Science.gov

Sample records for air pressure required

  1. 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.

  2. 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.

  3. 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.

  4. Extrusion energy and pressure requirements

    SciTech Connect

    Bhattacharya, M.; Hanna, M.A.

    1984-01-01

    Corn gluten meal samples at moisture contents of 14, 20 and 26% dry basis were extruded at barrel temperatures of 120, 145 and 170/sup 0/C with screw speeds of 100, 150 and 200 rpm. The specific energy requirements and specific operating pressure decreases as the moisture content and temperature were increased. The effect of screw speed on specific energy and pressure was inconclusive.

  5. Concepts of a Higher Hierarchical Level Require More Dual Situated Learning Events for Conceptual Change: A Study of Air Pressure and Buoyancy.

    ERIC Educational Resources Information Center

    She, Hsiao-Ching

    2002-01-01

    Examines the process of students' conceptual changes with regard to air pressure and buoyancy as a result of teaching with the dual situated learning model. Uses a model designed according to the students' ontological viewpoint on science concepts as well as the nature of these concepts. (Contains 40 references.) (Author/YDS)

  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. 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.

  9. 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,...

  10. 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.

  11. 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

  12. 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...

  13. 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...

  14. 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...

  15. 30 CFR 57.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false General requirements for boilers and pressure... NONMETAL MINES Compressed Air and Boilers § 57.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance...

  16. 30 CFR 57.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false General requirements for boilers and pressure... NONMETAL MINES Compressed Air and Boilers § 57.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance...

  17. 30 CFR 57.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false General requirements for boilers and pressure... NONMETAL MINES Compressed Air and Boilers § 57.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance...

  18. 30 CFR 56.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false General requirements for boilers and pressure... MINES Compressed Air and Boilers § 56.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  19. 30 CFR 56.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false General requirements for boilers and pressure... MINES Compressed Air and Boilers § 56.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  20. 30 CFR 56.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false General requirements for boilers and pressure... MINES Compressed Air and Boilers § 56.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  1. 30 CFR 57.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false General requirements for boilers and pressure... NONMETAL MINES Compressed Air and Boilers § 57.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance...

  2. 30 CFR 57.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false General requirements for boilers and pressure... NONMETAL MINES Compressed Air and Boilers § 57.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance...

  3. 30 CFR 56.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false General requirements for boilers and pressure... MINES Compressed Air and Boilers § 56.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  4. 30 CFR 56.13001 - General requirements for boilers and pressure vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false General requirements for boilers and pressure... MINES Compressed Air and Boilers § 56.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  5. Advanced Extravehicular Activity Pressure Garment Requirements Development

    NASA Technical Reports Server (NTRS)

    Ross, Amy

    2014-01-01

    The NASA Johnson Space Center advanced pressure garment technology development team is addressing requirements development for exploration missions. Lessons learned from the Z-2 high fidelity prototype development have reiterated that clear low-level requirements and verification methods reduce risk to the government, improve efficiency in pressure garment design efforts, and enable the government to be a smart buyer. The expectation is to provide requirements at the specification level that are validated so that their impact on pressure garment design is understood. Additionally, the team will provide defined verification protocols for the requirements. However, in reviewing exploration space suit high level requirements there are several gaps in the team's ability to define and verify related lower level requirements. This paper addresses the efforts in requirement areas such as mobility/fit/comfort and environmental protection (dust, radiation, plasma, secondary impacts) to determine the by what method the requirements can be defined and use of those methods for verification. Gaps exist at various stages. In some cases component level work is underway, but no system level effort has begun, in other cases no effort has been initiated to close the gap. Status of ongoing efforts and potential approaches to open gaps are discussed.

  6. Requirements for high-temperature air-cooled central receivers

    NASA Astrophysics Data System (ADS)

    Wright, J. D.; Copeland, R. J.

    1983-12-01

    The design of solar thermal central receivers will be shaped by the end user's need for energy. This paper identifies the requirements for receivers supplying heat for industrial processes or electric power generation in the temperature range 540 to 1000(0)C and evaluates the effects of the requirements on air cooled central receivers. Potential IPH applications are identified as large baseload users that are located some distance from the receiver. In the electric power application, the receiver must supply heat to a pressurized gas power cycle. The difficulty in providing cost effective thermal transport and thermal storage for air cooled receivers is a critical problem.

  7. 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.

  8. 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)...

  9. Air Force and DOD solar power requirements

    NASA Technical Reports Server (NTRS)

    Wise, Joseph F.

    1987-01-01

    It is noted that future power requirements are increasing for some expanded and new missions within the Air Force and Department of Defense. New requirements are needed in terms of lifetime, survivability, power level and performance. The photovoltaic arrays have a demonstrated record of reliable performance, life, affordable cost, and utility. It is argued that there is a need to push for the research and development resources needed to develop the technology base for these future power system needs.

  10. 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.

  11. 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.

  12. 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.

  13. 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)...

  14. 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.

  15. Energy requirements in pressure irrigation systems

    NASA Astrophysics Data System (ADS)

    Sánchez, R.; Rodríguez-Sinobas, L.; Juana, L.; Laguna, F. V.; Castañón, G.; Gil, M.; Benítez, J.

    2012-04-01

    Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure -sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems and their management possibilities. The work includes all processes involved from the diversion of water into irrigation specific infrastructure to water discharge by the emitters installed on the crop fields. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. It has been applied to extensive and intensive crop systems, such us extensive winter crops, summer crops and olive trees, fruit trees and vineyards and intensive horticulture in greenhouses. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity.

  16. 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:

  17. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Gas pressure gages; minimum requirements. 84.82...-Contained Breathing Apparatus § 84.82 Gas pressure gages; minimum requirements. (a) Gas pressure gages.... (c) Gas pressure gages other than those specified in paragraphs (a) and (b) of this section shall...

  18. Power Output and Air Requirements of a Two-stroke Cycle Engine for Aeronautical Use

    NASA Technical Reports Server (NTRS)

    Paton, C R; Kemper, Carlton

    1927-01-01

    This investigation was undertaken to determine the pressure and amount of air necessary for satisfactory high-speed, two-stroke cycle operation and thus permit the power requirements of the air pump or blower to be determined. Based on power output and air requirement here obtained the two-stroke cycle engine would seem to be favorable for aeronautical use. No attempts were made to secure satisfactory operation at idling speeds.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  6. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  7. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  8. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  9. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  10. 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.

  11. 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…

  12. 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.

  13. Clean Air Act Requirements and History

    EPA Pesticide Factsheets

    In 1970 congress designed the Clean Air Act to combat a variety of air pollution problems, and to tackle emerging pollution threats such as public health, national welfare, toxic air pollutants, acid rain, protection of the ozone layer, and regional haze.

  14. 14 CFR 294.84 - Air competency requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Air competency requirements. 294.84 Section... PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS Terms, Conditions, and Limitations of This Part § 294.84 Air competency requirements. Registrants shall conform to the airworthiness...

  15. 14 CFR 294.84 - Air competency requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Air competency requirements. 294.84 Section... PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS Terms, Conditions, and Limitations of This Part § 294.84 Air competency requirements. Registrants shall conform to the airworthiness...

  16. 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.

  17. 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.

  18. 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

  19. 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.…

  20. 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,…

  1. 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...

  2. 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…

  3. 40 CFR 52.346 - Air quality monitoring requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Air quality monitoring requirements. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.346 Air quality monitoring... VIII Administrator, the State submitted a revised Air Quality Monitoring State Implementation Plan....

  4. 40 CFR 52.346 - Air quality monitoring requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Air quality monitoring requirements. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.346 Air quality monitoring... VIII Administrator, the State submitted a revised Air Quality Monitoring State Implementation Plan....

  5. 40 CFR 52.346 - Air quality monitoring requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Air quality monitoring requirements. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.346 Air quality monitoring... VIII Administrator, the State submitted a revised Air Quality Monitoring State Implementation Plan....

  6. 40 CFR 52.346 - Air quality monitoring requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Air quality monitoring requirements. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.346 Air quality monitoring... VIII Administrator, the State submitted a revised Air Quality Monitoring State Implementation Plan....

  7. 40 CFR 52.346 - Air quality monitoring requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Air quality monitoring requirements. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.346 Air quality monitoring... VIII Administrator, the State submitted a revised Air Quality Monitoring State Implementation Plan....

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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…

  15. 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.

  16. 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.

  17. 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

  18. Thermodynamic models for bounding pressurant mass requirements of cryogenic tanks

    NASA Technical Reports Server (NTRS)

    Vandresar, Neil T.; Haberbusch, Mark S.

    1994-01-01

    Thermodynamic models have been formulated to predict lower and upper bounds for the mass of pressurant gas required to pressurize a cryogenic tank and then expel liquid from the tank. Limiting conditions are based on either thermal equilibrium or zero energy exchange between the pressurant gas and initial tank contents. The models are independent of gravity level and allow specification of autogenous or non-condensible pressurants. Partial liquid fill levels may be specified for initial and final conditions. Model predictions are shown to successfully bound results from limited normal-gravity tests with condensable and non-condensable pressurant gases. Representative maximum collapse factor maps are presented for liquid hydrogen to show the effects of initial and final fill level on the range of pressurant gas requirements. Maximum collapse factors occur for partial expulsions with large final liquid fill fractions.

  19. Clean Air Act requirements for trace-metals information

    SciTech Connect

    Pahl, D.; Hunt, W.; Evans, G.

    1992-01-01

    The Clean Air Act Amendments of 1990 have expanded the requirements for trace metal and air toxics information in urban areas and added new requirements for this information in rural areas and ecosystems. Specific provisions germane to trace metals and other air toxics compounds are found in Title III, Section 112 and in Title IX, Section 901. In response to these provisions, the United States Environmental Protection Agency (EPA) plans to conduct research in atmospheric monitoring networks in urban areas, in the Great Lakes watershed, and in regional components of a national Clean Air Act status and trends network.

  20. 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.

  1. Gas Requirements in Pressurized Transfer of Liquid Hydrogen

    NASA Technical Reports Server (NTRS)

    Gluck, D. F.; Kline, J. F.

    1961-01-01

    Of late, liquid hydrogen has become a very popular fuel for space missions. It is being used in such programs as Centaur and Saturn. Furthermore, hydrogen is the ideal working fluid for nuclear powered space vehicles currently under development. In these applications, liquid hydrogen fuel is generally transferred to the combustion chamber by a combination of pumping and pressurization. The pump forces the liquid propellant from the fuel tank to the combustion chamber; gaseous pressurant holds tank pressure sufficiently high to prevent cavitation at the pump inlet and to maintain the structural rigidity of the tank. The pressurizing system, composed of pressurant, tankage, and associated hardware can be a large portion of the total vehicle weight. Pressurant weight can be reduced by introducing the pressurizing gas at temperatures substantially greater than those of liquid hydrogen. Heat and mass transfer processes thereby induced complicate gas requirements during discharge. These requirements must be known to insure proper design of the pressurizing system. The aim of this paper is to develop from basic mass and energy transfer processes a general method to predict helium and hydrogen gas usage for the pressurized transfer of liquid hydrogen. This required an analytical and experimental investigation, the results of which are described in this paper.

  2. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-Contained Breathing Apparatus § 84.82 Gas pressure gages; minimum requirements. (a) Gas pressure gages employed on compressed breathing gas containers shall be calibrated in pounds per square inch. (b) Liquid... Oil” marked prominently on the gage. (i)(1) Apparatus using compressed breathing gas, except...

  3. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-Contained Breathing Apparatus § 84.82 Gas pressure gages; minimum requirements. (a) Gas pressure gages employed on compressed breathing gas containers shall be calibrated in pounds per square inch. (b) Liquid... Oil” marked prominently on the gage. (i)(1) Apparatus using compressed breathing gas, except...

  4. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-Contained Breathing Apparatus § 84.82 Gas pressure gages; minimum requirements. (a) Gas pressure gages employed on compressed breathing gas containers shall be calibrated in pounds per square inch. (b) Liquid... Oil” marked prominently on the gage. (i)(1) Apparatus using compressed breathing gas, except...

  5. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-Contained Breathing Apparatus § 84.82 Gas pressure gages; minimum requirements. (a) Gas pressure gages employed on compressed breathing gas containers shall be calibrated in pounds per square inch. (b) Liquid... Oil” marked prominently on the gage. (i)(1) Apparatus using compressed breathing gas, except...

  6. 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.

  7. 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.

  8. Rethinking C-17 Training Requirements: Air Refueling

    DTIC Science & Technology

    2015-06-19

    have to face fiscal realities that will require smart solutions to difficult problems regarding its capability to field a mission capable force...being effective, we must redouble our efforts to become more efficient. We must look at leveraging proven technologies and derivative alternates ...Mobility Command (AMC) will face fiscal realities that require smart solutions to difficult problems regarding its capability to field a mission capable

  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. Design and Test Requirements for Space Flight Pressurized Systems

    DTIC Science & Technology

    2014-11-26

    establishes the baseline requirements for the design, fabrication, assembly, installation, test, inspection, operation, and maintenance of pressure systems...18 4.8 Operation and Maintenance Requirements ..................................................................... 18 4.8.1 Operating Procedure...18 4.8.2 Inspection and Maintenance

  11. 2035 Air Dominance Requirements for State-On-State Conflict

    DTIC Science & Technology

    2011-02-16

    within range).17 The US has successfully demonstrated a megawatt-class, Chemical Oxygen Iodine Laser.18 Current assessments reveal a 100 kilowatt...the precise, coordinated application of the various elements of air, space and surface power to bring disproportionate pressure on enemy leaders to

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Integrating SOPs and air quality regulatory requirements at federal facilities

    SciTech Connect

    Rasmussen, S.

    1997-12-31

    While for many years it has been perceived that federal facilities have fewer environmental requirements and restrictions than industry, in fact they are now faced with more compliance requirements than most private sector sources. In addition to federal programs now applicable to federal facilities under the Federal Clean Air Act for example, federal facilities also are challenged with requirements driven by their own agencies. The Air Force Material Command (AFMC) in particular, has an aggressive program to standardize operations and compliance with Standard Operating Procedures (SOP) for air quality. In some cases, these SOP`s are more onerous than Environmental Protection Agency (EPA) programs, and in some instances, the requirements may take different approaches. In this paper, the authors will explore the challenges faced by federal facilities, with a case example of Hill Air Force Base, as they develop ways to comply with both. Specific example of how to develop an integrated program will be examined. At Hill AFB, the goal in the Air Quality Program has been Efficiency and Compliance. Where requirements overlap, one compliance program is developed and implemented. In cases where requirements differ, compliance methods are developed and proposed to both agencies for resolution. By integrating these programs, bases such as Hill AFB can be complaint and efficient.

  17. Advanced Extra-Vehicular Activity Pressure Garment Requirements Development

    NASA Technical Reports Server (NTRS)

    Ross, Amy; Aitchison, Lindsay; Rhodes, Richard

    2015-01-01

    The NASA Johnson Space Center advanced pressure garment technology development team is addressing requirements development for exploration missions. Lessons learned from the Z-2 high fidelity prototype development have reiterated that clear low-level requirements and verification methods reduce risk to the government, improve efficiency in pressure garment design efforts, and enable the government to be a smart buyer. The expectation is to provide requirements at the specification level that are validated so that their impact on pressure garment design is understood. Additionally, the team will provide defined verification protocols for the requirements. However, in reviewing exploration space suit high level requirements there are several gaps in the team's ability to define and verify related lower level requirements. This paper addresses the efforts in requirement areas such as mobility/fit/comfort and environmental protection (dust, radiation, plasma, secondary impacts) to determine the method by which the requirements can be defined and use of those methods for verification. Gaps exist at various stages. In some cases component level work is underway, but no system level effort has begun; in other cases no effort has been initiated to close the gap. Status of on-going efforts and potential approaches to open gaps are discussed.

  18. 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.

  19. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... respirators, demand and pressure-demand classes; test requirements. 84.163 Section 84.163 Public Health PUBLIC... RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.163 Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes;...

  20. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... respirators, demand and pressure-demand classes; test requirements. 84.163 Section 84.163 Public Health PUBLIC... RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.163 Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes;...

  1. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... respirators, demand and pressure-demand classes; test requirements. 84.163 Section 84.163 Public Health PUBLIC... RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.163 Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes;...

  2. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... respirators, demand and pressure-demand classes; test requirements. 84.163 Section 84.163 Public Health PUBLIC... RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.163 Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes;...

  3. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... respirators, demand and pressure-demand classes; test requirements. 84.163 Section 84.163 Public Health PUBLIC... RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.163 Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes;...

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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°.

  12. 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.

  13. 30 CFR 250.448 - What are the BOP pressure tests requirements?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What are the BOP pressure tests requirements... pressure tests requirements? When you pressure test the BOP system, you must conduct a low-pressure and a high-pressure test for each BOP component. You must conduct the low-pressure test before the...

  14. 30 CFR 250.448 - What are the BOP pressure tests requirements?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What are the BOP pressure tests requirements... pressure tests requirements? When you pressure test the BOP system, you must conduct a low-pressure and a high-pressure test for each BOP component. You must conduct the low-pressure test before the...

  15. 30 CFR 250.448 - What are the BOP pressure tests requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What are the BOP pressure tests requirements... pressure tests requirements? When you pressure test the BOP system, you must conduct a low-pressure and a high-pressure test for each BOP component. You must conduct the low-pressure test before the...

  16. 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.

  17. [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.

  18. 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.

  19. Estimation of fan pressure ratio requirements and operating performance for the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Gloss, B. B.; Nystrom, D.

    1981-01-01

    The National Transonic Facility (NTF), a fan-driven, transonic, pressurized, cryogenic wind tunnel, will operate over the Mach number range of 0.10 to 1.20 with stagnation pressures varying from 1.00 to about 8.8 atm and stagnation temperatures varying from 77 to 340 K. The NTF is cooled to cryogenic temperatures by the injection of liquid nitrogen into the tunnel stream with gaseous nitrogen as the test gas. The NTF can also operate at ambient temperatures using a conventional chilled water heat exchanger with air on nitrogen as the test gas. The methods used in estimating the fan pressure ratio requirements are described. The estimated NTF operating envelopes at Mach numbers from 0.10 to 1.20 are presented.

  20. 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.

  1. Air storage requirements for a 220 MWe CAES plant as a function of turbomachinery selection and operation

    SciTech Connect

    Karalis, A.J.; Sosnowicz, E.J.; Stys, Z.S.

    1985-04-01

    This paper examines the effects of compressor train selection, turbine operation and the generation/compression cycle for a 220 MWe CAES plant which operates with a HP turbine inlet pressure of 44 bar (638 psia). The required air storage mass for a particular CAES generation/compression cycle is a function of both the total air mass withdrawn (during generation) and the total air mass added (during compression). Thus, the air storage mass is dependent upon both the air mass flow rates and daily operating times for the individual turbine and compressor selected. The volumetric requirements of the underground cavities are examined as a function of geologic formation and inlet pressure. While constant volume air storage in a salt formation is emphasized, air storage in a variable volume compensated rock cavern and variable pressure storage in an aquifer are also discussed. Both a daily and weekly compression cycle are addressed and the affect of duty cycle on the compressor train selection is shown. For a given turbine design the effect of constant vs. variable pressure operation on overall plant performance is noted.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Facility Requirements of the Air Force Avionics Laboratory. Revision,

    DTIC Science & Technology

    1979-05-01

    a dozen locations in Area B, Wright-Patterson Air Force Base, Ohio. The Base Master Plan proposes eventually to consolidate the Avionics Laboratory in...only. To reassess the requirement for the planned third increment of Building 620, the Commander of the Avionics Laboratory contracted with the...alternative is to take no action other than the moves now planned . The second alternative is to move the Commander, his immediate staff and the one

  7. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  8. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  9. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  10. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  11. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  12. 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…

  13. 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…

  14. 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.

  15. 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.

  16. 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.

  17. Optimal frequency selection of multi-channel O2-band different absorption barometric radar for air pressure measurements

    NASA Astrophysics Data System (ADS)

    Lin, Bing; Min, Qilong

    2017-02-01

    Through theoretical analysis, optimal selection of frequencies for O2 differential absorption radar systems on air pressure field measurements is achieved. The required differential absorption optical depth between a radar frequency pair is 0.5. With this required value and other considerations on water vapor absorption and the contamination of radio wave transmission, frequency pairs of present considered radar system are obtained. Significant impacts on general design of differential absorption remote sensing systems are expected from current results.

  18. Prediction of pressurant mass requirements for axisymmetric liquid hydrogen tanks

    NASA Technical Reports Server (NTRS)

    Vandresar, N. T.

    1995-01-01

    Experimental data from several test series are compared to an existing correlation that predicts the amount of pressurant gas mass required to expel liquid hydrogen from axisymmetric tanks. It was necessary to use an alternate definition of the tank equivalent diameter to accommodate thermal mass in the tank wall that is initially warm and to accommodate liquid residuals in the tank after expulsion is stopped. With this modification, the existing correlation predicted mass requirements to within 14 percent of experimental results. Revision of the correlation constants using a nonlinear least-squares fit of the current experimental data has a minor effect, thus supporting the validity of the original correlation's form, its fitted constants, and the alternate definition of the tank equivalent diameter.

  19. 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.

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. 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.

  6. NESC Review of the 8-Foot High Temperature Tunnel (HTT) Oxygen Storage Pressure Vessel Inspection Requirements

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael; Raju, Ivatury; Piascik, Robert; Cameron, Kenneth; Kirsch, Michael; Hoffman, Eric; Murthy, Pappu; Hopson, George; Greulich, Owen; Frazier, Wayne

    2009-01-01

    The 8-Foot HTT (refer to Figure 4.0-1) is used to conduct tests of air-breathing hypersonic propulsion systems at Mach numbers 4, 5, and 7. Methane, Air, and LOX are mixed and burned in a combustor to produce test gas stream containing 21 percent by volume oxygen. The NESC was requested by the NASA LaRC Executive Safety Council to review the rationale for a proposed change to the recertification requirements, specifically the internal inspection requirements, of the 8-Foot HTT LOX Run Tank and LOX Storage Tank. The Run Tank is an 8,000 gallon cryogenic tank used to provide LOX to the tunnel during operations, and is pressured during the tunnel run to 2,250 pounds per square inch gage (psig). The Storage Tank is a 25,000 gallon cryogenic tank used to store LOX at slightly above atmospheric pressure as a external shell, with space between the shells maintained under vacuum conditions.

  7. 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.

  8. 40 CFR 60.2260 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reporting requirements for air curtain incinerators? 60.2260 Section 60.2260 Protection of Environment... or After June 1, 2001 Air Curtain Incinerators § 60.2260 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Prior to commencing construction on your air curtain...

  9. 40 CFR 60.2260 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting requirements for air curtain incinerators? 60.2260 Section 60.2260 Protection of Environment... or After June 1, 2001 Air Curtain Incinerators § 60.2260 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Prior to commencing construction on your air curtain...

  10. 40 CFR 60.2260 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reporting requirements for air curtain incinerators? 60.2260 Section 60.2260 Protection of Environment... or After June 1, 2001 Air Curtain Incinerators § 60.2260 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Prior to commencing construction on your air curtain...

  11. The Effect of Air Density on Atmospheric Electric Fields Required for Lightning Initiation from a Long Airborne Object

    NASA Technical Reports Server (NTRS)

    Bazelyan, E. M.; Aleksandrov, N. L.; Raizer, Yu. Pl.; Konchankov, A. M.

    2006-01-01

    The purpose of the work was to determine minimum atmospheric electric fields required for lightning initiation from an airborne vehicle at various altitudes up to 10 km. The problem was reduced to the determination of a condition for initiation of a viable positive leader from a conductive object in an ambient electric field. It was shown that, depending on air density and shape and dimensions of the object, critical atmospheric fields are governed by the condition for leader viability or that for corona onset. To establish quantitative criteria for reduced air densities, available observations of spark discharges in long laboratory gaps were analyzed, the effect of air density on leader velocity was discussed and evolution in time of the properties of plasma in the leader channel was numerically simulated. The results obtained were used to evaluate the effect of pressure on the quantitative relationships between the potential difference near the leader tip, leader current and its velocity; based on these relationships, criteria for steady development of a leader were determined for various air pressures. Atmospheric electric fields required for lightning initiation from rods and ellipsoidal objects of various dimensions were calculated at different air densities. It was shown that there is no simple way to extend critical ambient fields obtained for some given objects and pressures to other objects and pressures.

  12. 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.

  13. 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.

  14. 49 CFR 192.201 - Required capacity of pressure relieving and limiting stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Design of Pipeline Components § 192.201 Required capacity of pressure relieving and limiting stations. (a) Each pressure relief station or pressure limiting station or group of those stations installed to... 49 Transportation 3 2010-10-01 2010-10-01 false Required capacity of pressure relieving...

  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. 75 FR 72653 - Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-26

    ... RIN 3150-AI01 Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal... Regulations (10 CFR) part 50, section 61a to provide alternate fracture toughness requirements for...

  17. 48 CFR 1371.103 - Additional item requirements (AIR)-growth work.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements (AIR)-growth work. 1371.103 Section 1371.103 Federal Acquisition Regulations System DEPARTMENT OF... Provisions and Clauses 1371.103 Additional item requirements (AIR)—growth work. Insert clause 1352.271-72, Additional Item Requirements (AIR)—Growth Work, in all solicitations and contracts for ship repair....

  18. 48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Requirements (AIR)-growth work 1352.271-72 Section 1352.271-72 Federal Acquisition Regulations System... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103, insert the following clause: Additional Item Requirements (Air)—Growth Work (APR 2010) (a) This...

  19. 48 CFR 1371.103 - Additional item requirements (AIR)-growth work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... requirements (AIR)-growth work. 1371.103 Section 1371.103 Federal Acquisition Regulations System DEPARTMENT OF... Provisions and Clauses 1371.103 Additional item requirements (AIR)—growth work. Insert clause 1352.271-72, Additional Item Requirements (AIR)—Growth Work, in all solicitations and contracts for ship repair....

  20. 48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Requirements (AIR)-growth work 1352.271-72 Section 1352.271-72 Federal Acquisition Regulations System... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103, insert the following clause: Additional Item Requirements (Air)—Growth Work (APR 2010) (a) This...

  1. Air Force Weapons Laboratory Computational Requirements for 1976 Through 1980

    DTIC Science & Technology

    1976-01-01

    Air Force Weapons Laboratory , Attn: DYS, Kirtland AFB, NM 87117...final report was prepared by the Air Force Weapons Laboratory , Kirtland Air Force Base, New Mexico under Job Order 06CB. Dr. Clifford E. Rhoades, Jr... Force Base, New Mexico 87117 62601F, 06CB II. CONTROLLING OFFICE NAME AND ADDRESS Ai"- Force Weapons Laboratory / Jan 1076 Kirtland Air Force Base,

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner.

    PubMed

    Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

    2011-01-15

    Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 °C. First, its auto-ignition temperature is measured 365 °C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 °C to 255 °C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.

  10. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  11. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  12. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  13. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  14. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 49 CFR 173.301b - Additional general requirements for shipment of UN pressure receptacles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... pressure receptacles. 173.301b Section 173.301b Transportation Other Regulations Relating to Transportation....301b Additional general requirements for shipment of UN pressure receptacles. (a) General. The... gases in UN pressure receptacles. A UN pressure receptacle, including closures, must conform to...

  1. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  2. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  3. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  4. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  5. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  6. 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.

  7. 10 CFR 71.64 - Special requirements for plutonium air shipments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Special requirements for plutonium air shipments. 71.64... MATERIAL Package Approval Standards § 71.64 Special requirements for plutonium air shipments. (a) A package for the shipment of plutonium by air subject to § 71.88(a)(4), in addition to satisfying...

  8. 10 CFR 71.64 - Special requirements for plutonium air shipments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Special requirements for plutonium air shipments. 71.64... MATERIAL Package Approval Standards § 71.64 Special requirements for plutonium air shipments. (a) A package for the shipment of plutonium by air subject to § 71.88(a)(4), in addition to satisfying...

  9. 10 CFR 71.64 - Special requirements for plutonium air shipments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Special requirements for plutonium air shipments. 71.64... MATERIAL Package Approval Standards § 71.64 Special requirements for plutonium air shipments. (a) A package for the shipment of plutonium by air subject to § 71.88(a)(4), in addition to satisfying...

  10. 10 CFR 71.64 - Special requirements for plutonium air shipments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Special requirements for plutonium air shipments. 71.64... MATERIAL Package Approval Standards § 71.64 Special requirements for plutonium air shipments. (a) A package for the shipment of plutonium by air subject to § 71.88(a)(4), in addition to satisfying...

  11. 10 CFR 71.64 - Special requirements for plutonium air shipments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Special requirements for plutonium air shipments. 71.64... MATERIAL Package Approval Standards § 71.64 Special requirements for plutonium air shipments. (a) A package for the shipment of plutonium by air subject to § 71.88(a)(4), in addition to satisfying...

  12. 40 CFR 60.2260 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting requirements for air curtain incinerators? 60.2260 Section 60.2260 Protection of Environment... Incinerators § 60.2260 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Prior to commencing construction on your air curtain incinerator, submit the three items described...

  13. 40 CFR 60.2870 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reporting requirements for air curtain incinerators? 60.2870 Section 60.2870 Protection of Environment... Units Model Rule-Air Curtain Incinerators § 60.2870 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Keep records of results of all initial and annual opacity...

  14. 40 CFR 60.2260 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reporting requirements for air curtain incinerators? 60.2260 Section 60.2260 Protection of Environment... Incinerators § 60.2260 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Prior to commencing construction on your air curtain incinerator, submit the three items described...

  15. 40 CFR 60.2870 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reporting requirements for air curtain incinerators? 60.2870 Section 60.2870 Protection of Environment... Units that Commenced Construction On or Before November 30, 1999 Model Rule-Air Curtain Incinerators § 60.2870 What are the recordkeeping and reporting requirements for air curtain incinerators? (a)...

  16. 40 CFR 60.2870 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reporting requirements for air curtain incinerators? 60.2870 Section 60.2870 Protection of Environment... Units that Commenced Construction On or Before November 30, 1999 Model Rule-Air Curtain Incinerators § 60.2870 What are the recordkeeping and reporting requirements for air curtain incinerators? (a)...

  17. 40 CFR 60.2870 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting requirements for air curtain incinerators? 60.2870 Section 60.2870 Protection of Environment... Units Model Rule-Air Curtain Incinerators § 60.2870 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Keep records of results of all initial and annual opacity...

  18. 40 CFR 60.2870 - What are the recordkeeping and reporting requirements for air curtain incinerators?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting requirements for air curtain incinerators? 60.2870 Section 60.2870 Protection of Environment... Units Model Rule-Air Curtain Incinerators § 60.2870 What are the recordkeeping and reporting requirements for air curtain incinerators? (a) Keep records of results of all initial and annual opacity...

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. 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.

  9. 77 FR 67584 - Air Carrier Contract Maintenance Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... Stations, Report No. AV-2003-047 (July 8, 2003). In 2005, the IG issued a second report on air carriers...). \\4\\ Air Carrier's Outsourcing Use of Non-Certificated Repair Facilities, Report No. AV-2006-031 (Dec... Outsourcing of Aircraft Maintenance, Report No. AV-2008-090 (Sept. 30, 2008). \\7\\ The report noted...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Autonomous Integrated Receive System (AIRS) requirements definition. Volume 4: Functional specification for the prototype Automated Integrated Receive System (AIRS)

    NASA Technical Reports Server (NTRS)

    Chie, C. M.

    1984-01-01

    The functional requirements for the performance, design, and testing for the prototype Automated Integrated Receive System (AIRS) to be demonstrated for the TDRSS S-Band Single Access Return Link are presented.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 30 CFR 250.519 - What are the requirements for casing pressure management?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... management? 250.519 Section 250.519 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... Gas Well-Completion Operations Casing Pressure Management § 250.519 What are the requirements for casing pressure management? Once you install your wellhead, you must meet the casing pressure...

  1. 30 CFR 250.518 - What are the requirements for casing pressure management?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... management? 250.518 Section 250.518 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... Gas Well-Completion Operations Casing Pressure Management § 250.518 What are the requirements for casing pressure management? Once you install your wellhead, you must meet the casing pressure...

  2. 30 CFR 250.519 - What are the requirements for casing pressure management?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... management? 250.519 Section 250.519 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... Gas Well-Completion Operations Casing Pressure Management § 250.519 What are the requirements for casing pressure management? Once you install your wellhead, you must meet the casing pressure...

  3. 49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201 Individual specification requirements applicable to non-pressure tank car tanks....

  4. 49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank...

  5. 49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201 Individual specification requirements applicable to non-pressure tank car tanks....

  6. 49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank...

  7. 49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank...

  8. 49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank...

  9. 49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201 Individual specification requirements applicable to non-pressure tank car tanks....

  10. 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

  11. 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.

  12. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  13. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  14. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  15. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  16. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  17. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  18. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  19. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  20. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  1. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  2. 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.

  3. 30 CFR 250.425 - What are the requirements for pressure testing liners?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.425 What are the requirements for pressure testing liners? (a) You must test each drilling liner (and liner-lap) to a pressure at least...

  4. 30 CFR 250.425 - What are the requirements for pressure testing liners?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.425 What are the requirements for pressure testing liners? (a) You must test each drilling liner (and liner-lap) to a pressure at least...

  5. 30 CFR 250.425 - What are the requirements for pressure testing liners?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.425 What are the requirements for pressure testing liners? (a) You must test each drilling liner (and liner-lap) to a pressure at least...

  6. [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.

  7. 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)...

  8. 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)...

  9. 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…

  10. 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 ...

  11. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Air and water pollution control....45 Air and water pollution control requirements. The program must incorporate, by reference or otherwise, all requirements established by the Federal Water Pollution Control Act, as amended (Clean...

  12. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Air and water pollution control....45 Air and water pollution control requirements. The program must incorporate, by reference or otherwise, all requirements established by the Federal Water Pollution Control Act, as amended (Clean...

  13. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Air and water pollution control....45 Air and water pollution control requirements. The program must incorporate, by reference or otherwise, all requirements established by the Federal Water Pollution Control Act, as amended (Clean...

  14. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Air and water pollution control....45 Air and water pollution control requirements. The program must incorporate, by reference or otherwise, all requirements established by the Federal Water Pollution Control Act, as amended (Clean...

  15. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 3 2012-01-01 2012-01-01 false Air and water pollution control....45 Air and water pollution control requirements. The program must incorporate, by reference or otherwise, all requirements established by the Federal Water Pollution Control Act, as amended (Clean...

  16. 19 CFR 122.48a - Electronic information for air cargo required in advance of arrival.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Electronic information for air cargo required in... OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members...

  17. 19 CFR 122.48a - Electronic information for air cargo required in advance of arrival.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Electronic information for air cargo required in... OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members...

  18. 19 CFR 122.48a - Electronic information for air cargo required in advance of arrival.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Electronic information for air cargo required in... OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members...

  19. 49 CFR 232.107 - Air source requirements and cold weather operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Air source requirements and cold weather... source requirements and cold weather operations. (a) Monitoring plans for yard air sources. (1) A... to the equipment and territory of that railroad to cover safe train operations during cold...

  20. 49 CFR 232.107 - Air source requirements and cold weather operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Air source requirements and cold weather... source requirements and cold weather operations. (a) Monitoring plans for yard air sources. (1) A... to the equipment and territory of that railroad to cover safe train operations during cold...

  1. 49 CFR 232.107 - Air source requirements and cold weather operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Air source requirements and cold weather... source requirements and cold weather operations. (a) Monitoring plans for yard air sources. (1) A... to the equipment and territory of that railroad to cover safe train operations during cold...

  2. 49 CFR 232.107 - Air source requirements and cold weather operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Air source requirements and cold weather... source requirements and cold weather operations. (a) Monitoring plans for yard air sources. (1) A... to the equipment and territory of that railroad to cover safe train operations during cold...

  3. 49 CFR 232.107 - Air source requirements and cold weather operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Air source requirements and cold weather... source requirements and cold weather operations. (a) Monitoring plans for yard air sources. (1) A... to the equipment and territory of that railroad to cover safe train operations during cold...

  4. 76 FR 50164 - Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Air Force Combat Support: Adjusting Doctrine to Meet Expeditionary Air Force Requirements

    DTIC Science & Technology

    2007-11-02

    Force Battlelab Briefing”: U.S Air Force Air Expeditionary Force Battlelab Web Page, on-line, Netscape , 15 Mar 00, available from www.mountain.af.mil...Expeditionary Air Force Web Site, slide 4, on- line, Netscape , 2 Apr 00, www.af.mil/eaf/master.ppt This slide portrays how the Air Force has changed since...Center Web Page, on-line, Netscape , 26 Mar 00, available from www.hqafdc.maxwell.af.mil/library/doctrine/afdd2brief.ppt: slide 2 2 “The little

  13. Air Quality Science and Regulatory Efforts Require Geostationary Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Allen, D. J.; Stehr, J. W.

    2006-01-01

    Air quality scientists and regulatory agencies would benefit from the high spatial and temporal resolution trace gas and aerosol data that could be provided by instruments on a geostationary platform. More detailed time-resolved data from a geostationary platform could be used in tracking regional transport and in evaluating mesoscale air quality model performance in terms of photochemical evolution throughout the day. The diurnal cycle of photochemical pollutants is currently missing from the data provided by the current generation of atmospheric chemistry satellites which provide only one measurement per day. Often peak surface ozone mixing ratios are reached much earlier in the day during major regional pollution episodes than during local episodes due to downward mixing of ozone that had been transported above the boundary layer overnight. The regional air quality models often do not simulate this downward mixing well enough and underestimate surface ozone in regional episodes. Having high time-resolution geostationary data will make it possible to determine the magnitude of this lower-and mid-tropospheric transport that contributes to peak eight-hour average ozone and 24-hour average PM2.5 concentrations. We will show ozone and PM(sub 2.5) episodes from the CMAQ model and suggest ways in which geostationary satellite data would improve air quality forecasting. Current regulatory modeling is typically being performed at 12 km horizontal resolution. State and regional air quality regulators in regions with complex topography and/or land-sea breezes are anxious to move to 4-km or finer resolution simulations. Geostationary data at these or finer resolutions will be useful in evaluating such models.

  14. 29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... vessels, built after the effective date of this regulation, shall be marked and reported indicating that... pressure of the vessels. (b) Portable, unfired pressure vessels, not built to the code requirements of paragraph (a) of this section, and built prior to the effective date of this regulation, shall be...

  15. 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.

  16. 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.

  17. 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…

  18. Wind tunnel investigation of an all flush orifice air data system for a large subsonic aircraft. [conducted in a Langley 8 foot transonic pressure tunnel

    NASA Technical Reports Server (NTRS)

    Larson, T. J.; Flechner, S. G.; Siemers, P. M., III

    1980-01-01

    The results of a wind tunnel investigation on an all flush orifice air data system for use on a KC-135A aircraft are presented. The investigation was performed to determine the applicability of fixed all flush orifice air data systems that use only aircraft surfaces for orifices on the nose of the model (in a configuration similar to that of the shuttle entry air data system) provided the measurements required for the determination of stagnation pressure, angle of attack, and angle of sideslip. For the measurement of static pressure, additional flush orifices in positions on the sides of the fuselage corresponding to those in a standard pitot-static system were required. An acceptable but less accurate system, consisting of orifices only on the nose of the model, is defined and discussed.

  19. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    SciTech Connect

    Moore, Murray E.

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Flame Arrestor Design Requirements for Prolonged Exposure to Methane/Air, Butane/Air and Gasoline/Air Flames.

    DTIC Science & Technology

    1978-09-15

    EXPERIMENTAL FLAME ARRESTORS 9 Table 1 Summary of Instrumentation Variables Measured Measuring Instrument Accuracy Air tlow rate Meriam 50 MY 15-4 Flowmeter...with + 0.5% Meriam A844 Manometer Air temperature Omega CAIN-116G-24 Thermocouple + 11F Gas flow rate Meriam 50W201F flmnuter with + 0.5% Ellison IN

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation... REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition...

  14. 49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100...

  15. 49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100...

  16. 49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100...

  17. 30 CFR 250.518 - What are the requirements for casing pressure management?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What are the requirements for casing pressure management? 250.518 Section 250.518 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... SHELF Oil and Gas Well-Completion Operations Casing Pressure Management § 250.518 What are...

  18. Solar power R and D for Air Force space requirements

    NASA Technical Reports Server (NTRS)

    Wise, J. F.

    1980-01-01

    The requirements for improved solar power system technology for DOD satellites are reported. It is shown that the technology is required in several areas including solar cells, array blanket technology, energy storage and power system operation, and regulation and control. It is further shown that as the missions become more critical to defence, military aspects such as survivability, hardening, and eventually defence must be addressed.

  19. 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.

  20. 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.

  1. 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.

  2. Small turbines in distributed utility application: Natural gas pressure supply requirements

    SciTech Connect

    Goldstein, H.L.

    1996-05-01

    Implementing distributed utility can strengthen the local distribution system and help avoid or delay the expense of upgrading transformers and feeders. The gas turbine-generator set is an attractive option based on its low front-end capital cost, reliable performance at unmanned stations, and environmental performance characteristics. This report assesses gas turbine utilization issues from a perspective of fuel supply pressure requirements and discusses both cost and operational factors. A primary operational consideration for siting gas turbines on the electric distribution system is whether the local gas distribution company can supply gas at the required pressure. Currently available gas turbine engines require gas supply pressures of at least 150 pounds per square inch gauge, more typically, 250 to 350 psig. Few LDCs maintain line pressure in excess of 125 psig. One option for meeting the gas pressure requirements is to upgrade or extend an existing pipeline and connect that pipeline to a high-pressure supply source, such as an interstate transmission line. However, constructing new pipeline is expensive, and the small volume of gas required by the turbine for the application offers little incentive for the LDC to provide this service. Another way to meet gas pressure requirements is to boost the compression of the fuel gas at the gas turbine site. Fuel gas booster compressors are readily available as stand-alone units and can satisfactorily increase the supply pressure to meet the turbine engine requirement. However, the life-cycle costs of this equipment are not inconsequential, and maintenance and reliability issues for boosters in this application are questionable and require further study. These factors may make the gas turbine option a less attractive solution in DU applications than first indicated by just the $/kW capital cost. On the other hand, for some applications other DU technologies, such as photovoltaics, may be the more attractive option.

  3. An automated program for reinforcement requirements for openings in cylindrical pressure vessels

    NASA Technical Reports Server (NTRS)

    Wilson, J. F.; Taylor, J. T.

    1975-01-01

    An automated interactive program for calculating the reinforcement requirements for openings in cylindrical pressure vessels subjected to internal pressure is described. The program is written for an electronic desk top calculator. The program calculates the required area of reinforcement for a given opening and compares this value with the area of reinforcement provided by a proposed design. All program steps, operating instructions, and example problems with input and sample output are documented.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  10. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  11. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  12. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  13. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  14. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  15. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  16. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  17. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  18. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  19. 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.

  20. 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.

  1. PRN 93-5: Labeling Requirements of the Clean Air Act

    EPA Pesticide Factsheets

    A regulation under the Clean Air Act requires a warning statement on products (including pesticide products) manufactured with or containing Class I ozone-depleting substances, including chlorofluorocarbons, methyl chloroform and carbon tetrachloride.

  2. 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.

  3. 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.

  4. Air pressure effects on sea level changes during the twentieth century

    NASA Astrophysics Data System (ADS)

    Piecuch, Christopher G.; Thompson, Philip R.; Donohue, Kathleen A.

    2016-10-01

    Interpretation of tide gauge data in terms sea level (η) and ocean dynamics requires estimates of air pressure (pa) to determine the ocean's isostatic response—the inverted barometer effect (ηib). Three gridded pa products (HadSLP2, NOAA-20CRv2, and ERA-20C) are used alongside meteorological station pa and tide gauge η records to evaluate the contribution of ηib to η changes over the twentieth century. Agreement between gridded products is better during more recent periods and over regions with good historical data coverage, whereas it is worse for earlier time periods or in ocean areas with poor observational data coverage. Comparison against station data reveals the presence of systematic errors in the gridded products, for example, such that uncertainties estimated through differencing the gridded products underestimate the true errors by roughly 40% on interannual and decadal time scales. Notwithstanding such correlated errors, gridded products are still useful for interpretation of tide gauge data. Removing gridded estimates of ηib from η records reduces spatial variance in centennial trends across tide gauges by 10-30%, formal errors in centennial trends from individual gauges by ˜5%, and the temporal variance in detrended records by 10-15% on average (depending on choice of gridded product). Results here advocate for making the ηib correction to tide gauge records in studies of ocean circulation and global η over long, multidecadal, and centennial time scales using an ensemble mean taken across several gridded ηib products.

  5. 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.

  6. 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.

  7. Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings

    SciTech Connect

    Klocke, S.; Faakye, O.; Puttagunta, S.

    2014-10-01

    While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of Consortium for Advanced Residential Building's (CARB’s) multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  8. Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings

    SciTech Connect

    Klocke, S.; Faakye, O.; Puttagunta, S.

    2014-10-01

    ​While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of CARB's multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  9. Autonomous Integrated Receive System (AIRS) requirements definition. Volume 2: Design and development

    NASA Technical Reports Server (NTRS)

    Chie, C. M.; White, M. A.; Lindsey, W. C.; Davarian, F.; Dixon, R. C.

    1984-01-01

    Functional requirements and specifications are defined for an autonomous integrated receive system (AIRS) to be used as an improvement in the current tracking and data relay satellite system (TDRSS), and as a receiving system in the future tracking and data acquisition system (TDAS). The AIRS provides improved acquisition, tracking, bit error rate (BER), RFI mitigation techniques, and data operations performance compared to the current TDRSS ground segment receive system. A computer model of the AIRS is used to provide simulation results predicting the performance of AIRS. Cost and technology assessments are included.

  10. [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.

  11. 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.

  12. 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.

  13. Lighter-Than-Air and Pressurized Structures Technology for Unmanned Aerial Vehicles (UAVs)

    DTIC Science & Technology

    2010-01-01

    Cuben Fiber is a form of ultra-high molecular weight polyethylene ( UHMWPE ) and is produced by Cubic Tech Corp. While very light and very strong... UHMWPE -based fabrics require special techniques to form air-tight, if not helium-tight, seals. In addition, there are some proposed designs that may...length, the combined characteristics of weight and strength in UHMWPE -based fabrics are required to have high percentages of buoyancy. Cubic Tech

  14. Two-photon absorption laser induced fluorescence measurement of atomic oxygen density in an air atmospheric pressure plasma jet

    NASA Astrophysics Data System (ADS)

    Conway, Jim; Gogna, Gurusharan; Daniels, Stephen

    2016-09-01

    Two-photon Absorption Laser Induced Fluorescence (TALIF) is used to measure atomic oxygen number density [O] in an air Atmospheric Pressure Plasma Jet (APPJ). A novel technique based on photolysis of O2 is used to calibrate the TALIF system ensuring the same species (O) is probed during calibration and measurement. As a result, laser intensity can be increased outside the TALIF quadratic laser power region without affecting calibration reliability as any high intensity saturation effects will be identical for calibration and experiment. Higher laser intensity gives stronger TALIF signals helping overcome weak TALIF signals often experienced at atmospheric pressure due to collisional quenching. O2 photo-dissociation and two-photon excitation of the resulting [O] are both achieved within the same laser pulse. The photolysis [O] is spatially non-uniform and time varying. To allow valid comparison with [O] in a plasma, spatial and temporal correction factors are required. Knowledge of the laser pulse intensity I0(t), and wavelength allows correction factors to be found using a rate equation model. The air flow into the jet was fixed and the RF power coupled into the system varied. The resulting [O] was found to increase with RF power.

  15. Rigid-flexible outer sheath model using slider linkage locking mechanism and air pressure for endoscopic surgery.

    PubMed

    Yagi, Akihiko; Matsumiya, Kiyoshi; Masamune, Ken; Liao, Hongen; Dohi, Takeyoshi

    2006-01-01

    The objective of this paper is to develop an outer sheath for flexible endoscopic manipulators. This sheath can switch two states including flexible and rigid, and make a rigid curved path for inserting manipulators. The flexible mode can be curved into a required shape. The rigid mode can hold the shape of the sheath, and then keep the path for instruments. Through the managed path, the flexible manipulators become easy to reach the target. We proposed a serial multi joint model to realize the flexible mechanism. This model is composed of a set of frame units which are connected serially. Each unit can be rotated to a given angle around the center of the joint. We developed a slider-link mechanism and a gear stopper controlled by air pressure for rigid mode. We designed and fabricated the prototype with a diameter of 16 mm and length of 290 mm. The experiment showed that the device could be switched from the flexible mode to the rigid mode when the air pressure was over 150 kPa, and each joint could hold its angle against the maximum 400 mNm. The phantom experiment showed that the flexible devices are possible to transmit the wire tension to the endpoint of the manipulator without changing the curving shape with by the developed outer sheath device.

  16. 30 CFR 250.427 - What are the requirements for pressure integrity tests?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.427 What are the requirements for... setting depth. You must conduct each pressure integrity test after drilling at least 10 feet but no...

  17. 30 CFR 250.427 - What are the requirements for pressure integrity tests?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.427 What are the requirements for... setting depth. You must conduct each pressure integrity test after drilling at least 10 feet but no...

  18. 30 CFR 250.427 - What are the requirements for pressure integrity tests?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.427 What are the requirements for... setting depth. You must conduct each pressure integrity test after drilling at least 10 feet but no...

  19. 10 CFR 50.61 - Fracture toughness requirements for protection against pressurized thermal shock events.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Fracture toughness requirements for protection against... Construction Permits § 50.61 Fracture toughness requirements for protection against pressurized thermal shock... fracture mechanics techniques. This analysis must be submitted at least three years before RTPTS...

  20. 10 CFR 50.66 - Requirements for thermal annealing of the reactor pressure vessel.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Requirements for thermal annealing of the reactor pressure vessel. (a) For those light water nuclear power.... The use of a thermal annealing treatment is subject to the requirements in this section. A report... demonstrate that localized temperatures, thermal stress gradients, and subsequent residual stresses will...

  1. 10 CFR 50.66 - Requirements for thermal annealing of the reactor pressure vessel.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Requirements for thermal annealing of the reactor pressure vessel. (a) For those light water nuclear power.... The use of a thermal annealing treatment is subject to the requirements in this section. A report... demonstrate that localized temperatures, thermal stress gradients, and subsequent residual stresses will...

  2. 10 CFR 50.66 - Requirements for thermal annealing of the reactor pressure vessel.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Requirements for thermal annealing of the reactor pressure vessel. (a) For those light water nuclear power.... The use of a thermal annealing treatment is subject to the requirements in this section. A report... demonstrate that localized temperatures, thermal stress gradients, and subsequent residual stresses will...

  3. 75 FR 37711 - Automatic Dependent Surveillance-Broadcast (ADS-B) Out Performance Requirements To Support Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ..., Performance and Interoperability Requirements Document for Enhanced Air Traffic in Radar-Controlled Areas..., Performance and Interoperability Requirements Document for Enhanced Air Traffic in Radar-Controlled Areas... Interoperability Requirements Document for Enhanced Air Traffic in Radar-Controlled Areas Using ADS-B...

  4. 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.

  5. Validated prediction of pressurant gas requirements in cryogenic run tanks at subcritical and supercritical pressures

    NASA Astrophysics Data System (ADS)

    de Quay, Laurence

    The Generic Nanosatellite Bus (GNB) is a satellite platform developed at the Space Flight Laboratory (SFL) which allows many different payloads to be integrated with a family of generic components such that recurring costs are reduced and access to space is accelerated. Missions such as the BRIght Target Explorer, CanX-4/-5 and AISSat-1 make use of this bus. This thesis describes the assembly and integration procedures, methods and strategies used for the GNB. The design of the interconnection medium routing will be presented. It will also cover some aspects of thermal testing such as thermal shock procedures and the satellite support structure design for the thermal vacuum testing. This thesis is presented such that it may be used as a reference document for assembly and integration efforts of future nanosatellite missions, either following the GNB architecture or not. The compliance of the assembly, integration and testing requirements is demonstrated through validation and implementation. Step by step procedures are presented for GNB assembly, solar cell bonding and thermal tape application. The evolution of the integration design is described based on optimizing efforts and GNB design changes. Flexible circuits are presented as an alternative to the conventional harness for future missions. Finally, general assembly, integration and thermal testing recommendations are offered to add to the wealth of knowledge acquired by SFL in the proper design of nanosatellites.

  6. 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.

  7. 42 CFR 84.143 - Terminal fittings or chambers; Type B supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Terminal fittings or chambers; Type B supplied-air... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.143 Terminal fittings or chambers; Type B... positive pressures shall not be approved for use on Type B supplied-air respirators. (b) Terminal...

  8. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    SciTech Connect

    MULKEY, C.H.

    1999-07-06

    This document describes the results of the data quality objective (DQO) process undertaken to define data needs for state and federal requirements associated with toxic, hazardous, and/or radiological air emissions under the jurisdiction of the River Protection Project (RPP). Hereafter, this document is referred to as the Air DQO. The primary drivers for characterization under this DQO are the regulatory requirements pursuant to Washington State regulations, that may require sampling and analysis. The federal regulations concerning air emissions are incorporated into the Washington State regulations. Data needs exist for nonradioactive and radioactive waste constituents and characteristics as identified through the DQO process described in this document. The purpose is to identify current data needs for complying with regulatory drivers for the measurement of air emissions from RPP facilities in support of air permitting. These drivers include best management practices; similar analyses may have more than one regulatory driver. This document should not be used for determining overall compliance with regulations because the regulations are in constant change, and this document may not reflect the latest regulatory requirements. Regulatory requirements are also expected to change as various permits are issued. Data needs require samples for both radionuclides and nonradionuclide analytes of air emissions from tanks and stored waste containers. The collection of data is to support environmental permitting and compliance, not for health and safety issues. This document does not address health or safety regulations or requirements (those of the Occupational Safety and Health Administration or the National Institute of Occupational Safety and Health) or continuous emission monitoring systems. This DQO is applicable to all equipment, facilities, and operations under the jurisdiction of RPP that emit or have the potential to emit regulated air pollutants.

  9. 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.

  10. An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).

    ERIC Educational Resources Information Center

    McKnight, A. James; And Others

    This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an…

  11. 78 FR 73442 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; State Boards Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... Plan (SIP). The SIP revision addresses the State Boards' requirements for all criteria pollutants of the National Ambient Air Quality Standards (NAAQS). EPA is approving this SIP revision in accordance... SIPs to comply with the requirements regarding State Boards. Section 110(a)(2)(E)(ii) of the CAA...

  12. 42 CFR 84.148 - Type C supplied-air respirator, continuous flow class; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Type C supplied-air respirator, continuous flow class; minimum requirements. 84.148 Section 84.148 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... flow class; minimum requirements. (a) Respirators tested under this section shall be approved only...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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

  1. Effect of aviation fuel type and fuel injection conditions on the spray characteristics of pressure swirl and hybrid air blast fuel injectors

    NASA Astrophysics Data System (ADS)

    Feddema, Rick

    Feddema, Rick T. M.S.M.E., Purdue University, December 2013. Effect of Aviation Fuel Type and Fuel Injection Conditions on the Spray Characteristics of Pressure Swirl and Hybrid Air Blast Fuel Injectors. Major Professor: Dr. Paul E. Sojka, School of Mechanical Engineering Spray performance of pressure swirl and hybrid air blast fuel injectors are central to combustion stability, combustor heat management, and pollutant formation in aviation gas turbine engines. Next generation aviation gas turbine engines will optimize spray atomization characteristics of the fuel injector in order to achieve engine efficiency and emissions requirements. Fuel injector spray atomization performance is affected by the type of fuel injector, fuel liquid properties, fuel injection pressure, fuel injection temperature, and ambient pressure. Performance of pressure swirl atomizer and hybrid air blast nozzle type fuel injectors are compared in this study. Aviation jet fuels, JP-8, Jet A, JP-5, and JP-10 and their effect on fuel injector performance is investigated. Fuel injector set conditions involving fuel injector pressure, fuel temperature and ambient pressure are varied in order to compare each fuel type. One objective of this thesis is to contribute spray patternation measurements to the body of existing drop size data in the literature. Fuel droplet size tends to increase with decreasing fuel injection pressure, decreasing fuel injection temperature and increasing ambient injection pressure. The differences between fuel types at particular set conditions occur due to differences in liquid properties between fuels. Liquid viscosity and surface tension are identified to be fuel-specific properties that affect the drop size of the fuel. An open aspect of current research that this paper addresses is how much the type of aviation jet fuel affects spray atomization characteristics. Conventional aviation fuel specifications are becoming more important with new interest in alternative

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Precise time technology for selected Air Force systems: Present status and future requirements

    NASA Technical Reports Server (NTRS)

    Yannoni, N. F.

    1981-01-01

    Precise time and time interval (PTTI) technology is becoming increasingly significant to Air Force operations as digital techniques find expanded utility in military missions. Timing has a key role in the function as well as in navigation. A survey of the PTTI needs of several Air Force systems is presented. Current technology supporting these needs was reviewed and new requirements are emphasized for systems as they transfer from initial development to final operational deployment.

  11. Air Force Working Capital Fund: Actions Needed to Manage Cash Balances to Required Levels

    DTIC Science & Technology

    2014-07-01

    on receiving daily cash balances. • Because airlift rates are set to compete with private sector rates , they do not cover the full cost. The...the maximum cash requirement for fiscal year 2009. Air Force headquarters officials informed us that when they set the rates to be charged to CSAG and... Rates Too High for Supply Items Monthly Cash Balances Fluctuated Because of the Cyclical Nature of Events Page 12 GAO-14-480 Air Force

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. Cycling on rollers: influence of tyre pressure and cross section on power requirements.

    PubMed

    Reiser, Raoul; Watt, Jon; Peterson, Michael

    2003-07-01

    The resistance against a cyclist while riding on rollers is due mainly to rolling resistance produced by the deformation of the tyre as it rolls against small diameter drums. Resistance is then combined with wheel speed to set power output. The effect of tyre pressure and cross-section on power was investigated by systematically altering the pressure (552 kPa, 690 kPa, and 827 KPa) in a 20c, 23c, 25c, and 28c tyre of the same design while riding at a wheel speed of 45 kph. Average power over 1 minute was measured with a Power Tap Hub (Tune Corporation, Cambridge, Massachusetts, USA) on five occasions. Statistical significance was evaluated at p < 0.05. Power requirements increased significantly with each reduction in tyre pressure for all tyres and pressures except the 25c between 690 and 827 kPa. The 20c tyre required significantly more power from the cyclist at each tested tyre pressure when compared to the other tyres (which were not different from each other). The differences in resistance from tyre size were not observed when ridden on the road. Additionally, a slightly different tyre design from the same manufacturer responded similarly in the 20c, but was significantly different in the 23c size. It was also observed that power requirements increased significantly when both the wheels were ridden on the rollers as compared to just the rear wheel. These results indicate that the power requirements may be significantly altered by the cyclist by adjusting tyre pressure, tyre cross-section size, tyre type, and with the number of wheels contacting the rollers. However, the magnitude of these power requirements may not be suitable for intense workouts of trained cyclists.

  18. 40 CFR 60.2973 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Qualification Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.2973 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

  19. 40 CFR 60.2973 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Qualification Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.2973 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

  20. High-pressure pulsed avalanche discharges: Formulas for required preionization density and rate for homogeneity

    SciTech Connect

    Brenning, N.; Axnaes, I.; Nilsson, J.O.; Eninger, J.E.

    1997-02-01

    The requirements on preionization for the formation of spatially homogeneous pulsed avalanche discharges are examined. The authors derive two formulas which apply in the case of a slowly rising electric field, one which gives the required preionization density at breakdown, and one which gives the required preionization rate. These quantities are expressed as functions of the electrochemical properties of the gas, the neutral density, and the electric field rise time. They also treat the statistical effect that the electrons tend to form groups, in contrast to being randomly distributed in space, during the prebreakdown phase. This process is found to increase the required preionization rate significantly, typically by a factor of five for a discharge at atmospheric pressure. Homogeneous high-pressure discharges have been used for laser excitation, and have also been proposed for chemical plasma processing (ozone production) because of their good scaling properties and high efficiency.

  1. 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.

  2. Cardiovascular pressure measurement in safety assessment studies: technology requirements and potential errors.

    PubMed

    Sarazan, R Dustan

    2014-01-01

    In the early days of in vivo nonclinical pressure measurement, most laboratories were required to have considerable technical/engineering expertise to configure and maintain pressure transducers, amplifiers, tape recorders, chart recorders, etc. Graduate students and postdoctoral fellows typically had some training in the requirements and limitations of the technology they used and were closely engaged in the collection and evaluation of data from their own experiments. More recently, pressure sensing telemetry and data acquisition/analysis systems are provided by vendors as turnkey systems, often resulting in a situation where users are less familiar with the technicalities of their operation. Also, investigators are now more likely to be absent and rely on technical staff for the collection of raw in vivo pressure data from their experiments than in the past. Depending on the goals of an experiment, an investigator may require the measurement of a variety of different pressure parameters, over varying periods of time. A basic understanding of the requirements and limitations that can affect the accuracy and precision of these parameters is important to ensure that the results and conclusions from an experiment are reliable. Factors to consider include the possibility of hydrostatic pressure effects from blood inside the vasculature of the animal, depending on the location of the sensor, as well as from fluid inside a fluid-filled catheter system; long-term stability (lack of drift) of a sensor over time, which can affect the interpretation of absolute pressure changes over a prolonged experiment; frequency response of the sensor and associated electronics; and the phase shift that occurs depending on location of the sensor in the vasculature or because of a fluid-filled catheter system. Each of these factors is discussed, and the particular requirements of frequency response as applied to the measurement of cardiac left ventricular pressure are emphasized. When

  3. 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 ...

  4. 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.

  5. 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.

  6. 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.

  7. 10 CFR 50.66 - Requirements for thermal annealing of the reactor pressure vessel.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Requirements for thermal annealing of the reactor pressure vessel. (a) For those light water nuclear power... thermal annealing or to operate the nuclear power reactor following the annealing must be identified. The... licensee shall so confirm in writing to the Director, Office of Nuclear Reactor Regulation. The...

  8. 10 CFR 50.66 - Requirements for thermal annealing of the reactor pressure vessel.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Requirements for thermal annealing of the reactor pressure vessel. (a) For those light water nuclear power... thermal annealing or to operate the nuclear power reactor following the annealing must be identified. The... licensee shall so confirm in writing to the Director, Office of Nuclear Reactor Regulation. The...

  9. 30 CFR 250.448 - What are the BOP pressure tests requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the BOP pressure tests requirements? 250.448 Section 250.448 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling...

  10. 49 CFR 173.301b - Additional general requirements for shipment of UN pressure receptacles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... packaging is prescribed, for example as provided by paragraph (c)(2)(vi) or (d)(1) of this section, the UN... the bundle or manifolded unit. (c) Pressure receptacle valve requirements. (1) When the use of a valve... of causing hydrogen embrittlement. (g) Composite cylinders in underwater use. A composite...

  11. 49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Special commodity requirements for pressure tank car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...

  12. 30 CFR 250.426 - What are the recordkeeping requirements for casing and liner pressure tests?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the recordkeeping requirements for casing and liner pressure tests? 250.426 Section 250.426 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil...

  13. 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.

  14. 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

  15. The Clean Air Act Amendments of 1990: Hazardous Air Pollutant Requirements and the DOE Clean Coal Technology Program

    SciTech Connect

    Moskowitz, P.D.; DePhillips, M.; Fthenakis, V.M. ); Hemenway, A. )

    1991-01-01

    The purpose of the US Department of Energy -- Office of Fossil Energy (DOE FE) Clean Coal Technology Program (CCTP) is to provide the US energy marketplace with advanced, efficient, and environmentally sound coal-based technologies. The design, construction, and operation of Clean Coal Technology Demonstration Projects (CCTDP) will generate data needed to make informed, confident decisions on the commercial readiness of these technologies. These data also will provide information needed to ensure a proactive response by DOE and its industrial partners to the establishment of new regulations or a reactive response to existing regulations promulgated by the US Environmental Protection Agency (EPA). The objectives of this paper are to: (1) Present a preliminary examination of the potential implications of the Clean Air Act Amendments (CAAA) -- Title 3 Hazardous Air Pollutant requirements to the commercialization of CCTDP; and (2) help define options available to DOE and its industrial partners to respond to this newly enacted Legislation.

  16. The Clean Air Act Amendments of 1990: Hazardous Air Pollutant Requirements and the DOE Clean Coal Technology Program

    SciTech Connect

    Moskowitz, P.D.; DePhillips, M.; Fthenakis, V.M.; Hemenway, A.

    1991-12-31

    The purpose of the US Department of Energy -- Office of Fossil Energy (DOE FE) Clean Coal Technology Program (CCTP) is to provide the US energy marketplace with advanced, efficient, and environmentally sound coal-based technologies. The design, construction, and operation of Clean Coal Technology Demonstration Projects (CCTDP) will generate data needed to make informed, confident decisions on the commercial readiness of these technologies. These data also will provide information needed to ensure a proactive response by DOE and its industrial partners to the establishment of new regulations or a reactive response to existing regulations promulgated by the US Environmental Protection Agency (EPA). The objectives of this paper are to: (1) Present a preliminary examination of the potential implications of the Clean Air Act Amendments (CAAA) -- Title 3 Hazardous Air Pollutant requirements to the commercialization of CCTDP; and (2) help define options available to DOE and its industrial partners to respond to this newly enacted Legislation.

  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. A case study on determining air monitoring requirements in a radioactive materials handling area

    SciTech Connect

    Newton, G.J.; Bechtold, W.E.; Hoover, M.D.; Ghanbari, F.; Herring, P.S.; Jow, Hong-Nian

    1993-12-31

    A technical, defensible basis for the number and placement of air sampling instruments in a radioactive materials handling facility was developed. Historical air sampling data, process and physicochemical knowledge, qualitative smoke dispersion studies with video documentation, and quantitative trace gas dispersion studies were used to develop a strategy for number and placement of air samplers. These approaches can be used in other facilities to provide a basis for operational decisions. The requirements for retrospective sampling, personal sampling, and real-time monitoring are included. Other relevant operational decisions include selecting the numbers, placement, and appropriate sampling rates for instruments, identifying areas of stagnation or recirculation, and determining the adequacy and efficiency of any sampling transport lines. Justification is presented for using a graded approach to characterizing the workplace and determining air sampling and monitoring needs.

  20. Analysis of operational requirements for medium density air transportation. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The medium density air travel market was studied to determine the aircraft design and operational requirements. The impact of operational characteristics on the air travel system and the economic viability of the study aircraft were also evaluated. Medium density is defined in terms of numbers of people transported (20 to 500 passengers per day on round trip routes), and frequency of service ( a minumium of two and maximum of eight round trips per day) for 10 regional carriers. The operational characteristics of aircraft best suited to serve the medium density air transportation market are determined and a basepoint aircraft is designed from which tradeoff studies and parametric variations could be conducted. The impact of selected aircraft on the medium density market, economics, and operations is ascertained. Research and technology objectives for future programs in medium density air transportation are identified and ranked.

  1. 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}% ).

  2. 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.

  3. Adsorption Equilibria and Performance of a Pressure Swing Adsorption Air Separation Unit

    DTIC Science & Technology

    1984-01-01

    solution theory. At the lower temperatures the gas mixture behaved nonideally. - Column breakthrough data taken at 24 and -40%C shows that the length...70 9 Pressure range of the MGA gas sampling probes ................ 74 10 Weight of molecular sieve in dual column PSA apparatus ....... 77 11 Best...smaller energy requirements (1). The chemical industry has been aware of the advantages of PSA technology In such areas as gas purification, chemical

  4. A passive measurement of dissociated atom densities in atmospheric pressure air discharge plasmas using vacuum ultraviolet self-absorption spectroscopy

    SciTech Connect

    Laity, George; Fierro, Andrew; Dickens, James; Neuber, Andreas; Frank, Klaus

    2014-03-28

    We demonstrate a method for determining the dissociation degree of atmospheric pressure air discharges by measuring the self-absorption characteristics of vacuum ultraviolet radiation from O and N atoms in the plasma. The atom densities are determined by modeling the amount of radiation trapping present in the discharge, without the use of typical optical absorption diagnostic techniques which require external sources of probing radiation into the experiment. For an 8.0 mm spark discharge between needle electrodes at atmospheric pressure, typical peak O atom densities of 8.5 × 10{sup 17} cm{sup −3} and peak N atom densities of 9.9 × 10{sup 17} cm{sup −3} are observed within the first ∼1.0 mm of plasma near the anode tip by analyzing the OI and NI transitions in the 130.0–132.0 nm band of the vacuum ultraviolet spectrum.

  5. Technical assessment of workplace air sampling requirements at tank farm facilities. Revision 2

    SciTech Connect

    Olsen, P.A.; Brown, R.L.

    1995-03-22

    Tank Farm facilities compliance with the workplace air sampling (WPAS) program has been assessed. Requirements bases for determining compliance and recommendations are included. In the current condition all buildings are in compliance with the WPAS program. This document also supersedes WHC-SD-SQA-TA-20012, revision 0.

  6. 32 CFR 861.4 - DOD air transportation quality and safety requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... quality and safety criteria and requirements that reflect the type programs and practices DOD seeks from... carrier performance evaluations. The size of an air carrier, along with the type and scope of operations... expected to demonstrate some type of effective flight following capability. On the other hand, a major...

  7. 32 CFR 861.4 - DOD air transportation quality and safety requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... quality and safety criteria and requirements that reflect the type programs and practices DOD seeks from... carrier performance evaluations. The size of an air carrier, along with the type and scope of operations... expected to demonstrate some type of effective flight following capability. On the other hand, a major...

  8. 75 FR 33391 - Amendments to the Protocol Gas Verification Program and Minimum Competency Requirements for Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... the provisions pertaining to mercury monitoring and reporting, removing certain requirements... applications, removing the provisions pertaining to mercury monitoring and reporting, removing certain... trap testing from Section 6.1.2(a) of Appendix A, in view of the vacatur of the Clean Air...

  9. 78 FR 8273 - Approval of Air Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ...The Environmental Protection Agency (EPA) is proposing a source-specific federal implementation plan (FIP) requiring the Navajo Generating Station (NGS), located on the Navajo Nation, to reduce emissions of oxides of nitrogen (NOX) under the Best Available Retrofit Technology (BART) provision of the Clean Air Act (CAA or Act) in order to reduce visibility impairment resulting from......

  10. 76 FR 20536 - Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 75 RIN 2060-AQ06 Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing Correction In rule document 2011-6216 appearing on pages 17288-17325 in...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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).

  10. 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.

  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

    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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Evaluation of the constant pressure panel method (CPM) for unsteady air loads prediction

    NASA Technical Reports Server (NTRS)

    Appa, Kari; Smith, Michael J. C.

    1988-01-01

    This paper evaluates the capability of the constant pressure panel method (CPM) code to predict unsteady aerodynamic pressures, lift and moment distributions, and generalized forces for general wing-body configurations in supersonic flow. Stability derivatives are computed and correlated for the X-29 and an Oblique Wing Research Aircraft, and a flutter analysis is carried out for a wing wind tunnel test example. Most results are shown to correlate well with test or published data. Although the emphasis of this paper is on evaluation, an improvement in the CPM code's handling of intersecting lifting surfaces is briefly discussed. An attractive feature of the CPM code is that it shares the basic data requirements and computational arrangements of the doublet lattice method. A unified code to predict unsteady subsonic or supersonic airloads is therefore possible.

  17. 48 CFR 52.247-52 - Clearance and Documentation Requirements-Shipments to DOD Air or Water Terminal Transshipment...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Documentation Requirements-Shipments to DOD Air or Water Terminal Transshipment Points. 52.247-52 Section 52.247... and Documentation Requirements—Shipments to DOD Air or Water Terminal Transshipment Points. As... Requirements—Shipments to DOD Air or Water Terminal Transshipment Points (FEB 2006) All shipments to water...

  18. 40 CFR 52.36 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of... What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule... part 97 of this chapter constitute the Clean Air Interstate Rule Federal Implementation Plan...

  19. 40 CFR 52.36 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of... What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule... part 97 of this chapter constitute the Clean Air Interstate Rule Federal Implementation Plan...

  20. 40 CFR 52.36 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of... What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule... part 97 of this chapter constitute the Clean Air Interstate Rule Federal Implementation Plan...

  1. 40 CFR 52.36 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of... What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule... part 97 of this chapter constitute the Clean Air Interstate Rule Federal Implementation Plan...

  2. 30 CFR 285.659 - What requirements must I include in my SAP, COP, or GAP regarding air quality?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What requirements must I include in my SAP, COP, or GAP regarding air quality? 285.659 Section 285.659 Mineral Resources MINERALS MANAGEMENT SERVICE... must I include in my SAP, COP, or GAP regarding air quality? (a) You must comply with the Clean Air...

  3. 40 CFR 52.36 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of...) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS General Provisions § 52.36 What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

  4. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  5. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test; Type C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  6. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test; Type C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  7. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test; Type C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  8. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance test; Type C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  9. 40 CFR 60.3061 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.3061 Section 60.3061... Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.3061 What are the requirements for temporary-use incinerators and air curtain incinerators used in disaster recovery? Your incinerator or...

  10. 40 CFR 60.3061 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.3061 Section 60.3061... Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.3061 What are the requirements for temporary-use incinerators and air curtain incinerators used in disaster recovery? Your incinerator or...

  11. 40 CFR 60.3061 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.3061 Section 60.3061... Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.3061 What are the requirements for temporary-use incinerators and air curtain incinerators used in disaster recovery? Your incinerator or...

  12. 40 CFR 60.3061 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.3061 Section 60.3061... Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.3061 What are the requirements for temporary-use incinerators and air curtain incinerators used in disaster recovery? Your incinerator or...

  13. 40 CFR 60.3061 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.3061 Section 60.3061... Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.3061 What are the requirements for temporary-use incinerators and air curtain incinerators used in disaster recovery? Your incinerator or...

  14. 40 CFR 60.2969 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.2969 Section 60.2969... Commenced on or After June 16, 2006 Temporary-Use Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.2969 What are the requirements for temporary-use incinerators and air curtain...

  15. 40 CFR 60.2969 - What are the requirements for temporary-use incinerators and air curtain incinerators used in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-use incinerators and air curtain incinerators used in disaster recovery? 60.2969 Section 60.2969... Commenced on or After June 16, 2006 Temporary-Use Incinerators and Air Curtain Incinerators Used in Disaster Recovery § 60.2969 What are the requirements for temporary-use incinerators and air curtain...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 40 CFR 60.1930 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 60.1930 Section 60... Incinerators That Burn 100 Percent Yard Waste § 60.1930 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  11. 40 CFR 60.1930 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 60.1930 Section 60... Incinerators That Burn 100 Percent Yard Waste § 60.1930 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  12. 40 CFR 62.15385 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 62.15385 Section 62... Incinerators That Burn 100 Percent Yard Waste § 62.15385 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  13. 40 CFR 62.15385 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 62.15385 Section 62... Incinerators That Burn 100 Percent Yard Waste § 62.15385 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  14. 40 CFR 62.15385 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 62.15385 Section 62... Incinerators That Burn 100 Percent Yard Waste § 62.15385 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  15. 40 CFR 60.1930 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 60.1930 Section 60... Incinerators That Burn 100 Percent Yard Waste § 60.1930 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  16. 40 CFR 60.1930 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 60.1930 Section 60... Incinerators That Burn 100 Percent Yard Waste § 60.1930 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  17. 40 CFR 62.15385 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 62.15385 Section 62... Incinerators That Burn 100 Percent Yard Waste § 62.15385 What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100 percent yard waste? (a) Provide a notice of...

  18. Building America Case Study: Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings, Upstate New York (Fact Sheet)

    SciTech Connect

    Not Available

    2014-11-01

    While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of CARB's multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  19. 40 CFR 60.1455 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn 100...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... annual reporting dates (see § 60.19(c)). (h) Keep a copy of all reports onsite for a period of 5 years... reporting requirements for air curtain incinerators that burn 100 percent yard waste? 60.1455 Section 60....1455 What are the recordkeeping and reporting requirements for air curtain incinerators that burn...

  20. 30 CFR 585.659 - What requirements must I include in my SAP, COP, or GAP regarding air quality?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What requirements must I include in my SAP, COP, or GAP regarding air quality? 585.659 Section 585.659 Mineral Resources BUREAU OF OCEAN ENERGY... What requirements must I include in my SAP, COP, or GAP regarding air quality? (a) You must comply...

  1. 30 CFR 585.659 - What requirements must I include in my SAP, COP, or GAP regarding air quality?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What requirements must I include in my SAP, COP, or GAP regarding air quality? 585.659 Section 585.659 Mineral Resources BUREAU OF OCEAN ENERGY... What requirements must I include in my SAP, COP, or GAP regarding air quality? (a) You must comply...

  2. 30 CFR 285.659 - What requirements must I include in my SAP, COP, or GAP regarding air quality?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What requirements must I include in my SAP, COP, or GAP regarding air quality? 285.659 Section 285.659 Mineral Resources BUREAU OF OCEAN ENERGY... Pipeline Deviations § 285.659 What requirements must I include in my SAP, COP, or GAP regarding air...

  3. 30 CFR 585.659 - What requirements must I include in my SAP, COP, or GAP regarding air quality?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What requirements must I include in my SAP, COP, or GAP regarding air quality? 585.659 Section 585.659 Mineral Resources BUREAU OF OCEAN ENERGY... What requirements must I include in my SAP, COP, or GAP regarding air quality? (a) You must comply...

  4. Air Cushion Vehicle Operator Training System (ACVOTS). Simulator Requirements Analysis. Volume 2

    DTIC Science & Technology

    1982-06-01

    disadvantaqes associated with a model , however, remain. The laser-based system is currently underaoina extended evaluation in a helicopter simulator designed for... model . The basic system is well established, if rather ineffi- cient in its use of power and inflexible in nature. Some special design of the probe would...N-25-82 -22 . , ~it TRAINING SYSTEMS _ ANALYSIS & DESIGN L L" AIR CUSHION VEHICLE L OPERATOR TRAINING SYSTEM (ACVOTS) SIMULATOR REQUIREMENTS

  5. 75 FR 3617 - Outer Continental Shelf Air Regulations Update To Include New Jersey State Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-22

    ..., Reporting and recordkeeping requirements, Sulfur oxides. Dated: December 30, 2009. Judith A. Enck, Regional.... Variances N.J.A.C. 7:27-6.7. Exceptions Chapter 27 Subchapter 7--Sulfur (Effective 3/1/67) N.J.A.C. 7:27-7.1. Definitions N.J.A.C. 7:27-7.2. Control and prohibition of air pollution from sulfur compounds Chapter...

  6. Setting Requirements for Maintenance Manpower in the U.S. Air Force

    DTIC Science & Technology

    2002-01-01

    composition of active-duty enlisted manpower in wing-level aircraft maintenance organizations. The fo- cus is on maintenance apprentices, journeymen, and...and application of the Logistics Composite Model (LCOM); the ap- propriateness of man-hour availability rules; and the representation of certain Air...Required to Accom plish ............................... . 11 Chapter Three THE RED BOX: HOW THE LOGISTICS COMPOSITE MODEL W ORKS

  7. The cold and atmospheric-pressure air surface barrier discharge plasma for large-area sterilization applications

    SciTech Connect

    Wang Dacheng; Zhao Di; Feng Kecheng; Zhang Xianhui; Liu Dongping; Yang Size

    2011-04-18

    This letter reports a stable air surface barrier discharge device for large-area sterilization applications at room temperature. This design may result in visually uniform plasmas with the electrode area scaled up (or down) to the required size. A comparison for the survival rates of Escherichia coli from air, N{sub 2} and O{sub 2} surface barrier discharge plasmas is presented, and the air surface plasma consisting of strong filamentary discharges can efficiently kill Escherichia coli. Optical emission measurements indicate that reactive species such as O and OH generated in the room temperature air plasmas play a significant role in the sterilization process.

  8. Technical assessment of workplace air sampling requirements at tank farm facilities. Revision 1

    SciTech Connect

    Olsen, P.A.

    1994-09-21

    WHC-CM-1-6 is the primary guidance for radiological control at Westinghouse Hanford Company (WHC). It was written to implement DOE N 5480.6 ``US Department of Energy Radiological Control Manual`` as it applies to programs at Hanford which are now overseen by WHC. As such, it complies with Title 10, Part 835 of the Code of Federal Regulations. In addition to WHC-CM-1-6, there is HSRCM-1, the ``Hanford Site Radiological Control Manual`` and several Department of Energy (DOE) Orders, national consensus standards, and reports that provide criteria, standards, and requirements for workplace air sampling programs. This document provides a summary of these, as they apply to WHC facility workplace air sampling programs. This document also provides an evaluation of the compliance of Tank Farms` workplace air sampling program to the criteria, standards, and requirements and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance.

  9. 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.

  10. 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…

  11. 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…

  12. Technical assessment of compliance with workplace air sampling requirements at WRAP

    SciTech Connect

    HACKWORTH, M.F.

    1999-06-02

    The purpose of this Technical Assessment is to satisfy HSRCM-1, ''Hanford Site Radiological Control Manual'' Article 551.4 for a documented study of facility Workplace Air Monitoring (WAM) programs. HSRCM-1 is the primary guidance for radiological control at Waste Management Federal Services of Hanford, Inc. (WMH). The HSRCM-1 complies with Title 10. Part 835 of the Code of Federal Regulations (10CFR835). This document provides an evaluation of the compliance of the Waste Receiving and Processing facility (WRAP) WAM program to the criteria standards, requirements, and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance.

  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. Lung Volume and Continuous Positive Airway Pressure Requirements in Obstructive Sleep Apnea

    PubMed Central

    Heinzer, Raphael C.; Stanchina, Michael L.; Malhotra, Atul; Fogel, Robert B.; Patel, Sanjay R.; Jordan, Amy S.; Schory, Karen; White, David P.

    2005-01-01

    Previous studies have demonstrated that lung volume during wakefulness influences upper airway size and resistance, particularly in patients with sleep apnea. We sought to determine the influence of lung volume on the level of continuous positive airway pressure (CPAP) required to prevent flow limitation during non-REM sleep in subjects with sleep apnea. Seventeen subjects (apnea–hypopnea index, 42.6 ± 6.2 [SEM]) were studied during stable non-REM sleep in a rigid head-out shell equipped with a positive/negative pressure attachment for manipulation of extrathoracic pressure. An epiglottic pressure catheter plus a mask/pneumotachometer were used to assess flow limitation. When lung volume was increased by 1,035 ± 22 ml, the CPAP level could be decreased from 11.9 ± 0.7 to 4.8 ± 0.7 cm H2O (p < 0.001) without flow limitation. The decreased CPAP at the same negative extrathoracic pressure yielded a final lung volume increase of 421 ± 36 ml above the initial value. Conversely, when lung volume was reduced by 732 ± 74 ml (n = 8), the CPAP level had to be increased from 11.9 ± 0.7 to 17.1 ± 1.0 cm H2O (p < 0.001) to prevent flow limitation, with a final lung volume decrease of 567 ± 78 ml. These results demonstrate that relatively small changes in lung volume have an important effect on the upper airway in subjects with sleep apnea during non-REM sleep. PMID:15817803

  17. Plasma-assisted decomposition of methanol and trichloroethylene in atmospheric pressure air streams by electrical discharge processing

    SciTech Connect

    Hsiao, M.C.; Merritt, B.T.; Penetrante, B.M.; Vogtlin, G.E.; Wallman, P.H.

    1995-09-01

    Experiments are presented on the plasma-assisted decomposition of dilute concentrations of methanol and trichloroethylene in atmospheric pressure air streams by electrical discharge processing. This investigation used two types of discharge reactors, a dielectric-barrier and a pulsed corona discharge reactor, to study the effects of gas temperature and electrical energy input on the decomposition chemistry and byproduct formation. Our experimental data on both methanol and trichloroethylene show that, under identical gas conditions, the type of electrical discharge reactor does not affect the energy requirements for decomposition or byproduct formation. Our experiments on methanol show that discharge processing converts methanol to CO{sub {ital x}} with an energy yield that increases with temperature. In contrast to the results from methanol, CO{sub {ital x}} is only a minor product in the decomposition of trichloroethylene. In addition, higher temperatures decrease the energy yield for trichloroethylene. This effect may be due to increased competition from decomposition of the byproducts dichloroacetyl chloride and phosgene. In all cases plasma processing using an electrical discharge device produces CO preferentially over CO{sub 2}.

  18. Review of current practices and requirements for the inspection of prestressed concrete pressure vessels

    SciTech Connect

    Reimann, K.J.

    1980-12-01

    Code requirements for pre- and in-service inspection of prestressed concrete pressure vessels as utilized in gas-cooled reactors are reviewed and compared with practices and experiences during construction, commissioning, and operation of such reactors. The pre-service inspection relies heavily on embedded instrumentation for measurements of stresses, temperatures, and displacements. The same instrumentation is later used for in-service surveillance, which additionally includes visual examination of exposed surfaces, monitoring of tendon conditions, and measurement of tendon loads. Improvement of present monitoring instrumentation and/or techniques, rather than development of new in-service inspection methods, is recommended.

  19. 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.

  20. 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.