investigated a hybrid gas insulation system which has the combined features of providing an insulation coating and suitable insulation gas. We have developed the world's first 72kV SF6 gas-free GIS. This paper deals with key technologies for SF6 gas-free GIS such as the hybrid insulation structure, bellows for the high pressure vacuum circuit breaker, a newly designed disconnector and spacer and prevention of particle levitation. Test results of 72kV high pressure air-insulated GIS with the vacuum circuit breaker are described.

  19. Effects of the air pressure on the wave-packet dynamics of gaseous iodine molecules at room temperature

    NASA Astrophysics Data System (ADS)

    Fan, Rongwei; He, Ping; Chen, Deying; Xia, Yuanqin; Yu, Xin; Wang, Jialing; Jiang, Yugang

    2013-02-01

    Based on ultrafast laser pulses, time-resolved resonance enhancement coherent anti-Stokes Raman scattering (RE-CARS) is applied to investigate wave-packet dynamics in gaseous iodine. The effects of air pressure on the wave-packet dynamics of iodine molecules are studied at pressures ranging from 1.5 Torr to 750 Torr. The RE-CARS signals are recorded in a gas cell filled with a mixture of about 0.3 Torr iodine in air buffer gas at room temperature. The revivals and fractional revival structures in the wave-packet signal are found to gradually disappear with rising air pressure up to 750 Torr, and the decay behaviors of the excited B-state and ground X-state become faster with increasing air pressure, which is due to the collision effects of the molecules and the growing complexity of the spectra at high pressures.

  20. Effects of light intensity and air velocity on air temperature, water vapor pressure, and CO2 concentration inside a plant canopy under an artificial lighting condition.

    PubMed

    Kitaya, Y; Shibuya, T; Kozai, T; Kubota, C

    1998-01-01

    In order to characterize environmental variables inside a plant canopy under artificial lighting in the CELSS, we investigated the effects of light intensity and air velocity on air temperature, water vapor pressure, and CO2 concentration inside a plant canopy. Under a PPF of 500 micromoles m-2 s-1, air temperature was 2-3 degrees C higher, water vapor pressure was 0.6 kPa higher, and CO2 concentration was 25-35 micromoles mol-1 lower at heights ranging from 0 to 30 mm below the canopy than at a height 60 mm above the canopy. Increasing the PPF increased air temperature and water vapor pressure and decreased CO2 concentration inside the canopy. The air temperature was lower and the CO2 concentration was higher inside the canopy at an air velocity of 0.3 m s-1 than at an air velocity of 0.1 m s-1. The environmental variables inside the canopy under a high light intensity were characterized by higher air temperature, higher vapor pressure, and lower CO2 concentration than those outside the canopy.

  1. Your Garden Hose: A potential health risk due to Legionella spp. growth facilitated by free-living amoebae

    EPA Science Inventory

    Common garden hoses may generate aerosols of inhalable size (<10 um) during use. If aerosols are inhaled containing Legionella bacteria, Legionnaires' disease or Pontiac fever may result. Noting clinical cases have been linked to garden hose use. The hose environment is ideal ...

  2. Advancing a smart air cushion system for preventing pressure ulcers using projection Moiré for large deformation measurements

    NASA Astrophysics Data System (ADS)

    Cheng, Sheng-Lin; Tsai, Tsung-Heng; Lee, Carina Jean-Tien; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    A pressure ulcer is one of the most important concerns for wheelchair bound patients with spinal cord injuries. A pressure ulcer is a localized injury near the buttocks that bear ischial tuberosity oppression over a long period of time. Due to elevated compression to blood vessels, the surrounding tissues suffer from a lack of oxygen and nutrition. The ulcers eventually lead to skin damage followed by tissue necrosis. The current medical strategy is to minimize the occurrence of pressure ulcers by regularly helping patients change their posture. However, these methods do not always work effectively or well. As a solution to fundamentally prevent pressure ulcers, a smart air cushion system was developed to detect and control pressure actively. The air cushion works by automatically adjusting a patient's sitting posture to effectively relieve the buttock pressure. To analyze the correlation between the dynamic pressure profiles of an air cell with a patient's weight, a projection Moiré system was adopted to measure the deformation of an air cell and its associated stress distribution. Combining a full-field deformation imaging with air pressure measured within an air cell, the patient's weight and the stress distribution can be simultaneously obtained. By integrating a full-field optical metrology with a time varying pressure sensor output coupled with different active air control algorithms for various designs, we can tailor the ratio of the air cells. Our preliminary data suggests that this newly developed smart air cushion has the potential to selectively reduce localized compression on the tissues at the buttocks. Furthermore, it can take a patient's weight which is an additional benefit so that medical personnel can reference it to prescribe the correct drug dosages.

  3. Pattern recognition techniques for visualizing the biotropic waveform of air temperature and pressure

    NASA Astrophysics Data System (ADS)

    Ozheredov, V. A.

    2012-12-01

    It is known that long periods of adverse weather have a negative effect on the human cardiovascular system. A number of studies have set a lower limit of around 5 days for the duration of these periods. However, the specific features of the negative dynamics of the main weather characteristics—air temperature and atmospheric pressure—remained open. To address this problem, the present paper proposes a conjunctive method of the theory of pattern recognition. It is shown that this method approaches a globally optimal (in the sense of recognition errors) Neumann critical region and can be used to solve various problems in heliobiology. To illustrate the efficiency of this method, we show that some quickly relaxing short sequences of temperature and pressure time series (the so-called temperature waves and waves of atmospheric pressure changes) increase the risk of cardiovascular diseases and can lead to serious organic lesions (particularly myocardial infarction). It is established that the temperature waves and waves of atmospheric pressure changes increase the average morbidity rate of myocardial infarction by 90% and 110%, respectively. Atmospheric pressure turned out to be a more biotropic factor than air temperature.

  4. Predictive dynamic model of a small pressure swing adsorption air separation unit

    SciTech Connect

    Teague, K.G. Jr.; Edgar, T.F.

    1999-10-01

    A predictive dynamic model of a small pressure swing adsorption (PSA) air separation process was developed for the purposes of evaluation, optimization, and control of oxygen generation systems on board military aircraft. A mathematical model of the adsorption beds was formulated by application of fundamental mass- and energy-transport modeling techniques. These equations were discretized using the Galerkin finite element technique. The resulting ODE systems were coupled with ODEs describing the rate of change of pressure in each bed and models of the feed and exhaust valves and purge orifice. The model was developed so that it is possible to predict the dynamic response of product oxygen composition and feed air consumption to step changes in feed pressure, product flow rate, and cycle time. A laboratory PSA unit similar in size to an on-board oxygen generation system (OBOGS) was constructed to validate the model. The laboratory unit was constructed so that step changes could be implemented and the responses observed for comparison with the model. All parameters in the model were estimated from literature sources with the exception of the feed/exhaust valve and purge orifice discharge coefficients. Excellent dynamic predictions of bed pressure, cycle-averaged feed flow rate, and cycle-averaged bed temperature vs time in response to step changes in all three input variables compared to the two-bed PSA data were achieved without additional parameter estimation from two-bed data.

  5. New data for aerosols generated by releases of pressurized powders and solutions in static air

    SciTech Connect

    Ballinger, M.Y.; Sutter, S.L.; Hodgson, W.H.

    1987-05-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of potential airborne releases. Aerosols generated by accidents are being investigated by Pacific Northwest Laboratory to develop radioactive source-term estimation methods. Experiments measuring the mass airborne and particle size distribution of aerosols produced by pressurized releases were run. Carbon dioxide was used to pressurize uranine solutions to 50, 250, and 500 psig before release. The mass airborne from these experiments was higher than for comparable air-pressurized systems, but not as great as expected based on the amount of gas dissolved in the liquid and the volume of liquid ejected from the release equipment. Flashing sprays of uranine at 60, 125, and 240 psig produced a much larger source term than all other pressurized releases performed under this program. Low-pressure releases of depleted uranium dioxide at 9, 17.5, and 24.5 psig provided data in the energy region between 3-m spills and 50-psig pressurized releases.

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

    PubMed

    Miyairi, H; Muramatsu, A

    1979-07-01

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

  7. 30 CFR 77.1013 - Air drills; safeguards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Air drills; safeguards. 77.1013 Section 77.1013... Control § 77.1013 Air drills; safeguards. Air shall be turned off and bled from the air hoses before hand-held air drills are moved from one working area to another....

  8. 30 CFR 77.1013 - Air drills; safeguards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Air drills; safeguards. 77.1013 Section 77.1013... Control § 77.1013 Air drills; safeguards. Air shall be turned off and bled from the air hoses before hand-held air drills are moved from one working area to another....

  9. 30 CFR 77.1013 - Air drills; safeguards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Air drills; safeguards. 77.1013 Section 77.1013... Control § 77.1013 Air drills; safeguards. Air shall be turned off and bled from the air hoses before hand-held air drills are moved from one working area to another....

  10. 30 CFR 77.1013 - Air drills; safeguards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Air drills; safeguards. 77.1013 Section 77.1013... Control § 77.1013 Air drills; safeguards. Air shall be turned off and bled from the air hoses before hand-held air drills are moved from one working area to another....

  11. 30 CFR 77.1013 - Air drills; safeguards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Air drills; safeguards. 77.1013 Section 77.1013... Control § 77.1013 Air drills; safeguards. Air shall be turned off and bled from the air hoses before hand-held air drills are moved from one working area to another....

  12. Decay of femtosecond laser-induced plasma filaments in air, nitrogen, and argon for atmospheric and subatmospheric pressures

    NASA Astrophysics Data System (ADS)

    Aleksandrov, N. L.; Bodrov, S. B.; Tsarev, M. V.; Murzanev, A. A.; Sergeev, Yu. A.; Malkov, Yu. A.; Stepanov, A. N.

    2016-07-01

    The temporal evolution of a plasma channel at the trail of a self-guided femtosecond laser pulse was studied experimentally and theoretically in air, nitrogen (with an admixture of ˜3% O2), and argon in a wide range of gas pressures (from 2 to 760 Torr). Measurements by means of transverse optical interferometry and pulsed terahertz scattering techniques showed that plasma density in air and nitrogen at atmospheric pressure reduces by an order of magnitude within 3-4 ns and that the decay rate decreases with decreasing pressure. The argon plasma did not decay within several nanoseconds for pressures of 50-760 Torr. We extended our theoretical model previously applied for atmospheric pressure air plasma to explain the plasma decay in the gases under study and to show that allowance for plasma channel expansion affects plasma decay at low pressures.

  13. Analysis of an Aircraft Honeycomb Sandwich Panel with Circular Face Sheet/Core Disbond Subjected to Ground-Air Pressurization

    NASA Technical Reports Server (NTRS)

    Rinker, Martin; Krueger, Ronald; Ratcliffe, James

    2013-01-01

    The ground-air pressurization of lightweight honeycomb sandwich structures caused by alternating pressure differences between the enclosed air within the honeycomb core and the ambient environment is a well-known and controllable loading condition of aerospace structures. However, initial face sheet/core disbonds intensify the face sheet peeling effect of the internal pressure load significantly and can decrease the reliability of the sandwich structure drastically. Within this paper, a numerical parameter study was carried out to investigate the criticality of initial disbonds in honeycomb sandwich structures under ground-air pressurization. A fracture mechanics approach was used to evaluate the loading at the disbond front. In this case, the strain energy release rate was computed via the Virtual Crack Closure Technique. Special attention was paid to the pressure-deformation coupling which can decrease the pressure load within the disbonded sandwich section significantly when the structure is highly deformed.

  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. A case series of thermal scald injuries in dogs exposed to hot water from garden hoses (garden hose scalding syndrome).

    PubMed

    Quist, Erin M; Tanabe, Mika; Mansell, Joanne E K L; Edwards, Jeffrey L

    2012-04-01

    In this report, we present a series of cases of thermal burns (scalds) in dogs resulting from exposure to hot water from a garden hose that had been lying in the sun. These dogs typically inhabited the southern and western regions of the USA, where the recorded high temperatures often exceed 32°C (90°F) during the warm summer months. Dogs with thermal scald injury in these cases presented with linear thermal burns along the dorsum, in addition to a variety of other macroscopic lesions that were dependent upon the degree of burn exposure and ranged from local erythema to ulcerated, necrotic and sloughing skin. Chronic, healed wounds were often alopecic, with markedly thickened skin and characteristically smooth and glassy scar tissue formation. Histologically, the lesions of thermal scald injury in these dogs were indistinguishable from any other second or third degree burn, and consisted of full-thickness dermal and epidermal necrosis with occasional fibrinoid necrosis of vessel walls, vasculitis and intravascular thrombosis. Here, we closely examine 10 cases of dogs with dorsal thermal burns collected from Texas, Arizona, California, Utah, Nevada, Indiana, Michigan and North Carolina and propose the term 'garden hose scalding syndrome (GHS)' to describe this unique type of scald injury.

  17. The impact of mass flow and masking on the pressure drop of air filter in heavy-duty diesel engine

    NASA Astrophysics Data System (ADS)

    Hoseeinzadeh, Sepideh; Gorji-Bandpy, Mofid

    2012-04-01

    This paper presents a computational fluid dynamics (CFD) calculation approach to predict and evaluate the impact of the mass-flow inlet on the pressure drop of turbocharger`s air filtfer in heavy-duty diesel engine. The numerical computations were carried out using a commercial CFD program whereas the inlet area of the air filter consisted of several holes connected to a channel. After entering through the channel, the air passes among the holes and enters the air filter. The effect of masking holes and hydraulic diameter is studied and investigated on pressure drop. The results indicate that pressure drop increase with decreasing of hydraulic diameter and masking of the holes has considerable affect on the pressure drop.

  18. Design of a two dimensional planer pressurized air labyrinth seal test rig

    NASA Astrophysics Data System (ADS)

    Konicki, Joseph S.

    1993-12-01

    A two-dimensional planer labyrinth seal test rig was designed to operate with air supplied at 45 psig and temperatures up to 150 F. The rig operates with a manually specified test section pressure up to 30 psig yielding Mach numbers to 0.9 and gap Reynolds numbers to 100,000. The air flow rate through the seal will be controlled by setting inlet pressure and adjusting an outlet control valve. The test section measurements are 18 inches wide by 1.5 inches depth by 6 inches in length and provides for 10:1 large scale geometry seals to be used to facilitate measurements. Design maximum seal gap size is 0.15 inches. The test section has a glass viewing port to allow flow field measurement by non-intrusive means such as Laser Doppler Velocimeter (LDV) with seals containing up to 5 sealing knives. Measurements of pressure, temperature and flow fields can also be simultaneously measured by probes inserted in the seal itself, or mounted on the removable/replaceable top plate. Inlet flow is conditioned through the use of a dump diffuser incorporating screens, honeycombs, expansion and contraction portions. The inlet flow to the test section can be modified from uniform to various non-uniform conditions by employing profile generators such as screens and winglets. A detailed mechanical design has been conducted including stress analysis and seal flow rate predictions.

  19. Air emission into a water shear layer through porous media. Part 2: Cavitation induced pressure attenuation

    SciTech Connect

    Myer, E.C.; Marboe, R.C.

    1994-12-31

    Cavitation near the casing of a hydroturbine can lead to damage through both cavitation erosion and mechanical vibration of the casing and the associated piping. Cavitation erosion results from the collapse of cavitation bubbles on or near a surface such as the casing wall. Mechanical vibrations transmitted to the casing directly through the collapse of bubbles on the casing wall indirectly through a coupling of the acoustic pressure pulse due to a nearby collapse on the turbine blade. Air emission along the casing can reduce the intensity of the tip vortex and the gap cavitation through ventilation of the cavity. Reduction in the machinery vibration is obtained by reduction of the intensity of cavitation bubble collapse and attenuation and scattering of the radiated acoustic pressure. This requires a bubble layer which may be introduced in the vicinity of the turbine blade tips. This layer remains for some distance downstream of the blades and is effective for attenuation of tip vortex induced noise and blade surface cavitation noise. For the purpose of characterizing this bubble layer within a water pipe, the authors spanned a pipe with a two dimensional hydrofoil and emitted air through porous media (20 and 100 micron porosity sintered stainless steel) into the shear flow over the hydrofoil. This paper is limited to an investigation of the attenuation of acoustic pressure propagating to the casing rather than the reduction in acoustic source level due to collapse cushioning effects.

  20. Heat transfer and pressure distributions on hemisphere-cylinders in methane-air combustion products at Mach 7

    NASA Technical Reports Server (NTRS)

    Weinstein, I.

    1973-01-01

    Heat-transfer and pressure distributions were measured over the surfaces of three hemisphere-cylinder models tested at a nominal Mach number of 7 in the Langley 8-foot high-temperature structures tunnel which uses methane-air products of combustion as a test medium. The results showed that the heat-transfer and pressure distributions over the surface of the models were in good agreement with experimental data obtained in air and also with theoretical predictions.

  1. Metal-air cells comprising collapsible foam members and means for minimizing internal pressure buildup

    NASA Technical Reports Server (NTRS)

    Woodruff, Glenn (Inventor); Putt, Ronald A. (Inventor)

    1994-01-01

    This invention provides a prismatic zinc-air cell including, in general, a prismatic container having therein an air cathode, a separator and a zinc anode. The container has one or more oxygen access openings, and the air cathode is disposed in the container in gaseous communication with the oxygen access openings so as to allow access of oxygen to the cathode. The separator has a first side in electrolytic communication with the air cathode and a second side in electrolytic communication with the zinc anode. The separator isolates the cathode and the zinc anode from direct electrical contact and allows passage of electrolyte therebetween. An expansion chamber adjacent to the zinc anode is provided which accommodates expansion of the zinc anode during discharge of the cell. A suitable collapsible foam member generally occupies the expansion space, providing sufficient resistance tending to oppose movement of the zinc anode away from the separator while collapsing upon expansion of the zinc anode during discharge of the cell. One or more vent openings disposed in the container are in gaseous communication with the expansion space, functioning to satisfactorily minimize the pressure buildup within the container by venting gasses expelled as the foam collapses during cell discharge.

  2. Antimicrobial nanoparticle-coated electrostatic air filter with high filtration efficiency and low pressure drop.

    PubMed

    Sim, Kyoung Mi; Park, Hyun-Seol; Bae, Gwi-Nam; Jung, Jae Hee

    2015-11-15

    In this study, we demonstrated an antimicrobial nanoparticle-coated electrostatic (ES) air filter. Antimicrobial natural-product Sophora flavescens nanoparticles were produced using an aerosol process, and were continuously deposited onto the surface of air filter media. For the electrostatic activation of the filter medium, a corona discharge electrification system was used before and after antimicrobial treatment of the filter. In the antimicrobial treatment process, the deposition efficiency of S. flavescens nanoparticles on the ES filter was ~12% higher than that on the pristine (Non-ES) filter. In the evaluation of filtration performance using test particles (a nanosized KCl aerosol and submicron-sized Staphylococcus epidermidis bioaerosol), the ES filter showed better filtration efficiency than the Non-ES filter. However, antimicrobial treatment with S. flavescens nanoparticles affected the filtration efficiency of the filter differently depending on the size of the test particles. While the filtration efficiency of the KCl nanoparticles was reduced on the ES filter after the antimicrobial treatment, the filtration efficiency was improved after the recharging process. In summary, we prepared an antimicrobial ES air filter with >99% antimicrobial activity, ~92.5% filtration efficiency (for a 300-nm KCl aerosol), and a ~0.8 mmAq pressure drop (at 13 cm/s). This study provides valuable information for the development of a hybrid air purification system that can serve various functions and be used in an indoor environment.

  3. A study of the glow discharge characteristics of contact electrodes at atmospheric pressure in air

    SciTech Connect

    Liu, Wenzheng Sun, Guangliang Li, Chuanhui; Zhang, Rongrong

    2014-04-15

    Electric field distributions and discharge properties of rod-rod contact electrodes were studied under the condition of DBD for the steady generation of atmospheric pressure glow discharge plasma (APGD) in air. We found that under the effect of the initial electrons generated in a nanometer-scale gap, the rod-rod cross-contact electrodes yielded APGD plasma in air. Regarding the rod-rod cross-contact electrodes, increasing the working voltage expanded the strong electric field area of the gas gap so that both discharge area and discharge power increased, and the increase in the number of contact points kept the initial discharge voltage unchanged and caused an increase in the plasma discharge area and discharge power. A mesh-like structure of cross-contact electrodes was designed and used to generate more APGD plasma, suggesting high applicability.

  4. Simulation of a runaway electron avalanche developing in an atmospheric pressure air discharge

    SciTech Connect

    Oreshkin, E. V.; Barengolts, S. A.; Chaikovsky, S. A.; Oreshkin, V. I.

    2015-12-15

    To gain a better understanding of the operation of atmospheric pressure air discharges, the formation of a runaway electron beam at an individual emission site on the cathode has been numerically simulated. The model provides a description of the dynamics of the fast electrons emitted into an air gap from the surface of the emission zone by solving numerically two-dimensional equations for the electrons. It is supposed that the electric field at the surface of the emission zone is enhanced, providing conditions for continuous acceleration of the emitted electrons. It is shown that the formation of a runaway electron beam in a highly overvolted discharge is largely associated with avalanche-type processes and that the number of electrons in the avalanche reaches 50% of the total number of runaway electrons.

  5. JT8D revised high-pressure turbine cooling and other outer air seal program

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1979-01-01

    The JT8D high pressure turbine was revised to reduce leakage between the blade tip shrouds and the outer air seal, and engine testing was performed to determine the effect on performance. The addition of a second knife-edge on the blade tip shroud, the extension of the honeycomb seal land to cover the added knife-edge and an existing spoiler on the shroud, and a material substitution in the seal support ring to improve thermal growth characteristics are included. A relocation of the blade cooling air discharge to insure adequate cooling flow is required. Significant specific fuel consumption and exhaust gas temperature improvements were demonstrated with the revised turbine in sea level and simulated altitude engine tests. Inspection of the revised seal hardware after these tests showed no unusual wear or degradation.

  6. BOREAS AFM-5 Level-2 Upper Air Network Standard Pressure Level Data

    NASA Technical Reports Server (NTRS)

    Barr, Alan; Hrynkiw, Charmaine; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS AFM-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing AES aerological network, both temporally and spatially. This data set includes basic upper-air parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure from data collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  7. Simulation of a runaway electron avalanche developing in an atmospheric pressure air discharge

    NASA Astrophysics Data System (ADS)

    Oreshkin, E. V.; Barengolts, S. A.; Chaikovsky, S. A.; Oreshkin, V. I.

    2015-12-01

    To gain a better understanding of the operation of atmospheric pressure air discharges, the formation of a runaway electron beam at an individual emission site on the cathode has been numerically simulated. The model provides a description of the dynamics of the fast electrons emitted into an air gap from the surface of the emission zone by solving numerically two-dimensional equations for the electrons. It is supposed that the electric field at the surface of the emission zone is enhanced, providing conditions for continuous acceleration of the emitted electrons. It is shown that the formation of a runaway electron beam in a highly overvolted discharge is largely associated with avalanche-type processes and that the number of electrons in the avalanche reaches 50% of the total number of runaway electrons.

  8. Focused excimer laser initiated, radio frequency sustained high pressure air plasmas

    SciTech Connect

    Giar, Ryan; Scharer, John

    2011-11-15

    Measurements and analysis of air breakdown processes and plasma production by focusing 193 nm, 300 mJ, 15 MW high power laser radiation inside a 6 cm diameter helical radio frequency (RF) coil are presented. Quantum resonant multi-photon ionization (REMPI) and collisional cascade laser ionization processes are exploited that have been shown to produce high-density (n{sub e} {approx} 7 x 10{sup 16}/cm{sup 3}) cylindrical seed plasmas at 760 Torr. Air breakdown in lower pressures (from 7-22 Torr), where REMPI is the dominant laser ionization process, is investigated using an UV 18 cm focal length lens, resulting in a laser flux of 5.5 GW/cm{sup 2} at the focal spot. The focused laser power absorption and associated shock wave produce seed plasmas for sustainment by the RF (5 kW incident power, 1.5 s) pulse. Measurements of the helical RF antenna load impedance in the inductive and capacitive coupling regimes are obtained by measuring the loaded antenna reflection coefficient. A 105 GHz interferometer is used to measure the plasma electron density and collision frequency. Spectroscopic measurements of the plasma and comparison with the SPECAIR code are made to determine translational, rotational, and vibrational neutral temperatures and the associated neutral gas temperature. From this and the associated measurement of the gas pressure the electron temperature is obtained. Experiments show that the laser-formed seed plasma allows RF sustainment at higher initial air pressures (up to 22 Torr) than that obtained via RF-only initiation (<18 Torr) by means of a 0.3 J UV laser pulse.

  9. Sterilization effect of atmospheric pressure non-thermal air plasma on dental instruments

    PubMed Central

    Sung, Su-Jin; Huh, Jung-Bo; Yun, Mi-Jung; Chang, Brian Myung W.; Jeong, Chang-Mo

    2013-01-01

    PURPOSE Autoclaves and UV sterilizers have been commonly used to prevent cross-infections between dental patients and dental instruments or materials contaminated by saliva and blood. To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated. MATERIALS AND METHODS After inoculating E. coli and B. subtilis the diamond burs and polyvinyl siloxane materials were sterilized by exposing them to the plasma for different lengths of time (30, 60, 90, 120, 180 and, 240 seconds). The diamond burs and polyvinyl siloxane materials were immersed in PBS solutions, cultured on agar plates and quantified by counting the colony forming units. The data were analyzed using one-way ANOVA and significance was assessed by the LSD post hoc test (α=0.05). RESULTS The device was effective in killing E. coli contained in the plasma device compared with the UV sterilizer. The atmospheric pressure non-thermal air plasma device contributed greatly to the sterilization of diamond burs and polyvinyl siloxane materials inoculated with E. coli and B. subtilis. Diamond burs and polyvinyl siloxane materials inoculated with E. coli was effective after 60 and 90 seconds. The diamond burs and polyvinyl siloxane materials inoculated with B. subtilis was effective after 120 and 180 seconds. CONCLUSION The atmospheric pressure non-thermal air plasma device was effective in killing both E. coli and B. subtilis, and was more effective in killing E. coli than the UV sterilizer. PMID:23508991

  10. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    PubMed Central

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues. PMID:22163518

  11. Energy distribution of runaway electrons generated by a nanosecond discharge in atmospheric-pressure air

    NASA Astrophysics Data System (ADS)

    Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Kostyrya, I. D.; Lomaev, M. I.; Petin, V. K.; Rybka, D. V.; Shlyakhtun, S. V.

    2008-12-01

    The spectra of an ultrashort avalanche electron beam generated by a nanosecond discharge in atmospheric-pressure air were investigated. The temporal characteristics of the beam current pulses, gap voltage, and discharge current in a gas diode were measured with a time resolution of ˜0.1 ns. A simple technique was developed for recovering electron spectra from the curves of beam attenuation by aluminum foils. The effect of the cathode design, electrode gap length, and generator parameters on the electron spectra were studied using seven setups. It is shown that generation of electrons with anomalously high energies requires the use of cathodes with increased curvature radius.

  12. Research Update: Direct conversion of amorphous carbon into diamond at ambient pressures and temperatures in air

    SciTech Connect

    Narayan, Jagdish Bhaumik, Anagh

    2015-10-01

    We report on fundamental discovery of conversion of amorphous carbon into diamond by irradiating amorphous carbon films with nanosecond lasers at room-temperature in air at atmospheric pressure. We can create diamond in the form of nanodiamond (size range <100 nm) and microdiamond (>100 nm). Nanosecond laser pulses are used to melt amorphous diamondlike carbon and create a highly undercooled state, from which various forms of diamond can be formed upon cooling. The quenching from the super undercooled state results in nucleation of nanodiamond. It is found that microdiamonds grow out of highly undercooled state of carbon, with nanodiamond acting as seed crystals.

  13. Integrated LTCC pressure/flow/temperature multisensor for compressed air diagnostics.

    PubMed

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  14. Finite element modelling of high air pressure forming processes for polymer sheets

    NASA Astrophysics Data System (ADS)

    Jiang, W.-G.; Warby, M. K.; Whiteman, J. R.; Abbott, S.; Shorter, W.; Warwick, P.; Wright, T.; Munro, A.; Munro, B.

    In this paper we describe the mathematical modelling and computational simulation of the high air pressure (HAP) thermoforming process which is used in the creation of thin walled polymeric structures. This involves, using data from material tests, an elastic-plastic constitutive equation valid for large deformations and a constrained deformation in which there is frictional contact between the polymeric sheet and a constraining surface (the mould surface). Despite a number of simplifying assumptions and some uncertainities in the mathematical model the finite element computations presented predict quite well the actual shape and thickness distribution which are found on sample products.

  15. Energy distribution of runaway electrons generated by a nanosecond discharge in atmospheric-pressure air

    SciTech Connect

    Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Kostyrya, I. D.; Lomaev, M. I.; Petin, V. K.; Rybka, D. V.; Shlyakhtun, S. V.

    2008-12-15

    The spectra of an ultrashort avalanche electron beam generated by a nanosecond discharge in atmospheric-pressure air were investigated. The temporal characteristics of the beam current pulses, gap voltage, and discharge current in a gas diode were measured with a time resolution of {approx}0.1 ns. A simple technique was developed for recovering electron spectra from the curves of beam attenuation by aluminum foils. The effect of the cathode design, electrode gap length, and generator parameters on the electron spectra were studied using seven setups. It is shown that generation of electrons with anomalously high energies requires the use of cathodes with increased curvature radius.

  16. Spectrum of the Runaway Electron Beam Generated During a Nanosecond Discharge in Air at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.

    2016-04-01

    The spectrum of supershort avalanche runaway electron beam generated in air at atmospheric pressure is experimentally investigated using a time-of-flight spectrometer and attenuation curves. It is shown that the maximum of the electron energy distribution for the main (second) group of electrons is less than the energy eUm, where Um is the maximal voltage across the gap, and the difference between these energies depends on the design of the cathode and the interelectrode gap in a gas diode. It is confirmed that there are three groups of electrons with different energies in the runaway electron beam spectrum.

  17. Temporal and spatial structure of a runaway electron beam in air at atmospheric pressure

    SciTech Connect

    Levko, D.; Krasik, Ya. E.; Tarasenko, V. F.; Rybka, D. V.; Burachenko, A. G.

    2013-05-21

    The time- and spatial structure of a runaway electron beam generated in air at atmospheric pressure by a high-voltage pulse with a rise time of {approx}300 ps is studied experimentally and numerically. It is obtained that the duration of the runaway electron current is a few tens of picoseconds, and it can consist of two or many peaks. It is shown that the many-peak temporal structure of the beam is caused by the non-simultaneous appearance of several emission centers on the cathode edge.

  18. Effects of ear-canal pressurization on middle-ear bone- and air-conduction responses

    PubMed Central

    Homma, Kenji; Shimizu, Yoshitaka; Kim, Namkeun; Du, Yu; Puria, Sunil

    2014-01-01

    In extremely loud noise environments, it is important to not only protect one’s hearing against noise transmitted through the air-conduction (AC) pathway, but also through the bone-conduction (BC) pathways. Much of the energy transmitted through the BC pathways is concentrated in the mid-frequency range around 1.5–2 kHz, which is likely due to the structural resonance of the middle ear. One potential approach for mitigating this mid-frequency BC noise transmission is to introduce a positive or negative static pressure in the ear canal, which is known to reduce BC as well as AC hearing sensitivity. In the present study, middle-ear ossicular velocities at the umbo and stapes were measured using human cadaver temporal bones in response to both BC and AC excitations, while static air pressures of ±400 mm H2O were applied in the ear canal. For the maximum negative pressure of −400 mm H2O, mean BC stapes-velocity reductions of about 5–8 dB were observed in the frequency range from 0.8 to 2.5 kHz, with a peak reduction of 8.6(± 4.7) dB at 1.6 kHz. Finite-element analysis indicates that the peak BC-response reduction tends to be in the mid-frequency range because the middle-ear BC resonance, which is typically around 1.5–2 kHz, is suppressed by the pressure-induced stiffening of the middle-ear structure. The measured data also show that the BC responses are reduced more for negative static pressures than for positive static pressures. This may be attributable to a difference in the distribution of the stiffening among the middle-ear components depending on the polarity of the static pressure. The characteristics of the BC-response reductions are found to be largely consistent with the available psychoacoustic data, and are therefore indicative of the relative importance of the middle-ear mechanism in BC hearing. PMID:19944139

  19. Effect of Fuel-Air Ratio, Inlet Temperature, and Exhaust Pressure on Detonation

    NASA Technical Reports Server (NTRS)

    Taylor, E S; Leary, W A; Diver, J R

    1940-01-01

    An accurate determination of the end-gas condition was attempted by applying a refined method of analysis to experimental results. The results are compared with those obtained in Technical Report no. 655. The experimental technique employed afforded excellent control over the engine variables and unusual cyclic reproducibility. This, in conjunction with the new analysis, made possible the determination of the state of the end-gas at any instant to a fair degree of precision. Results showed that for any given maximum pressure the maximum permissible end-gas temperature increased as the fuel-air ratio was increased. The tendency to detonate was slightly reduced by an increase in residual gas content resulting from an increase in exhaust backpressure with inlet pressure constant.

  20. Remote Sensing Global Surface Air Pressure Using Differential Absorption BArometric Radar (DiBAR)

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Harrah, Steven; Lawrence, Wes; Hu, Yongxiang; Min, Qilong

    2016-01-01

    Tropical storms and severe weathers are listed as one of core events that need improved observations and predictions in World Meteorological Organization and NASA Decadal Survey (DS) documents and have major impacts on public safety and national security. This effort tries to observe surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at the 50-55 gigahertz O2 absorption band. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 4 millibars (approximately 1 millibar under all weather conditions). With these sea level pressure measurements, the forecasts of severe weathers such as hurricanes will be significantly improved. Since the development of the DiBAR concept about a decade ago, NASA Langley DiBAR research team has made substantial progress in advancing the concept. The feasibility assessment clearly shows the potential of sea surface barometry using existing radar technologies. The team has developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted lab, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will lead us to an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

  1. High fidelity radiative heat transfer models for high-pressure laminar hydrogen-air diffusion flames

    NASA Astrophysics Data System (ADS)

    Cai, Jian; Lei, Shenghui; Dasgupta, Adhiraj; Modest, Michael F.; Haworth, Daniel C.

    2014-11-01

    Radiative heat transfer is studied numerically for high-pressure laminar H2-air jet diffusion flames, with pressure ranging from 1 to 30 bar. Water vapour is assumed to be the only radiatively participating species. Two different radiation models are employed, the first being the full spectrum k-distribution model together with conventional Radiative Transfer Equation (RTE) solvers. Narrowband k-distributions of water vapour are calculated and databased from the HITEMP 2010 database, which claims to retain accuracy up to 4000 K. The full-spectrum k-distributions are assembled from their narrowband counterparts to yield high accuracy with little additional computational cost. The RTE is solved using various spherical harmonics methods, such as P1, simplified P3 (SP3) and simplified P5 (SP5). The resulting partial differential equations as well as other transport equations in the laminar diffusion flames are discretized with the finite-volume method in OpenFOAM®. The second radiation model is a Photon Monte Carlo (PMC) method coupled with a line-by-line spectral model. The PMC absorption coefficient database is derived from the same spectroscopy database as the k-distribution methods. A time blending scheme is used to reduce PMC calculations at each time step. Differential diffusion effects, which are important in laminar hydrogen flames, are also included in the scalar transport equations. It was found that the optically thin approximation overpredicts radiative heat loss at elevated pressures. Peak flame temperature is less affected by radiation because of faster chemical reactions at high pressures. Significant cooling effects are observed at downstream locations. As pressure increases, the performance of RTE models starts to deviate due to increased optical thickness. SPN models perform only marginally better than P1 because P1 is adequate except at very high pressure.

  2. Laser-based measurements of OH in high pressure CH4/air flames

    NASA Technical Reports Server (NTRS)

    Battles, B. E.; Hanson, R. K.

    1991-01-01

    Narrow-linewidth laser absorption measurements are reported from which mole fraction and temperature of OH are determined in high-pressure (1-10 atm), lean CH4/air flames. These measurements were made in a new high pressure combustion facility which incorporates a traversable flat flame burner, providing spatially and temporally uniform combustion gases at pressures up to 10 am. A commercially avialable CW ring dye laser was used with an intracavity doubling crystal to provide near-UV single mode output at approximately 306 nm. The UV beam was rapidly scanned over 120 GHz (0.1 sec scan duration) to resolve the absorption lineshape of the A-X (0,0) R1(7)/R1(11) doublet of the OH radical. From the doublet's absorption lineshape, the temperature was determined; and from peak absorption, Beer's Law was employed to find the mole fraction of OH. These data were obtained as a function of height above the flame at various pressures.

  3. The lunar semidiurnal air pressure tide in in-situ data and ECMWF reanalyses

    NASA Astrophysics Data System (ADS)

    Schindelegger, Michael; Dobslaw, Henryk

    2016-04-01

    A gridded empirical model of the lunar semidiurnal air pressure tide L2 is deduced through multiquadric interpolation of more than 2000 globally distributed tidal estimates from land barometers and moored buoys. The resulting climatology serves as an independent standard to validate the barometric L2 oscillations that are present in ECMWF's (European Centre for Medium-Range Weather Forecasts) global atmospheric reanalyses despite the omission of gravitational forcing mechanisms in the involved forecast routines. Inconsistencies between numerical and empirical L2 solutions are found to be small even though the reanalysis models typically underestimate equatorial peak pressures by 10-20% and produce slightly deficient tidal phases in latitudes south of 30°N. Through using a time-invariant reference surface over both land and water and assimilating marine pressure data without accounting for vertical sensor movements due to the M2 ocean tide, ECMWF-based tidal solutions are also prone to strong local artifacts. Additionally, the dependency of the lunar tidal oscillation in atmospheric analysis systems on the meteorological input data is demonstrated based on a recent ECMWF twentieth-century reanalysis (ERA-20C) which draws its all of its observational constraints from in-situ registrations of pressure and surface winds. The L2 signature prior to 1950 is particularly indicative of distinct observing system changes, such as the paucity of marine data during both World Wars or the opening of the Panama Canal in 1914 and the associated adjustment of commercial shipping routes.

  4. FIRE HOSE INSTABILITY DRIVEN BY ALPHA PARTICLE TEMPERATURE ANISOTROPY

    SciTech Connect

    Matteini, L.; Schwartz, S. J.; Hellinger, P.; Landi, S.

    2015-10-10

    We investigate properties of a solar wind-like plasma, including a secondary alpha particle population exhibiting a parallel temperature anisotropy with respect to the background magnetic field, using linear and quasi-linear predictions and by means of one-dimensional hybrid simulations. We show that anisotropic alpha particles can drive a parallel fire hose instability analogous to that generated by protons, but that, remarkably, can also be triggered when the parallel plasma beta of alpha particles is below unity. The wave activity generated by the alpha anisotropy affects the evolution of the more abundant protons, leading to their anisotropic heating. When both ion species have sufficient parallel anisotropies, both of them can drive the instability, and we observe the generation of two distinct peaks in the spectra of the fluctuations, with longer wavelengths associated to alphas and shorter ones to protons. If a non-zero relative drift is present, the unstable modes propagate preferentially in the direction of the drift associated with the unstable species. The generated waves scatter particles and reduce their temperature anisotropy to a marginally stable state, and, moreover, they significantly reduce the relative drift between the two ion populations. The coexistence of modes excited by both species leads to saturation of the plasma in distinct regions of the beta/anisotropy parameter space for protons and alpha particles, in good agreement with in situ solar wind observations. Our results confirm that fire hose instabilities are likely at work in the solar wind and limit the anisotropy of different ion species in the plasma.

  5. Flight Investigation of the Cooling Characteristics of a Two-Row Radial Engine Installation. 2 - Cooling-Air Pressure Recovery and Pressure Distribution

    DTIC Science & Technology

    1946-07-01

    I 1 n ^ £ Ä ̂ N i - 1 \\ ̂ =J r i > 0 • W Air flo 8 7 1 »H pN ;> ^ fefe * r^ IS & ̂ s I 6 y ^r 5 y. < 1 ** >—< £r... fefe |^S? 2 4 6 8 10 12 14 10 18 Cylinder, front row (a) Cyl inder-head pressure». Air flow j^bb£=L£W —ik

  6. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today.

  7. 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 ...

  8. Two-Dimensional Electron Density Measurement of Positive Streamer Discharge in Atmospheric-Pressure Air

    NASA Astrophysics Data System (ADS)

    Inada, Yuki; Ono, Ryo; Kumada, Akiko; Hidaka, Kunihiko; Maeyama, Mitsuaki

    2016-09-01

    The electron density of streamer discharges propagating in atmospheric-pressure air is crucially important for systematic understanding of the production mechanisms of reactive species utilized in wide ranging applications such as medical treatment, plasma-assisted ignition and combustion, ozone production and environmental pollutant processing. However, electron density measurement during the propagation of the atmospheric-pressure streamers is extremely difficult by using the conventional localized type measurement systems due to the streamer initiation jitters and the irreproducibility in the discharge paths. In order to overcome the difficulties, single-shot two-dimensional electron density measurement was conducted by using a Shack-Hartmann type laser wavefront sensor. The Shack-Hartmann sensor with a temporal resolution of 2 ns was applied to pulsed positive streamer discharges generated in an air gap between pin-to-plate electrodes. The electron density a few ns after the streamer initiation was 7*1021m-3 and uniformly distributed along the streamer channel. The electron density and its distribution profile were compared with a previous study simulating similar streamers, demonstrating good agreement. This work was supported in part by JKA and its promotion funds from KEIRIN RACE. The authors like to thank Mr. Kazuaki Ogura and Mr. Kaiho Aono of The University of Tokyo for their support during this work.

  9. Optical emission spectroscopy of nanosecond repetitively pulsed microplasmas generated in air at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Orriere, Thomas; Moreau, Eric; Benard, Nicolas; Pai, David

    2015-09-01

    Nanosecond repetitively pulsed (NRP) microplasmas are generated in room temperature air at atmospheric pressure, in order to investigate the enhanced control of discharge properties via the combined effects of spatial confinement and nanosecond repetitive pulsing. Discharges were generated using high-voltage pulses of 15-ns duration applied to a tungsten pin-to-pin reactor, with inter-electrode gap distances (d) from 2 mm down to 0.2 mm. Optical emission spectroscopy and electrical characterization performed on the discharge indicate that heat transfer and plasma chemistry are influenced by the microplasma geometry. Ultrafast gas heating is observed upon deducing the rotational temperature of N2 from the measured emission spectrum of the N2 (C -->B) (0, 2) and (1, 3) transition bands, but use of the microplasma geometry (d = 0.2 mm) results in lower gas temperatures than in larger discharge gaps (d = 2 mm), including at high pulse repetition frequency (30 kHz) where substantial steady-state gas heating can occur. The measured Stark broadening of the Hα transition is significantly greater than for previously studied NRP discharges in air at atmospheric pressure, indicating that the maximum electron number density may be correspondingly much greater, up to 1018 cm-3. Furthermore, for NRP microplasmas, the intensities of emission from excited atomic ions (O+ and N+) are much higher than those of excited neutral atoms (O and N), in contrast to NRP discharges generated in larger discharge gaps.

  10. Emission spectroscopy of an atmospheric pressure plasma jet operated with air at low frequency

    NASA Astrophysics Data System (ADS)

    Giuliani, L.; Gallego, J. L.; Minotti, F.; Kelly, H.; Grondona, D.

    2015-03-01

    Low-temperature, high-pressure plasma jets have an extensive use in plasma biology and plasma medicine, such as pathogen deactivation, wound disinfection, stopping of bleeding without damage of healthy tissue, acceleration of wound healing, control of bio-film proliferation, etc. In this work, a spectroscopic characterization of a typical plasma jet, operated in air at atmospheric pressure, is reported. Within the spectrum of wavelengths from 200 to 450 nm all remarkable emissions of N2 were monitored. Spectra of the N2 2nd positive system (C3Πu-B3Πg) emitted in air are the most convenient for plasma diagnostics, since they enable to determine electronic Te, rotational Tr and vibrational Tv temperatures by fitting the experimental spectra with the simulated ones. We used SPECAIR software for spectral simulation and obtained the best fit with all these temperatures about 3500K. The conclusion that all temperatures are equal, and its relatively high value, is consistent with the results of a previous work, where it was found that the experimentally determined electrical characteristic was consistent with the model of a thermal arc discharge, together with a highly collisional cathode sheet.

  11. Use of MODIS Cloud Top Pressure to Improve Assimilation Yields of AIRS Radiances in GSI

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Radiances from hyperspectral sounders such as the Atmospheric Infrared Sounder (AIRS) are routinely assimilated both globally and regionally in operational numerical weather prediction (NWP) systems using the Gridpoint Statistical Interpolation (GSI) data assimilation system. However, only thinned, cloud-free radiances from a 281-channel subset are used, so the overall percentage of these observations that are assimilated is somewhere on the order of 5%. Cloud checks are performed within GSI to determine which channels peak above cloud top; inaccuracies may lead to less assimilated radiances or introduction of biases from cloud-contaminated radiances.Relatively large footprint from AIRS may not optimally represent small-scale cloud features that might be better resolved by higher-resolution imagers like the Moderate Resolution Imaging Spectroradiometer (MODIS). Objective of this project is to "swap" the MODIS-derived cloud top pressure (CTP) for that designated by the AIRS-only quality control within GSI to test the hypothesis that better representation of cloud features will result in higher assimilated radiance yields and improved forecasts.

  12. Effect of non-thermal air atmospheric pressure plasma jet treatment on gingival wound healing

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Hwan; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2016-02-01

    Non-thermal atmospheric pressure plasmas have been applied in the biomedical field for the improvement of various cellular activities. In dentistry, the healing of gingival soft tissue plays an important role in health and aesthetic outcomes. While the biomedical application of plasma has been thoroughly studied in dentistry, a detailed investigation of plasma-mediated human gingival fibroblast (HGF) migration for wound healing and its underlying biological mechanism is still pending. Therefore, the aim of this study is to apply a non-thermal air atmospheric pressure plasma jet (NTAAPPJ) to HGF to measure the migration and to reveal the underlying biological mechanisms involved in the migration. After the characterization of NTAAPPJ by optical emission spectroscopy, the adherent HGF was treated with NTAAPPJ or air with a different flow rate. Cell viability, lipid peroxidation, migration, intracellular reactive oxygen species (ROS), and the expression of migration-related genes (EGFR, PAK1, and MAPK3) were investigated. The level of statistical significance was set at 0.05. NTAAPPJ and air treatment with a flow rate of 250-1000 standard cubic centimetres per minute (sccm) for up to 30 s did not induce significant decreases in cell viability or membrane damage. A significant increase in the migration of mitomycin C-treated HGF was observed after 30 s of NTAAPPJ treatment compared to 30 s air-only treatment, which was induced by high levels of intracellular reactive oxygen species (ROS). An increase in migration-related gene expression and EGFR activation was observed following NTAAPPJ treatment in an air flow rate-dependent manner. This is the first report that NTAAPPJ treatment induces an increase in HGF migration without changing cell viability or causing membrane damage. HGF migration was related to an increase in intracellular ROS, changes in the expression of three of the migration-related genes (EGFR, PAK1, and MAPK1), and EGFR activation. Therefore

  13. 46 CFR 167.45-25 - Fire mains and hose connections.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... NAUTICAL SCHOOL SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-25 Fire mains and hose connections. All pipes used as mains for conducting water from fire pumps on nautical school ships shall be...

  14. Valiant load-balanced robust routing under hose model for WDM mesh networks

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoning; Li, Lemin; Wang, Sheng

    2006-09-01

    In this paper, we propose Valiant Load-Balanced robust routing scheme for WDM mesh networks under the model of polyhedral uncertainty (i.e., hose model), and the proposed routing scheme is implemented with traffic grooming approach. Our Objective is to maximize the hose model throughput. A mathematic formulation of Valiant Load-Balanced robust routing is presented and three fast heuristic algorithms are also proposed. When implementing Valiant Load-Balanced robust routing scheme to WDM mesh networks, a novel traffic-grooming algorithm called MHF (minimizing hop first) is proposed. We compare the three heuristic algorithms with the VPN tree under the hose model. Finally we demonstrate in the simulation results that MHF with Valiant Load-Balanced robust routing scheme outperforms the traditional traffic-grooming algorithm in terms of the throughput for the uniform/non-uniform traffic matrix under the hose model.

  15. 46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch... conform to the specification required by this paragraph. (n) Coupling shall conform to the requirements...

  16. 46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... metal. Couplings shall either: (1) Use National Standard fire hose coupling threads for the 11/2 inch... conform to the specification required by this paragraph. (n) Coupling shall conform to the requirements...

  17. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study)

    PubMed Central

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  18. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study).

    PubMed

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP.

  19. Retrieval Pump Flexible Suction Hose Dynamic Response Induced by Impact of a Mixer Pump Jet

    SciTech Connect

    Enderlin, C.W.; Terrones, G.; Bamberger, J.A.; White, M.; Combs, W.H.

    1999-10-07

    Experiments were conducted to investigate whether it may be feasible to simultaneously mix and retrieve radioactive waste slurries that are stored in million-gallon, double-shell tanks at the Hanford Site in Richland, Washington. Oscillating mixer pumps, located near the floor of these tanks, are used to mobilize and mix the slurry prior to retrieval. Operational scenarios that may be beneficial for retrieval may require simultaneous operation of a decant/transfer pump and the jet mixer pumps. The effects of jet-induced agitation and jet impingement upon the decant/transfer pump's flexible suction hose have not previously been experimentally evaluated. Possible effects of the jet impacting the hose include hose fatigue, hose collision or entanglement with other structures, and induced static and dynamic loads on the decant/transfer pump equipment. The objective of this work was to create operating conditions in a test tank that produce a dynamic response (in the flexible suction hose upon impingement from an above-floor jet) that is similar to that anticipated in the actual tank. A scaling analysis was conducted to define the interactions between the jet, the tank floor and the suction hose. The complexity of scaling the multi-layer flexible hose (matching its hydroelastic parameters at full and 1/4-scale) led to an alternate approach, that of matching the expected full-scale forces on the full-scale hose in the scaled tank. Two types of tests were conducted: characterization of the jet velocity profile in the test tank at two axial locations from the nozzle and observation of the motion induced in the flexible retrieval hose from impact by the jet. The velocity profile of the jet in the test tank was measured to compare the measured profiles with profile predictions for an above-floor jet. These data were used to obtain a refined estimate of the velocity profile and therefore, the force acting upon the test article at a particular location in the tank. The hose

  20. Microwave air plasmas in capillaries at low pressure I. Self-consistent modeling

    NASA Astrophysics Data System (ADS)

    Coche, P.; Guerra, V.; Alves, L. L.

    2016-06-01

    This work presents the self-consistent modeling of micro-plasmas generated in dry air using microwaves (2.45 GHz excitation frequency), within capillaries (<1 mm inner radius) at low pressure (300 Pa). The model couples the system of rate balance equations for the most relevant neutral and charged species of the plasma to the homogeneous electron Boltzmann equation. The maintenance electric field is self-consistently calculated adopting a transport theory for low to intermediate pressures, taking into account the presence of O- ions in addition to several positive ions, the dominant species being O{}2+ , NO+ and O+ . The low-pressure small-radius conditions considered yield very-intense reduced electric fields (˜600-1500 Td), coherent with species losses controlled by transport and wall recombination, and kinetic mechanisms strongly dependent on electron-impact collisions. The charged-particle transport losses are strongly influenced by the presence of the negative ion, despite its low-density (˜10% of the electron density). For electron densities in the range (1-≤ft. 4\\right)× {{10}12} cm-3, the system exhibits high dissociation degrees for O2 (˜20-70%, depending on the working conditions, in contrast with the  ˜0.1% dissociation obtained for N2), a high concentration of O2(a) (˜1014 cm-3) and NO(X) (5× {{10}14} cm-3) and low ozone production (<{{10}-3}% ).

  1. Atmospheric pressure resistive barrier air plasma jet induced bacterial inactivation in aqueous environment

    NASA Astrophysics Data System (ADS)

    Thiyagarajan, Magesh; Sarani, Abdollah; Gonzales, Xavier

    2013-03-01

    An atmospheric pressure resistive barrier air plasma jet is designed to inactivate bacteria in aqueous media in direct and indirect exposure modes of treatment. The resistive barrier plasma jet is designed to operate at both dc and standard 50-60 Hz low frequency ac power input and the ambient air at 50% humidity level was used as the operating gas. The voltage-current characteristics of the plasma jet were analyzed and the operating frequency of the discharge was measured to be 20 kHz and the plasma power was measured to be 26 W. The plasma jet rotational temperatures (Trot) are obtained from the optical emission spectra, from the N2C-B(2+) transitions by matching the experimental spectrum results with the Spectra Air (SPECAIR) simulation spectra. The reactive oxygen and nitrogen species were measured using optical emission spectroscopy and gas analyzers, for direct and indirect treatment modes. The nitric oxides (NO) were observed to be the predominant long lived reactive nitrogen species produced by the plasma. Three different bacteria including Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and Neisseria meningitidis (Gram-negative) were suspended in an aqueous media and treated by the resistive barrier air plasma jet in direct and indirect exposure modes. The results show that a near complete bacterial inactivation was achieved within 120 s for both direct and indirect plasma treatment of S. aureus and E. coli bacteria. Conversely, a partial inactivation of N. meningitidis was observed by 120 s direct plasma exposure and insignificant inactivation was observed for the indirect plasma exposure treatment. Plasma induced shifts in N. meningitidis gene expression was analyzed using pilC gene expression as a representative gene and the results showed a reduction in the expression of the pilC gene compared to untreated samples suggesting that the observed protection against NO may be regulated by other genes.

  2. Hosed vs. unhosed: interruptions of the Atlantic Meridional Overturning Circulation in a global coupled model, with and without freshwater forcing

    NASA Astrophysics Data System (ADS)

    Brown, Nicolas; Galbraith, Eric D.

    2016-08-01

    It is well known that glacial periods were punctuated by abrupt climate changes, with large impacts on air temperature, precipitation, and ocean circulation across the globe. However, the long-held idea that freshwater forcing, caused by massive iceberg discharges, was the driving force behind these changes has been questioned in recent years. This throws into doubt the abundant literature on modelling abrupt climate change through "hosing" experiments, whereby the Atlantic Meridional Overturning Circulation (AMOC) is interrupted by an injection of freshwater to the North Atlantic: if some, or all, abrupt climate change was not driven by freshwater input, could its character have been very different than the typical hosed experiments? Here, we describe spontaneous, unhosed oscillations in AMOC strength that occur in a global coupled ocean-atmosphere model when integrated under a particular background climate state. We compare these unhosed oscillations to hosed oscillations under a range of background climate states in order to examine how the global imprint of AMOC variations depends on whether or not they result from external freshwater input. Our comparison includes surface air temperature, precipitation, dissolved oxygen concentrations in the intermediate-depth ocean, and marine export production. The results show that the background climate state has a significant impact on the character of the freshwater-forced AMOC interruptions in this model, with particularly marked variations in tropical precipitation and in the North Pacific circulation. Despite these differences, the first-order patterns of response to AMOC interruptions are quite consistent among all simulations, implying that the ocean-sea ice-atmosphere dynamics associated with an AMOC weakening dominate the global response, regardless of whether or not freshwater input is the cause. Nonetheless, freshwater addition leads to a more complete shutdown of the AMOC than occurs in the unhosed oscillations

  3. Modeling the chemical kinetics of high-pressure glow discharges in mixtures of helium with real air

    NASA Astrophysics Data System (ADS)

    Stalder, K. R.; Vidmar, R. J.; Nersisyan, G.; Graham, W. G.

    2006-05-01

    Atmospheric and near-atmospheric pressure glow discharges generated in both pure helium and helium-air mixtures have been studied using a plasma chemistry code originally developed for simulations of electron-beam-produced air plasmas. Comparisons are made with experimental data obtained from high-pressure glow discharges in helium-air mixtures developed by applying sinusoidal voltage wave forms between two parallel planar metallic electrodes covered by glass plates, with frequencies ranging from 10 to 50 kHz and electric field strengths up to 5 kV/cm. The code simulates the plasma chemistry following periodic pulsations of ionization in prescribed E/N environments. Many of the rate constants depend on gas temperature, electron temperature, and E/N. In helium plasmas with small amounts (~850 ppm) of air added, rapid conversion of atomic helium ions to molecular helium ions dominate the positive ion kinetics and these species are strongly modulated while the radical species are not. The charged and neutral species concentrations at atmospheric pressure with air impurity levels up to 10 000 ppm are predicted. The negative ion densities are very small but increase as the air impurity level is raised, which indicates that in helium-based systems operated in open air the concentration of negative ions would be significant. If water vapor at typical humidity levels is present as one of the impurities, hydrated cluster ions eventually comprise a significant fraction of the charged species.

  4. Use of nose cap and fuselage pressure orifices for determination of air data for space shuttle orbiter below supersonic speeds

    NASA Technical Reports Server (NTRS)

    Larson, T. J.; Siemers, P. M., III

    1980-01-01

    Wind tunnel pressure measurements were acquired from orifices on a 0.1 scale forebody model of the space shuttle orbiter that were arranged in a preliminary configuration of the shuttle entry air data system (SEADS). Pressures from those and auxiliary orifices were evaluated for their ability to provide air data at subsonic and transonic speeds. The orifices were on the vehicle's nose cap and on the sides of the forebody forward of the cabin. The investigation covered a Mach number range of 0.25 to 1.40 and an angle of attack range from 4 deg. to 18 deg. An air data system consisting of nose cap and forebody fuselage orifices constitutes a complete and accurate air data system at subsonic and transonic speeds. For Mach numbers less than 0.80 orifices confined to the nose cap can be used as a complete and accurate air data system. Air data systems that use only flush pressure orifices can be used to determine basic air data on other aircraft at subsonic and transonic speeds.

  5. High-Reynolds-number turbulent-boundary-layer wall pressure fluctuations with skin-friction reduction by air injection.

    PubMed

    Winkel, Eric S; Elbing, Brian R; Ceccio, Steven L; Perlin, Marc; Dowling, David R

    2008-05-01

    The hydrodynamic pressure fluctuations that occur on the solid surface beneath a turbulent boundary layer are a common source of flow noise. This paper reports multipoint surface pressure fluctuation measurements in water beneath a high-Reynolds-number turbulent boundary layer with wall injection of air to reduce skin-friction drag. The experiments were conducted in the U.S. Navy's Large Cavitation Channel on a 12.9-m-long, 3.05-m-wide hydrodynamically smooth flat plate at freestream speeds up to 20 ms and downstream-distance-based Reynolds numbers exceeding 200 x 10(6). Air was injected from one of two spanwise slots through flush-mounted porous stainless steel frits (approximately 40 microm mean pore diameter) at volume flow rates from 17.8 to 142.5 l/s per meter span. The two injectors were located 1.32 and 9.78 m from the model's leading edge and spanned the center 87% of the test model. Surface pressure measurements were made with 16 flush-mounted transducers in an "L-shaped" array located 10.7 m from the plate's leading edge. When compared to no-injection conditions, the observed wall-pressure variance was reduced by as much as 87% with air injection. In addition, air injection altered the inferred convection speed of pressure fluctuation sources and the streamwise coherence of pressure fluctuations.

  6. A global ground truth view of the lunar air pressure tide L2

    NASA Astrophysics Data System (ADS)

    Schindelegger, Michael; Dobslaw, Henryk

    2016-01-01

    A comprehensive model of the lunar air pressure tide L2 is developed on the basis of 2315 ground truth estimates from land barometers and moored buoys. Regional-scale features of the tide and its seasonal modulations are well resolved by the in situ scatter and gridded to a 2° mesh through multiquadric interpolation. The resulting climatologies serve as an independent standard to validate the lunar semidiurnal tidal signal that is present in ERA-Interim reanalysis products despite the absence of L2-related gravitational forcing mechanisms in the prescribed model physics. Inconsistencies between the reanalysis solution of the barometric lunar tide and its empirical account are generally small, yet when averaged over the period 1979-2010, ERA-Interim underestimates the 100 μbar open ocean tidal amplitude in the Tropics by up to 20 μbar and produces times of peak pressure that are too early by 10 lunar minutes. Large-amplitude features of the reanalysis tide off the coast of Alaska, the eastern U.S., and Great Britain are evidently spurious, introduced to the analysis system by assimilating marine pressure data at an invariant reference surface instead of properly accounting for vertical sensor movements associated with the M2 ocean tide. Additionally, a credible L2 signal is documented for the ERA-20C pilot reanalysis of the twentieth century. The fact that this model rests upon input data from mere surface observations provides an unambiguous indication that the lunar tidal oscillation in atmospheric analysis systems is closely tied to the assimilation of conventional pressure measurements from stations and marine objects.

  7. Association between long-term air pollution and increased blood pressure and hypertension in China.

    PubMed

    Dong, Guang-Hui; Qian, Zhengmin Min; Xaverius, Pamela K; Trevathan, Edwin; Maalouf, Salwa; Parker, Jamaal; Yang, Laiji; Liu, Miao-Miao; Wang, Da; Ren, Wan-Hui; Ma, Wenjun; Wang, Jing; Zelicoff, Alan; Fu, Qiang; Simckes, Maayan

    2013-03-01

    Several studies have investigated the short-term effects of ambient air pollutants in the development of high blood pressure and hypertension. However, little information exists regarding the health effects of long-term exposure. To investigate the association between residential long-term exposure to air pollution and blood pressure and hypertension, we studied 24 845 Chinese adults in 11 districts of 3 northeastern cities from 2009 to 2010. Three-year average concentration of particles with an aerodynamic diameter ≤10 µm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxides (NO(2)), and ozone (O(3)) were calculated from monitoring stations in the 11 districts. We used generalized additive models and 2-level logistic regressions models to examine the health effects. The results showed that the odds ratio for hypertension increased by 1.12 (95% confidence interval [CI], 1.08-1.16) per 19 μg/m(3) increase in PM(10), 1.11 (95% CI, 1.04-1.18) per 20 μg/m(3) increase in SO(2), and 1.13 (95% CI, 1.06-1.20) per 22 μg/m(3) increase in O(3). The estimated increases in mean systolic and diastolic blood pressure were 0.87 mm Hg (95% CI, 0.48-1.27) and 0.32 mm Hg (95% CI, 0.08-0.56) per 19 μg/m(3) interquartile increase in PM(10), 0.80 mm Hg (95% CI, 0.46-1.14) and 0.31 mm Hg (95% CI, 0.10-0.51) per 20 μg/m(3) interquartile increase in SO(2), and 0.73 mm Hg (95% CI, 0.35-1.11) and 0.37 mm Hg (95% CI, 0.14-0.61) per 22 μg/m(3) interquartile increase in O(3). These associations were only statistically significant in men. In conclusion, long-term exposure to PM(10), SO(2), and O(3) was associated with increased arterial blood pressure and hypertension in the study population.

  8. Laser-induced cooling of a Yb:YAG crystal in air at atmospheric pressure.

    PubMed

    Soares de Lima Filho, Elton; Nemova, Galina; Loranger, Sébastien; Kashyap, Raman

    2013-10-21

    We report for the first time the experimental demonstration of optical cooling of a bulk crystal at atmospheric pressure. The use of a fiber Bragg grating (FBG) sensor to measure laser-induced cooling in real time is also demonstrated for the first time. A temperature drop of 8.8 K from the chamber temperature was observed in a Yb:YAG crystal in air when pumped with 4.2 W at 1029 nm. A background absorption of 2.9 × 10⁻⁴ cm⁻¹ was estimated with a pump wavelength at 1550 nm. Simulations predict further cooling if the pump power is optimized for the sample's dimensions.

  9. Solvent Selection for Pressurized Liquid Extraction of Polymeric Sorbents Used in Air Sampling

    PubMed Central

    Primbs, Toby; Genualdi, Susan; Simonich, Staci

    2014-01-01

    Pressurized liquid extraction (PLE) was evaluated as a method for extracting semivolatile organic compounds (SOCs) from air sampling media; including quartz fiber filter (QFF), polyurethane foam (PUF), and a polystyrene divinyl benzene copolymer (XAD-2). Hansen solubility parameter plots were used to aid in the PLE solvent selection in order to reduce both co-extraction of polyurethane and save time in evaluating solvent compatibility during the initial steps of method development. A PLE solvent composition of 75:25% hexane:acetone was chosen for PUF. The XAD-2 copolymer was not solubilized under the PLE conditions used. The average percent PLE recoveries (and percent relative standard deviations) of 63 SOCs, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine, amide, triazine, thiocarbamate, and phosphorothioate pesticides, were 76.7 (6.2), 79.3 (8.1), and 93.4 (2.9) % for the QFF, PUF, and XAD-2, respectively. PMID:18220448

  10. Atmospheric pressure discharge plasma decomposition for gaseous air contaminants -- Trichlorotrifluoroethane and trichloroethylene

    SciTech Connect

    Oda, Tetsuji; Yamashita, Ryuichi; Takahashi, Tadashi; Masuda, Senichi

    1996-03-01

    The decomposition performance of gaseous environmental destructive contaminants in air by using atmospheric pressure discharged plasma including the surface discharge induced plasma chemical processing (SPCP) was examined. The main contaminants tested were chlorofluorocarbon (CFC-113) and trichloroethylene, typically. The discharge exciting frequency range studied was wide--50 Hz to 50 kHz. Results showed the low frequency discharge requires high voltage to inject high electric power in the gas and to decompose the contaminants. A Gas Chromatograph Mass Spectrometer was used to analyze discharge products of dense CFC-113 or trichloroethylene. Among the detected products were HCl, CClFO, and CHCl{sub 3}. Two different electrode configurations; the silent discharge (coaxial) electrode and the coil-electrode were also tested and compared to each other as a gas reactor.

  11. A simple atmospheric pressure room-temperature air plasma needle device for biomedical applications

    NASA Astrophysics Data System (ADS)

    Lu, X.; Xiong, Z.; Zhao, F.; Xian, Y.; Xiong, Q.; Gong, W.; Zou, C.; Jiang, Z.; Pan, Y.

    2009-11-01

    Rather than using noble gas, room air is used as the working gas for an atmospheric pressure room-temperature plasma. The plasma is driven by submicrosecond pulsed directed current voltages. Several current spikes appear periodically for each voltage pulse. The first current spike has a peak value of more than 1.5 A with a pulse width of about 10 ns. Emission spectra show that besides excited OH, O, N2(C-B), and N2+(B-X) emission, excited NO, N2(B-A), H, and even N emission are also observed in the plasma, which indicates that the plasma may be more reactive than that generated by other plasma jet devices. Utilizing the room-temperature plasma, preliminary inactivation experiments show that Enterococcus faecalis can be killed with a treatment time of only several seconds.

  12. Experimental modeling of air blowing into a turbulent boundary layer using an external pressure flow

    NASA Astrophysics Data System (ADS)

    Kornilov, V. I.; Boiko, A. V.

    2016-10-01

    We have experimentally investigated the characteristics of an incompressible turbulent boundary layer on a plane plate upon the passive blowing of air through a fine-perforated surface and flushing it by supplying an external pressure flow through a wind tunnel using an intake device equipped with an attachment for draining the boundary layer on the inactive side of the plate. A stable decrease in the local values of the surface coefficient of friction, which reaches 80% at the end of the perforated region, has been detected over the length of the plate. The possibility of controlling surface friction by changing the velocity of the external flow and selecting the meshes and filters at the inlet to the flow passage has been demonstrated.

  13. Soft X-ray radiation due to a nanosecond diffuse discharge in atmospheric-pressure air

    NASA Astrophysics Data System (ADS)

    Kostyrya, I. D.; Tarasenko, V. F.

    2010-02-01

    A source of soft X-rays with an effective photon energy of 9 keV and a subnanosecond pulse width is built around a gas diode filled with atmospheric-pressure air and a UAEB-150 generator. A collector placed behind a grounded mesh electrode detects an electron beam and a pulse with positive polarity, the latter being due to an electric field surrounding the mesh. It is shown that the intensity of soft X-rays from the gas-diode-based source depends on the material of a massive potential anode; namely, it grows with an increase in the atomic number of the cathode material. In the case of a tantalum anode, X-ray photons with an effective energy of 9 and 17 keV contribute to the exposure dose.

  14. Subnanosecond pulsed X-ray source based on nanosecond discharge in air at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Kostyrya, I. D.; Tarasenko, V. F.

    2009-06-01

    We have studied the characteristics of an X-ray source based on a gas diode filled with air at atmospheric pressure. Driven by a SLEP-150 pulser with a maximum voltage amplitude of ˜140 kV, a pulse full width at half maximum (FWHM) of ˜1 ns, and a leading front width of ˜0.3 ns, a soft X-ray source produces subnanosecond pulses with an FWHM not exceeding 600 ps and an exposure dose of ˜3 mR per pulse. It is shown that the main contribution to the measured exposure dose is due to X-ray quanta with an effective energy of ˜7.5 keV.

  15. Synthesis of ammonia directly from air and water at ambient temperature and pressure

    PubMed Central

    Lan, Rong; Irvine, John T. S.; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

  16. Synthesis of ammonia directly from air and water at ambient temperature and pressure.

    PubMed

    Lan, Rong; Irvine, John T S; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

  17. Cell immobilization on polymer by air atmospheric pressure plasma jet treatment

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Hwan; Kwon, Jae-Sung; Om, Ji-yeon; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2014-08-01

    The study of cell immobilization on delicate polymer by an air atmospheric pressure plasma jet (AAPPJ) is required for its medical application. The aim of this study was to evaluate whether AAPPJ treatment induce cell immobilization effect on delicate polymers without significant change of surface roughness by AAPPJ treatment. After surface roughness, dynamic contact angle, and chemical characteristics were investigated, the immobilization effect was evaluated with the mouse fibroblast L929 cell line. Surface roughness change was not observed (P > 0.05) in either delicate dental wax or polystyrene plate (PSP) as advancing and receding contact angles significantly decreased (P < 0.05), thanks to decreased hydrocarbon and formation of oxygen-related functional groups in treated PSP. Adherent L929 cells with elongated morphology were found in treated PSP along with the formation of immobilization markers vinculin and actin cytoskeleton. Increased PTK2 gene expression upregulated these markers on treated PSP.

  18. The meteorological data of William Hutchinson and a Liverpool air pressure time series spanning 1768-1999

    NASA Astrophysics Data System (ADS)

    Woodworth, Philip L.

    2006-10-01

    This paper discusses some of the meteorological measurements made at Liverpool by Captain William Hutchinson in the second half of the eighteenth century. It gives an overview of the various data sets, most of which are now in computer-accessible form, and provides assessments of their quality, the aim being to gain an overall impression of how good an observer Hutchinson was. His air pressure data have been studied in detail, through comparisons with information from other UK stations, and via investigation of the sea-level response to air pressure changes as observed in his tidal measurements. A first attempt has been made to construct a Liverpool air pressure time series spanning 1768-1999, by means of the combination of Hutchinson's data with later information from the Liverpool docks and Bidston Observatory.

  19. Helium:oxygen versus air:oxygen noninvasive positive-pressure ventilation in patients exposed to sulfur mustard.

    PubMed

    Ghanei, Mostafa; Rajaeinejad, Mohsen; Motiei-Langroudi, Rouzbeh; Alaeddini, Farshid; Aslani, Jafar

    2011-01-01

    Exposure to sulfur mustard (SM) causes a variety of respiratory symptoms, such as chronic bronchitis and constrictive bronchiolitis. This study assessed the effectiveness of noninvasive positive-pressure ventilation, adjunct with 79:21 helium:oxygen instead of 79:21 air:oxygen, in 24 patients with a previous exposure to SM presenting with acute respiratory failure. Both air:oxygen and helium:oxygen significantly decreased systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse rate, respiratory rate, dyspnea, and increased oxygen saturation (P values: .007, .029, .002, <.001, <.001, <.001, and .002 for air:oxygen, respectively, and <.001, .020, .001, <.001, <.001, <.001, and .002, for helium:oxygen, respectively). Moreover, helium:oxygen more potently improved systolic pressure, mean arterial pressure, pulse rate, respiratory rate, and dyspnea (P values: .012, .048, <.001, <.001, and .012, respectively). The results of our study support the benefit of using helium:oxygen adjunct with noninvasive positive-pressure ventilation in patients exposed to SM with acute respiratory decompensation.

  20. Ozone production in parallel multichannel dielectric barrier discharge from oxygen and air: the influence of gas pressure

    NASA Astrophysics Data System (ADS)

    Yuan, Dingkun; Wang, Zhihua; Ding, Can; He, Yong; Whiddon, Ronald; Cen, Kefa

    2016-11-01

    This research aims to investigate the influence of gas pressure (0.1 Mpa-0.2 Mpa) on ozone generation in a parallel multichannel dielectric barrier discharge (DBD) reactor with a narrow gap (0.2 mm). In addition to determining ozone concentration and ozone yield characteristics with gas pressure variation, this paper examines the possible reasons leading to the inconsistency with previous reported results. All the experimental results are plotted on the basis of specific input energy (SIE) in order to conduct the comparison within identical power density. By reviewing the experimental results, the possible cause leading to the inconsistency concerning gas pressure dependences of ozone generation was found using different comparison bases. Results show that ozone generation is slightly suppressed with an increase of gas pressure with an initial increase in SIE. The results of the ozone yield show that an increase of gas pressure would have a favorable effect on ozone production efficiency with an SIE larger than 400 J l-1 in oxygen while ozone yield reaches the maximum at 0.14 Mpa with an SIE larger than 150 J l-1 in air. Increasing gas pressure would lead to a higher critical SIE value at which ozone yield firstly decreases with an increase of SIE both in oxygen and air. The results of nitrogen oxide byproducts show that both NO x byproducts emission and the discharge poisoning effect are suppressed by increasing gas pressure in air plasmas.

  1. Respiratory effects of warm and dry air at increased ambient pressure.

    PubMed

    Thorsen, E; Rønnestad, I; Segadal, K; Hope, A

    1992-03-01

    We have measured in 7 divers forced vital capacity (FVC), forced expired volume in 1 s (FEV1), and forced midexpiratory flow rate (FEF25-75%) before and after exposure to dry or humid breathing gas of 35.3 degrees-36.8 degrees C (air) when diving to pressures of 117-600 kPa. The response was compared with the subjects' reactivity to pharmacologic bronchoprovocation with methacholine. Baseline FEV1 and FEF25-75% decreased in accordance with increasing gas density. Relative to baseline, there was a significant reduction after the dives in FEV1 of 4.0 +/- 6.1% (P less than 0.05) and in FEF25-75% of 8.6 +/- 9.7% (P less than 0.01) with exposure to dry breathing gas. By analysis of variance the reduction in the lung function variables below baseline were related to the breathing gas characteristic (dry/humid) (P less than 0.01), bronchial hyperreactivity (P less than 0.02), and ambient pressure (P less than 0.02) independently of each other. There was no significant change in FVC after the exposures. Humid breathing gas was considered more comfortable than dry breathing gas, and the upper comfort limit for breathing gas temperature was higher with humid breathing gas. Convective respiratory heat loss was negligible in these experiments, indicating that dry gas itself had a significant bronchoconstrictive effect. Bronchial hyperreactivity may cause increased risk of development of bronchial obstruction and air trapping during diving.

  2. Soot Surface Oxidation in Laminar Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix I

    NASA Technical Reports Server (NTRS)

    Xu, F.; El-Leathy, A. M.; Kim, C. H.; Faeth, G. M.; Yuan, Z.-G. (Technical Monitor); Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2003-01-01

    Soot surface oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round fuel jets burning in coflowing dry air considering acetylene-nitrogen, ethylene, propyiene-nitrogen, propane and acetylene-benzene-nitrogen in the fuel stream. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of major stable gas species (N2, H2O, H2, O2, CO, CO2, CH4, C2H2, C2H6, C3H6, C3H8, and C6H6) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by deconvoluted Li/LiOH atomic absorption and flow velocities by laser velocimetry. For present test conditions, it was found that soot surface oxidation rates were not affected by fuel type, that direct rates of soot surface oxidation by O2 estimated from Nagle and Strickland-Constable (1962) were small compared to observed soot surface oxidation rates because soot surface oxidation was completed near the flame sheet where O2 concentrations were less than 3% by volume, and that soot surface oxidation rates were described by the OH soot surface oxidation mechanism with a collision efficiency of 0.14 and an uncertainty (95% confidence) of +/- 0.04 when allowing for direct soot surface oxidation by O2, which is in reasonably good agreement with earlier observations of soot surface oxidation rates in both premixed and diffusion flames at atmospheric pressure.

  3. An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Jung, Wooseok; Barrett, Matthew; Brooks, Carla; Rivera, Andrew; Birdsell, Dawn N.; Wagner, David M.; Zenhausern, Frederic

    2015-12-01

    We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30-100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis.

  4. Implementation of pressurized air injection system in a Kaplan prototype for the reduction of vibration caused by tip vortex cavitation

    NASA Astrophysics Data System (ADS)

    Rivetti, A.; Angulo, M.; Lucino, C.; Hene, M.; Capezio, O.; Liscia, S.

    2016-11-01

    Blade tip cavitation is a well-known phenomenon that affects the performance of large-diameter Kaplan turbines and induces structural vibration. Injection of pressurized air has been found to yield promising results in reducing those damaging effects. In this work, the results of an experimental test of air injection on a 9.5-m-diameter Kaplan turbine are reported. Experiments were performed for several load conditions and for two different net heads. Accelerations, pressure pulsation and noise emission were monitored for every tested condition. Results show that, at the expense of a maximum efficiency drop of 0.2%, air injection induces a decrease on the level of vibration from 57% up to 84%, depending on the load condition. Such decrease is seen to be proportional to the air flow rate, in the range from 0.06 to 0.8‰ (respect to the discharge at the best efficiency point).

  5. Elimination of diazinon insecticide from cucumber surface by atmospheric pressure air-dielectric barrier discharge plasma.

    PubMed

    Dorraki, Naghme; Mahdavi, Vahideh; Ghomi, Hamid; Ghasempour, Alireza

    2016-12-06

    The food industry is in a constant search for new technologies to improve the commercial sterilization process of agricultural commodities. Plasma treatment may offer a novel and efficient method for pesticide removal from agricultural product surfaces. To study the proposed technique of plasma food treatment, the degradation behavior of diazinon insecticide by air-dielectric barrier discharge (DBD) plasma was investigated. The authors studied the effect of different plasma powers and treatment times on pesticide concentration in liquid form and coated on the surface of cucumbers, where the diazinon residue was analyzed with mass spectroscopy gas chromatography. Our results suggest that atmospheric pressure air-DBD plasma is potentially effective for the degradation of diazinon insecticide, and mainly depends on related operating parameters, including plasma treatment time, discharge power, and pesticide concentrations. Based on the interaction between reactive oxygen species and electrons in the plasma with the diazinon molecule, two degradation pathway of diazinon during plasma treatment are proposed. It was also found that produced organophosphate pesticides are harmless and less hazardous compounds than diazinon.

  6. Use of MODIS Cloud Top Pressure to Improve Assimilation Yields of AIRS Radiances in GSI

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA's Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Previously, it has been shown that cloud top designation associated with quality control procedures within the Gridpoint Statistical Interpolation (GSI) system used operationally by a number of Joint Center for Satellite Data Assimilation (JCSDA) partners may not provide the best representation of cloud top pressure (CTP). Because this designated CTP determines which channels are cloud-free and, thus, available for assimilation, ensuring the most accurate representation of this value is imperative to obtaining the greatest impact from satellite radiances. This paper examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing analysis increments and numerical forecasts generated using operational techniques with a research technique that swaps CTP from the Moderate-resolution Imaging Spectroradiometer (MODIS) for the value of CTP calculated from the radiances within GSI.

  7. Discharge modes of a DC operated atmospheric pressure air plasma jet

    NASA Astrophysics Data System (ADS)

    Kolb, Juergen; Pei, Xuekai; Kredl, Jana; Lu, Xinpei

    2016-09-01

    By flowing air or nitrogen through a microhollow cathode discharge geometry an afterglow plasma jet can be generated at atmospheric pressure in air. The plasma jet has been successfully used for the inactivation of bacteria and yeast. The responsible reaction chemistry is based on the production of high concentrations of nitric oxide. Production yields depend in particular on gas flow rate and energy dissipated in the plasma. The same parameters also determine different modes of operation for the jet. A true DC operation is achieved for low to moderate gas flow rate of about 1 slm and discharge currents on the order of 10 mA. When increasing the gas flow rate to 10 slm the operation is changing to a self-pulsing mode with characteristics similar to the ones observed for a transient spark. By increasing the current a DC operation can be achieved again also at higher gas flow rates. The parameter regimes for different modes of operation can be described by the reduced electric field E/N.

  8. Afterglow chemistry of atmospheric-pressure helium-oxygen plasmas with humid air impurity

    NASA Astrophysics Data System (ADS)

    Murakami, Tomoyuki; Niemi, Kari; Gans, Timo; O'Connell, Deborah; Graham, William G.

    2014-04-01

    The formation of reactive species in the afterglow of a radio-frequency-driven atmospheric-pressure plasma in a fixed helium-oxygen feed gas mixture (He+0.5%O2) with humid air impurity (a few hundred ppm) is investigated by means of an extensive global plasma chemical kinetics model. As an original objective, we explore the effects of humid air impurity on the biologically relevant reactive species in an oxygen-dependent system. After a few milliseconds in the afterglow environment, the densities of atomic oxygen (O) decreases from 1015 to 1013 cm-3 and singlet delta molecular oxygen (O2(1D)) of the order of 1015 cm-3 decreases by a factor of two, while the ozone (O3) density increases from 1014 to 1015 cm-3. Electrons and oxygen ionic species, initially of the order of 1011 cm-3, recombine much faster on the time scale of some microseconds. The formation of atomic hydrogen (H), hydroxyl radical (OH), hydroperoxyl (HO2), hydrogen peroxide (H2O2), nitric oxide (NO) and nitric acid (HNO3) resulting from the humid air impurity as well as the influence on the afterglow chemistry is clarified with particular emphasis on the formation of dominant reactive oxygen species (ROS). The model suggests that the reactive species predominantly formed in the afterglow are major ROS O2(1D) and O3 (of the order of 1015 cm-3) and rather minor hydrogen- and nitrogen-based reactive species OH, H2O2, HNO3 and NO2/NO3, of which densities are comparable to the O-atom density (of the order of 1013 cm-3). Furthermore, the model quantitatively reproduces the experimental results of independent O and O3 density measurements.

  9. Effects of moderate strength cold air exposure on blood pressure and biochemical indicators among cardiovascular and cerebrovascular patients.

    PubMed

    Zhang, Xiakun; Zhang, Shuyu; Wang, Chunling; Wang, Baojian; Guo, Pinwen

    2014-02-27

    The effects of cold air on cardiovascular and cerebrovascular diseases were investigated in an experimental study examining blood pressure and biochemical indicators. Zhangye, a city in Gansu Province, China, was selected as the experimental site. Health screening and blood tests were conducted, and finally, 30 cardiovascular disease patients and 40 healthy subjects were recruited. The experiment was performed during a cold event during 27-28 April 2013. Blood pressure, catecholamine, angiotensin II (ANG-II), cardiac troponin I (cTnI), muscle myoglobin (Mb) and endothefin-1 (ET-1) levels of the subjects were evaluated 1 day before, during the 2nd day of the cold exposure and 1 day after the cold air exposure. Our results suggest that cold air exposure increases blood pressure in cardiovascular disease patients and healthy subjects via the sympathetic nervous system (SNS) that is activated first and which augments ANG-II levels accelerating the release of the norepinephrine and stimulates the renin-angiotensin system (RAS). The combined effect of these factors leads to a rise in blood pressure. In addition, cold air exposure can cause significant metabolism and secretion of Mb, cTnI and ET-1 in subjects; taking the patient group as an example, ET-1 was 202.7 ng/L during the cold air exposure, increased 58 ng/L compared with before the cold air exposure, Mb and cTnI levels remained relatively high (2,219.5 ng/L and 613.2 ng/L, increased 642.1 ng/L and 306.5 ng/L compared with before the cold air exposure, respectively) 1-day after the cold exposure. This showed that cold air can cause damage to patients' heart cells, and the damage cannot be rapidly repaired. Some of the responses related to the biochemical markers indicated that cold exposure increased cardiovascular strain and possible myocardial injury.

  10. Effect of airstream velocity on mean drop diameters of water sprays produced by pressure and air atomizing nozzles

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1977-01-01

    A scanning radiometer was used to determine the effect of airstream velocity on the mean drop diameter of water sprays produced by pressure atomizing and air atomizing fuel nozzles used in previous combustion studies. Increasing airstream velocity from 23 to 53.4 meters per second reduced the Sauter mean diameter by approximately 50 percent with both types of fuel nozzles. The use of a sonic cup attached to the tip of an air assist nozzle reduced the Sauter mean diameter by approximately 40 percent. Test conditions included airstream velocities of 23 to 53.4 meters per second at 293 K and atmospheric pressure.

  11. Etching of polymers, proteins and bacterial spores by atmospheric pressure DBD plasma in air

    NASA Astrophysics Data System (ADS)

    Kuzminova, A.; Kretková, T.; Kylián, O.; Hanuš, J.; Khalakhan, I.; Prukner, V.; Doležalová, E.; Šimek, M.; Biederman, H.

    2017-04-01

    Many studies proved that non-equilibrium discharges generated at atmospheric pressure are highly effective for the bio-decontamination of surfaces of various materials. One of the key processes that leads to a desired result is plasma etching and thus the evaluation of etching rates of organic materials is of high importance. However, the comparison of reported results is rather difficult if impossible as different authors use diverse sources of atmospheric plasma that are operated at significantly different operational parameters. Therefore, we report here on the systematic study of the etching of nine different common polymers that mimic the different structures of more complicated biological systems, bovine serum albumin (BSA) selected as the model protein and spores of Bacillus subtilis taken as a representative of highly resistant micro-organisms. The treatment of these materials was performed by means of atmospheric pressure dielectric barrier discharge (DBD) sustained in open air at constant conditions. All tested polymers, BSA and spores, were readily etched by DBD plasma. However, the measured etching rates were found to be dependent on the chemical structure of treated materials, namely on the presence of oxygen in the structure of polymers.

  12. Diffuse plasma treatment of polyamide 66 fabric in atmospheric pressure air

    NASA Astrophysics Data System (ADS)

    Li, Lee; Peng, Ming-yang; Teng, Yun; Gao, Guozhen

    2016-01-01

    The polyamide 66 (PA66) fabrics are hard to be colored or glued in industrial production due to the poor hydrophily. Diffuse plasma is a kind of non-thermal plasma generated at atmospheric pressure in air. This paper proposes that large-scale diffuse plasma generated between wire electrodes can be employed for improving the hydrophily of PA66 fabrics. A repetitive nanosecond-pulse diffuse-discharge reactor using a cylindrical wire electrode configuration is presented, which can generate large-scale non-thermal plasmas steadily at atmospheric pressure without any barrier dielectric. Then the reactor is used to treat PA66 fabrics in different discharge conditions. The hydrophilicity property of modified PA66 is measured by wicking test method. The modified PA66 is also analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to prove the surface changes in physical microstructure and chemical functional groups, respectively. What's more, the effects of treatment time and treatment frequency on surface modification are investigated and discussed.

  13. Interaction of Atmospheric-Pressure Air Microplasmas with Amino Acids as Fundamental Processes in Aqueous Solution.

    PubMed

    Zhou, Renwu; Zhou, Rusen; Zhuang, Jinxing; Zong, Zichao; Zhang, Xianhui; Liu, Dongping; Bazaka, Kateryna; Ostrikov, Kostya

    2016-01-01

    Plasma medicine is a relatively new field that investigates potential applications of cold atmospheric-pressure plasmas in bioengineering, such as for bacterial inactivation and degradation of organic molecules in water. In order to enunciate mechanisms of bacterial inactivation at molecular or atomic levels, we investigated the interaction of atmospheric-pressure air microplasmas with amino acids in aqueous solution by using high-resolution mass spectrometry (HRMS). Results show that the oxidation effect of plasma-induced species on the side chains of the amino acids can be categorized into four types, namely hydroxylation, nitration, dehydrogenation and dimerization. In addition, relative activities of amino acids resulting from plasma treatment come in descending order as follows: sulfur-containing carbon-chain amino acids > aromatic amino acids > five-membered ring amino acids > basic carbon-chain amino acids. Since amino acids are building blocks of proteins vital to the growth and reproduction of bacteria, these results provide an insight into the mechanism of bacterial inactivation by plasma.

  14. The effects of air pressure on spontaneous otoacoustic emissions of lizards.

    PubMed

    van Dijk, Pim; Manley, Geoffrey A

    2013-06-01

    Small changes of air pressure outside the eardrum of five lizard species led to changes in frequency, level, and peak width of spontaneous otoacoustic emissions (SOAE). In contrast to humans, these changes generally occurred at very small pressures (<20 mbar). As in humans, SOAE amplitudes were generally reduced. Changes of SOAE frequency were both positive and negative, while in humans, they are mostly positive. In addition, in lizards, these effects often showed obvious hysteresis and non-repeatability. The correlation between peak width and height was negative in two species (comparable to humans) and positive in one species. In two other species, no correlation was found. Consequently, a simple oscillator model that explained the negative correlation in humans could not be generally applied to lizards. This presumably reflects the fact that in lizards, the spontaneous otoacoustic emission of sound from the ear consists of a combination of stable oscillations (as in humans), unstable narrow-band oscillations, and broad-band emissions, evident as "plateaus" in emission spectra.

  15. Interaction of Atmospheric-Pressure Air Microplasmas with Amino Acids as Fundamental Processes in Aqueous Solution

    PubMed Central

    Zhou, Renwu; Zhou, Rusen; Zhuang, Jinxing; Zong, Zichao; Zhang, Xianhui; Liu, Dongping; Bazaka, Kateryna; Ostrikov, Kostya

    2016-01-01

    Plasma medicine is a relatively new field that investigates potential applications of cold atmospheric-pressure plasmas in bioengineering, such as for bacterial inactivation and degradation of organic molecules in water. In order to enunciate mechanisms of bacterial inactivation at molecular or atomic levels, we investigated the interaction of atmospheric-pressure air microplasmas with amino acids in aqueous solution by using high-resolution mass spectrometry (HRMS). Results show that the oxidation effect of plasma-induced species on the side chains of the amino acids can be categorized into four types, namely hydroxylation, nitration, dehydrogenation and dimerization. In addition, relative activities of amino acids resulting from plasma treatment come in descending order as follows: sulfur-containing carbon-chain amino acids > aromatic amino acids > five-membered ring amino acids > basic carbon-chain amino acids. Since amino acids are building blocks of proteins vital to the growth and reproduction of bacteria, these results provide an insight into the mechanism of bacterial inactivation by plasma. PMID:27183129

  16. Pilot Study of the Effects of Simulated Turbine Passage Pressure on Juvenile Chinook Salmon Acclimated with Access to Air at Absolute Pressures Greater than Atmospheric

    SciTech Connect

    Carlson, Thomas J.; Abernethy, Cary S.

    2005-04-28

    The impacts of pressure on juvenile salmon who pass through the turbines of hydroelectric dams while migrating downstream on the Columbia and Snake rivers has not been well understood, especially as these impacts relate to injury to the fish's swim bladder. The laboratory studies described here were conducted by Pacific Northwest National Laboratory for the US Army Corps of Engineers Portland District at PNNL's fisheries research laboratories in 2004 to investigate the impacts of simulated turbine passage pressure on fish permitted to achieve neutral buoyancy at pressures corresponding to depths at which they are typically observed during downstream migration. Two sizes of juvenile Chinook salmon were tested, 80-100mm and 125-145mm total length. Test fish were acclimated for 22 to 24 hours in hyperbaric chambers at pressures simulating depths of 15, 30, or 60 ft, with access to a large air bubble. High rates of deflated swim bladders and mortality were observed. Our results while in conclusive show that juvenile salmon are capable of drawing additional air into their swimbladder to compensate for the excess mass of implanted telemetry devices. However they may pay a price in terms of increased susceptibility to injury, predation, and death for this additional air.

  17. Your garden hose: a potential health risk due to Legionella spp. growth facilitated by free-living amoebae.

    PubMed

    Thomas, Jacqueline M; Thomas, Torsten; Stuetz, Richard M; Ashbolt, Nicholas J

    2014-09-02

    Common garden hoses may generate aerosols of inhalable size (≤10 μm) during use. If humans inhale aerosols containing Legionella bacteria, Legionnaires' disease or Pontiac fever may result. Clinical cases of these illnesses have been linked to garden hose use. The hose environment is ideal for the growth and interaction of Legionella and free-living amoebae (FLA) due to biofilm formation, elevated temperatures, and stagnation of water. However, the microbial densities and hose conditions necessary to quantify the human health risks have not been reported. Here we present data on FLA and Legionella spp. detected in water and biofilm from two types of garden hoses over 18 months. By culturing and qPCR, two genera of FLA were introduced via the drinking water supply and reached mean densities of 2.5 log10 amoebae·mL(-1) in garden hose water. Legionella spp. densities (likely including pathogenic L. pneumophila) were significantly higher in one type of hose (3.8 log10 cells·mL(-1), p < 0.0001). A positive correlation existed between Vermamoebae vermiformis densities and Legionella spp. densities (r = 0.83, p < 0.028). The densities of Legionella spp. identified in the hoses were similar to those reported during legionellosis outbreaks in other situations. Therefore, we conclude that there is a health risk to susceptible users from the inhalation of garden hose aerosols.

  18. Dual-pump CARS of Air in a Heated Pressure Vessel up to 55 Bar and 1300 K

    NASA Technical Reports Server (NTRS)

    Cantu, Luca; Gallo, Emanuela; Cutler, Andrew D.; Danehy, Paul M.

    2014-01-01

    Dual-pump Coherent anti-Stokes Raman scattering (CARS) measurements have been performed in a heated pressure vessel at NASA Langley Research Center. Each measurement, consisting of 500 single shot spectra, was recorded at a fixed location in dry air at various pressures and temperatures, in a range of 0.03-55×10(exp 5) Pa and 300-1373 K, where the temperature was varied using an electric heater. The maximum output power of the electric heater limited the combinations of pressures and temperatures that could be obtained. Charts of CARS signal versus temperature (at constant pressure) and signal versus pressure (at constant temperature) are presented and fit with an empirical model to validate the range of capability of the dual-pump CARS technique; averaged spectra at different conditions of pressure and temperature are also shown.

  19. Do sudden air temperature and pressure changes affect cardiovascular morbidity and mortality?

    NASA Astrophysics Data System (ADS)

    Plavcová, E.; Davídkovová, H.; Kyselý, J.

    2012-04-01

    Previous studies have shown that sudden changes in weather (usually represented by air temperature and/or pressure) are associated with increases in daily mortality. Little is understood about physiological mechanisms responsible for the impacts of weather changes on mortality, and whether similar patterns appear for morbidity as well. Relatively little is known also about differences in the magnitude of the mortality response in provincial regions and in cities, where the impacts may be exacerbated by air pollution effects and/or heat island. The present study examines the effects of sudden air temperature and pressure changes on morbidity (represented by hospital admissions) and mortality due to cardiovascular diseases in the population of the Czech Republic (approx. 10 million inhabitants) and separately in the city of Prague (1.2 million inhabitants). The events are selected from data covering 1994-2009 using the methodology introduced by Plavcová and Kyselý (2010), and they are compared with the datasets on hospital admissions and daily mortality (both standardized to account for long-term changes and the seasonal and weekly cycles). Relative deviations of morbidity/mortality from the baseline were averaged over the selected events for days D-2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. The study aims at (i) identifying those weather changes associated with increased cardiovascular morbidity/mortality, separately in summer and winter, (ii) comparing the effects of weather changes on morbidity and mortality, (iii) identifying whether urban population of Prague is more/less vulnerable in comparison to the population of the whole Czech Republic, (iv) comparing the effects for different cardiovascular diseases (ischaemic heart diseases, ICD-10 codes I20-I25; cerebrovascular diseases, I60-I69; hypertension, I10; atherosclerosis, I70) and individual population groups (by age

  20. Pulsed positive discharges in air at moderate pressures near a dielectric rod

    NASA Astrophysics Data System (ADS)

    Dubinova, A.; Trienekens, D.; Ebert, U.; Nijdam, S.; Christen, T.

    2016-10-01

    We study pulsed positive discharges in air in a cylindrically symmetric setup with an electrode needle close (about 1 mm) above the top of a dielectric cylindrical rod of 4 mm in diameter mounted at its bottom on a grounded plate electrode. We present ICCD (intensified charge-coupled device) pictures and evaluations of experiments as well as simulations with a fluid discharge model; the simulations use cylindrical symmetry. In the experiments, there is an initial inception cloud phase, where the cylindrical symmetry is maintained, and later a streamer phase, where it is broken spontaneously. At 75-150 mbar, discharges with cylindrical symmetry are not attracted to the dielectric rod, but move away from it. The dielectric rod plays the sole role of an obstacle that shades (in the context of photoionization) a cone-shaped part of the inception cloud; the cone size is determined by the geometry of the setup. The material properties of the dielectric rod, such as its dielectric permittivity and the efficiency of the photon induced secondary electron emission do not have a noticeable effect. This is due to the abundance of photoionization in air, which supplies a positive discharge with free electrons and allows it to propagate along the electric field lines. Using some simple field calculations, we show that field enhancement due to dielectric polarization does not play a significant role in our geometry as long as the discharge maintains its cylindrical symmetry. The field component towards the rod is insufficiently enhanced to cause the discharge to move towards the rod. Any additional electrons produced by the dielectric surface do not influence this discharge morphology. This interpretation is supported by both experiments and simulations. At higher pressures (400-600 mbar) or for larger gaps between the needle and the dielectric rod, the inception cloud reaches its maximal radius within the gap between needle and rod and destabilizes there. In those cases

  1. Positive and negative gas-phase ion chemistry of chlorofluorocarbons in air at atmospheric pressure.

    PubMed

    Bosa, Elisabetta; Paradisi, Cristina; Scorrano, Gianfranco

    2003-01-01

    This paper presents a report on the ionization/dissociation of some representative chlorofluorocarbons (CFCs) induced by corona discharges in air at atmospheric pressure. Both positive and negative ions formed from Freons 1,1,1-trichlorotrifluoroethane (CFC 113a), 1,1,2-trichlorotrifluoroethane (CFC 113), and 1,1,1,2-tetrachlorodifluoroethane (CFC 112a) were analyzed using an atmospheric pressure chemical ionization mass spectrometry (APCI-MS) instrument. Energy-resolved mass spectra were obtained by modulating the kinetic energy of the ions via adjustment of the sampling cone potential (V(cone)). Positive ion spectra of the CFCs (M) at low V(cone) show no signals due to either M(+)* or MH(+) but only those due to species [M - Cl](+) and CX(3)(+) (X = Cl, F), likely formed via C-Cl and C-C bond cleavages following ionization via charge exchange. Charge localization in the products of C-C bond cleavage in M(+)* is driven by the stability of the neutral fragment. At low V(cone) the hydrates [M - Cl](+)(H(2)O) are also observed. In the case of 1,1,2,-trichlorotrifluoroethane, [M - F](+) species also form as a result of ion-molecule reactions. As V(cone) is increased collision-induced dissociation of [M - Cl](+) and [M - F](+), i.e., the perhalogenated cations C(2)X(5)(+) (X = Cl, F), takes place via carbene elimination. In some cases such elimination is preceded or accompanied by rearrangements involving transfer of halogen from one carbon to the other. Evidence is also presented for the occurrence of a condensation reaction of C(2)Cl(3)F(2)(+) with water to form a C(2)Cl(2)F(2)HO(+) species via elimination of HCl. Negative ion spectra are dominated by Cl(-) and its ion-neutral complexes with M and with water. Additional components of the plasma include ion-neutral complexes O(3)(-)(M), the molecular anion M(-) (observed only with 1,1,2-trichlorotrifluoroethane), and an interesting species corresponding to [M - Cl + O](-). The origin and structure of these [M - Cl + O

  2. Calculating osmotic pressure of glucose solutions according to ASOG model and measuring it with air humidity osmometry.

    PubMed

    Wei, Guocui; Zhan, Tingting; Zhan, Xiancheng; Yu, Lan; Wang, Xiaolan; Tan, Xiaoying; Li, Chengrong

    2016-09-01

    The osmotic pressure of glucose solution at a wide concentration range was calculated using ASOG model and experimentally determined by our newly reported air humidity osmometry. The measurements from air humidity osmometry were compared with the well-established freezing point osmometry and ASOG model calculations at low concentrations and with only ASOG model calculations at high concentrations where no standard experimental method could serve as a reference for comparison. Results indicate that air humidity osmometry measurements are comparable to ASOG model calculations at a wide concentration range, while at low concentrations freezing point osmometry measurements provide better comparability with ASOG model calculations.

  3. Tumor-dependent kinetics of partial pressure of oxygen fluctuations during air and oxygen breathing.

    PubMed

    Cárdenas-Navia, L Isabel; Yu, Daohai; Braun, Rod D; Brizel, David M; Secomb, Timothy W; Dewhirst, Mark W

    2004-09-01

    The primary purpose of this study was to examine the kinetics of partial pressure of oxygen (pO2) fluctuations in fibrosarcoma (FSA) and 9L tumors under air and O2 breathing conditions. The overall hypothesis was that key factors relating to oxygen tension fluctuations would vary between the two tumor types and as a function of the oxygen content of the breathing gas. To assist in the interpretation of the temporal data, spatial pO2 distributions were measured in 10 FSA and 8 9L tumors transplanted into the subcutis of the hind leg of Nembutal-anesthetized (50 mg/kg) Fischer 344 rats. Recessed-tip oxygen microelectrodes were inserted into the tumor, and linear pO2 measurements were recorded in 50-microm steps along a 3-mm path, and blood pressure was simultaneously measured via femoral arterial access. Additionally, pO2 was measured at a single location for 90 to 120 minutes in FSA (n=11) or 9L tumors (n=12). Rats were switched from air to 100% O2 breathing after 45 minutes. Temporal pO2 records were evaluated for their potential radiobiological significance by assessing the number of times they crossed a 10-mm-Hg threshold. In addition, the data were subjected to Fourier analysis for air and O2 breathing. FSA and 9L tumors had spatial median pO2 measurements of 4 and 1 mm Hg, respectively. 9L had more low pO2 measurements < or =2.5 mm Hg than did FSA, whereas between 2.5 and 10 mm Hg this pattern was reversed. Pimonidazole staining patterns in FSA and 9L tumors supported these results. Temporal pO2 instability was observed in all experiments during air and O2 breathing. Threshold analyses indicated that the 10 mm Hg threshold was crossed 2 to 5 times per hour, independent of tumor type. However, the magnitude of 9L pO2 fluctuations was approximately eight times greater than FSA fluctuations, as assessed with Fourier transform analysis (Wilcoxon, P < 0.005). O2 breathing significantly increased median pO2 in FSA from 3 to 8 mm Hg (P < 0.005) and caused a

  4. Performance of a hydrogen burner to simulate air entering scramjet combustors. [simulation of total temperature, total pressure, and volume fraction of oxygen of air at flight conditions

    NASA Technical Reports Server (NTRS)

    Russin, W. R.

    1974-01-01

    Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.

  5. The association of annual air pollution exposure with blood pressure among patients with sleep-disordered breathing.

    PubMed

    Liu, Wen-Te; Lee, Kang-Yun; Lee, Hsin-Chien; Chuang, Hsiao-Chi; Wu, Dean; Juang, Jer-Nan; Chuang, Kai-Jen

    2016-02-01

    While sleep-disordered breathing (SDB), high blood pressure (BP) and air pollution exposure have separately been associated with increased risk of cardiopulmonary mortality, the association linking air pollution exposure to BP among patients with sleep-disordered breathing is still unclear. We collected 3762 participants' data from the Taipei Medical University Hospital's Sleep Center and air pollution data from the Taiwan Environmental Protection Administration. Associations of 1-year mean criteria air pollutants [particulate matter with aerodynamic diameters ≤10 μm (PM10), particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5), nitrogen dioxide (NO2) and ozone (O3)] with systolic BP (SBP) and diastolic BP (DBP) were investigated by generalized additive models. After controlling for age, sex, body mass index (BMI), temperature and relative humidity, we observed that increases in air pollution levels were associated with decreased SBP and increased DBP. We also found that patients with apnea-hypopnea index (AHI) ≥30 showed a stronger BP response to increased levels of air pollution exposure than those with AHI<30. Stronger effects of air pollution exposure on BP were found in overweight participants than in participants with normal BMI. We concluded that annual exposure to air pollution was associated with change of BP among patients with sleep-disordered breathing. The association between annual air pollution exposure and BP could be modified by AHI and BMI.

  6. Protective supplied-breathing-air garment

    DOEpatents

    Childers, E.L.; von Hortenau, E.F.

    1982-05-28

    A breathing-air garment for isolating a wearer from hostile environments containing toxins or irritants is disclosed. The garment includes a suit and a separate head-protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air-delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air-delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit sealed with an adhesive sealing flap.

  7. 46 CFR 154.517 - Piping: Liquid pressure relief.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Piping: Liquid pressure relief. 154.517 Section 154.517... and Process Piping Systems § 154.517 Piping: Liquid pressure relief. The cargo loading and discharge crossover headers, cargo hoses, and cargo loading arms must have means to relieve cargo pressure and...

  8. 46 CFR 154.517 - Piping: Liquid pressure relief.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Piping: Liquid pressure relief. 154.517 Section 154.517... and Process Piping Systems § 154.517 Piping: Liquid pressure relief. The cargo loading and discharge crossover headers, cargo hoses, and cargo loading arms must have means to relieve cargo pressure and...

  9. 46 CFR 154.517 - Piping: Liquid pressure relief.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Piping: Liquid pressure relief. 154.517 Section 154.517... and Process Piping Systems § 154.517 Piping: Liquid pressure relief. The cargo loading and discharge crossover headers, cargo hoses, and cargo loading arms must have means to relieve cargo pressure and...

  10. Survey and bibliography on attainment of laminar flow control in air using pressure gradient and suction, volume 1

    NASA Technical Reports Server (NTRS)

    Bushnell, D. M.; Tuttle, M. H.

    1979-01-01

    A survey was conducted and a bibliography compiled on attainment of laminar flow in air through the use of favorable pressure gradient and suction. This report contains the survey, summaries of data for both ground and flight experiments, and abstracts of referenced reports. Much early information is also included which may be of some immediate use as background material for LFC applications.

  11. The Effect of Conceptual Change Approach to Eliminate 9th Grade High School Students' Misconceptions about Air Pressure

    ERIC Educational Resources Information Center

    Akbas, Yavuz; Gencturk, Ebru

    2011-01-01

    The aim of this study was to determine the effectiveness of teaching based on conceptual change overcome misconceptions of 9th grade high school students about the subject of air pressure. The sampling of the study was formed with two classes of 9th grade students from a general high school in the city-center of Trabzon. A quasi-experimental…

  12. Peak Sound Pressure Levels and Associated Auditory Risk from an H[subscript 2]-Air "Egg-Splosion"

    ERIC Educational Resources Information Center

    Dolhun, John J.

    2016-01-01

    The noise level from exploding chemical demonstrations and the effect they could have on audiences, especially young children, needs attention. Auditory risk from H[subscript 2]- O2 balloon explosions have been studied, but no studies have been done on H[subscript 2]-air "eggsplosions." The peak sound pressure level (SPL) was measured…

  13. Soot Oxidation in Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix K

    NASA Technical Reports Server (NTRS)

    Xu, F.; El-Leathy, A. M.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2001-01-01

    Soot oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round jets burning in coflowing air considering acetylene, ethylene, propylene and propane as fuels. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation mainly occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of stable major gas species (N2, H2O, H2, O2, CO, CO2, CH4, C2H2,C2H4, C2H6, C3H6, and C3H8) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by the deconvoluted Li/LiOH atomic absorption technique and flow velocities by laser velocimetry. It was found that soot surface oxidation rates are not particularly affected by fuel type for laminar diffusion flames and are described reasonably well by the OH surface oxidation mechanism with a collision efficiency of 0.10, (standard deviation of 0.07) with no significant effect of fuel type in this behavior; these findings are in good agreement with the classical laminar premixed flame measurements of Neoh et al. Finally, direct rates of surface oxidation by O2 were small compared to OH oxidation for present conditions, based on estimated O2 oxidation rates due to Nagle and Strickland-Constable (1962), because soot oxidation was completed near the flame sheet where O2 concentrations were less than 1.2% by volume.

  14. Soot Oxidation in Laminar Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix D

    NASA Technical Reports Server (NTRS)

    Xu, F.; El-Leathy, A. M.; Faeth, G. M.

    2000-01-01

    Soot oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round jets burning in coflowing air considering acetylene, ethylene, proplyene and propane as fuels. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation mainly occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of stable major gas species (N2, H2O, H2, 02, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H6, and C3H8) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by the deconvoluted Li/LiOH atomic absorption technique and flow velocities by laser velocimetry. It was found that soot surface oxidation rates are not particularly affected by fuel type for laminar diffusion flames and are described reasonably well by the OH surface oxidation mechanism with a collision efficiency of 0.10, (standard deviation of 0.07) with no significant effect of fuel type in this behavior; these findings are in good agreement with the classical laminar premixed flame measurements of Neoh et al. Finally, direct rates of surface oxidation by O2 were small compared to OH oxidation for present conditions, based on estimated O2 oxidation rates due to Nagle and Strickland-Constable, because soot oxidation was completed near the flame sheet where O2 concentrations were less than 1.2% by volume.

  15. Association between blood pressure changes during self-paced outdoor walking and air temperature.

    PubMed

    Otsuki, Takeshi; Ishii, Nanako

    2017-03-01

    Exaggerated elevation of systolic blood pressure (SBP) during exercise is a risk factor for future cardiovascular disease. Although there are differences between the outdoor exercise and exercise tests in the laboratory setting, there is little information regarding SBP changes during practical outdoor exercise. We investigated SBP changes during self-paced outdoor walking and the relationship to air temperature. Subjects (n = 109, 47-83 years) walked outdoors at their own pace wearing a blood pressure monitor on their wrist. SBP increased during walking compared to rest, but was higher at the 1 km mark than both the 2 and 3 km marks (rest, 124 ± 14 mmHg; 1 km, 140 ± 16 mmHg; 2 km, 136 ± 18 mmHg; 3 km, 135 ± 18 mmHg). SBP at rest, air temperature, body mass index (BMI) and walking intensity during the first 1 km were identified as predictors of SBP at the 1 km mark in the stepwise regression analysis, independent of other confounders (R(2)  = 0·606). SBP at the 1 km mark was higher in the lower temperature group (11·6-14·3°C, 145 ± 14 mmHg) than in the intermediate (15·1-16·7°C, 140 ± 18 mmHg) and higher (17·0-19·6°C, 136 ± 16 mmHg) temperature groups, independent of SBP at rest, BMI and walking intensity. These results suggest that increases in SBP are higher on lower temperature days and are greater at 1 km than at 2 and 3 km. It is therefore recommended that measures are taken against the cold on lower temperature days to attenuate the SBP response during onset of walking.

  16. Identification, characterization and antibiotic resistance of bacterial isolates obtained from waterpipe device hoses.

    PubMed

    Masadeh, Majed M; Hussein, Emad I; Alzoubi, Karem H; Khabour, Omar; Shakhatreh, Muhamad Ali K; Gharaibeh, Mahmoud

    2015-05-13

    The general lack of knowledge about the health effects of waterpipe smoking is among the reasons for its global spread. In this study, bacterial contamination of waterpipe hoses was investigated. Twenty hoses were collected from waterpipe cafés and screened for bacterial pathogens using standard culture and isolation techniques. Additionally, resistance of isolated bacteria to common antibiotics was determined by identifying the minimum inhibitory concentration (MIC) of each isolate. Forty eight bacterial isolates were detected. Isolates included both Gram-positive and Gram-negative pathogens from species that included Micrococcus (12), Corynebacterium (13) and Bacillus (9). In addition, some of the detected pathogens were found to be resistant to aztreonam (79%), cefixime (79%), norfloxacin, amoxicillin (47%), clarithromycin (46%) and enrofloxacin (38%). In conclusion, the hose of the waterpipe device is a good environment for the growth of bacterial pathogens, which can then be transmitted to users.

  17. Probe measurements of electron energy spectrum in Helium/air micro-plasma at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Demidov, V. I.; Adams, S. F.; Miles, J. A.; Koepke, M. E.; Kurlyandskaya, I. P.; Hensley, A. L.; Tolson, B. A.

    2016-09-01

    It is experimentally demonstrated that a wall probe may be a useful instrument for interpretation of electron energy spectrum in a micro-plasma with a nonlocal electron distribution function at atmospheric pressure. Two micro-plasma devices were fabricated with three layers of molybdenum metal foils with thickness of 0.1 mm separated by two sheets of mica insulation with thickness of 0.11 mm. In one device a hole with the diameter of 0.2 mm formed a cylindrical discharge cavity that passed through the entire five layers. In the second device the hole has the diameter of 0.065 mm. In both devices the inner molybdenum layer formed a wall probe, while the outer layers of molybdenum served as the hollow cathode and anode. The discharge was open into air with flow of helium gas. It is found that the wall probe I-V trace is sensitive to the presence of helium metastable atoms. The first derivative of the probe current with respect to the probe potential shows peaks revealing fast electrons at specific energies arising due to plasma chemical reactions. The devices may be applicable for developing analytical sensors for extreme environments, including high radiation and vibration levels and high temperatures. This work was performed while VID held a NRC Research Associateship Award at AFRL.

  18. Characterization Of Nano-Second Laser Induced Plasmas From Al Target In Air At Atmospheric Pressure

    SciTech Connect

    Hegazy, H.; Abdel-Rahim, F. M.; Nossair, A. M. A.; Allam, S. H.; El-Sherbini, Th. M.

    2008-09-23

    In the present work we study the effect of the laser beam energy on the properties of the plasma generated by focusing an intense laser beam on Al solid target in air at atmospheric pressure. Plasma is generated using a Nd:YAG pulsed laser at 1064 nm wavelength, 6 ns pulse duration with a maximum pulse energy of 750mJ. The emission spectrum is collected using an Echelle spectrometer equipped with ICCD camera Andor type. The measurements were performed at several delay times between 0 to 9 {mu}s. Measurements of temperature and electron density of the produced plasmas at different laser energies and at different delay times are described using different emission spectral lines. Based on LTE assumption, excitation temperature is determined from the Boltzmann plot using O I spectral lines at 777.34, 794.93, and 848.65 nm and the electron density is determined from Stark width of Al II at 281.6 and 466.3 nm. The determined density is compared with the density determined from H{sub {alpha}} spectral line.

  19. Functionalization of graphene by atmospheric pressure plasma jet in air or H2O2 environments

    NASA Astrophysics Data System (ADS)

    Huang, Weixin; Ptasinska, Sylwia

    2016-03-01

    The functionalization of graphene, which deforms its band structure, can result in a metal-semiconductor transition. In this work, we report a facile strategy to oxidize single-layer graphene using an atmospheric pressure plasma jet (APPJ) that generates a variety of reactive plasma species at close to ambient temperature. We systematically characterized the oxygen content and chemical structure of the graphene films after plasma treatment under different oxidative conditions (ambient air atmosphere or hydrogen peroxide solution) by X-ray Photoelectron Spectroscopy (XPS). Plasma-treated graphene films containing more than 40% oxygen were obtained in both oxidative environments. Interestingly, prolonged irradiation led to the reduction of graphene oxides. N-doping of graphene also occurred during the APPJ treatment in H2O2 solution; the nitrogen content of the doped graphene was dependent on the duration of irradiation and reached up to 8.1% within 40 min. Moreover, the H2O2 solution served as a buffer layer that prevented damage to the graphene during plasma irradiation. Four-point probe measurement revealed an increase in sheet resistance of the plasma-treated graphene, indicating the transition of the material property from semi-metallic to semiconducting.

  20. Nanosecond Repetitively Pulsed Discharges in Air at Atmospheric Pressure -- Experiment and Theory of Regime Transitions

    NASA Astrophysics Data System (ADS)

    Pai, David; Lacoste, Deanna; Laux, Christophe

    2009-10-01

    In atmospheric pressure air preheated from 300 to 1000 K, the Nanosecond Repetitively Pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and inter-electrode gap distance) of each discharge regime. Notably, there is a minimum gap distance for the existence of the glow regime that increases with decreasing gas temperature. A theory is developed to describe the Corona-to-Glow (C-G) and Glow-to-Spark (G-S) transitions for NRP discharges. The C-G transition is shown to depend on the Avalanche-to-Streamer Transition (AST) as well as the electric field strength in the positive column. The G-S transition is due to the thermal ionization instability. The minimum gap distance for the existence of the glow regime can be understood by considering that the applied voltage of the AST must be lower than that of the thermal ionization instability. This is a previously unknown criterion for generating glow discharges, as it does not correspond to the Paschen minimum or to the Meek-Raether criterion.